The Effect of Tillage Systems and Different Sources of Fertilizer on Corn Yield and Soil Nutrients

In line with sustainable agriculture development, an experiment was conducted including tillage as the main factor in two conventional systems (plowing and mixing fertilizer with soil) and no tillage (leaving residuals of green manure and direct corn sowing). The fertilizer resources were T0: control, T1: barley green manure without chemical and manure fertilizers, T2: barley green manure with full use of the recommended chemical fertilizer (NPK) to barley containing urea, super triple phosphate and potassium sulphate respectively as 165, 90, and 75 kg/ ha, T3: green manure with two -third residual of chemical fertilizer for barley and a third of the residual to corn, T4: green manure with one- third chemical fertilizer for barley and two-third for corn, T5: barley green manure mixed with 50% manure and 50% chemical fertilizer, and T6: green manure with 40 tons of manure used as a sub-plot in the split plot and in completely random blocks with three replications for two crop years ( 2013-2014) at the Agricultural Research Station, Sistan. The results showed that in comparison with no-tillage, the conventional tillage resulted in a significant increase in grain yield, the contents of nitrogen, phosphorus, potassium and soil organic carbon, bulk density and moisture content of the soil decreased in the conventional tillage. Sources of fertilizer (organic and chemical fertilizers) significantly increased soil organic carbon, nitrogen, phosphorus, potassium, and soil moisture content. The pH and soil bulk density factors decreased after using manure sources. Interaction tillage in the fertilizer sources showed that in the conventional tillage and Treatment T5 (mixture of manure, green and chemical fertilizers) the highest yield of corn was obtained with an average of 8471 kg/ha. The results of this experiment reported that using conventional tillage system with mixture of 50% manure, green and chemical fertilizers can increase corn grain yield, provide the dynamics of nitrogen, phosphorus, potassium, organic carbon, and improve soil bulk density and soil pH.