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

Fatemeh Alipour Mobaraki

doi:10.17951/pjss.2018.51.1.93

Abstract

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.

Highlights

238 thousand hectares of rice fields of Guilan produce one million tons of rice straw each year
The results showed a significant effect of rice residues management and tillage system on soil organic matter and total nitrogen
There was a significant interaction between residues management and tillage on soil organic matter, total nitrogen, surface water infiltration into the soil, and 1,000-grain weight

Summary

Introduction

238 thousand hectares of rice fields of Guilan produce one million tons of rice straw each year. Most farmers attempt to burn these agricultural residues, which are a huge source of nutritious and organic matter. Organic matter as a source of nutrients (nitrogen, sulfur, phosphorus and potassium) helps to retain nutrients and prevents their loss through increasing the cation and anion exchange capacity. Organic matter improves buffer properties and pH stability of soil (Oorts et al 2004, Liang et al 2006). Organic matter reduces the negative effects of pesticides, heavy metals and many other pollutants in soil (Farenhorst 2006, Shepherd et al 2001). It can be said that the loss of crop residues and organic matter is a threat to sustainable agriculture and crops (Ghimire et al 2012, 2014, 2017). It is essential to maintain or increase soil organic matter

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Conclusion