摘要
降雨导致土壤表面结皮形成封闭是自然现象,它能降低土壤入渗,增加土表径流,导致土壤侵蚀。该文系统地研究了不同性质土壤表面的封闭作用过程,分别确定封闭过程中的物理机械作用和化学作用。试验采用了具有不同土壤交换性钠百分率(ESP)值(2、5、10、20)和黏粒含量(10%、20%、40%、60%)的4种土壤进行降雨模拟试验,通过土壤表面播撒磷石膏(PG)(2000 kg/hm2)和PG与聚丙烯酰胺(PAM)(PG 2000 kg/hm2+PAM 20 kg/hm2)混合物的处理,分别抑制了土壤的化学封闭和物理封闭,论述了ESP值和黏粒含量对土壤化学封闭和物理封闭作用的影响,结果表明:在高ESP值土壤中,化学封闭作用占土壤封闭的主导作用;低ESP值土壤中,土壤的物理封闭作用增大。当黏粒含量较低时,土壤物理封闭作用较低;当黏粒含量较大时,土壤物理封闭作用显著增大。
Seal formation on the soil surface during rainstorms reduces rain infiltration and leads to runoff and erosion. The objective of this study is to investigate the soil seal formation in different soils, and to analyze the chemical and physical processes in it. Experiments were conducted with four different soils with different Exchangeable Sodium Percentage（ESP）（2, 5, 10 and 20） and different clay contents（10%, 20%, 40% and 60%） under rainfall simulation. The effects of ESP and clay content of soil on seal formation were discussed by means of shielding chemical and physical seal formation with spreading phosphogypsum（PG） （2000 kg/hm^2） and PG plus （polyacrylamide） PAM（PG 2000 kg/hm^2＋ PAM 20 kg/hm^2） on soil surface. In high ESP soils, chemical seal formation is predominated, and in low ESP soils, the physical seal formation take more shares. The physical seal formation is in low degree with low clay content soils, however, developed well in high clay content soils.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2007年第5期51-55,共5页
Transactions of the Chinese Society of Agricultural Engineering
基金
黄土高原土壤侵蚀与旱地农业国家重点实验室基金
