摘要
试验利用电导法在稳态供水条件下，对不同粒级土壤中溶质的移动及其施肥土壤中Ｎ的向下迁移过程及迁移数量进行定性和定量研究，讨论了土壤颗粒大小对土壤持肥、持水特征的影响，并揭示了不同粒级土壤中溶质Ｎ的迁移与水分运动的关系。根据渗出液的电导率与其ＮＯ－３－Ｎ含量之间关系：ｙ＝０．２３６＋０．００５ｘ，估算出各粒级土壤中加入的肥料Ｎ的淋溶量。结果表明：土壤的持肥、持水特征，以及Ｎ的迁移和水分运动与土壤颗粒组成有关。一般持水性较高的粒级（如＜０．３ｍｍ），其持肥能力亦较强，但饱和导水率较低，溶质Ｎ的迁移速度也比较缓慢。本试验旨在为土壤耕作和培肥、改善土壤结构。
Qualitative and quantitative studies on fertilizer N downward transfer in soils with different particle size fractions under steady state of flow are conducted by using electic conductivity method. The paper discusses the effect of soil paricle size on water and fertilizer retention, and the relationship between N transfer and water movement in soils. Using the linear correlation between the conductivity and NO 3-N content of the leakage water: Y =0.236+0.005 X , the amounts of leached N at a given time in the soils with fertilizer N are estimated from the conductivities of the leakage water. The results show that, at a higher water potential, the soil with a smaller particle size of <0.3 mm contains more water than the soils with a bigger size. The water with a high absorbability, in general, has a great fertilizer retention, but a low saturated hydraulic conductivity and a slow N transfer rate. The objective of the study is to provide references for bettering tillage and fertilization, increasing soil water and fertilizer retention as well as improving soil structure.
出处
《干旱地区农业研究》
CSCD
北大核心
1997年第1期64-68,共5页
Agricultural Research in the Arid Areas
基金
国家自然科学基金
关键词
土壤粒级
土壤持水性
淋溶作用
溶质迁移
soil particle size, soil water holding capacity, leaching effect, solute transfer
