Depletion of Micronutrients From Soil and Their Uptake in Rice-Wheat Rotation

Depletion and uptake of Zn. Cu. Mn and Fe was studied/or 3 years in a rice-wheat rotation at four fertility levels in a clay loam soil. The pooled yield of paddy was 179.6q ha⁻¹, higher than that of 123.4 q ha⁻¹ of wheat grain. On an average. the uptake of Zn, Cu, Mn and Fe by single crop of rice was 252, 199.801 and 3431 g ha⁻¹ compared with 170,80,281 and 1833 g ha⁻¹ respectively. by wheat at medium fertility level. The uptake of Zn, Cu, Mn and Fe by a quintal biomass at medium fertility level was 1.7, 0.83, 2.9 and 199 by wheat and was 1.95, 1.54, 6.2 and 26.5 g by rice, respectively. At medium fertility level. Zn in soil decreasedfrom 1.9 to 1.2, Cu from 2.2 to 1.9. Mn from 4.4 to 3.3 and Fe from 24.4 to 20.0 mg kg⁻¹ soil after 6 crops, three each of rice and wheat.