Effect of Different Fertilizers and Approaches on Nutrient Use Efficiency and Economics of Aerobic Rice Under Rice-Cowpea Cropping Sequence in Ecological Conditions of Karnataka, India
Jayanthi T *
Department of Soil Science and Agricultural Chemistry, UAS, GKVK, Bangalore, Karnataka, India.
Umesh H.R
AICRP on LTFE, Department of Soil Science and Agricultural Chemistry, UAS, GKVK, Bangalore, Karnataka, India.
Savitha Madappa
Department of Crop Physiology, University of Agricultural Sciences, GKVK, Bangalore Karnataka -560065, India.
Latha H.S
AICRP for Dry land Agriculture, University of Agricultural Sciences, GKVK, Bangalore, Karnataka, India.
Ashok L.B
Department of Soil Science and Agriculture Chemistry, College of Agriculture, Karekere, Hasan, Karnataka, India.
Nunavath Umilsingh
Department of Agronomy, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India.
*Author to whom correspondence should be addressed.
Abstract
At the University of Agricultural Sciences, GKVK, Bengaluru, a field experiment was conducted in 2015-16 and 2016-17 to examine the impact of fertigation on the yield, nutrient usage efficiency, and economics of aerobic rice in an aerobic rice–cowpea cropping sequence. In a randomized block design, hybrid rice was tested in aerobic conditions with 16 treatments that were reproduced three times. The results indicated that significantly higher grain (62.98 q ha-1) and straw (85.26 q ha-1) yield of rice was recorded in 100% STCR dose through WSF at 8 DI. Similarly higher NRn (3.50 kg q-1) and NRp (0.86 kg q-1) of grain production in 100% STCR dose with WSF at 8 DI on contrary, higher NRk of 2.27 kg q-1 was noticed in 100% STCR with WSF at 4 DI. While higher AUE-N (32.51 kg kg-1), AUE-P (65.02 kg kg-1) and AUE-K (65.02 kg kg-1) were recorded in 30% RDF with WSF at 8 DI. The higher ACRE-N (78.60 %) was recorded with 100% RDF with WSF at 8 DI and higher ACRE-P (44.40%) was recorded with 30% RDF with WSF at 8 DI. Notably higher ACRE-K (132.51%) was recorded in 30% STCR with WSF at 8 DI. However, supplement of 30% STCR dose with WSF at 8 DI obtained notably higher IUE-N (35.05 kg kg-1), IUE-P (163.27 kg kg-1) and IUE-K ( 60.11 kg kg-1). Significantly higher PFP-N, P and K (261.23, 522.46 and 522.46, respectively) were recorded in 30% RDF with WSF at 8 DI. Among all treatments, 100% RDF through CF at 4 DI found significantly higher B: C ratio (2.74) during both years of pooled data.
Keywords: Agronomic use efficiency, apparent crop recovery efficiency, partial factor productivity, net returns, cost of cultivation, B: C ratio