Document Type : Research Paper
Authors
1
Assistant Professor., Soil and Water Research Institute, Agricultural Research Education and Extension Organization (AREEO), Karaj, Iran
2
Assistant Professor., Soil and Water Research Department, Khuzestan Agricultural and Natural Resources Research and Education Center, AREEO, Ahwaz, Iran
3
Assistant Professor., Soil and Water Research Institute, AREEO, Karaj, Iran
4
Assistant Professor, Soil and Water Research Department, Mazandaran Agricultural and Natural Resources Research and Education Center, AREEO, Sari, Iran
5
Assistant Professor., Rice Research Institute of Iran, AREEO, Rasht, Iran
6
Researcher, Soil and Water Research Institute, AREEO, Karaj, Iran
Abstract
Meeting the demand for rice in the country as a strategic product is of special importance. The objective of this study was to investigate the effect of soil properties on rice yield and their rating to prepare a table of soil and landscape requirements of this crop for use in land suitability assessment studies. For this purpose, 99 rice fields in Mazandaran, Guilan, and Khuzestan provinces were selected. In each farm, a soil profile was studied and a land use questionnaire was completed. After the necessary physical and chemical analyses, a simultaneous multivariate regression between yield and different soil properties was investigated. Then, in order to prepare a table of soil and landscape requirements for rice, simple regression relationships between effective soil characteristics and yield were investigated and rated for different land suitability classes. Verification of the proposed table was performed using data from 18 rice fields (about 18% of the whole data). The results showed that the range of yield, lime, sand, clay and silt in selected fields was extensive, but the percentage of exchangeable sodium and soil salinity were in a more limited range. In multivariate regression, the variables of salinity, ESP, lime, soil reaction, percentage of clay and sand, respectively, were efficient. The coefficient of determination of the proposed equation was about 0.38. Also, the value of the coefficient of determination between yield and soil index for verification data was about 0.71, which indicates the reliability of the proposed table in this study.
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