免耕对土壤剖面孔隙分布特征的影响  

Effect of no-tillage on pore distribution in soil profile

作　　者：杨永辉[1,2] 武继承 毛永萍[3] 何方 张洁梅 高翠民[1,2] 潘晓莹 王越[1,2] YANG Yonghui1,2, WU Jicheng1,2, MAO Yongping3, HE Fang1,2, ZHANG Jiemei1,2, GAO Cuimin1,2, PAN Xiaoying1,2, WANG Yue1,2(1. Institute of Plant Nutrition ＆ Resource Environment, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China; 2. Yuanyang Experimental Station of Crop Water Use, Ministry of Agriculture, Yuanyang 453514, China; 3. Jinshui District General Hospital, Zhengzhou 450001, Chin)

机构地区：[1]河南省农业科学院植物营养与资源环境研究所,郑州450002 [2]农业部作物高效用水原阳科学观测站,原阳453514 [3]郑州市金水区总医院,郑州450001

出　　处：《中国生态农业学报》2018年第7期1019-1028,共10页Chinese Journal of Eco-Agriculture

基　　金：国家重点研发计划项目(2017YFD0301102);国家自然科学基金项目(U1404404);河南省农业科学院优秀青年科技基金项目(2016YQ12)和河南省重点研发与推广专项(182102110060)资助~~

摘　　要：探明长期免耕措施对土壤孔隙特征、土壤结构及土壤水分参数等影响,可为阐明在小麦、玉米轮作过程中,长期进行免耕对土壤剖面物理特征的改善及其作用机理提供科学依据。采用CT扫描法定量分析了免耕和常规耕作0~100 cm土层土壤孔隙(80~1 000μm、>1 000μm、>80μm)的数目、孔隙度及孔隙在土壤剖面上的分布特征,同时采用常规方法测定了土壤大团聚体、土壤容重、有效水含量及饱和导水率等。结果表明:长期免耕不仅提高了土壤>1 000μm、80~1 000μm、>80μm孔隙数,且其孔隙度也相应提高,较常规耕作孔隙数分别提高55.3%、58.2%、57.9%,孔隙度分别提高97.4%、39.4%、72.6%。同时土壤孔隙形态也得到了改善,孔隙成圆率提高。对不同土层而言,免耕更利于提高0~25 cm土层80~1 000μm和>80μm孔隙数以及0~45 cm土层>1 000μm孔隙数,且显著提高了0~20 cm和25~40 cm土层>1 000μm、>80μm及0~20 cm土层80~1 000μm的土壤孔隙度。说明长期免耕对土壤剖面孔隙的分布产生一定影响。此外,免耕提高了0~25 cm土层土壤的有效水含量、0~55 cm土层饱和导水率和>0.25 mm水稳性团聚体含量,降低了土壤容重,其作用深度在55 cm以上土层。通过CT扫描测得的土壤孔隙参数与常规方法测定的土壤物理参数之间存在极好的相关性,说明可从微观土壤孔隙特征来表征宏观的土壤物理性质。总之,长期免耕有利于改善土壤结构和土壤孔隙状况,提高土壤的渗透能力及土壤水分的有效性,促进作物的生长。Soil pore structure plays an important role in soil water movement in both topsoil and subsoil, and it is closely related to soil surface runoff and permeability. CT scanning has accurately revealed the number, size and location of macro-pores （＞1 mm in diameter）. Long-term tillage can greatly influence the physical properties of soil profile, while non-tillage can improve soil structure, increase soil fertility and soil porosity, and thereby decrease soil bulk density and promote crop growth. Studies of non-tillage effects on soil pore have mostly been focused on the ploughed layer. Further study is needed to determine the impact of long-term non-tillage on soil pore volume, size and distribution along soil profile by using the CT scanning method and combining with soil structure, soil bulk density and soil moisture parameters investigation by using conventional method, especially for the deep soil （0-100 cm） layer. Thus in order to determine the effect of long-term no-tillage measure on pore characteristics, structure and water parameters of soil, CT scanning was used to quantitatively analyze soil pore volume （80-1 000 μm, ＞1 000 μm and ＞80 μm）, porosity, and pore distribution of the 0-100 cm soil profile under long-term no-tillage and conventional tillage conditions in this study. A conventional method was adopted to determine macro-aggregate amount, bulk density, field water capacity, effective water content and saturated hydraulic conductivity. The results showed that no-tillage treatment increased numbers and porosities of soil pores＞1 000 μm, 80-1 000 μm and ＞80 μm. The numbers increased respectively by 55.3%, 58.2% and 57.9%, while porosities increased by 97.4%, 39.4% and 72.6% of ＞1 000 μm, 80-1 000 μm and ＞80 μm pores under non-tillage treatment compared with the conventional tillage treatment. It was also found that pore shape and pore circularity improved under non-tillage treatment. For different soil layers, no-tillage treatment increased numbers of 80-1 000 μm p

关 键 词：免耕 小麦玉米轮作 CT扫描 土壤结构 土壤孔隙 土壤团聚体 水分参数 

分 类 号：S152.5[农业科学—土壤学]