Varietal-Spacial Difference Effect on Performance and Nutritive Content of Soybean (Glycine Max L.), Case Study of Nyamira County

Abstract

Soybean is an important crop not only in African countries, but also in the entire world being one of the most protein yielding-legume from its seeds which is used as food among other uses of the crop such as Nitrogen fixation. However, in Africa, low production levels have been recorded over the years with Africa contributing to 1% of the entire world soybean production. This attributed to little breeding programs being conducted on soybean varieties leading to poor performance of the crop in relation to growth and yield. This research therefore aimed at studying the varietal-spacial difference effect on performance and nutritive content of soybean in Nyamira County. The experiment was laid in RCBD with soybean varieties, DPSB 19, Nyala and Gazelle for trial to assess their performance with the current breeding on them under different spacing (30cm, 45cm and 70cm) on maize (pioneer DH04). Soybean pure-stand was used to act as the control experiment during the trials to determine if maize intercrop proved any added advantages in the performance and nutritive composition of the soybean grains. Three blocks used provided the replicates. The experiment was conducted on two trials in separate sites in Nyamira County, namely, Ekerenyo and North Mugirango. Data was collected on the growth of soybean, yield of soybean, soybean spacing and variety interaction effect on maize intercrop on the performance and the protein and oil percentage composition analysis in relation to the different varieties*spacing based on the different performances recorded. Data was subjected to ANOVA test at 5% significant level and correlation analysis using SPSS version 28. From the study results, the growth of soybean varieties was significantly affected by maize intercrop under different spacing. This was evident where Gazelle at 45cm showed average quicker maturity at 80 days while DPSB19 at 30cm gave shorter average height at 43.23cm. There was a significant difference on yield production of soybean varieties when intercropped with maize on different spacing evident where DPSB19 at 30cm had the highest average weight grain with 14.10g per 100 seeds. The interaction of spacing and varieties on soybean performance under maize intercrop had a significant difference. This was evident from the results where soybean on intercrop showed greater yield and growth performance rather than on pure stand. There was a significant difference on the protein and oil grain contents of the soybean varieties where DPSB19 had the highest protein percentage with 40% while Gazelle had the highest oil percentage with 22%. The researcher recommended DPSB19 variety on maize intercrop to be the best performing in terms of yield with the highest seeds weight, better bred for shorter height and rich in protein as compared to the other varieties. The researcher also recommended Gazelle to have high oil content at 22% on the nutritive content of soybean