EFFECTS OF RYE AND COMMON VETCH COVER CROPS AS PURE AND MIXED ON SOIL PHYSICOCHEMICAL CHARACTERISTICS

Soil conservation and the improvement of characteristics are the most important aims of sustainable agriculture. The cover crop planting during fallow can be beneficial in order to achieve these aims. Therefore, this study was conducted in order to investigate the effects of rye (Secale cereale L.)and common vetch (Vicia sativa L.) cover crops planted as pure and mixed on soil physicochemical characteristics during the 2011-2012 growing season at the Agricultural Research Farm of Razi University, Kermanshah, Iran. The experiment was a split plot in time based on a randomized complete block design with three replications. Three cover crop treatments including rye (Secale cereale L.), common vetch (Vicia sativa L.) and mixed (rye + common vetch) and two incorporation date (March and April) were considered. Control plot (without cover crop) was also included in each block. Results indicated that the presence of cover crops significantly reduced soil nitrate content as compared with control and rye showed a higher reducing effect. The presence of cover crops until March led to a significant reduction in soil electrical conductivitycompared to control. In comparison between the two incorporation times, the April incorporated treatments showed lower organic matter persentage and higher electrical conductivity. Soil physical characteristics were not influenced by the type of the cover crop treatments, but the presence of cover crops until April reduced soil porosity