Changes in Soil Physical Characteristics Affected by Green Manuring of Different Cereals

In order to determine the influence of different cereals as green manures on organic carbon and soil physical properties, an experiment was conducted in 2011 in Khaton Abad Agricultural Research Station of Islamic University (Khorasgan branch), Esfahan, Iran (latitude 32^o 40^/ N, longitude 51^o 58^/ E, and 1570 m elevation). A completely randomized block design with 3 replications was used. Green manures were included barley, rye, triticale and clover with two levels of farm yard manures namely, 30 and 60 ton/ha and one treatment of chemical fertilization as a control treatment and decomposition time of manures in two levels, the first one is one day after turning green manure to soil and the second one is 4 weeks after returning of them. Manure was mixed with soil immediately after spreading it. All crops were returned to the soil with mouldboard ploughing, before heading stage for cereal, and 10 percentage of flowering for clover, respectively. All experimental characteristics, namely, EC, pH, CaCO₃, organic carbon (OC), P₂O₅, K₂O, Zn, Mn, Fe and Cu significantly influenced by treatment. The highest EC, organic carbon, P₂O₅, K₂O, Zn and Mn of the soil was related to application of 60 kg N/ha. The maximum pH and Fe content of soil was obtained in application of 30 kg N/ha and in a treatment in which rye was burning. The treatment in which clover was used as a green manure has obtained the highest Cu content of soil, which had significant difference with other treatments. There were no significant differences in CaCO₃ among application of 30 kg N/ha, control treatment, rye as a green manure, triticale as green manure, and triticale as a green manure after four weeks. Control treatment had obtained the lowest EC, Organic carbon, P₂O₅, K₂O, Zn, Fe and Cu of soil. Moreover, the maximum CaCO₃ and Mn of soil were achieved in a treatment in which clover was used as a green manure. The treatment in which rye was used as a green manure had obtained the highest pH.