Dry-matter accumulation, nutrient uptake and changes in soil-fertility status as influenced by different organic and inorganic sources of nutrients to forage sorghum (Sorghum bicolor)

Abstract

A field experiment was conducted during rainy seasons of 1997-99 with forage sorghum [Sorghum bicolor (L.) Moench] in clay loam and medium fertile soil of semi-arid climate at Jhansi, to study the effect of organic and inorganic nutrients on its dry matter accumulation and nutrient uptake and changes in fertility status of the soil. Application of 50% recommended dose of NP (40 kg N + 20 kg P2O5/ha) + vermicompost and farmyard manure @ 5 tonnes/ha recorded significantly higher dry-matter accumulation (25.35 g/plant and 30.19 g/plant at 50 and 75 days after sowing, respectively) and dry matter yield (11.2 tonnes/ha) over the other treatments. Maximum increase in dry matter (85-87%) was attained between 25 and 50 days after sowing, corresponding with highest crop-growth rate (0.90 g/plant/day) with this treatment. Application of vermicompost and farmyard manure recorded higher NP uptake than the other levels with inorganic sources only except the 100% recommended dose of NP. The residual build up of organic carbon and available NPK in soil improved with vermicompost was maximum followed by farmyard manure and inorganic fertilizers.