What is no-till farming?
Description and Definition of no-tillage or zero tillage
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.
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).
References:
CTIC, 2011. Conservation Technology Information Center 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.
DLG, 1997. Direktsaat. Merkblatt 301 der Deutschen Landwirtschafts-Gesellschaft,16 S.
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.
ahnt, G., 1976. Ackerbau ohne Pflug, Voraussetzungen, Verfahren und Grenzen der Direktsaat im Körnerfruchtbau. Ulmer, Stuttgart, 126 S.
Köller, K. und Linke, C., 2001. Erfolgreicher Ackerbau ohne Pflug. 2. Aufl. DLG-Verlag, Frankfurt a.M. 176 S.
Linke, C., 1998. Direktsaat – eine Bestandsaufnahme unter besonderer Berücksichtigung technischer, agronomischer und ökonomischer Aspekte. Dissertation, Universität Hohenheim, 482 S.
Phillips, S. and Young, H. 1973. No-Tillage Farming. Reiman Associates, Milwaukee, Wisconsin. 224 S.
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.
