S. Raghavendra, J. Vishwanath, K. Narayan Rao, M.V. Ravi, M.A. Bellakki, S.N. Vinodakumar and K.M. Prashanth
Abstract
Fifteen composite representative soil samples from an area of 10 ha in farmersÂ’ field at Kyarehal village near Gangavati were characterized for sodicity. A wide variation in surface as well sub-surface soils with respect to ESP was observed in the sampling. A pot culture experiment with maize (Zea mays L.) in a sodic soil having ESP 24.6 was conducted to assess the biomass yield and uptake of micronutrient. The highest biomass yield of maize (22.6 g pot-1) at 45 DAS was observed in T2 (100% GR) which was on par with T4 (50% GR+FYM) and T6 (50% GR + green manure) but significantly higher than T1 (control), T5 (50% GR + paddy straw) and T3 (50% GR). Both tissue concentrations and uptake of NPK were highest in T6 which were on par with T4 for N and T2 and T4 for P and K but significantly higher than rest of the treatments. The tissue concentration and uptake of Zn (35.7 ppm and 0.79 mg/pot) and Fe (117.5 ppm and 2.64 mg/pot) were highest in T6 and were more than the critical levels. The concentration and uptake of Zn and Fe in T6 were on par with T2 and T4. Whereas, tissue concentration and uptake of Mn (116.8 ppm and 2.64 mg/pot) and Cu (45 ppm and 1.02 mg/pot) were highest in T2 and were more than the critical levels. The tissue Mn concentration and uptake in T2 were on par with T6. The tissue Cu concentration in T2 was on par with T3 whereas uptake in T2 was significantly higher than rest of the treatments. Thus, substitution of either FYM or green manure with 50% GR can not only minimize the dependence on mined gypsum but could also help in attaining higher yields on par with 100% GR.