Optimizing Green Gram-Sorghum Intercropping in Dryland Kenya: The Impact of Double Row Planting on System Productivity

Abstract

Small scale farmers in dryland areas normally grow green gram (Vigna radiata L.) under sole crop system. However, studies done on intercropping systems have established that plant arrangement patterns affect crop growth and yield of the companion crops. To advance a better understanding of the effect of crop arrangement in green gram varieties intercropped with sorghum (Sorghum bicolor L.), two field experiments were conducted in Mwala and Katangi during the 2022 short rains season in dryland areas of Kenya. This study was explored under two intercrop arrangement patterns (Single row; alternate rows of sorghum and green gram; double row, double alternate rows of sorghum and green gram) as well as checks of both sole crops. Four green gram varieties such as KS20, N26, Biashara, and Karembo were intercropped with sorghum variety Seredo. Treatments were placed in a randomized complete block design with a split-plot arrangement where crop arrangement system formed the main plots while the green gram variety assumed the subplots and replicated three times. Data were subjected to analysis of variance using R software and treatment means separated by Fisherʼs least significant difference at 5% probability. The results of the present study show that sole green gram recorded the highest yield of 0.9 t ha-1 the same way sole sorghum recorded the highest yield of 2.7 t ha-1. Variety N26 recorded highest yield of 1.0 t ha-1 despite Biashara variety recording higher seed weight than N26 by 29%. Double row recorded a higher area time equivalent ratio of 1.5, and benefit-cost ratio of 4.3. In conclusion, double row of variety N26 was found to be more efficient and profitable for adoption in southeastern Kenya. However, future research could be done across contrasting sites in different seasons and focus on the optimum spacing that can reduce intercropping competition and improve yield performance.