Effects of Tillage Depths, Organic Amendments and Nitrogen on Yield of Winter Sorghum on a Vertisol in South India

Abstract

A field experiment was conducted during the winter seasons of 1994–95 and 1995–96 to study the effects of tillage depths, organic amendments, and nitrogen application on grain yield and yield components, i.e., head length, head girth, grain weight per plant, 1000-grain weight, and grains per head of sorghum on a Vertisol at Bijapur, South India. Among three tillage treatments, the grain yield increased more due to deep tillage during 1994–95 as compared to 1995–96. Medium and deep tillage increased the grain yield by 23% and 57% during 1994–95, and 14% and 34% during 1995–96 compared with shallow tillage. Greater grain yield in medium and deep tilled plots was attributed to more dry matter accumulation in the head with higher harvest index. Among three organic amendments, application of Leucaena at 2.5 t ha−1 increased the grain yield by 9% (mean of 1994–95 and 1995–96) over vermicompost at 1.0 t ha−1 and this was attributed to larger head size with higher dry matter accumulation in the head. Sorghum grain yield increased significantly with application of 25 kg N ha−1 during 1994–95 and 50 kg N ha−1 during 1995–96. This was attributed to increased head weight as a result of higher grain weight per plant and 1000-grain weight and harvest index in the plots with application of higher N rates.