The adaptive capacity of maize-based conservation agriculture systems to climate stress in tropical and subtropical environments: A meta-regression of yields

TY - JOUR

T1 - The adaptive capacity of maize-based conservation agriculture systems to climate stress in tropical and subtropical environments

T2 - A meta-regression of yields

AU - Steward, Peter R.

AU - Dougill, Andrew J.

AU - Thierfelder, Christian

AU - Pittelkow, Cameron M.

AU - Stringer, Lindsay C.

AU - Kudzala, Maxwell

AU - Shackelford, Gorm E.

N1 - Funding Information: We thank the many publication and report authors that responded to e-mail queries providing clarity and additional information to the meta-dataset. This work was supported by the UK’s Natural Environment Research Council’s (NERC) and Department for International Development’s (DfID) El Niño 2016 Programme [grant reference NE/P004091/1 ]. The work is further aligned with the MAIZE and CCAFS CGIAR Research Programs whose financial support of conservation agriculture research and long-term trials is greatly acknowledged. Publisher Copyright: © 2017 The Authors

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Conservation agriculture is widely promoted across sub-Saharan Africa as a sustainable farming practice that enhances adaptive capacity to climate change. The interactions between climate stress, management, and soil are critical to understanding the adaptive capacity of conservation agriculture. Yet conservation agriculture syntheses to date have largely neglected climate, especially the effects of extreme heat. For the sub-tropics and tropics, we use meta-regression, in combination with global soil and climate datasets, to test four hypotheses: (1) that relative yield performance of conservation agriculture improves with increasing drought and temperature stress; (2) that the effects of moisture and temperature stress exposure interact; (3) that the effects of moisture and temperature stress are modified by soil texture; and (4) that crop diversification, fertilizer application rate, or the time since no-till implementation will enhance conservation agriculture performance under climate stress. Our results support the hypothesis that the relative maize yield performance of conservation agriculture improves with increasing drought severity or exposure to high temperatures. Further, there is an interaction of moisture and heat stress on conservation agriculture performance and their combined effect is both non-additive and modified by soil clay content, supporting our second and third hypotheses. Finally, we found only limited support for our fourth hypothesis as (1) increasing nitrogen application rates did not improve the relative performance of conservation agriculture under high heat stress; (2) crop diversification did not notably improve conservation agriculture performance, but did increase its stability with heat stress; and (3) a statistically robust effect of the time since no-till implementation was not evident. Our meta-regression supports the narrative that conservation agriculture enhances the adaptive capacity of maize production in sub-Saharan Africa under drought and/or heat stress. However, in very wet seasons and on clay-rich soils, conservation agriculture yields less compared to conventional practices.

AB - Conservation agriculture is widely promoted across sub-Saharan Africa as a sustainable farming practice that enhances adaptive capacity to climate change. The interactions between climate stress, management, and soil are critical to understanding the adaptive capacity of conservation agriculture. Yet conservation agriculture syntheses to date have largely neglected climate, especially the effects of extreme heat. For the sub-tropics and tropics, we use meta-regression, in combination with global soil and climate datasets, to test four hypotheses: (1) that relative yield performance of conservation agriculture improves with increasing drought and temperature stress; (2) that the effects of moisture and temperature stress exposure interact; (3) that the effects of moisture and temperature stress are modified by soil texture; and (4) that crop diversification, fertilizer application rate, or the time since no-till implementation will enhance conservation agriculture performance under climate stress. Our results support the hypothesis that the relative maize yield performance of conservation agriculture improves with increasing drought severity or exposure to high temperatures. Further, there is an interaction of moisture and heat stress on conservation agriculture performance and their combined effect is both non-additive and modified by soil clay content, supporting our second and third hypotheses. Finally, we found only limited support for our fourth hypothesis as (1) increasing nitrogen application rates did not improve the relative performance of conservation agriculture under high heat stress; (2) crop diversification did not notably improve conservation agriculture performance, but did increase its stability with heat stress; and (3) a statistically robust effect of the time since no-till implementation was not evident. Our meta-regression supports the narrative that conservation agriculture enhances the adaptive capacity of maize production in sub-Saharan Africa under drought and/or heat stress. However, in very wet seasons and on clay-rich soils, conservation agriculture yields less compared to conventional practices.

KW - Africa

KW - Climate change

KW - Climate-smart agriculture

KW - Drought

KW - No-till

KW - Sustainable agriculture

UR - http://www.scopus.com/inward/record.url?scp=85032476816&partnerID=8YFLogxK

U2 - 10.1016/j.agee.2017.09.019

DO - 10.1016/j.agee.2017.09.019

M3 - Article

AN - SCOPUS:85032476816

SN - 0167-8809

VL - 251

SP - 194

EP - 202

JO - Agriculture, Ecosystems and Environment

JF - Agriculture, Ecosystems and Environment

ER -