Effect of Intercroping Maize and Soybean on Soil Fertility

Abstract

"This study was carried out to determine the effect of intercropping maize with soybean on soil fertility. The study was conducted at two sites and evaluated three soybean varieties (hybrid SB19, GAZELLE – a local variety, hybrid TGX1990-5F) as sole crop and intercropped with maize, with maize pure stand as control. In the intercropped plots, one row of soybean was planted after every alternate row of maize. Data collected included soil nutrient status before planting and at harvest and nodulation in soybean. Variety TGX1990-5F had significantly more nodules followed by GAZELLE and SB19 was the last in sole crop and in intercrop at Embu during long rains and short rains (p ≤ 0.05). Mwea produced more nodules compared to Embu. Intercropping maize and soybean had no effect on the number of nodules per plant both seasons.However, TGX1990-5F fixed higher N of 0.39% compared to 0.29% for SB19 in sole crop respectively between sites for the first season after harvesting. TGX1990-5F showed higher N compared to GAZELLE in intercrops between sites for the second season after harvesting. Depending on the requirement of the plants nutrients, TGX1990-5F fixed moderate N for feeding plant. However, GAZELLE showed high Organic Carbon, Potassium and Phosphorus after harvesting than other varieties in both sites and rains seasons. Thus, variety TGX1990-5F can be recommended to smallscale farmers for intercropping with maize because it produced higher nodules and fixed higher N, hence reducing the cost for N fertilizers."