Irrigation method for reducing heavy metal content of paddy rice based on soil water potential indexes

Abstract

The invention discloses an irrigation method for reducing the heavy metal content of paddy rice based on soil water potential indexes. During the tillering stage and milk-ripe stage of the growing period of the paddy rice, the soil water potential of a plowing layer of a paddy field serves as a threshold standard for irrigation; in the secondary growing period, irrigation is conducted when the soil water potential of the plowing layer is reduced to -15 KPa and stopped when the soil water potential rises to 0 KPa; the flooded state of the surface of the paddy field is kept in other growing periods of the paddy rice. Compared with other conventional irrigation methods, through the adoption of the irrigation method for reducing the heavy metal content of the paddy rice based on the soil water potential indexes, the contents of heavy metals Cd, Pb, Hg and Cr in the paddy rice can be reduced by 44.7%, 20.0%, 26.7% and 12.0% respectively, the yield of the paddy rice can be increased by 5.93%, the water amount for irrigation is reduced by 40.5%, and the utilization efficiency of water is increased by 78.1%; the irrigation method is simple to operate, low in usage cost and suitable for producing paddy rice products with low heavy metal contents on vast paddy fields polluted by heavy metal at light and medium degrees.

Description

technical field [0001] The invention belongs to the field of agriculture, and in particular relates to an irrigation method for reducing heavy metal content in rice based on soil water potential indicators. Background technique [0002] Rice is one of the most important food crops in China, with a planting area of ​​30.4 million hectares in 2015 2 , the total output reached 201 million tons, and the planting area and total output accounted for 27% and 36% of the grain respectively. Rice is the most important ration consumption crop in China, accounting for about 60% of all ration consumption, and rice ration consumption accounts for 85% of total rice consumption. Therefore, rice cultivation occupies an extremely important position in my country's food crop production. However, the problem of heavy metal pollution in farmland soil in my country is not optimistic. According to the "National Soil Pollution Survey Bulletin" (Ministry of Environmental Protection, etc., 2014),...

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Problems solved by technology

[0006] Soil moisture content is difficult to judge accurately by the naked eye alone, and the conventional drying method to measure soil moisture content is time-consuming and laborious, and the work efficiency is low

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