|Why?||What is NT-farming||Benefits||Laws||Paradigms||Sustainability||Critical steps to no-till adoption|
|Historical review||Advances||Economics mechanized||Economics small farmers|
WHY NO- TILLAGE?
105 Million hectares under No- tillage world wide can't be wrong!
|"The only thing that improved the quality of my life more than no-till was electricity.
wife of a no till farmer from Ohio
Said on 2/5/97 at a CTIC Meeting in Kansas City, Mo.
It is extremely important to formulate an adequate and explicit definition of no-tillage if consistent and comparable results are to be achieved among different researchers. Often contradicting research results in this field are only and exclusively the consequence of using local jargon and different definitions by different researchers and of a different understanding of how no-tillage should be put into praxis. For this reason it is necessary to find a consensus of an accurate description and definition of no-tillage. If this can not be achieved soon than we will continue to have contradicting and conflicting results in no-tillage research at the national and international level.
No-tillage or zero tillage is a farming system in which the seeds are directly deposited into untilled soil which has retained the previous crop residues. It is also referred to as no-till. Special no-till seeding equipment with discs (low disturbance) or narrow tine coulters (higher disturbance) open a narrow slot into the residue covered soil which is only wide enough to put the seeds into the ground and cover them with soil. The aim is to move as little soil as possible in order not to bring weed seeds to the surface and not stimulating them to germinate. No other soil tillage operation is done. The residues from the previous crops will remain largely undisturbed at the soil surface as mulch. If the soil is disturbed even only superficially then the system can not be termed no-tillage and is defined as mulch tillage (CTIC, 2011). Seeding systems that till and mix more than 50% of the soil surface while seeding can not be defined as no-tillage (Linke, 1998, Sturny et al., 2007). Adequate weed management is the key to successful application of the system. Weed control is performed in this system using herbicides and also through the adoption of appropriate crop rotations including the use of adapted, aggressive species of cover crops. Some of the environment relevant effects of no-tillage as erosion control, improvement of water quality, increased water infiltration which leads also to reduced flood hazard and climate related consequences through carbon sequestration in the soil, will come into effect only after several years of continuous, uninterrupted application.
The no-tillage technology is being applied globally on over 100 Million ha under the most diverse climate and soil conditions (Derpsch, et al., 2010). The success of this conservation production system is based on its continuous, permanent application, similar to a permanent pasture (Sturny et al., 2007) and on biological diversification through crop rotation and cover crops. Special requirements of the system must be satisfied to avoid failures and the necessary steps towards a successful transition to no-till need to be followed (Duiker and Myres, 2006, Derpsch, 2008). The fact that the soil is not tilled and remains permanently covered with crop residues leads to efficient erosion control, to sequestration of atmospheric carbon in the soil, to increased biological activity in the soil, to better conservation of water and to higher economic returns through time (Derpsch, 2010). Moreover, no-till is the only farming system that fully meets the requirements of a sustainable agricultural production even under extreme soil and climate conditions.
In summary, no-tillage can be defined as a system of planting (seeding) crops into untilled soil by opening a narrow slot or trench only of sufficient width and depth to obtain proper seed coverage. No other soil tillage is done (Phillips and Young 1973).
CTIC, 2011. Conservation Technology Information Center homepage http://www.ctic.purdue.edu/media/pdf/TillageDefinitions.pdf consulted March 2011
Derpsch, R., 2008, Critical Steps to No-till Adoption, In: No-till Farming Systems. Goddard, T., Zoebisch, M.A., Gan, Y., Ellis, W., Watson, A. and Sombatpanit, S., Eds., 2008, WASWC. p 479 – 495
Derpsch, R., Friedrich, T., Kassam, A. und Li, H.W., 2010. Current status of adoption of no-till farming in the world and some of its main benefits. Int. J. Agric. & Biol. Eng. Vol. 3. Nº 1.
Duiker, S. and Myres, J.C., 2006. Steps towards a successful transition to no-till. College of Agricultural Science, Agricultural Research and Cooperative Extension, PennState University, 36 S.
Linke, C., 1998. Direktsaat – eine Bestandsaufnahme unter besonderer Berücksichtigung technischer, agronomischer und ökonomischer Aspekte. Dissertation, Universität Hohenheim, 482 pp.
Phillips, S. and Young, H. 1973. No-Tillage Farming. Reiman Associates, Milwaukee, Wisconsin. 224 p.
Sturny W.G., Chervet A. Maurer-Troxler C., Ramseier L., Müller M., Schafflützel R., Richner W., Streit B., Weisskopf P. und Zihlmann U. 2007. Direktsaat und Pflug im Systemvergleich – eine Synthese, AGRARForschung (jetzt "Agrarforschung Schweiz") 14 (8): 350-357.
Benefits of high residue farmingConservation tillage systems offer numerous benefits that intensive tillage systems cannot match. These advantages have been summarized as follows:
Source: ISTRO, 1997: International Soil Tillage Research Organization (ISTRO), INFO- EXTRA, Vol. 3 Nr° 1, January 1997.
The laws of diminishing yields in the
In nature there are laws that rule the
diminishing productivity of soils, which have to be taken into account in agricultural and
livestock production. Those who disrespect these laws are promoting the degradation of soils and
the loss of soil productivity. To respect these laws is indispensable if we aim to obtain a
sustainable agricultural production.
Additionally soil carbon is lost very
fast to the atmosphere (as carbon dioxide) after the soil is intensively tilled. This results in
unacceptable CO2 emissions into the atmosphere, and instead of carbon being deposited in the soil
improving its fertility, tillage contributes to the greenhouse effect and to the global warming of
New Paradigms in Agricultural Production
cultivation systems in the tropics and subtropics, with intensive soil tillage, will end in soil
degradation and loss of crop productivity. This will result in poverty, exodus of farmers from rural
areas, resulting in an increase of city slums and marginal populations, and finally in social
conflicts. If we are to offer the farm family a chance to survive on the farm and if sustainable
agriculture is to be achieved, than the paradigms of soil use and management must be changed and
new farming practices must be implemented. In this paper, the old and new paradigms are presented
and the consequences of these two forms of soil management are analysed.
|OLD PARADIGMS||NEW PARADIGMS|
CONSEQUENCES OF SOIL PREPARATION
AND BARE SOIL
CONSEQUENCES OF NO- TILLAGE AND PERMANENT SOIL COVER
|OFF FARM EFFECTS OF SOIL EROSION||OFF FARM EFFECTS OF NEW
Sustainable land use is not possible (ecologically, socially & economically).
Soil resource explotation.
Sustainable land use ensured (ecologically, socially & economically).
Rational, site- oriented use of the soil.
IMPLICATIONS OF NO- TILLAGE VERSUS SOIL PREPARATION ON
Despite progress in genetics and breeding, fertilisation, plant
protection and management, there is a clear tendency of diminishing yield over time.
FAO predicts, that if soil losses continue unchecked the potential rainfed crop
production will decline by about 15% in two decades in Africa, about 19% in Southeast
Asia, and by more than 41% in Southwest Asia (Kelly, 1983).
|Nitrogen appl./ year||No- tillage||Conventional tillage|
|kg/ ha||% Organic Matter|
These organic matter contents were also reflected on maize
yields after 20 years in the same experiment (Thomas, 1990).
HISTORICAL REVIEW OF NO- TILLAGE CULTIVATION OF CROPS
No- tillage and reduced tillage have been used since ancient times by indigenous
cultures, simply because man has not the muscle force to till any significant area of land to a
significant depth by hand. The ancient Egyptians and the Incas in the Andes of South America for
example, used a stick to make a hole in the ground and put seeds by hand into unprepared soil. In
modern, mechanised agriculture, no- tillage cultivation of crops was attempted long time ago, but
it was not until the advent of modern herbicides that the technique could be put into practice. Back
in the 1940s Edward Faulkner induced a change to eliminate tillage by the plough and reduce tillage
in his famous book "Plowman's Folly" (1943).
No- tillage is defined in this paper as the planting of crops in previously
unprepared soil by opening a narrow slot, trench, or band only of sufficient width and depth to
obtain proper seed coverage. No other soil preparation is performed (Phillips and Young, 1973).
We also refer here to permanent no-tillage rather than not tilling the soil occasionally. No-
tillage is the term used in North America while direct-drilling or zero tillage is used in the
United Kingdom and Europe. Aerial seeding is of course the ultimate form of zero tillage.
A SHORT HISTORY OF TILLAGE
The plough has been developed in early days of agriculture and was first pulled
by man and later by animals. The use of the plough is often mentioned in the Bible and one of the
best known citations is "they shall beat their swords into plough shares" (Isaiah 2. V. 4.).
