摘要
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（100，200 mg／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 m g／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NO3－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350～400 kg／hm2．
In a research reported in this paper ,the soil column leaching method was used to study the effects of different nitrogen fertilizers （urea ,ammonium nitrate and ammonium sulfate） on soil surface electrochemical properties of laterite ,and to explore the nitrogen balance of the soil‐crop system .Compared with the original soil ,the number of soil surface charge significantly decreased by 6. 24% in CK （blank control ,or no fertiliza‐tion） ,significantly increased in X1 and X2 （ammonium nitrate at N 100 and 200 mg/kg） ,and dropped by 6.51% in L1 and L2 （ammonium sulfate at N 100 and 200 mg/kg） or by 1.42% in N1 and N2 （urea at N 100 and 200 mg/kg） .At higher nitrogen levels （N 300 mg/kg and 400 mg/kg） ,the soil surface charge num‐ber of the three nitrogen treatments had no significant difference with the original soil ,and with increasing ni‐trogen rate ,the final number of laterite surface charge was lower than that of the original soil .The surface charge density and electric field strength of laterite increased with nitrogen application rate ,but were higher than those of the original soil in N3 and N4 （urea at N 300 and 400 mg/kg） only ,by 1.74% and 38.73% , respectively .The electric field in the soil affected the leaching of NO 3- ,hydrogen ion adsorption and leaching of exchangeable base cations .With the same nitrogen level ,treatments of urea application had significantly higher laterite surface charge density and electric field strength than treatments of ammonium nitrate and ammonium sulfate ,being 98.6% higher in N4 than in X4 .The capacity and intensity of nitrogen adsorption were found to be of important significance for the preservation and supply of available nutrients .Under the conditions of this experiment ,urea nitrogen was more suitable for crops ,and the rational application rate was in the range of 350 -400 kg/hm2 .
出处
《西南大学学报（自然科学版）》
CAS
CSCD
北大核心
2015年第11期137-143,共7页
Journal of Southwest University(Natural Science Edition)
基金
国家十二五科技支撑计划项目(2012BAD14B18)
关键词
氮肥
砖红壤
表面电化学性质
氮素平衡
nitrogen fertilizer
laterite
surface electrochemical property
the balance of nitrogen
