The Impact Interaction of Three Different Tillage Methods and Rice Residual Management on Soil Physical Properties and Rice Growth

One of the major problems of rice cultivation in Guilan is traditional rice cultivation along with autumn tillage and burning last year’s residual, which besides wasting this valuable organic source is followed by environmental pollution in September and October each year. This study aimed to evaluate three different methods of tillage as far as soil physical properties and rice growth under crop residual burning and conservation conditions are concerned. Therefore, an area of 1,800 square meters was chosen in Islamabad Village, Pirbazar District, Rasht. A factorial experiment was designed and conducted in a randomized complete block design with 6 treatments in 3 replications and in 18 plots (each plot = 10 × 10 square meters). Treatments included tillage factor with no-tillage, autumn and winter tillage methods; and residue management factor included crop residual burning and conservation. The results showed that the amount of soil organic matter in residual burning and residual conservation was 2.18% and 2.69%, respectively, showing a 0.51% increase in organic matter. The amount of organic matter in no-tillage method (2.20%) showed a signifiant decrease of 0.32% and 0.38% compared with autumn tillage (2.52%) and winter tillage (2.58%), respectively. Surface water infitration in soil before performing treatments was 2.01 mm per minute, which was signifiantly increased by 2.81 mm per minute in crop residual conservation treatment, 2.91 mm per minute in winter tillage and 2.38 mm per minute in autumn tillage. Rice grain weight was signifiantly increased in residual conservation and no-tillage conditions. According to the results of this study, incorporation of rice residues into the soil by plowing can be recommended.