But the plough of biblical times had nothing to do with modern ploughs of the 19th century. In those
days a plough was nothing else than a branch from a tree that scratched or scarified the soil
surface without mixing the soil layers. Ploughs that inverted the soil layers and thus gave a
better weed control were not developed until the 17th century. Only in the 18th and 19th century
did ploughs become more and more sophisticated. But it was not until the end of the 18th century
that German, Dutch and British developments of this tool led to an almost perfect shape of the
mouldboard, that turned the soil by 135° and was very efficient in weed control. It is this plough
that avoided famine and death at the end of the 18th century, since it was the only tool that could
effectively control quack grass (Agropyron repens), a weed that had spread all over Europe and could
not be controlled with "conventional" tools. Because the modern plough saved Europe from
famine and poverty it became a symbol of "modern" agriculture and is used as such by many
agricultural research institutes, universities, agronomy schools, etc. One of these early ploughs
of 1884 is displayed at the agricultural museum of the University of Hohenheim, in Stuttgart,
Germany, and in a festival is taken around the city of Hohenheim each year, to commemorate the
invention of this implement. By knowing the history of this tool, it becomes understandable why
Europeans and especially Germans are often such fervent advocates of the plough, which has turned
to be the most often used symbol of agriculture world- wide.
EARLY CULTIVATION WITHOUT TILLAGE
No- tillage and reduced tillage have been used since ancient times by the so
called "primitive cultures" for the cultivation of crops, simply because man has not the muscle
force to till any significant area of land to a significant depth by hand.
DEVELOPMENT IN EUROPE
The invention of the herbicide Paraquat in 1955 in the UNITED KINGDOM was the start of modern no-
tillage development in Europe and also world-wide. This discovery led the Imperial Chemical Company,
ICI, to initiate research without soil tillage. In 1973/74 the area under no- tillage in Great
Britain increased to 200,000 ha and 10 years later to 275,000 ha (Table 1), thus the UK had the
second largest area under no- tillage in the world after the USA (Derpsch, 1984). Field
experiments in England showed that, if well managed, direct-drilling and reduced cultivation
could give similar yields of winter cereals to those after ploughing, when straw residues were
burnt. However, when restrictions on straw burning were introduced and problems occurred from
the build-up of weeds and volunteer cereals many farmers who used these methods resumed the use
of the plough and direct drilling almost ceased to be applied (Christian, 1994).
DEVELOPMENT IN THE UNITED STATES
Research on conservation tillage with early versions of a chisel plough was
started in the Great Plains in the 1930s, to alleviate the damage caused by wind erosion, after
the occurrence of the famous "dust bowl". Stubble mulch farming was developed in the
Great Plains, as a forerunner of no- tillage.
DEVELOPMENT IN LATIN AMERICA
BRAZIL: The first attempt to apply the no-tillage technology was made by the Faculty of Agronomy
of the University of Rio Grande do Sul, in Não-Me-Toque, in 1969 (Borges, 1993). With the help of
USAID a Buffalo no-tillage planter was imported from the USA, and one hectare was subjected to
direct drilling with sorghum in the same year. Unfortunately this machine was destroyed by fire
putting an end to this early development.
DEVELOPMENT IN AFRICA
Earliest research on no- tillage in Africa was carried out in the late
sixties in Ghana (Kannegieter, 1967, 1969, Ofori and Nanday, 1969, Ofori 1973). Research work
at the IITA (International Institute of Tropical Agriculture) in Ibadan, Nigeria started in 1970
(FAO, 1993). Rattan Lal has been one of the most prominent researchers and prolific writers on
this subject at IITA. First publications by Lal were written in 1973 (Lal, 1973 a, b). Forty one
of his publications are listed as references in the IITA Monograph N° 2, which summarises 12 years
of work at this Institute (Lal, 1983). Other scientists working at national research institutes and
universities in Nigeria also started studies on a range of soils in the 1970s to compare the effect
of different tillage methods on soil properties, crop growth and yield (Agboola and Fayemi, Aina,
Wilkinson, cited by FAO, 1993). Similar studies were also initiated in other African countries
including Liberia by Lal and Dinkins, Ivory Coast by Roose and Senegal by Nicou and Chopart (FAO,
1993). Despite the wealth of research information on no-tillage and mulch farming in Africa, the
technology has not spread to a great extent among farmers. Also, there is only little information
available on the development of no- tillage in this continent. A study on the potential use of no-
tillage in Africa conducted by GTZ (GTZ, 1998), indicates, that the technology is already being
used to some extent in the following countries: Angola, Benin, Ghana, Ivory Coast, Kenya,
Mozambique, Niger, South Africa, Tanzania, Zambia and Zimbabwe. In most countries in Southeast
Africa some work on conservation tillage practices (either at research stations or on farms) is
being done and no- tillage is practiced successfully in larger farms. The most common crops being
used in no-tillage are maize, sorghum, wheat and cotton.
DEVELOPMENT IN AUSTRALIA AND NEW ZEALAND
Before no- tillage of crops was applied, pastures were directly drilled in Australia and
New Zealand. In 1964 Plant Protection Ltd and ICI Australia Ltd undertook a joint programme
on bipyridyls for crop establishment without tillage in Australia (Barret et al., 1972).
First experiments were conducted in the Eastern States (Rowell, 1968). Little information
could be obtained on the development of no-tillage in Australia other than that the technology
is applied on about 1 million hectares (Hebblethwaite, 1997). Australia has serious erosion
problems and this is an important reason why no-tillage is being increasingly used.
DEVELOPMENT IN ASIA
It has been difficult to obtain information on the development of no- tillage
in Asia. According to Table 1 no-tillage is being practiced in Japan, Malaysia and Sri Lanka over
a limited area. It was reported that conservation tillage is practiced in India, Indonesia,
Korea, Philippines, Taiwan and Thailand. More detailed information could be gathered from Japan.
The author gratefully acknowledges the help received from many colleagues, friends and farmers in the preparation of this paper, without which this report would not have been possible. It would be a too long list, to mention all who have contributed in one way or another in making available information requested by the author. The major contributors to this paper have been Dr. Grant Thomas, University of Kentucky, USA; Dr. Friedrich Tebrügge, Justus- Liebig- University, Giessen, Germany; Dr. Kurt Steiner, GTZ, Eschborn, Germany; Dr. Theodor Friedrich, FAO, Rome; Maury Sade, FEBRAPDP, Ponta Grossa, Brazil; Dr. Roberto Peiretti, AAPRESID, Rosario, Argentina; Dr. Makie Kokubun, JIRCAS, Tsukuba, Japan.
Baker, C.J., 1970. Some thoughts on techniques of direct drilling, Massey Shp.
Fmg. A. 121
|Table 1. Area under no- tillage in the seventies and eighties (Hectares)|
|Country||1973/ 74||1983/ 84|
|Japan, Malaysia, Sri Lanka||200,000||250,000|
|Table 2. Total area under no- tillage in different countries in 1996/ 97 (Hectares)|
|Country||Area under no- tillage|
|Uruguay + Chile + Bolivia5)||500,000|
Source Hebblethwaite, 1997
Published in: Proceedings, The 1st JIRCAS Seminar on Soybean Research. No- tillage Cultivation and Future Research Needs, March 5- 6, 1998, Iguassu Falls, Brazil, JIRCAS Working Report No. 13, p 1- 18, 1998.
Frontiers in Conservation Tillage and
Advances in Conservation Practice
Constraints and limitations for no-tillage adoption in South America and how they have been overcome
Primary needs associated with the technology’s further use and adaptation and constraints to extensive use.
Control of soil erosion is still one of the main driving forces for no-tillage adoption. No technique yet devised by mankind has been anywhere near as effective at halting soil erosion and making food production truly sustainable as no-tillage (Baker et al., 1996). The long term gains from widespread conversion to no-tillage could be greater than from any other innovation in third world agricultural production. (Warren, 1983).
General situation of
no-tillage in the world
Table 1: Total area under No-tillage in
different countries (hectares)
|Country||Area under No- tillage
in ha 2007/ 2008
|South Afrika 12||368.000|
|Chile16||180.000||New Zealand 17||162.000|
Source: Derpsch, R. and Friedrich, T., 2010
Information provided by: 1) CTIC, 2007; 2) AAPRESID, 2010; 3) FEBRAPDP, 2005/06; 4) Australian Bureau of Statistics, 2009; 5) Dr. Doug McKell, Soil Conserv. Council of Canada, 2006; 6) MAG & CAPECO, 2008; 7) Li Hongwen, 2008; 8) Mekhlis Suleimenov, 2007; 9) ANAPO, Bolivia, 2007; 10) ) Miguel Carballal AUSID, 2007; 11) Emilio González-Sánchez, AEAC/SV, 2008; 12) Richard Fowler, 2008; 13) Rafael E. Perez, 2004; 14) APAD, 2008; 15) Timo Rouhianinen, FINCA, 2008; 16) Carlos Crovetto, 2008; 17) John Baker, 2008; 18) Fabio Leiva, 2008; 19) Estimate by the authors.
Remark: Some data on the area under No-tillage in Canada shows 6.7 million ha in that country. These numbers do allow for fall tillage with high soil disturbance. When applying the term no-tillage more strictly (low disturbance and no fall tillage) then the area is only 4.08 million ha for Canada.
Although the biggest area under No-tillage is found in the USA, in this country the technology is applied only on 16,3% of the total cultivated area, against 21% in Brazil, 32% in Argentina and 52% in Paraguay. In relation to the total cultivated area, Paraguay has the highest adoption rate of no-tillage in the world (Figure 1).
