Effects of Three-Strata Forage Cropping System on Yield and Yield Components of Food Crops and Soil Chemical Properties in Western Kenya

Abstract

The exploitation of diverse cropping practices alongside residue incorporation has remained low among small-holder rural farming households in Kenya. A three-year experiment was conducted in Ng’elechom and Obekai in Teso south, Busia County to evaluate the three-strata forage system (TSFS) which integrates forages for animal feeds with food crops thereby enhancing residue incorporation. The objective of this study was to determine the effects of TSFS on yield and yield components of diversified food crops and its impact on the dynamics of soil chemical properties. Food crops including cereals, legumes and African leafy vegetables were evaluated under TSFS and in no TSFS cropping systems. In TSFS system, desmodium, brachiaria grass and pigeon peas were grown in the peripheral area of the farm as forages. The treatments were laid on a randomized complete block design at two locations for 3 years (2019, 2020 and 2021) and performance of agronomic traits measured. After a 3-year field experiment was done, soil samples both in TSFS and in no TSFS were sampled and changes in soil chemical properties analysed. Data from both the field experiment and laboratory analysis were subjected to Analysis of variance (ANOVA) in SAS software and means separated using LSD at 5% level of significance. Results revealed that the effects of cropping system, location and season on crop yields were significant at p<0.001. Yield increase of 30.69% and 12.71% was observed in the third season in maize grown in TSFS and in no TSFS respectively. Beans on the other hand recorded a yield increase of 76.52% and 56.25% in TSFS and in no TSFS respectively. The same trend was observed in African leafy vegetables, where yield increase of 49.31% and 39.47% in cowpeas was obtained in TSFS and in no TSFS respectively, during the third season. Crotalaria also recorded a yield increase of 72.36% and 34.39% in the TSFS and in no TSFS, respectively. In TSFS, there was an increase of 17.06%, 23.07%, 8.21% in soil pH, total nitrogen (TN) and soil organic carbon (SOC), respectively. A decrease of 48.27% in soil exchangeable acidity in the TSFS system was observed. However, there was no variation in levels of manganese (Mn) in soil both in TSFS and no TSFS systems. The food crops yielded higher in TSFS than in no TSFS system and therefore this could be an alternative cropping system for curbing food and feed shortage as it improves soil fertility.