Establishment of Critical Limits of Zinc in Soils Using Multi-extractants for Paddy Crop Grown in Central India

Rakesh Dhakad, G. S. Tagore, B. L. Sharma, H. K. Rai, G. D. Sharma
2020 International Journal of Current Microbiology and Applied Sciences  
Introduction Rice is one of the most important global staple food crops and is a primary food source for more than one third of the global population (Prasad et al., 2010) . Nutritionally, the grain comprises 80% starch, 7.5% protein, 0.5% ash and 12% water. In Asia, India has the largest area under rice cultivation (44.3 million ha) accounting for 29.4 per cent of the global rice area. Though the productivity level in India is low (2.04 t ha -1 ) as compared to Japan (6.25 t ha -1 ), China
more » ... ha -1 ), China (6.24 t ha -1 ) and Indonesia (4.25 t ha -1 ) which can be attributed International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 9 Number 2 (2020) Journal homepage: Field experiments were conducted during Kharif season 2015-16 at twenty farmer's field to refine the critical limit of Zinc in soils for rice crop grown in Mandla district of Madhya Pradesh. The soils of study sites varied in available Zn from 0.12 to 2.17 mg kg -1 and classified in three groups i.e., deficient (<0.60 mg Zn kg -1 ), marginal (>0.60 to <1.2 mg Zn kg -1 ) and adequate (>1.2 mg Zn kg -1 ). The soils were clayey, neutral to slight alkaline in reaction and low in organic carbon. The Zn treatments (0, 2, 4, 6 and 8 kg Zn ha -1 through ZnSO 4 7H 2 O and 60 kg N, 60 kg P 2 O 5 and 40 kg K 2 O through urea, single super phosphate (SSP) and muriate of potash, respectively were applied at the time of sowing in a factorial RBD and 60 kg N ha -1 was applied at tillering stage. The rice MTU-1010 variety was sown @ 80 kg seed ha -1 at 22.5 cm row to row spacing and harvested at maturity (120 DAS). The findings suggested that the increasing levels of Zn addition significantly increased the grain yield over control and optimum was at 6.0 kg Zn ha -1 . The grain yield was identical at 6.0 and 8.0 kg Zn ha -1 . In field situation, the critical limit of Zn was calculated to be 0.62 mg kg -1 using Cate and Nelson statistical method and gave a predictability value of 53 per cent. Critical limits of Zn in soil for rice calculated to be 1.12 mg kg -1 by NH 4 HCO 3 DTPA, 0.57 mg kg -1 by NH 4 OAC, 0.88 mg kg -1 by EDTA (NH 4 ) 2 CO 3 and 0.31 mg kg -1 by 0.05 N HCl + 0.025 N H 2 SO 4 . Critical levels of Zn were found to be 12.7 mg kg -1 for paddy grain. In study area, paddy crop responded to Zn application. Hence, the application of 6 kg Zn ha -1 in soil through ZnSO 4 7H 2 O will enhance the productivity of rice.
doi:10.20546/ijcmas.2020.902.150 fatcat:s4vaf5rf7fg5hmnmztn2rwohke