|
Based on the previous studies, this study in August 2010 in Lanzhou City Qinwangchuan Irrigation chose 19 representative samples, soil samples were collected according to specifications 70. According to GB/T50123-1999 standard soil test method provides a method of soil and the amount of soluble salts of potassium, sodium, calcium, magnesium, chloride, sulfate, carbonate, bicarbonate ion concentration by ion chromatography the nitrate concentrations. This experiment aims to illustrate Qinwangchuan irrigated soil salinization status, compared to the last survey of scholars Analysis of the data cited large Qin and after implementation of the project's impact on irrigated soil salinization, and propose specific preventive measures reasonably , for the construction of the new city of Lanzhou provide some data support, hope to deal with the problems caused by relevant departments. By analyzing the data and concluded: secondary salinization of irrigated areas are mainly distributed in the water channels and branch road, water and other depressions on both sides of the fringe areas along the old salinization outward expansion zone, as well as light sandy loam soil quality, heavy silty soil distribution areas; Qinwangchuan regional soil salinization area and lead large projects uncompleted than before about an increase of nearly 27 percentage points; salinization of large areas as sulfate chloride type salts, followed by the sulfuric salt; vertical distribution of soil salinity can be attributed to five types, comparison with previous scholars found Qinwangchuan region after irrigation emergence of a new salt accumulation in the middle of the distribution type, the type is mainly distributed in the Liao slots and five baidunzi other basins in the eastern region, the soil is slightly saline soil. Overall, secondary salinization of irrigated areas in the basin of south-central range, particularly in the south of the most serious government Chuan Zhen, pawn shops and other areas Fang slope salt spots a large area, the soil type is saline. Analysis of salinization same time, I nitrate samples were analyzed with the nitrate content in most areas the depth of the soil layer decreases with an increase, and found that the phenomenon of soil texture, irrigation status. Since the nitrate content of the vast region is very low, in the following 200mg/kg, so do not do focus on. For analysis of the results, the need to reform the past farming systems, improve drainage facilities, promote irrigation and drip irrigation and other water-saving irrigation, afforestation under village conditions, improve the ecological environment field, government investments in technology, especially in well irrigated monitoring items, first hand. With water and salt balance as the starting point through the regulation and management of irrigation water salinity reached on the regulation and management of the soil salinity in irrigated areas to achieve full dynamic equilibrium is irrigated salinization Qinwangchuan basic idea of ??prevention. Through the joint efforts of relevant departments, make Qinwangchuan become Lanzhou ideal agro-ecological zones and satellite town.
|