A study of the potential use of no-tillage in Africa has been made by GTZ in 1998. The study concludes, that no-tillage ensures optimum soil protection and is therefore the system of choice for those regions where sufficient biomass can be produced to provide all-year-round ground cover. The ecological constraining factors for spreading no-tillage in this continent are: low precipitation with low biomass production, short growing seasons, sandy soils with tendency to compaction and soils at risk of waterlogging. The socio-economic constraining factors are: strong demand for crop residues as forage for livestock, uncertain land use rights, poorly developed infrastructure (market, credit, extension service), distinct market preference for one crop (e.g. maize), and high demand on the farm management. The study also concludes, that in regions and under conditions where no-tillage is not possible, the second best choice is minimum tillage (GTZ, 1998).
While no-tillage was researched in the USA already in the 1940’s and more intensively in the late 1950’s, and in Europe in the 1960’s and 1970’s, it was not until 1971 that research on this technology started in Brazil and Latin America (Derpsch, 1998). At first no-tillage was conceived as an efficient technology for soil conservation, since the spread of arable farming had brought about the widespread occurrence of erosion in the southern states of Brazil. With time the technology has evolved to a truly sustainable production system with positive economic, environmental and social consequences.
In the MERCOSUR Countries (Brazil, Argentina, Paraguay and Uruguay) the technology has experienced a twenty fold expansion between 1987 and 1997 against a 4,6 fold increase of the area in the USA in the same period (Figure 2). From 1997 to 1998 the MERCOSUR Countries experienced an expansion of 28% of the area under no-tillage as against 3,7% in the USA. The following may be the main factors that induced such a rapid change in Latin America: 1) Efficient and economic erosion control under climatic conditions with high erosion and soil degradation potential. 2) Appropriate knowledge was available in the region through research and development as well as farmers experiences. 3) Widespread use of cover crops for weed suppression (reduction in the use of herbicides), organic matter build up, biological pest control, etc. 4) The same consistent message, positive to no-tillage has generally been voiced by all sectors involved (private and public) without contradictions. 5) No-tillage has been the only conservation tillage technology recommended to farmers. 6) There has been an aggressive farmer to farmer extension through farmers associations. 7) Publications with adequate, practical and useful information were made available to farmers and extensionists. 8) Economic evaluations with system approach showed high economic returns of no-tillage, as well as the use of cover crops and crop rotations in the system. Economic returns are immediate and substantial. 9) There have been no major forces against the system. 10) Latin American farmers have had to be very competitive in the global market, since in general there are no subsidies.
Constraints and limitations for no-tillage adoption in South America and how they have been overcome
For small and medium sized mechanized farms we would recommend that farmers buy a no-tillage machine suitable for wide row crops (i. e. soybeans, maize, sorghum, sunflower) and for narrow row crops (wheat, oats, rye and green manure cover crops in general). Failure in buying a multipurpose machine puts farmers that do not have enough capital to buy two specialized machines in a situation where they cannot plant narrow row crops and therefore they are not able to seed small grains or green manure cover crops and use adequate crop rotations. Leaving the land in fallow during winter time results in high weed infestation and high costs to eliminate these weeds.
The production and availability of a greater variety of more efficient herbicides together with a greater diversity of more efficient no-tillage seeding equipment in Brazil and Argentina has led to an unprecedented growth of no-tillage in South America.
Herbicide application technology
Concepts about liming and fertilization have changed a lot in Latin America after shifting to the no-tillage system. Experience shows us that we have to forget everything we have learned in the University about fertilization and liming and get acquainted with the new concepts in fertility management in this system. Pioneer farmer Nonô Pereira of Ponta Grossa, Paraná, Brazil, together with the soil scientist Joao Carlos Moraes de Sá have developed a system of no-tillage into native pasture, on soils that have a high aluminum saturation, low pH and in general low fertility levels (Farmers spray off the native pasture 3 to 4 months before seeding to ensure a good kill of woody grasses). Despite this fact, farmers applying relatively low amounts of lime on the soil surface and using medium fertilizer levels, can harvest around 3.000 kg/ha soybeans already in the first year. This is probably due to the high organic matter content of these soils, that have never been touched by tillage tools before. Similar experiences are now being made on poor, acid soils and native pasture in Paraguay.
Soil crusting:In general crusting of soils is not a problem in no-tillage. Because the mulch cover avoids the direct impact of the raindrops on the bare soil surface crusts do not develop. We have found, that soils which very badly tend to crusting in conventional tillage do not present crusting problems in no-tillage, as long as the soil is well covered with sufficient plant residues.
It is general knowledge that badly drained soils are not suited for no-tillage. Luckily most tropical soils in South America are well drained and are generally well suited for this technology.
Soil surface roughness
Soil compaction in permanent no-tillage is an issue that is discussed over and over again in Latin America. We have found that in general researchers have a different perception than farmers in looking at this problem. Since researchers have very sophisticated tools to measure compaction and easily demonstrate that soils are more compact under no-tillage than under conventional tillage, we have seen that many researchers see compaction as a very serious problem in the no-tillage system. We are observing that in general scientists and researchers in Latin America tend to overstate the problem of soil compaction. In contrast to researchers, farmers in Latin America measure compaction not in terms of soil density in g/cm3 or in penetration resistance but in terms of crop response and yields. If yields are as good or better in no-tillage than in conventional tillage, the farmer does not care about compaction. Also farmers measure compaction in terms of penetration of seeding equipment into the soil. If soils are too hard to give good penetration to the cutting elements of a planter than the farmer is going to have a bad stand.
For the purpose of evaluating farmers perception on the problem of soil compaction, three no-till pioneer farmers from Brazil where interviewed in 1997 to express their views on this problem. The interviewed farmers were Nonô Pereira (22 years of permanent no-tillage), Frank Dikstra (22 years of continuos no-tillage) and Herbert Bartz (26 year of continuous no-tillage), totaling 70 years of experience. Their soils vary from about 80% sand to about 80% clay. The farmers were unanimous in stating, that they do not perceive compaction as a problem in permanent no-tillage (Revista Plantio Direto, 1999). They also stated that there is no need to till the soil every so often after no-tillage has been established. Finally they said, that the best way to avoid compaction in the no-tillage system is to produce maximum amounts of soil cover, use green manure cover crops and crop rotations, so that roots and biological activity as well as earthworms and insects, etc., loosen the soil. Good soil cover is also essential to maintain higher moisture content on the soil surface and this will result in better penetration of cutting elements of the seeding equipment.
Besides the limiting factors mentioned a farmer also has to learn about the influence of no-tillage on chemical, physical and biological soil properties, its impact on surface water and the environment, on yields and most important on the economics of the system. Several comprehensive publications with research results have been published in the region since 1981, i. e. IAPAR, 1981; Derpsch, et al., 1991; Crovetto, 1996; Panigatti, et al., 1998; etc. Also the proceedings of many conferences held in Argentina, Brazil, Chile and Paraguay are available for detailed information on the performance of the system. In this respect AAPRESID in Argentina and FEBRAPDP in Brazil (the Federations of no-till farmers in both countries), have contributed strongly in the diffusion of site specific knowledge on the system and have helped greatly to spread the technology all over Latin America.
Primary needs associated with the technology’s further use and adaptation and constraints to extensive use.
Crop rotations and green
manure cover crops
Research conducted in southern Brazil shows consistent reductions in weed infestation with crop rotations in no-tillage and conventional tillage (Table 2).
Table 2: Number of weeds per m3
with and without crop rotation in two tillage systems in Rio Grande do Sul, Brazil (
Ruedell, 1990, adapted by Gazziero, 1998)
|Occurrence of weeds||
|Broad leaved weeds in wheat||
|Narrow leaved weeds in wheat||
|Broad leaved weeds in soybeans||
NT = No-tillage, CT = Conventional tillage
Good no-till farmers in Latin America see it as good farming practice to use GMCC’s and crop rotations independently of the price situation of crops. Once farmers have discovered the benefits of these practices they don’t want to miss them. Sorrenson (1984), between others, has clearly shown the economic advantages of using crop rotation and the right cover crops. While many people still think that when using GMCC’s you are adding costs without getting anything back, farmers especially in Brazil and Paraguay have learned that economics of no-tillage can be substantially increased with their use.
Research conducted by Kliewer (1998) in Paraguay has shown, that crop rotation and short term GMCC’s can reduce the cost of herbicides drastically to US$ 36,62/ha in the case of Crotalaria juncea (52 days GMCC) and to US$ 37,39 in the case of sunflower (57 days GMCC), as against costs of US$ 107,66 when only herbicides and monoculture were used. Kliewer (unpublished, 1998) also reported soybean yields after black oats of 2600 kg/ha without using any herbicides at all. Weed measurements 96 days after seeding soybeans showed 93 kg/ha of dry matter of weeds/ha after black oats, as against 7390 kg/ha after fallow. In the last case soybeans yielded not more than 780 kg/ha. Using a rotation where long and short term GMCC’s or cash crops are seeded as soon as possible after harvesting the previous crop, or after rolling down GMCC’s with a knife roller, it was possible not to use herbicides in no-tillage for as much as three years in a row. In some cases when farmers are using crop rotations, only eliminating weeds with a total herbicide before planting is necessary without any herbicide application during the growing season at all. If some weeds escape, the few weeds that develop can be efficiently and economically controlled by hand hoeing because labor is cheap.
