Ecological method for abating agricultural non-point source pollution in rice planting regions

Abstract

The invention discloses an ecological method for abating agricultural non-point source pollution in rice planting regions. According to the method, the whole process from the time when the agricultural non-point source pollution flows out of the farmland to the time when the agricultural non-point source pollution enters a downstream receiving water body is considered, the specific pollution decreasing technology containing three defense lines is provided, source control for reducing agricultural non-point source pollution emission through filed water-saving irrigation and comprehensive water-fertilizer regulation serves as the first defense line, agricultural non-point source pollution removal and purification conducted through ecological ditches serves as the second defense line, agricultural non-point source pollution removal and purification conducted through small reservoirs and wet land serves as the third defense line, the three defense lines are in a series connection relation, in other words, the head end is provided with the first defense line, the first defense line is linked to the second defense line, and finally the second defense line is linked to the third defense line. By means of the ecological method, the effect of discharging and purifying nitrogen and phosphorus in the agricultural non-point source pollution is good, the utilization rate of nitrogen and phosphorus is raised, construction cost and operation cost are both low, plant diversity of the rice irrigation regions is enriched, and the method is suitable for being popularized in the regions in the South where rice is planted.

Description

technical field [0001] The present invention relates to the technical field of agricultural water conservancy, in particular to an ecological control method for agricultural non-point source pollution in rice planting areas with comprehensive source control, three defense lines of ecological ditches and ponds and weirs, especially suitable for agricultural non-point source pollution in southern rice irrigation areas governance. Background technique [0002] In recent years, due to the limitation of land resources, increasing grain yield per unit area is the main measure to increase grain production in my country. At present, one of the measures to increase grain yield per unit area is the high input of resources such as fertilizers, resulting in low resource utilization and increased environmental pollution. According to statistics, the current input of chemical fertilizers per unit area in my country is 2.6 times the world average level. Excessive input of chemical fertil...

AI Technical Summary

Problems solved by technology

For example, the existing drainage ditches: (1) adopt cross-section lining to make the drainage ditch have no ecological function, which is not conducive to the growth of animals and plants; (2) the natural narrow and deep cross-section slope is steep, and the drainage ditch is easy to deposit sediment (3) There are weeds with no obvious decontamination effect on the slope, which is not conducive to the removal and purification of pollutants; (4) Without reasonable control buildings, drainage cannot be effectively reused

[0005] At the same time, the existing ponds and weirs mainly have the following problems: (1) The daily water level is deep, which is not conducive to the growth of aquatic plants, especially emergent plants, resulting in a decline in the decontamination function; (2) The plane shape is irregular, and the water flow path is usually relatively narrow. Short, there are "dead water areas" and other areas that cannot flow through, and the decontamination potential cannot be fully utilized; (3) The size of the single pond weir is unreasonable: if the area is too small, it is easy to silt, and if the area is too large, the daily water level will be high and affect plant growth. Large footprint is not conducive to promotion

[0006] At present, there are very few studies on the removal of agricultural non-point source pollution in Tangyan Wetland. There have been many practices on the transformation of drainage ditches into ecological ditches to control agricultural non-point source pollution. The source control of pollution and the decontamination function of pond weir wetlands, therefore, there is still a lot of room for improvement in the ability to control agricultural non-point source pollution in rice planting areas

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