Effect of Integrated Use of Organic and Chemical Fertilizers on Growth, Yield and Micronutrients Uptake in Rice (Oryza sativa) - Wheat (Triticum aestivum) System

摘要

Intensive cultivation of rice-wheat system and imbalanced fertilizer application resulted multi-nutrient deficiency and depletion of organic matter from the soil. However, owing to the steadily increasing demands for food by the overgrowing populations, a complete shift to an organic farming system is not possible. Therefore, field experiments were conducted for two years on a sandy loam soil at Agricultural Research Farm, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, UttarPradesh to study the effect of three organic sources i.e., sewage sludge (SS), vermicompost (VC) and Sesbania green manure (GM) in combination with 75% of recommended fertilizers (RDF) on growth, yield and micronutrient uptake by rice-wheat cropping system. Other treatments were: absolute control, 100% RDF + S Zn B and customized fertilizer (CF). The plant height of rice and wheat in RDF + S Zn B was statistically at par with 100% RDF at harvest. The number of tillers was recorded the highest in case of75% RDF + 25% N through organic amendments (T_5, T_6 and T_7) which was statistically at par with each other both in rice and wheat. In year II in rice and wheat, grain yield was similar under all the organic treatments, which produced significantly lower yields over 100% RDF with S, Zn, B (T_3) and customized fertilizer (T_4) but was at par with RDF (T_2). Application of organic treatments at 25% of recommended N could sustain the yield of rice-wheat system along with 75% RDF. Total uptake of Fe increased significantly by application of 75% RDF along with 25% N through GM in year I and II in rice. The highest total uptake of Fe was recorded in T_4 (CF) and T_5 in year I and II in wheat. Total uptake (grain + straw) of Cu was higher in the treatment receiving customized fertilizer (T_4) in both year I and II in rice-wheat as compared to other treatments. The maximum total uptake of Cu was recorded in T_7 (75% RDF with 25% N through GM) in both years of rice-wheat system. Application of 100% RDF + S,Zn, B (T_3) had the maximum total uptake of Zn in case of year I and II in rice whereas in year I and II in wheat application of CF (T_4) had the highest Zn uptake. The maximum B concentration in rice-wheat was recorded in treatment which received 100% RDF + S, Zn, B in both the years. Use of organics in combination with chemical fertilizers could sustain yields of rice and wheat and maintained adequate supply of Zn in soil.