构建肥沃耕层对沙性土壤水分物理性质及玉米产量的影响

摘要

沙性土壤是我国一种重要的耕作土壤,但是由于其矿物结构简单,耕层土壤保水性能差,养分含量少,属于中低产土壤,如何构建肥沃的沙性土壤耕层,有效地提高沙性土壤的耕地地力是目前急需解决的问题.本研究以内蒙古赤峰市的典型沙性土壤为研究对象,以未进行耕翻的地块为对照,分析了不同肥沃耕层构建方式(耕翻和物料施用)、深度(20 cm(T20),35 cm(T35)和50 cm(T50))和构建物料(牛粪和黑土)对沙性土壤耕层水分物理性质的影响.研究结果表明不同耕翻深度和构建物料施用深度是影响剖面物理性质变化的重要因素.不同构建方式均能够促进土壤>2 mm和0.25 mm~2 mm团聚体的形成,表现为牛粪(M)> 黑土(B)>耕翻(T)>对照(CK);构建物料的施用显著地减少沙性土壤的容重,增加了总孔隙度、田间持水量和饱和持水量,说明肥沃耕层构建能够增加土壤持水能力,其中以施用牛粪处理效果最显著;利用牛粪构建肥沃耕层显著地减少了沙性土壤的饱和导水率,与CK、施用黑土和耕翻相比,降低了17.2%~45.3%;不同构建深度玉米产量表现为T35>T50>T20,表明沙土适宜的肥沃耕层构建深度为35 cm,与CK、耕翻和施用黑土相比,施用牛粪后玉米的产量增加了38.8%,34.7%和7.2%.因此,沙性土壤肥沃耕层构建过程中适宜的深度为35 cm,适宜的构建物料为牛粪.表2,图7,参20.%Sandy soil is an important arable soil in China,and is a kind of medium-low yield soil with simple mineral structure,low water capacity and nutrient contents.It has attracted more and more attention on how to improve and enhance sandy soil production by constructed fertile layer.Typical sandy soil distributed in Chifeng Inner Mongolia was selected to study the effects of constructed soil layer way (tillage and materials incorporation),depth (T20,T35,T50) and materials (manure and black soil) on soil aggregate fraction,soil properties and maize yield,with no treatment as control(CK).The results showed that the depth of constructing fertile layer and material application impacted soil properties in soil profile.Constructing fertile cultivated layer increased soil aggregate fraction contents >2 mm and 0.25 mm~2 mm with the trend of manure>black soil>plowing>CK.Materials incorporation decreased soil bulk density,increased soil total porosity,field water capacity and saturation water capacity with best effect by manure application treatment,indicating that constructing fertile cultivated layer could increase sandy soil water capacity.Compared with CK,black soil incorporation and plowing,soil water conductivity in manure application was increased by 17.2%~45.3%.Maize yield in different constructing depth showed T35>T50>T20,indicating that optimized depth of fertile cultivated layer was 35 cm,while maize yield under manure application treatment was increased by 38.8%,34.7% and 7.2%,compared with CK,plowing and black soil incorporation.Therefore,suitable fertile cultivated layer depth was 35 cm with manure incorporation.