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ARS Home » Midwest Area » St. Paul, Minnesota » Soil and Water Management Research » Research » Publications at this Location » Publication #305744

Research Project: INCREASING SUSTAINABILITY AND MITIGATING GREENHOUSE GAS EMISSIONS OF FOOD AND BIOFUEL PRODUCTION SYSTEMS OF THE UPPER MIDWEST U.S.

Location: Soil and Water Management Research

Title: Productivity limits and potentials of the principles of conservation agriculture

Author
item PITTELKOW, CAMERON - University Of California
item LIANG, XINQIANG LIANG - Zhejiang University
item LINDQUIST, BRUCE - University Of California
item VAN GROENIGEN, KEES JAN - Northern Arizona University
item LEE, JUHWAN - Swiss Federal Institute Of Technology Zurich
item LUNDY, MARK - University Of California
item SIX, JOHAN - Swiss Federal Institute Of Technology Zurich
item Venterea, Rodney - Rod
item VAN KESSEL, CHRIS - University Of California

Submitted to: Nature
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/29/2014
Publication Date: 1/15/2015
Publication URL: http://handle.nal.usda.gov/10113/60480
Citation: Pittelkow, C., Liang, X., Lindquist, B., van Groenigen, K., Lee, J., Lundy, M., Six, J., Venterea, R.T., van Kessel, C. 2015. Productivity limits and potentials of the principles of conservation agriculture. Nature. 517:365-368.

Interpretive Summary: One of the primary challenges of our time is to feed a growing and more demanding world population with reduced external inputs and minimal environmental impacts, all under more variable and extreme climate conditions of the future. Conservation agriculture (CA) represents a set of three crop management principles (direct planting of crops with minimum soil disturbance (i.e. no-till), permanent soil cover by crop residues or cover crops, and crop rotation) that has received strong international support to help address this challenge, with recent CA efforts focusing on smallholder farming systems in Sub-Saharan Africa and South Asia. However, CA is highly debated, both with respect to its effects on crop yields and its applicability in different farming contexts. Here, we conducted a global meta-analysis of 5551 paired yield observations from 613 studies comparing no-till, the original and central concept of CA, to conventional tillage practices across 33 crops and 60 countries. Overall, our results show that no-till reduces yields on average by 4.7%. Importantly, we found that when the other two CA principles are implemented, the negative impacts of no-till are minimized and it takes less time for no-till to match conventional yields following no-till adoption. Moreover, in rainfed agroecosystems under dry climates, no-till in combination with the other two principles significantly increases productivity. While farming systems are multifunctional and both environmental and socio-economic factors need to be considered, our meta-analysis indicates that no-till is an effective longer-term climate change adaptation strategy in ever-becoming-drier regions of the world, but only when it is integrated with residue retention and crop rotation. These results will be of interest to producers, policy-makers, and scientists interested in promoting agricultural practices that enhance crop and food production while protecting environmental quality.

Technical Abstract: One of the primary challenges of our time is to feed a growing and more demanding world population with reduced external inputs and minimal environmental impacts, all under more variable and extreme climate conditions of the future. Conservation agriculture (CA) represents a set of three crop management principles (direct planting of crops with minimum soil disturbance (i.e. no-till), permanent soil cover by crop residues or cover crops, and crop rotation) that has received strong international support to help address this challenge, with recent CA efforts focusing on smallholder farming systems in Sub-Saharan Africa and South Asia. However, CA is highly debated, both with respect to its effects on crop yields and its applicability in different farming contexts. Here, we conducted a global meta-analysis of 5551 paired yield observations from 613 studies comparing no-till, the original and central concept of CA, to conventional tillage practices across 33 crops and 60 countries. Overall, our results show that no-till reduces yields on average by 4.7% (95% CI: -5.7 to -3.7%) . Importantly, we found that when the other two CA principles are implemented, the negative impacts of no-till are minimized and it takes less time for no-till to match conventional yields following no-till adoption. Moreover, in rainfed agroecosystems under dry climates, no-till in combination with the other two principles significantly increases productivity. While farming systems are multifunctional and both environmental and socio-economic factors need to be considered, our meta-analysis indicates that no-till is an effective longer-term climate change adaptation strategy in ever-becoming-drier regions of the world, but only when it is integrated with residue retention and crop rotation.