Response of Soybean Cultivars to Application of Organic and Chemical Fertilizers

In order to investigation the effect of different organic fertilizers amounts (municipalcompost, vermicompost and sewage sludge) on yield and yield components of differentsoybean cultivars, an experiment was conducted in 2006 at Sari Higher Education Complexof Agricultural Sciences and Natural Resources. A split plot experiment based onrandomized complete block design with three replications was used. Main plots wereincluded 8 fertilizer treatments consisted of two rates (20 and 40 ton ha-1) of municipalcompost, vermicompost and sewage sludge, chemical fertilizer treatment (the 75 kg ha-1 of potassium soulphat and ammonium phosphate) and control or without organic or chemical fertilizer. Sub plots consisted of three genotypes of soybean (032, 033 and JK). Maximum grain yield was recorded in levels of 20 and 40 ton ha-1 sewage sludge, 40 ton ha-1 municipal compost and chemical fertilizer. Different soybean cultivars had significantdifferences in terms of yield and yield components. Among different cultivars maximumgrain yield were produced in JK and 033 cultivars. The result of mean comparisons showedthat interaction effects of fertilizer and cultivar were significant for biomass, harvest index,1000 seed weight, number of pod per plant and number of seed per pod. The highest pod number per plant was belonged to JK and 033 genotypes in 40 ton per hectare sewage sludge and vermicompost treatments, respectively. Among different mentioned traits, all of them except 1000 seed weight had a positive and significant correlation with grain yield.Over all, it seems that disposal of organic waste on agricultural lands could be consideredas one of the suitable and practicable environmental option and optimization manure usingin our country.