Effect of Groundnut Shell Amendment and Tillage Implements on Soil Properties, Growth and Yield of Rainfed Sorghum

In most rainfed areas, crop productivity is strongly affected by lack of soil fertility and unreliable rainfall. Therefore, enhancing soil organic carbon as well as selecting the right tillage methods that improves soil condition is highly needed. A field experiment was conducted at the training and research farm in the Centre for Dryland Agriculture, Bayero University, Kano, Nigeria, to investigate the effect of groundnut shells as soil amendment using different tillage implements on growth and yield of rain-fed sorghum. The treatments consisted of three groundnut shell rates (0 t/ha, 5 t/ha and 10 t/ha) and three types of tillage implements viz. cultivator, rotavator and offset disc harrow. The results showed the application of groundnut shells significantly decreased the values of soil bulk density and increased soil water storage compared to non-application (0 t/ha). Water holding capacity and soil water storage were significantly affected by different tillage implements. Both cultivator and the offset disc harrow had higher values of water holding capacity and soil water storage in comparison with the rotavator. However, the effect of different groundnut shell rates and tillage implements on soil organic carbon was not significant. Moreover, the application of groundnut shell compared to non-application had a positive influence on sorghum plant height, stem girth, leaf area index and days to 50% heading; as well as it is increased both sorghum grain and stover yield by 20.9% and 17.3%, respectively, at 10 t/ha rate and by 13.5% and 10.9%, respectively, at the rate of 5 t/ha. On the other hand, the tillage implements did not show a significant effect on the sorghum growth and yield attributes except on 1000 seed weight, where it was higher under rotavator followed by cultivator.