Research conducted in Brazil has shown that black oats used as a green manure cover crop before soybeans can increase soybean yield by as much as 63% as compared to soybeans after wheat (Derpsch, et al., 1991).
Good knowledge about green and dry matter production and profitability of green manure cover crops, how to fit them into different crop rotations and what residual fertilizer effect we can expect of each GMCC planted before the main cash crops is essential for dissemination of their use. Several publications have contributed in filling this knowledge gap mainly in Brazil (Sorrenson and Montoya, 1984; Monegat, 1991; Derpsch, 1991; Derpsch and Calegari, 1992; Calegari et al., 1992).
GMCC’s and crop rotation are the key factors for the unprecedented growth of no-tillage especially in Brazil and Paraguay. Linked to the spread of cover crops is the use of a "knife roller" to put the cover crops down to the ground. This implement is not terribly expensive and in many cases can be made locally or by the farmer himself. The implement can be pulled by medium sized tractors or by animal traction and has contributed a lot in reducing herbicide rates in the no-tillage system. The knife roller has become an essential tool for managing GMCC’s in many countries of South America. Alternatively steel bars can be welded on top of the discs of disc harrows and the implement used for the same purpose.
Finally we have to admit that all over the world farmers adopt technologies because they are economic and are positive to their pockets and seldom because they are environmentally friendly. Therefore an economic evaluation of the system under the different agroecologic and socio-economic conditions is essential to have better arguments for adoption. Of course it is misleading to analyze the results of only one or two cropping seasons. Instead an evaluation of the whole system with all its components has to be made, putting value to timeliness, longer life of tractors and less repair costs in this system, improvement of soil fertility, reduced costs for fertilizers and pesticides, the environmental benefits of the system, etc.
Thorough economic studies with a system approach have been made by Sorrenson and Montoya (1984) in Brazil and again by Sorrenson et al., (1997 and 1998) in Paraguay. The economic evaluation in 1998 in Paraguay was made on small farms of generally less than 20 ha without tractor mechanization. The study concludes that the total economic benefits arising from adoption of the no-tillage technique on 480.000 ha in Paraguay have been calculated to be US$ 941 million (Sorrenson, 1998). The same author claims that "no other farming techniques have been shown to have such a high impact on farmers’ incomes, reduce their production costs and risks, and at the same time be environmentally sustainable and generate very considerable net social gains to society"
Steps in no-tillage
There are some critical factors that should be considered before starting no-tillage. Therefore we recommend the following to farmers:
The historical development of no-tillage crop production and the successful application in mechanized farms in Latin America, has been closely related to: the availability of appropriate knowledge under different agro-ecological and socio-economic conditions; the availability of a variety of efficient low-cost herbicides; the availability of appropriate machines at adequate prices; the practice of adequate crop rotations including green manure cover crops and most important, a mental change of farmers, technicians, extensionists and researchers away from soil degrading tillage operations to a truly sustainable production system in agriculture.
The practice of adequate crop rotations including green manure cover crops is probably the main factor of successful and widespread adoption of the technology in many regions of Latin America. Experience has shown that green manure cover crops do not cost, they will pay. The study of the economic implication of these practices has shown, that economic returns of no-tillage could be substantially increased by the use of crop rotations and green manure cover crops.
Baker, C.J., Saxton, K.E. and Ritchie, W.R., 1996: No-tillage Seeding, Science and Practice. CAB International, Wallingford, Oxon, UK, 158 pp
Calegari, A., Mondardo, A., Bulisani, E.A., Wildner, L.do P., Costa, M.B.B., Alcantara, P.B., Miyasaka, S. e Amado, T.J.C. 1992: Adubação verde no sul do Brasil, AS- PTA, Rio de Janeiro, 346 p.
Crovetto, C., 1992. Rastrojos sobre el suelo. Una intoducción a la cero labranza. Edidorial Universitaria, Santiago, 301pp.
Derpsch, R. e Calegari, A., 1985: Guia de plantas para adubaçao verde de inverno. IAPAR, Londrina, Documentos 9, Maio de 1985, 96 p.
Derpsch, R., 1998: Historical review of no-tillage cultivation of crops. Proceedings, First JIRCAS Seminar on soybean research, March 5 - 6, 1998, Foz do Iguaçu, Brazil, JIRCAS Working Report N° 13, p 1 - 18.
Derpsch, R., Roth, C.H., Sidiras, N. and Köpke, U., 1991. Controle da erosão no Paraná, Brasil: Sistemas de cobertura do solo, plantio direto e preparo conservacionista do solo. GTZ, Eschborn, SP 245.
Fundação ABC, 1996: Tecnologia de aplicação de defensivo. Fundação ABC para Assistencia e Divulgação Técnica Agropecuária, Castro, PR, Brazil, 36 pp
Gazziero, D. L. P., 1998: Control of weeds in no- tillage cultivation. Proceedings, First JIRCAS Seminar on soybean research, March 5 - 6, 1998, Foz do Iguaçu, Brazil, JIRCAS Working Report N° 13, p 43 – 52
GTZ, 1998: Conserving Natural Resources and Enhancing Food Security by Adopting No- tillage. An Assessment of the Potential for Soil- conserving Production systems in Various Agro- ecological Zones of Africa. GTZ Eschborn, Tropical Ecology Support Program, TÖB publication number: TÖB F-5/e, 53 pp
IAPAR, 1981: Plantio direto no estado do Paraná. Fundação Instituto Agronomico do Paraná, Circular N° 23, 244 pp
Kelly, H. W., 1983: Keeping the land alive. Soil erosion, its causes and cures. FAO Soils Bulletin N° 50, FAO, Rome. 78 pp
Kliewer, I., Casaccia, J., Vallejos, F., 1998: Viabilidade da redução do uso de herbicidas e custos no controle de plantas daninhas nas culturas de trigo e soja no sistema de plantio direto, através do emprego de adubos verdes de curto período. Resumo de Palestras: I Seminário Nacional Sobre Manejo e Controle de Plantas Daninhas em Plantio Direto, 10 – 12. 8. 1998, Passo Fundo, RS, Editora Aldeia Norte, Passo Fundo, 120 - 123
Lorenzi, H., 1994: Manual de identificação e controle de plantas daninhas, plantio direto e convencional, 4ª edição, Editora Plantarum, Nova Odessa, Brazil, 299 pp
Monegat, C., 1991: Plantas de cobertura do solo. Características e manejo em pequenas propriedades. Chapecó (SC). Ed. do Autor, 336 p.
Panigatti, J.L., Marelli, H., Buschiazzo, D., Gil, R., (Editors), 1998,: Siembra Directa. INTA - Editorial Hemisferio Sur, Buenos Aires, 333 pp
Revista Plantio Direto, 1999 É preciso descompactar o solo?, Revista Plantio Direto – Janeiro/ Fevereiro de 1999, p 16 - 19.
Rodrigues, B.N., Almeida, F.S., e 1998: Guia de herbicidas. 4ª Edição, Editora dos autores, Londrina 1998, 648 pp
Ruedell, J., 1990: Efeito do manejo do solo e da rotação de culturas sobre a população de plantas daninhas e na produtividade das culturas. En: Primeras Jornadas Nacionales de Cero Labranza. Concepción, Sociedad de Conservación de Suelos de Chile, p. 169-182
Sorrenson, W.J., Montoya, L.J., 1984: Implicações econômicas da erosão do solo e de práticas conservacionistas no Paraná, Brasil, IAPAR, Londrina, GTZ, Eschborn ( no publicado), 231 p.
Sorrenson, W.J., López Portillo, J., Nuñez, M., 1997: Economics of No- tillage and crop rotations – policy and investment implications, FAO Report N° 97/075/ ISP-PAR, 1 October 1997,
Sorrenson, W.J., Duarte, C., López Portillo, J., 1998: Economics of No- till compared to conventional cultivation systems on small farms in Paraguay, policy and investment implications., Report Soil Conservation Project MAG – GTZ, August 1998
Warren, 1983: Technology transfer in no- tillage crop production in the third world agriculture. In: No- tillage crop production in the tropics. Proc. Symp., Monrovia, Liberia Published by Int. Plant. Prot. Center, Oregon State Univ., Corvallis, OR, 25-31.
To be published in the proceedings of the 10th ISCO Conference:
SOIL CONSERVATION PROJECT (MAG/ GTZ)
ECONOMICS OF NO- TILLAGE AND CROP ROTATIONS
POLICY AND INVESTMENT IMPLICATIONS
FAO Report No: 97/075 ISP-PAR
Date: 1 October 1997
William J. Sorrenson, Investment Centre, FAO
E- Mail: firstname.lastname@example.org
Justo López Portillo, DIA/ MAG
Mario Núñez, DIA, MAG
(Only the summary and conclusions are presented here)
Please refer to the main author or to the MAG- GTZ Soil Conservation Project for the full report.
