Effects of climate-smart agricultural practices on crop yields, soil carbon, and nitrogen pools in Africa: a meta-analysis

Kichamu-Wachira, Edith and Xu, Zhihong and Reardon-Smith, Kathryn and Biggs, Duan and Wachira, Geoffrey and Omidvar, Negar (2021) Effects of climate-smart agricultural practices on crop yields, soil carbon, and nitrogen pools in Africa: a meta-analysis. Journal of Soils and Sediments. pp. 1-11. ISSN 1439-0108


Abstract

Purpose
Climate-smart agriculture (CSA) practices have been advanced as an alternative to conventional farming practices due to their importance in climate mitigation and soil quality improvement, while also enhancing food production. However, few studies have quantitatively investigated the effects of a range of CSA practices on crop yield, soil carbon, and nitrogen pools. This study adds to this limited body of work by synthesizing such studies and evaluates the effect of individual and combinations of widely implemented CSA practices in Africa—green manure (GM), conservation tillage (no-tillage, reduced tillage), and crop residue retention (CR)—on food crop yield, soil organic carbon (SOC) concentration, and soil total nitrogen (TN).

Materials and methods
This study conducted a meta-analysis of results reported in 60 peer-reviewed articles to examine the effects of CSA management (GM, CR, and conservation tillage) on crop yield, SOC concentration, and soil TN in Africa.

Results and discussion
The implementation of CSA practices significantly increased crop yield and SOC concentrations (mean effect 9.2% and 14.7%, respectively), although no significant change was evident in soil TN. In terms of yield increase, GM was the most effective practice, increasing yield by 63.5%, followed by CR (5.8%). Conservation tillage and CR increased SOC by 16.4% and 13%, respectively, but no significant difference was observed with GM. Further analysis suggested that integrating CSA practices (conservation tillage and GM; conservation tillage and CR) had a more pronounced effect on both SOC concentration and yield under lower nitrogen fertilizer levels.

Conclusion
Our meta-analysis showed that CSA management resulted in higher yields and SOC concentrations, thus suggesting the importance of CSA practices in enhancing food production and climate mitigation in Africa. It also highlights the potential of the integration of CSA practices to improve SOC and TN pools and consequently crop productivity.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Applied Climate Sciences (1 Aug 2018 -)
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Applied Climate Sciences (1 Aug 2018 -)
Date Deposited: 24 Feb 2021 03:15
Last Modified: 24 Feb 2021 03:15
Uncontrolled Keywords: Climate mitigation; Climate adaptation; Green manure; Conservation tillage; Crop residue
Fields of Research (2008): 07 Agricultural and Veterinary Sciences > 0701 Agriculture, Land and Farm Management > 070108 Sustainable Agricultural Development
05 Environmental Sciences > 0503 Soil Sciences > 050301 Carbon Sequestration Science
05 Environmental Sciences > 0502 Environmental Science and Management > 050205 Environmental Management
Fields of Research (2020): 41 ENVIRONMENTAL SCIENCES > 4101 Climate change impacts and adaptation > 410199 Climate change impacts and adaptation not elsewhere classified
41 ENVIRONMENTAL SCIENCES > 4106 Soil sciences > 410601 Land capability and soil productivity
30 AGRICULTURAL, VETERINARY AND FOOD SCIENCES > 3004 Crop and pasture production > 300499 Crop and pasture production not elsewhere classified
Socio-Economic Objectives (2008): D Environment > 96 Environment > 9603 Climate and Climate Change > 960301 Climate Change Adaptation Measures
D Environment > 96 Environment > 9609 Land and Water Management > 960904 Farmland, Arable Cropland and Permanent Cropland Land Management
B Economic Development > 82 Plant Production and Plant Primary Products > 8298 Environmentally Sustainable Plant Production > 829899 Environmentally Sustainable Plant Production not elsewhere classified
Socio-Economic Objectives (2020): 18 ENVIRONMENTAL MANAGEMENT > 1806 Terrestrial systems and management > 180605 Soils
26 PLANT PRODUCTION AND PLANT PRIMARY PRODUCTS > 2601 Environmentally sustainable plant production > 260199 Environmentally sustainable plant production not elsewhere classified
Identification Number or DOI: https://doi.org/10.1007/s11368-021-02885-3
URI: http://eprints.usq.edu.au/id/eprint/41415

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