Residual Effects of Two Organic Matters With or Without Nitrogen on Growth and Chemical Composition of Wheat and Some Soil Chemical Properties

AbstractEfficient use and management of organic matter are important aspects of sustainable agricultural. Organic matter is relatively low in majority of soils in Iran, and continuous use of N fertilizer would create environmental hazards. Therefore, the combined use of N fertilizer and organic wastes is an effective strategy. The purpose of this study was investigating of residual effects of different sources of organic matters with or without nitrogen on wheat dry matter and soil chemical characteristics. Treatments included two organic matter sources (municipal solid waste compost and cow manure), in four rates (0, 1, 2, and 4%) and three N levels (0, 75, 150 mg kg-1 soil). The experiment was carried out in factorial manner in a completely randomized design with three replications. Treatments applied in rice and the residual effects were studied on growth and chemical composition of wheat and some soil chemical characteristics after wheat harvest. Application of both organic matter sources enhanced wheat growth. With compost, addition of N did not affect crop growth while with cow manure, application of N led to increase wheat growth in all organic matter levels. The effect of N was the most in the higher cow manure levels. Application of N alone did not affect wheat growth. Wheat plants enriched by either of the two organic wastes accumulated more phosphorus (P), potassium (K), iron (Fe), manganese (Mn), chlorine (Cl) and sodium (Na) than control plants. Post harvest soil sampling indicated that addition of organic matter significantly increased study chemical characteristics. Organic matter, total nitrogen, available P, Fe, Zn, Cu and Mn, soil electrical conductivity and sodium adsorption ratio in soil enriched with organic matter were more than those in control. In general, residual effects of cow manure particularly with chemical nitrogen on dry matter and soil chemical characteristics were more than those of compost.