E- Mail: email@example.com
(1) The introduction of soybeans to the southern and eastern parts of Paraguay in the early 1970s, followed by wheat in the mid 1970s, using conventional mechanised soil preparation practices with disc ploughs and harrows, initiated a process of widespread soil degradation and erosion. These have now reached levels that threaten the sustainability of commercial agriculture in Paraguay. However, in the neighbouring Brazilian states of Parana, Santa Catarina and Rio Grande do Sul, cost- effective, no- tillage/ crop rotation technologies, which have important soil conservation characteristics, have been researched and developed in similar agro- ecological zones and are now quite extensively used throughout the central and southern parts of Brazil.
(2) The technique of no- tillage (NT) was first used in Paraguay in the late 1970s. Following a slow start, its adoption by Paraguayan farmers gathered momentum increasing from 20,000 ha in 1991/ 92 to an impressive 250,000 ha in 1995/ 96, accounting for about 19% of the land cultivated mechanically.
(3) In 1993, the Ministerio de Agricultura y Ganadería (MAG) and the Deutsche Gesellschaft fur Technische Zusammenarbeit (GTZ), started a project aimed at adapting and further disseminating no- tillage in combination with rotations of both cash and green manure crops in the major grain producing departments of Paraguay. Since very little was known about the economics of these technologies in Paraguay, MAG in association with the GTZ, initiated a detailed investigation, the results of which are detailed in this report.Methodology
(4) Eighteen farmers, representative of the MAG/ GTZ project target groups of small, medium and large mechanised farmers in south- eastern Paraguay, were selected for in- depth study on the basis of their representativity and availability of farm records1. Most of these farms were in the Itapua and San Pedro departments. Following recommended practice, no- tillage (NT) and crop rotations were being introduced gradually on most of these farms, normally over four to five years. The time series data collected during the study enabled a valid comparison of NT and conventional cultivation (CC) under roughly the same physical and management conditions over several seasons. Interviews were also held with other farmers during the course of the study to canvas their attitudes towards soil erosion and the NT/ crop rotation technologies.
(5) Based on the farm data collected during the study, and some secondary data (from farmer co- operatives), two sets of representative crop budgets under CC and NT were prepared, one set for each region. In addition, machinery costs (both fixed and variable) were assembled for each region and crop rotations, which were linked to crop budgets to accommodate residual nutrient effects, were specified. The crop budgets, machinery costs, crop rotations and resource endowments (land, labour and capital) were all combined in models of typical farms for each region, so that the financial and economic impacts of NT and crop rotations could be quantified and compared to CC cropping systems.
(6) The farm models were prepared using universally available spreadsheet software. A subsidiary objective of the study was to make the models accessible to extensionists and farmers through extension programmes. Hence the models were structured to permit easy inputting of variables peculiar to an individual farm such as farm size, capital invested, labour complement, rate of adoption of no-tillage, crop yields, crop and farm input prices, interest rate, etc., so as to assist a farmer to decide on how he should introduce NT on his farm, including the choice of crop rotations.Discussion and Results
(7) The effectiveness of NT in limiting soil erosion in the humid tropics is well known. Besides substantially reducing soil erosion losses, improving soil chemical, physical and biological properties, raising organic matter content, with consequent beneficial impacts on crop productivity, the cropping season is considerably extended. In Paraguay, conventional tilling of the soil is sensitively weather dependent and normally takes between 30- 75 days from harvesting to sowing a subsequent crop. Using NT, this time period is reduced to less than 15 days (the harvester may even be followed immediately by the seeding machine), thus significantly extending the cropping season and providing an opportunity to introduce more crops during the cropping year.
(8) The benefits of introducing green manure crops are also quite well known. Soil erosion losses are further reduced by maintaining soil cover and mulch throughout the year, nutrient recycling and water infiltration are increased, weeds are suppressed, and pest and disease cycles are broken lowering the use of pesticides.
(9) The study has shown that there are a number of additional benefits from adopting NT and crop rotations in place of CC cropping systems. These include: (1) reduced tractor hours and lowered permanent farm labour and machinery costs; (2) savings in fertiliser, insecticide, fungicide and herbicide usage per crop over time in NT compared to CC; and (3) cost savings in NT through eliminating contour terracing and the replanting of crops following heavy rain which is often needed under CC.
(10) Attention is drawn in the report to the fact that the use of NT and crop rotations call for new management skills, particularly, to cost-effectively control weeds. Farmers require a number of years to master these skills, although this period can be significantly reduced through development and extension support oriented by farmers' interests. The key skills required are: (1) selecting the type and quantity of herbicide used; (2) regulation of sprayer pressure, output, speed and timing of herbicide application; (3) the choice and sequencing of cash and green manure crops in rotations; (4) minimising the time between harvesting and the sowing of a subsequent crop; (5) managing ground cover and crop residues; and (6) using spot spraying with weed- specific herbicides or manual labour, where cost- effective, to control sporadic patches of weeds as opposed to blanket spraying with broad- pectrum herbicides. If these skills are not mastered, inevitably weed infestation increases, production costs rise, and crop yields may fall, which combine to significantly erode farm profits. Farmers then revert back to CC methods as they attempt to survive for some more time before reaching the inevitable point of having to abandon their land when it is no longer productive and economic to cultivate2.
(11) Comprehensive, yet practical and user- friendly, farm models were developed during the study to enable detailed quantification of the financial benefits and economic impacts of NT/ crop rotations compared to CC cropping practices over 10 years. NT can be introduced over a number of years with the rate of adoption being specified by the user. The recommended practice is to introduce NT over 4 years; normally 10% of the farm in the first year, 40% in the second, 70% in the third and over the whole farm from the fourth year onwards.
(12) Differences in crop yields, as well as per crop fertiliser and herbicide usage (the most significant items of farm costs) were observed on the farms studied under both CC and NT. In general, depending on the crop, yields under CC were following a declining trend3, while the reverse was occurring under NT when used in combination with green manure cover crops and crop rotations. Based on detailed analysis of the case study farms, as well as published research data from Parana (analysed by Sorrenson and Montoya, 1989), crop yields under CC decline over a period of about 10 years by between 5%-15% (depending on the crop), while over approximately the same time period under NT, they increase between 5%- 20% (again depending on the crop). These trends in crop yields were found to impact strongly on farm incomes. Savings in herbicide and fertiliser inputs, per crop, under NT compared to CC, which are partially dependent on the crop rotation being followed, range from 30% to 50%, respectively, over approximately the same period and significantly impact on farm variable costs and profits.4
(13) The most commonly used rotations in San Pedro and Itapua, which vary in length from 3 to 5 years, were incorporated in the farm models and are shown below. It can be observed that the number (and range) of crops grown during a cropping year is greater under NT than CC. With NT it is possible to grow soybeans and maize during the main season, as well as out-of-season, and to grow a variety of green manure crops between cash crops to maintain good ground cover on the soil surface to suppress weed growth and to benefit from their residual nutrient effects.
CC 1. O-S¦W-S¦SF-M
NT 2. O-S¦W-S¦OOr-M-So¦O-S¦SF-M
CC 1. O-S¦W-S¦O-S¦O-S|
NT 2. O-S¦W-S¦O-OOr-Mo
CC= conventional cultivation NT= no tillage ¦designates end of cropping year|
O= oats S= soybean So= off- season soybeans SF=sunflower M= maize Mo= off- season maize
W= wheat OOr= oats and oilseed radish C= crotalaria SG= sorghum OV= oats and vicia
(14) The possibilities of introducing sunflower and maize in Itapua under CC are limited because of the longer growing seasons and extra time required to prepare the soil (wetter, heavier soils compared to the warmer climate and sandy soils of San Pedro).Farm-level Financial Analysis Results
(15) The financial impacts of NT and crop rotations are analysed in detail by Sorrenson et al (1997). The financial performance of a typical medium-sized farm (45 ha) and a large- sized farm (135 ha) are traced over a period of 10 years for the San Pedro and Itapua regions. Results are outputted from the farm models for the overall farm, but can also be traced separately for each crop and for each crop rotation. Because the farm models are based on a thorough analysis, spanning an number of years of case study farms, the results can be confidently considered as indicative of what is actually being realised in practice by Paraguayan farmers.
(16) Annual income (by crop), variable and fixed costs (by major categories), net farm income, return on capital and annual tractor hours, are calculated for a typical farm. All revenues and costs are expressed in local currency (Guaraníes - Gs) or United States dollars (US$). The prices used were those prevailing in 1995/ 96.5 The same set of prices was used in all years, together with "expected" levels of input/ output coefficients, so that financial performance figures reflect the dynamic effects of soil tillage/ cropping system on crop productivity, quantities of farm inputs used and other farm costs devoid of price changes and other random changes due primarily to climatic variation6.San Pedro
(17) The results of the first and tenth years of a typical large farm (135 ha) in San Pedro are detailed in Table A and summarised below. Farm income decreases (from US$ 77,030 to US$ 68,630) under CC in response to declining crop yields which have been built into the model based on research results from Parana, Brazil, and actual farmer experience in San Pedro. Under NT it increases considerably (from US$ 75,010 to US$ 93,760). At the same time farm costs (both variable and fixed costs, the latter exclusive of the cost of NT equipment) are lower under NT compared to CC. Net farm income increases considerably under NT from US$ 8,570 in year 1 to US$ 31,140 in year 10, while under CC it is calculated to decrease from US$ 4,930 to -US$ 3,010. The changes in income and variable costs under NT, between the first and tenth years, reflect increasing crop yields, a higher cropping intensity and savings per crop in fertiliser, herbicide and insecticide. It is significant to note that these results are based on actual farmer experience in San Pedro.
