No-till farming, such as used in this Illinois soybean field, shows promise in dry regions but causes lower yields in cold, moist areas like Northern Europe, a new study finds. Credit: Paige Buck/USDA NRCS Illinois photo
October 23, 2014 University of California – Davis
No-till farming appears to hold promise for boosting crop yields only in dry regions, not in the cool, moist areas of the world, this study found. As the core principle of conservation agriculture, no-till has been promoted worldwide in an effort to sustainably meet global food demand….Conservation agriculture is currently practiced on 125 million hectares of land globally, an area nearly as big as the total U.S. cropland. Three key principles guide the concept: minimizing soil disturbance (also called no-till farming), protecting the soil with cover crops or leftover crop residue, and rotating the crops.
The goals of conservation agriculture are to improve long-term productivity, profits and food security, particularly under the threat of climate change. Because conservation agriculture avoids tillage, it is less time-consuming and can be more cost-effective than conventional farming methods. In recent years, however, there has been some disagreement about the impact of no-till farming practices on yield.
….For example, yield reductions were minimized when the principles of crop rotation and residue retention were also practiced, highlighting the importance of implementing all three conservation agriculture principles as part of an integrated management system rather than no-till alone. Moreover, when adopted in dry climates in combination with the other two principles of conservation agriculture, no-till farming performed significantly better than conventional tillage, likely due to the higher retention of soil moisture. Dryland ecosystems are home to 38 percent of the world’s population, and millions of acres of land in arid regions of sub-Saharan Africa and South Asia have been identified as suitable for sustainable intensification. Yet, the authors also caution that practicing no-till in dryland areas without the implementation of the other two principles of conservation agriculture decreases yields.
In regions with moist climates and sufficient precipitation, no-till farming actually resulted in yields that were on average 6 to 9 percent lower than with conventional tillage methods….
Cameron M. Pittelkow, Xinqiang Liang, Bruce A. Linquist, Kees Jan van Groenigen, Juhwan Lee, Mark E. Lundy, Natasja van Gestel, Johan Six, Rodney T. Venterea, Chris van Kessel. Productivity limits and potentials of the principles of conservation agriculture. Nature, 2014; DOI: 10.1038/nature13809