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就土壤有效养分的保蓄和提供而言,土壤对氮素的吸附量及强度大小对其有重要影响.以砖红壤为研究对象,采用土柱淋溶方法,研究了施用不同氮肥对砖红壤表面电化学性质的影响,探讨了土壤保蓄和提供植物有效养料.结果表明:(1)CK处理的土壤表面电荷数比原土明显下降了6.24%;在低氮肥水平(100,200mg/kg)下,硝铵处理的表面电荷量显著高于原土;而硫铵和尿素处理比原土低6.51%和1.42%;在高氮肥水平(300,400 mg/kg)下,3种氮肥处理的表面电荷数与原土无明显差异.(2)与原土相比,3种氮肥处理的比表面积均显著增大,其中尿素处理的比表面积随施氮水平的变化而显著增大,特别是N3和N4处理的比表面积显著高于N1和N2处理.(3)随着施氮量的增加,砖红壤的表面电荷密度和电场强度呈相同的增加趋势.在同一施氮水平下,尿素处理的砖红壤表面电荷密度和电场强度均显著高于硝铵和硫铵处理,其中N4比X4处理高了98.6%.土壤表面电化学性质会影响氮肥所转化的NO-3的淋失、氢离子的吸附以及交换性盐基离子淋失,为科学施氮,调节土壤—作物体系的氮素平衡,故在选择施用氮肥时应适当适量.本试验条件下,尿素相较于其他两种氮肥更适合砖红壤,且氮肥的合理施用量应控制在350~400kg/hm2.
In terms of the conservation and supply of soil available nutrients, the amount and intensity of soil nitrogen adsorption have an important impact on.Taking the brick red soil as the research object, soil column leaching method was used to study the application of different nitrogen fertilizers on the red brick soil The results showed that: (1) the surface charge of CK decreased by 6.24% compared with the original soil; at low nitrogen fertilizer level (100, 200mg / kg) , The surface charge of ammonium nitrate treatment was significantly higher than that of native soil; while the treatment of ammonium sulfate and urea was 6.51% and 1.42% lower than that of native soil; and the surface charge of three nitrogen treatments was high at high nitrogen fertilizer level (300 and 400 mg / kg) (2) Compared with the original soil, the specific surface area of the three nitrogen treatments significantly increased, of which the specific surface area of urea treatment significantly increased with the change of nitrogen application level, especially N3 and N4 treatment was significantly higher than that of N1 and N2 treatment. (3) With the increase of nitrogen application rate, the surface charge density and electric field intensity of red brick soil showed the same trend of increase.Under the same nitrogen application level, The surface charge density and electric field intensity of red soil were significantly higher than that of ammonium nitrate and sulfur Ammonium treatment, in which N4 was 98.6% higher than that of X4 treatment. The electrochemical properties of soil surface affected the leaching of NO-3, the adsorption of hydrogen ions and the leaching of exchangeable base ions by nitrogen fertilizer. Soil-crop system nitrogen balance, so the choice of nitrogen fertilizer should be appropriate amount.In this test conditions, urea is more suitable for the brick red soil than the other two nitrogen fertilizers, and the rational application of nitrogen fertilizer should be controlled at 350 ~ 400kg / hm2.