Effect of micronutrients, organic manures and lime on bio-fortified rice production in acid soils of Eastern Himalayan region

摘要

The field experiment was conducted at Langol Research farm of ICAR Research complex for North Eastern Hill Region (NEHR), Manipur Centre during kharif season of 2013 and 2014 in a sandy loam soil with pH 5.2, nitrogen 350kg/ha, phosphorus 10.22 kg/haand potassium 472 kg/ ha. The experiment was laid down in a split plot design with 16 treatment combinations. The main plots treatments consisted of different sources of organic manures Viz., Control, Farm yard manure (FYM) 5t/ha, Cowpea itinerary (Vignaunguiculata) green manures 5t/ha and FYM (2.5t/ha) + CP (2.5t/ha) + Lime (400kg/ha) and the sub plot treatment consisted of different sources of micronutrients viz., Control (No micronutrients), application of ZnS04 (0.5%) spray, Fe S04(2%) and Sodium selenate (0.1%). A common chemical dose of fertilizers 60 kg N + 13.1 Kg P + 25.0 kg ha"1 was used for the experiment. The percent N, P and K content of Cowpea green manure (Vigna unguiculata) and FYM, manure were 0.7-0.5-0.6 and 0.50 -0.29- 0.61 was estimated and organic manures were incorporated before 15 days of sowing. The results revealed that application of FYM (2.5 t/ha) + crop residue (2.5 t/ha) + lime (400 kg/ha) recorded highest rice grain (3.60 t/ha in 2013 and 3.00t/ha in 2014) and straw (5.20 t/ha in 2013 and 4.87 t/ha in 2014) yield, content of N, P, K, Zn , Fe and Se (1.43%, 0.51%, 0.31%, 21.0 mg/kg 20.95 mg/kg and 0.04 mg/kg respectively) in rice grain over the other nutrient management practices. The same treatment also recorded highestcrop profitability (Rs/day/ha = 410.65/-) and better in available organic carbon, N, P, K, Zn and Fe status in the soil after harvest of the crop. The application of organic manures increased available soil organic carbon (0.20% to 0.35%), nitrogen (31.16 - 77.22 kg/ha), phosphorus (0.7-4.14 kg/ha ), potassium (18.79 - 59.47 kg/ha), Zinc (0.03-0.18 g/kg) and Iron (19.47 - 35.86 g/kg) which can be considered as good carbon as well as budget for major and micro nutrient over the control plot under the study. On the other hand foliar spray of micronutrient Zinc (0.5%) and Iron (2%) was found to increase the quality grain production of rice through increases in Zn and Fe content of rice grain which is 53% and 38.34% respectively.