(18) The results for a typical large farm (135 ha) in the Itapua region are detailed in Table B and are summarised below. As in San Pedro, the changes in farm income and costs are also based on actual farmer experience in the region. Farm income decreases (from US$ 64,690 to US$ 61,450) while under NT it increases considerably (from US$ 63,670 to US$ 102,860). Farm costs (both variable and fixed costs, the latter exclusive of the cost of NT equipment) increase under NT compared to CC, but these increases are less than the corresponding increases in farm income. Thus, net farm income increases considerably under NT, from US$ 9,770 in year 1 to US$ 33,700 in year 10, while under CC it is calculated to decrease from US$ 7,300 to US$ 1,100.
Comparative Summary - San Pedro and Itapua|
(19) Highlighted below are the changes between the first and tenth years in net farm income, as well as return on capital and tractor hours, calculated for two representative large farms (135 ha) in San Pedro and Itapua.
|Farm Model (135 ha) - Net Farm Income US$|
|First Year||Tenth Year||First Year||Tenth Year|
|Farm Model (135 ha) - Return on Capital (%)|
|First Year||Tenth Year||First Year||Tenth Year|
|Farm Model (135 ha) - Annual Tractor Hours|
|First Year||Tenth Year||First Year||Tenth Year|
(20) All three performance criteria exhibit significant improvements under NT compared to CC in both regions studied. The net farm income figures for NT do not include the purchase cost of a no- tillage drill and auxiliary equipment. These costs can vary largely depending on the type of machinery purchased and whether a farmer opts to buy new or used equipment. Should new machinery be purchased, costs average about US$ 15,000 per farm. Net farm income increases in both regions are expected to be sufficient to pay for the NT equipment within 2 years. Often farmers lower their set- up costs in NT by initially hiring a no- tillage drill, through adapting their conventional drills for no- till, or by purchasing used NT machinery.
(21) The changes in the returns on capital of NT compared to CC are quite impressive. In these calculations allowance is made for the additional investment in NT machinery, costed as new machinery. NT and crop rotations are shown to substantially improve the financial performance of cropping farms in the regions studied, whilst under CC, financial viability becomes seriously threatened within a 10 year time-span.
(22) In both regions, despite increased cropping intensities, total annual tractor hours fall quite sharply by the tenth year in NT compared to CC, with consequential savings in tractor costs and permanent farm labour.Financial Rates of Returns
(23) Financial rates of return on the marginal investment in NT equipment were calculated over 10 years for medium and large farms in San Pedro and Itapua. It was assumed that new equipment would be purchased. The results are shown below together with average rates of return over the 10 years analysed.
|Region||Farm Size||Financial Rate of Return(%)||Average Rate of Return(%)
|San Pedro||Medium (45 ha)
Large (135 ha)
|Itapua||Medium (45 ha)
Large (135 ha)
(24) The adoption of NT and crop rotations is much more attractive financially in both regions for large farmers than medium-sized farmers. The reason for this is because in the farm model analysis, it is assumed that the investment costs in NT equipment would be the same irrespective of farm size. Therefore, larger- sized farms are able to capitalise on considerable economies of scale. Savings in permanent labour costs are also greater on the larger farms. Nevertheless, NT and crop rotations are still financially attractive for medium-scale farmers.
(25) Small farmers can also benefit considerably from NT and crop rotations. The focus of this study was the mechanised areas where most of the soil erosion is occurring in Paraguay7. The study also included an analysis of the benefits a number of small farmers are obtaining from the mechanised NT/crop rotation technologies. These farmers plant 4-5 ha of soybeans through contracting neighbouring farmers with tractors for their cultivation, spraying, sowing and harvesting operations. These farmers, who are conscious of the costs of soil erosion, have adopted new crop rotations and have their soybean crops directly sown. Ignoring the effects of reduced soil erosion, annual cost savings per small farmer, are estimated at about US$ 440.Risk Analysis
(26) In all 10 years simulated, net farm income on the large farms was higher under NT than CC in both regions (see table below). Risks, defined as the probability of the net farm income falling below zero in any year, are analysed in the report. It is concluded that risks to a farmer lower considerably following the adoption of NT/ crop rotations compared to CC cropping. The main reasons for this are: (1) higher and more stable yields in NT compared to CC due to improved soil structure, higher water infiltration and soil moisture retention, and reduced pest and diseases; (2) the impact of lowering farm income when soybean and wheat prices fall is less under NT compared to CC because it is possible to diversify into other cash crops; (3) reduced fuel costs under NT compared to CC and therefore lowered impact of increases in the real price of fuel; (4) over time, lower fertiliser and herbicide costs per crop under NT compared to CC as the impact of green manure crops, and the reduced fallow periods between crops, take effect.
|Farm Models - Simulated Net Farm Income
(US$ per Year)
(27) Situations are rarely encountered in agricultural technology development whereby highly attractive financial returns are accompanied by a lowering of risks. Generally more profitable technologies carry with them concomitantly higher risks, necessitating the weighing-up by farmers of accepting higher profits with higher risks, as opposed to operating on a lower average profit but with lower risks.Country-level Economic Analysis Results
(28) Farm models of representative medium and large farms for Itapua and San Pedro were used as the building blocks for an ex-ante economic evaluation of a soil conservation participatory R&D, training and extension project proposed in the report. The project, designed to speed-up the rate of successful adoption of NT/ crop rotations in south- eastern Paraguay, would support on- farm trials, farmer workshops and seminars, study tours, up to 50 additional extensionists who would be specially trained and dedicated to the project, as well as a project management facility. The main output of the project would be a higher rate of adoption of no-tillage, in combination with financially attractive crop rotations, estimated to increase from the present about 20% of farmers to 60%, 75% and 80% by the 5th, 10th and 20th years respectively with the project. Without the project it is estimated that the rate of adoption would increase to 40%, 50% and 55% respectively by the 5th, 10th and 20th years. The direct costs that would be associated with the project over 10 years are estimated at about US$ 20 million. The expected Economic Rate of Return (ERR) over a 20 year period is estimated at 57%. Past research and development costs on NT/ crop rotations have been treated as sunk costs and therefore ignored. In economic prices, the annual incremental crop output valued at farm gate is estimated to rise from US$ 15 million (m), to US$ 32 m and US$ 43 m respectively in the 5th, 10th and 20th years.Policy and Investment Implications
(29) Two important agricultural policy issues arise from this study. The first is an issue concerning extension policy. Because most soil erosion in Paraguay occurs on the mechanised annually cropped areas, it is these areas -- and the medium and large farmers concerned -- which must be the principal target of soil conservation efforts if sustainable agricultural cropping is to be achieved. However, at present Government of Paraguay (GOP) policy does not support any extension efforts directed at mechanised farmers. Instead public extension efforts are focused exclusively on small farmers using animal traction. Before the proposed interventions designed to increase the rate of sustainable adoption of the NT/ crop rotation techniques can be advanced, the GOP will need to readdress its agricultural extension policy. The study suggests that GOP should support extension efforts for the medium and large cropping farmers through the extension services of the farmer co- operatives, since a successful and cost- effective farmer discussion group model already exists in the country, albeit on a very small scale in two farmer co- operatives. Contracting of private sector extension operators to provide specific extension services, within the context of the proposed interventions, should also be considered and also calls for revising existing extension policies.
(30) The second policy issue relates to the methods of soil conservation to be supported by the GOP. There are three basic choices: (1) outdated conventional methods using contour terraces under CC; (2) reduced tillage combined with contour terracing; (3) NT in combination with crop rotations. Sorrenson and Montoya (1989) analysed these options in detail in Paraná, Brazil, and concluded that the third option was by far the most cost-effective. The work reported in this paper confirms that this option is financially attractive to farmers, cost-effective, economic and environmentally sustainable. GOP should make a clear policy choice on which option it wishes to follow so as to avoid inefficient use of resources in soil conservation efforts, including the Binacional Itaipu Soil Conservation Programme with Brazil and the World Bank assisted Natural Resource Management Project initiated in 1996. So far, a clear policy choice has not been taken and considerable confusion exists.
