Abstract
Conservation agriculture (CA) practices are being widely promoted in many areas in sub-Saharan Africa to recuperate degraded soils and improve ecosystem services. This study examined the effects of three tillage practices [conventional moldboard plowing (CT), hand hoeing (MT) and no-tillage (NT)], and three cropping systems (continuous maize, soybean–maize annual rotation, and soybean/maize intercropping) on soil quality, crop productivity, and profitability in researcher and farmer managed on-farm trials from 2010 to 2013 in northwestern Ghana. In the researcher managed mother trial, the CA practices of NT, residue retention and crop rotation/intercropping maintained higher soil organic carbon, and total soil N compared to conventional tillage practices after 4 years. Soil bulk density was higher under NT than under CT soils in the researcher managed mother trails or farmers managed baby trials after 4 years. In the researcher managed mother trial, there was no significant difference between tillage systems or cropping systems in maize or soybean yields in the first three seasons. In the fourth season, crop rotation had the greatest impact on maize yields with CT maize following soybean increasing yields by 41 and 49% compared to MT and NT maize, respectively. In the farmers’ managed trials, maize yield ranged from 520 to 2700 kg ha-1 and 300 to 2000 kg ha-1 for CT and NT, respectively, reflecting differences in experience of farmers with NT. Averaged across farmers, CT cropping systems increased maize and soybean yield ranging from 23 to 39% compared with NT cropping systems. Partial budget analysis showed that the cost of producing maize or soybean is 20–29% cheaper with NT systems and gives higher returns to labor compared to CT practice. Benefit-to-cost ratios also show that NT cropping systems are more profitable than CT systems. We conclude that with time, implementation of CA practices involving NT, crop rotation, intercropping of maize and soybean along with crop residue retention presents a win–win scenario due to improved crop yield, increased economic return, and trends of increasing soil fertility. The biggest challenge, however, remains with producing enough biomass and retaining same on the field.
Highlights
Smallholder farming dominates agriculture in Sub-Saharan African (SSA) operating on less than 2 hectares in total land holding
The impact of NT, CT and cropping systems on soil quality and crop productivity was measured during four seasons under researcher and farmer managed conditions
In the researcher managed mother trial, the results showed that the Conservation agriculture (CA) practices of NT, residue retention and crop rotation/intercropping can maintain higher soil quality compared to conventional practices
Summary
Smallholder farming dominates agriculture in Sub-Saharan African (SSA) operating on less than 2 hectares in total land holding. Increasing productivity and economic returns to smallholder farming in a sustainable manner is a central challenge to achieving global poverty reduction and environmental management objectives (FAO, 2012a). This challenge can be addressed by identifying, promoting, and realizing widespread and durable adoption of technologies for sustainable agricultural intensification. Conservation agriculture (CA) is one such approach that aims to sustainably improve farm productivity, profits, and food security by combining three principles These three principles are: minimum mechanical soil disturbance, permanent soil cover, and crop rotation (FAO, 2012b). There has been widespread adoption of CA with significant farmer profitability achieved through increased agricultural productivity and reduced input costs
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
