Yield potential and land-use efficiency of onion (Allium cepa L.) intercropped with peanut (Arachis hypogaea L.) under organic soil fertility management in South-Kivu, Eastern DR Congo

Abstract

Intercropping and organic soil fertility are eco-friendly agricultural practices for sustainable agriculture. The aim of this study was to determine the yield potential and land-use efficiency of onion intercropped with groundnut under organic soil fertility management. A two-year field experiment was conducted in 2019 and 2020 under a complete factorial design with two crops and 2 varieties per crop (Bombay and creole for onion and A65 and JL24 for groundnut). Crops implementation was realized in sole and mixture under farmyard manure (FYM) single application, FYM seasonal application, FYM + NPK 1 – 1 – 2, and the control. The average yields were recorded while the intercropping efficiency was analysed using the land equivalent ratio (LER), competitiveness ratio, and aggressiveness index. Results showed that creole variety had the highest yield (17 t.ha-1) across years. FYM under single and seasonal application effectively increased the onion yield with similar values (8 to 16 t.ha-1). The LER analysis showed a yield gain for Bombay + A65 (total LER= 2.25) in 2019 and (2.38) in 2020 for Creole+A65. Analysis of competitiveness indices showed that the onion variety Bombay was more competitive than A65 (1.06). The same trend was recorded when onion variety Creole was intercropped with the same groundnut variety (1.93). FYM in single and seasonal application also affects the competitiveness of onion on groundnut (0.99 and 1.07). The present study shows that onion – groundnut intercropping under organic fertilizers could be a viable option to support the ecological intensification of onion cultivation in eastern DRC.