Soil Temperature Effects on the Nitrogen Availability in Soils and Growth of Sorghum (Co. 25)

Two field experiments were carried out one after the other to study the effect of date of sowing and soil temperature on the soil nitrogen availability and yield of sorghum (Co. 25). Crops sown at weekly intervals were the treatments. Mean soil temperature at different depths, available soil N at different stages, leaf area index were assessed and correlation among different parameters established. The results indicated that time of sowing sorghum crop influenced the soil available N due to variations in soil temperature and the eanopv development at different levels as measured by leaf area indices. Mean soil temperature increased with depths upto 30 cm. Also available N varied at different stages of crop growth but invariably higher in early sown crops Qanuary sown). Soil temperature at 15 cm depth influenced the available soil N most and consequently the leaf area index. This was reflected in the yield also.