Author
LUNDY, MARK - University Of California | |
PITTELKOW, CAMERON - University Of Illinois | |
LINQUIST, BRUCE - University Of California | |
LIANG, XINQIANG - Zhejiang University | |
VAN GROENIGEN, KEES JAN - Northern Arizona University | |
LEE, JUHWAN - Swiss Federal Institute Of Technology Zurich | |
SIX, JOHAN - Swiss Federal Institute Of Technology Zurich | |
Venterea, Rodney - Rod | |
VAN KESSEL, CHRIS - University Of California |
Submitted to: Field Crops Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/19/2015 Publication Date: 8/14/2015 Publication URL: http://handle.nal.usda.gov/10113/61324 Citation: Lundy, M., Pittelkow, C., Linquist, B.A., Liang, X., Van Groenigen, K., Lee, J., Six, J., Venterea, R.T., Van Kessel, C. 2015. Nitrogen fertilization reduces yield declines following no-till adoption. Field Crops Research. 183:204–210. Interpretive Summary: Conservation agriculture (CA) is a system of production practices that is being widely implemented globally and promoted as a means of sustainable intensification and climate change mitigation. However, no-till (NT) practices, a fundamental component of CA, have been shown to reduce crop yields. In order to maintain yields following adoption of CA, it has been recently suggested that fertilizer application should be considered as an integral component of CA. To determine the contribution of nitrogen (N) fertilizer in minimizing yield declines following NT implementation, we assessed 2673 paired comparisons of NT and conventional tillage (CT) systems from 323 studies reported in the peer-reviewed literature from 1980 to 2013. Overall, we found that yields decreased by 8% and 4% in tropical/subtropical and temperate regions, respectively, following the implementation of NT. Fertilizer N rate was the most important management variable for predicting NT yield declines in tropical/subtropical regions, explaining 10% of the overall yield decline compared to 5% in temperate regions. Applying N fertilizer at rates of up to 152 and 85 kg N per ha per yr (during the first two years of NT adoption) and 128 and 36 kg N per ha per yr (independent of NT duration) significantly reduced NT yield declines in tropical/subtropical and temperate regions, respectively. These results, based on a global data set across a broad range of crops, indicate that yield reductions due to NT can be offset, in part, by adequate N fertilization particularly during the first two years of NT adoption. Our findings highlight the importance of N fertilizer in counteracting yield declines in CA systems, especially in tropical/subtropical regions. 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: Conservation agriculture (CA) has been promoted as a method of sustainable intensification and climate change mitigation and is being widely practiced and implemented globally. However, notill (NT) practices, a fundamental component of CA, have been shown to reduce yields. In order to maintain yields following adoption of CA, it has been recently suggested that fertilizer application should be an integral component of CA. To determine the contribution of nitrogen (N) fertilizer in minimizing yield declines following no-till (NT) implementation, we assessed 2673 paired comparisons of NT and conventional tillage (CT) systems from 323 studies reported in the peer-reviewed literature from 1980 to 2013. Overall, we found that yields decreased by 7.8% and 3.8% in tropical/subtropical and temperate regions, respectively, following the implementation of NT. Fertilizer N rate was the most important management variable for predicting NT yield declines in tropical/subtropical regions, explaining 10% of the overall yield decline compared to 5% in temperate regions. Applying N fertilizer at rates of up to 152 ± 50 standard error (SE) and 85 ± 25 SE kg N ha-1 yr-1 (during the first two years of NT adoption) and 128 ± 27 SE and 36 ± 16 SE kg N ha-1 yr-1 (independent of NT duration) significantly reduced NT yield declines in tropical/subtropical and temperate regions, respectively. These results, based on a global data set across a broad range of crops, indicate that yield reductions due to NT can be offset, in part, by adequate N fertilization particularly during the first two years of NT adoption. Our findings highlight the importance of N fertilizer in counteracting yield declines in CA systems, especially in tropical/subtropical regions. |