(31) There are a number of investment implications which arise from the study. Aside from the direct costs of the proposed soil conservation participatory R&D, training and extension interventions, estimated at US$ 20 million over 10 years, investment in additional NT equipment is estimated to be about US 7 m per year during the initial years and reducing thereafter. Although there should be sufficient funds to cover farmers' additional needs for short term finance, there are limited funds available for financing farm machinery over medium terms of 5-7 years. The GOP, through the Banco Nacional de Fomento, should actively pursue with bilateral or international financing agencies, increasing the availability of funds to finance the additional investment which would be needed in NT equipment.Conclusions
(32) Benefits to farmers from the adoption of no- tillage, in combination with sensible crop rotations, could be substantial. However, in order for farmers to realise these benefits, besides adopting NT, they must markedly alter their cropping systems, switching from monocropping practices to diversified crop rotations, including the use of green manure crops. This necessitates the learning and mastering of an array of new crop management skills. It is clear that participatory R&D, training and extension are needed to speed up the learning of these skills. While the suppliers of machinery and pesticides are active in the extension of NT -- aimed at increasing their sales and not farmers' profits -- farmer co- operatives and farmers deserve to be supported so that the potential benefits to society, which could be captured from these techniques, are optimised.
(33) The study has indicated that investment in public goods over a 10 year period, in the form of participatory R&D, specialist training and extension programmes in no- tillage and crop rotations, would increase the rate of adoption of these technologies and be an economically attractive investment for Paraguay. These efforts should facilitate farmer-led development and private sector extension initiatives. This could be achieved by supporting self-organised groups of no- till farmers either directly, or indirectly through the technical departments of farmer co-operatives. The proposed participatory R&D, extension and training and awareness activities, in combination with substantially increased farm profits, are expected to provide sufficient incentives to encourage most Paraguayan cropping farmers to adopt NT and more diverse crop rotations. These changes in farm production methods are expected to reverse the current trend of declining crop productivity and lead to an economically, ecologically and socially sustainable form of commercial cropping in Paraguay.
(34) The MAG/ GTZ project should be considered as a pilot phase of the proposed participatory R&D/ training/ extension project. The possibility of immediately expanding the MAG/ GTZ activities through the World Bank supported Natural Resources Management Project8 should be carefully evaluated since it would save valuable time and would provide useful information which could be incorporated in the formulation of the project identified in this report.
ECONOMICS SMALL FARMERS
ECONOMICS OF NO- TILL COMPARED TO
CONVENTIONAL CULTIVATION SYSTEMS ON
SMALL FARMS IN PARAGUAY
POLICY AND INVESTMENT IMPLICATION
William J. Sorrenson, Consultant GTZ
E- Mail: firstname.lastname@example.org
Cesar Duarte, DIA, MAG
Justo López Portillo, DIA/ MAG
(Only the summary, conclusions and recomendations are presented here)
Please refer to the main author or to the MAG- GTZ Soil Conservation Project for the full report.
E- Mail: email@example.com
This report documents the findings of a study into the economics of no- till systems compared to conventional cultivation systems on small farms in Paraguay. The study was conducted during a three month period in May- July 1998 and was funded by the MAG- GTZ project "Desarrollo y Difusion de Sistemas de Aprovechamiento del Suelo Orientados a su Conservacion".
Soil erosion and soil degradation in the tropics are now considered to have reached catastrophic levels and threaten the viability of agriculture in much of the tropics. Facing the debilitating effects of declining productivity and incomes, due to soil erosion and soil degradation in conventional cultivation annual cropping systems, farmers throughout the tropics have been quick to adopt no- till, in what is becoming recognised as a technological revolution. Practical experience in Paraguay and elsewhere in South America suggests that no- till in combination with green manure crops and crop rotations are cost-effective methods of soil conservation. Uneconomic unsustainable conventional cultivation systems are transformed into economic sustainable ones with the potential to generate enormous private and social gains.
No- till was introduced on tractor- mechanised medium and large farms in Paraguay in 1990. By 1997 some 480,000 ha, 51% of the total cultivated area in Paraguay, was no- tilled. The total economic benefits arising from this spectacular adoption of the technique are enormous. Their magnitude can be appreciated from the US$941 million that has been calculated for the year 1997. This estimate includes the savings in lost nutrients in the soil that was saved from erosion on the no- tilled areas, plus the costs saved in reduced tractor hours, less fuel and lowered inputs of fertiliser.
In comparison to the meteoric rise of no- till on tractor- mechanised farms, no- till has hardly reached small farms. While the number of small farms in Paraguay total almost 248,000 and occupy 1.5 million ha, the area of no-till on small farms has been estimated at only 4,500 ha. This area includes areas occasionally no- tilled. The area permanently no- tilled on small farms is likely to be less than 2,000 ha involving no more than 150 farmers.
It is estimated that 1.2 million people live on small farms, 80% of whom live below the poverty line. Rural poverty has been increasing and small farm families have been suffering from declining incomes and deteriorating levels of nutrition and health. As a consequence, urban drift has been escalating. The urban population, as a percentage of the total Paraguayan population, increased from 37% in 1972 to 50% in 1992. A root cause of urban drift is undoubtedly declining productivity due to soil erosion and soil degradation and diminishing farm incomes. It is most unfortunate and ironic that many of the small farmer families who abandon their farms in search of a better life in fact face worsening conditions. Most end up living in and around cities in impoverished slum areas.
Despite the worsening situation faced by small farmers, and the significant number who have been abandoning their farms and moving into urban areas, they still make a major contribution to the Paraguayan economy. While small farmers occupy only 6% of the country's agricultural area they still generate 35% of the sector's output. This is a major contribution to the economy since the agricultural sector is the backbone of the Paraguayan economy generating 26% of the economy's Gross Domestic Product, 90% of all exports and employs 37% of the workforce.Edelira and San Pedro
The report documents detailed case studies of seven farms in two representative regions of the country where most experience has been built- up with no- till on small farms - Edelira and San Pedro. Farms studied were selected as being representative of most small farms and varied in size from 5- 20 ha. In Edelira farmers had 5 or 6 years of experience with no- till and in San Pedro the two no- till adopters had only 2 years of no- till experience. The performance of these farms before the adoption of no- till, i.e. when the farms were conventionally cultivated, were compared to their performance after the adoption of no- till. Two farms which have not adopted no- till, one in each region, were also analysed in- depth to provide a further check on the current performance of conventional cultivation systems. In addition detailed analysis was carried out of five typical farms in Paraguari considered representative of small farms on an estimated 367,400 ha of extremely degraded soils of Central Paraguay.
This study shows that the yields of cotton, soybeans, tobacco and maize, important income earning crops for small farmers, have been falling rapidly in unsustainable conventional cultivation systems. These systems enter an ever increasing downward spiral of diminishing yields and incomes and inevitably reach a point where farmers are forced to abandon their farms.
Soil fertility and organic matter levels rise rapidly when no- till and green manure crops are introduced immediately raising significantly farm incomes. Under conventional cultivation, in most cases small farmers do not use any fertiliser, very little if any manure and generally no soil conservation measures are taken. Due to significant soil erosion, high quantities of soil nutrients and organic matter are lost. In the opinions of the no- till adopter farmers', crop yields immediately improve under no- till. Crop yield data are provided in the report for each of the case study farms. These clearly illustrate trends of declining yields under conventional cultivation and immediately increasing yields after the adoption of green manure crops and no- till. An example of the dramatically quick response to the introduction of no- till and mucuna is the introduction of tobacco on the two no- till farms studied in San Pedro. In the second year of using no- till, tobacco has been reintroduced into these farming systems. A highly profitable crop demanding higher levels of fertility, previously tobacco was only viable to grow for one or two years after the felling of forest on newly cropped land. This is a sign that soil fertility has rapidly recuperated.
The study shows that crop production costs fall substantially after the adoption of no- till. Not only are soil preparation costs saved, but farm labour requirements fall and the cost of weeding in most instances also lowers. On one of the farms studied in Edelira, soil preparation for soybeans costed US$59/ ha accounting for 24% of the total production costs. These costs were eliminated under no- till. On the same farm, substantial savings (US$76/ha) in the costs of weeding were realised under no- till compared to conventional cultivation and annual farm labour requirements fell from 300 person-days to 239 person- days.
The study clearly demonstrates that the financial performance of conventional cultivation systems is poor and that in contrast no- till offers an almost instantaneous and dramatic improvement. Not only do crop incomes rise but crop production costs are significantly reduced. The order of magnitudes are illustrated below. Conventional systems are calculated to be marginally economic when all factors of production, including family labour, are costed at market rates. In distinct contrast, the farming systems where no- till and green manure crops have been introduced have shown a dramatic improvement.
While the conventional farming case study (Sr. Bruno) currently has a net farm income of less than US$600 and a return to labour of less than US1.50 per day, all three farms where no-till has been adopted have net farm incomes between about US$3,200 and US$5,800 with returns to labour from US$16 to US$24 per day. This is an impressive improvement over the farm that is still conventionally cultivated where the poor performance of the farm is primarily due to its heavy reliance on soybeans. Not only does it have a low yield (average 2,500 kg/ha) but the farmer also receives a relatively low price for his crop from a local soybean trader (12%- 15% below what the local farmer co-operative Colonias Unidas pays). He also pays a high rate of interest for credit borrowed from the trader (5% per month = 60% per annum) which significantly raises his costs of production. This farmer is caught in a proverbial vicious cycle of dependency on his local trader - a common occurrence amongst small farmers. The results of the no- till adopters are equally impressive when they are compared to the past performance of these farms when they were conventionally tilled. The increases in net farm incomes have been between 35% and 99%.
