The effect of sawdust and nitrogen on soil quality indices under bean (Phaseolus vulgaris L.) cultivation

The use of agricultural and industrial wastes as a organic materials are increased. In order to evaluate of the effect of sawdust and nitrogen on soil quality indices under bean cultivation, an experiment was conducted on split plot with RCBD design with three replications. Sawdust in 4 levels 0, 5, 10 and 15 ton/ha as a main factor and nitrogen fertilizer in 3 levels 75, 150 and 225 kg/ha. and then mixed with soil. In the use of nitrogen,the maximum grain yield was 1302.8 kg/ha were obtained of 225 kg/ha of urea application. In traits of soil properties, sawdust in all traits and nitrogen fertilizer on some traits had meaningful effects. With increasing of sawdust, all of trait increased, but the increasing of traits with increasing of nitrogen showed some of traits. The investigating of rates of sawdust on MWDwet showed the difference between 5 and 10 ton/ha of sawdust was not significant, but by applying of 15 ton/ha difference and was significant. The maximum effect of MWDwet was 0.84 mm were obtained of 15 ton/ha of sawdust, in compared with 10 ton/ ha and control increasing was 100 and 265% respectively. This research indicates that sawdust as an organic conditioner and nitrogen fertilizer improved the quality of soil and the use of this treatments increased porosity, water holding capacity in FC and PWP points and organic carbon. Thus, sawdust can be used as a suitable organic fertilizer to improve the organic matter of soil and unsuitable condition of soil.