The current net farm income on the conventionally cultivated farm of Sr. Agustin is US$1,416, which is about comparable to the net farm incomes (on a per hectare basis) earned on the other two farms when they were conventionally cultivated. What is particularly impressive is how the net farm incomes and returns to labour have increased only 2 years after the introduction of no- till, particularly on the small 5- hectare farm.
Farmers in Edelira and San Pedro have been receiving readily available high- level technical assistance, initial stocks of green manure crop seeds and free no- till machinery and equipment. All farmers interviewed acknowledge the need for continuous technical assistance. However, the detailed analyses carried out in the study suggest that even if farmers were to pay themselves for the initial seeds of green manure crops and for the machinery/equipment in small groups of 3-4 farmers per group, these technologies would still be highly profitable for them. The study therefore shows that no- till would have a high economic pay-off to the state and is financially attractive to small farmers.
Before a significant number of small farmers can adopt no- till, they will need access to competent technical assistance and long-term credit at affordable rates to purchase a minimum of equipment and machinery. Depending on what equipment and machinery are purchased, costs per farmer would vary from about US$800-US$3,000 for a group of three farmers and from US$600 to US$2,200 for a group of four farmers. At the current interest rate charged by the CAH of 17.5% interest per annum, loans of at least 6-7 years duration would be needed.Paraguari
Paraguari was selected as representative areas of extremely degraded soils in Central Paraguay. No- till has not yet reached small farmers on these poorly degraded soils.
The likely financial impact of a proposed MAG- GTZ fertility restoration programme, and the introduction of no- till and green manure crops, were evaluated in the study for a 5- hectare model farm. The data on which this model is based was obtained by studying in detail five typical farms in Paraguari and Ybycui. The farm model analysis also incorporated the results of 11 pilot parcelas which were installed on small farms by the MAG- GTZ Soil Conservation Project in 1997. The proposed fertility recuperation interventions involve restoring the fertility on 1 hectare of a farm over three years. The results are shown for a scenario in which 75% of the costs of the technical inputs of lime, seed and fertiliser in the first year are subsidised. Such a policy would be necessary for the programme to be financially viable and acceptable to small farmers. A projection is also made of the likely financial performance of the farm if soil fertility was restored and no- till was adopted over the total cultivated area of 3.75 ha. It would probably take a typical small farmer from 9-12 years to reach this stage. The results are also impressive as can be seen in the table below. The net farm income is estimated to rise substantially from minus US$176 to positive US$298 while labour reduces slightly from 126 to 118 person- days.
|Net Farm Income
1This cost includes the US$ 150 required for the two matracas and the maize silo.
The Paraguari results indicate that for a model 5- hectare farm under conventional cultivation the system is uneconomic when all factors of production are costed at market rates. The main reason for this is the very low crop yields realised on the extremely degraded soils where cotton yields average 800 kg/ ha, mandioca 8 t/ ha and maiz colorado 600 kg/ ha. Farmers continue to farm under such circumstances minimising their production costs. In the majority of cases no fertiliser or pesticide inputs are ever purchased. They use their own seed and rely on family labour which they do not have to pay for, although of course both have opportunity costs. In many instances farmers own their own work oxen, or they hire these from neighbouring farmers and pay for this in production or through their own labour.>
The study also explores the capability of a typical small farmer to service loan commitments. A typical farmer would need to borrow between US$400 to US$500 to finance the cost of two matracas, a small 2,000 kg maize silo, as well as 25% of the cost of the technical inputs required in the first year and 100% of those required in the second year. The study shows that this would be financially feasible providing a loan for at least 4 years was provided, interest was charged at the current CAH rate of 17.5% and interest only was charged in the first year and principal was repaid in equal annual instalments for the remaining three years. It would be necessary however, to incorporate loan repayment delay and loan write- off clauses to cover possible crop failures due to circumstances beyond the control of the farmer, such as severe drought or pest attack, to eliminate the risk of financial ruin.
The results for Paraguari indicate that, investment in fertiliser and high green- mass producing green manure crops, and the introduction of no- till/ green manure crops, on small farms in the extremely degraded soil zones of Central Paraguari would be highly economic to the nation and to the small farmers.A Proposed Programme for the Restoration of Soil Fertility in Central Paraguay
A 4- year first phase programme proposed for recuperating soil fertility on the
extremely degraded soils of Central Paraguay is detailed in the report. The first
phase would consist of four components: (1) 250 farm demonstration plots; (2)
machinery and equipment; (3) extension; (4) technical assistance. The costs of
this programme have been have been calculated at about US$1.1 million inclusive
of price contingencies. Government of Paraguay would need to contribute about 60%.
Farmers' labour contributions are estimated to total about US$180,000, equivalent
to 19% of the programme costs. A line of credit for participating farmers would total
about 21%. Including the credit portion of the project costs means that farmers'
will pay 40% of the total programme costs. The project would need specialist technical
support, which it is assumed will be provided free of charge by GTZ to the Government of Paraguay.
Through the planned extension activities, involving national congresses and local symposia and field days, contact would be made with at least 2,000 other small farmers. In addition training courses funded through the programme at the DEAG Training Centre in San Lorenzo would be an integral part of the extension activities. These training courses are designed to widen the impact of the programme beyond the extensionists and small farmers directly involved. An additional 60 extensionists and 240 leader small farmers would be trained in the basic principles of soil conservation and the restoration of soil fertility on the extremely degraded soils, in no- till and green manure crops. They would be selected from other parts of Central Paraguay where soils are extremely degraded. This would provide an opportunity for them to learn from the first phase field experiences and to help set the stage for a subsequent second- phase expanded programme.Immediate Government Support
Because it will be imperative for the successful adoption of no- till and crop rotations that well trained competent extension services and long- term credit are accessible to small farmers, as a next step the study strongly advises that Government immediately support two pilot programmes. The first should be the first phase programme proposed in this report for the restoration of soil fertility in Central Paraguay summarised above. The second should be a small farmer no- till/ crop rotation expansion programme in Itapua and San Pedro which would focus on building- up technical capacity for ensuring the necessary extension services and long- term credit are built up in these regions. It is recommended that these services should be supported through the local farmer co- operatives that exist in these regions.
This report has specified the resource requirements and institutional arrangements
for the first proposal. There is a need to specify these for the second programme.
While this was outside of the scope of the study, the report does provide considerable
data and analysis on which a detailed proposal could be formulated.
Throughout this report a number of specific recommendations have been made. The more important general recommendations arising from this study are highlighted below.
Enormous socio- economic and environmental benefits could be obtained from the restoration of the fertility of extremely degraded soils and from the substitution of conventional cultivation systems with crop rotations and no- till. Unlike medium and large farmers who have the technical and financial capacity to realise a lot of these benefits themselves, small farmers will require a lot of publicly- funded help if they too are to benefit from these technologies. Government support in the following areas is strongly recommended since it will be essential and fully justified on socio-economic and environmental grounds:
There is need now to move beyond purely technical aspects of no- till and green manure crops in small farming systems. It is now known that technically no- till and green manure crops work well under small farm conditions. Not only have they been well accepted by the few small farmers who have had the opportunity to use them, but it is now known from the findings of this study that they are highly profitable for small farmers. However, while there is a need to continue this technical work along the lines recommended above, there is an urgent need now to ensure that farmers can get access to trained and competent extension services as well as the seeds of green manure crops and the necessary machinery and equipment. Up to now these have been provided without any charge to a very small number of farmers through MAG- DEAG with the assistance of GTZ.
Emphasis needs to be placed now on:
It is recommended that pilot projects be initiated in Itapua with the Colonias Co- operative and in San Pedro with the Small Farmer Co- operative there. A number of groups of small farmers should be formed (3- 4 per group) and assisted to access credit. These co- operatives can act as intermediaries to prepare investment plans to present to banks (CAH possibly BNF) and to administer the loan repayments. Short- term technical assistance is recommended to build up capacity in these two co- operatives for this.
For the immediate future, two specific programmes are highly recommended:
These immediate programmes are recommended now to prevent spreading limited manpower resources too thinly, since the institutional capacity to implement them is very limited, and to ensure that there will be measurable impacts. From these programmes, important experiences and lessons will provide a sound foundation for expanding later cost- effectively into other parts of Paraguay and institutional capacity will have increased through these initial programmes.
A limited number of simple crop variety and fertiliser trials on- farms should be an integral part of these immediate programmes. This is because there are absolutely no crop yield data, under small farm conditions in Paraguay, of the main crop varieties at differing levels of fertiliser and for alternative crop rotations incorporating residual nutrients of green manure crops. It is imperative that these data be generated as soon as possible so that farmers can rationally decide on what crop varieties, levels of fertiliser and green manure crop/crop rotations, best suit their needs. This development work, which should be practically based on-farms, should be part of the soil conservation efforts of DEAG, but will need to be done in close association with DIA. It will be imperative that trials are kept simple yet comprehensive enough to be meaningful. Emphasis would be placed on farmer participation/farmer acceptability of the options tested and on economic analysis of data rather than statistical analysis.