仵峰, 张凯, 宰松梅, 王华震, 赵璨. 小麦玉米秸秆掺土还田量对土壤水分运动特性的影响[J]. 农业工程学报, 2015, 31(24): 101-105. DOI: 10.11975/j.issn.1002-6819.2015.24.016
    引用本文: 仵峰, 张凯, 宰松梅, 王华震, 赵璨. 小麦玉米秸秆掺土还田量对土壤水分运动特性的影响[J]. 农业工程学报, 2015, 31(24): 101-105. DOI: 10.11975/j.issn.1002-6819.2015.24.016
    Wu Feng, Zhang Kai, Zai Songmei, Wang Huazhen, Zhao Can. Impact of mixed straw on soil hydraulic properties[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2015, 31(24): 101-105. DOI: 10.11975/j.issn.1002-6819.2015.24.016
    Citation: Wu Feng, Zhang Kai, Zai Songmei, Wang Huazhen, Zhao Can. Impact of mixed straw on soil hydraulic properties[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2015, 31(24): 101-105. DOI: 10.11975/j.issn.1002-6819.2015.24.016

    小麦玉米秸秆掺土还田量对土壤水分运动特性的影响

    Impact of mixed straw on soil hydraulic properties

    • 摘要: 为探求小麦、玉米秸秆还田对土壤水分运动特性的影响,利用非饱和导水率测定仪测定土壤水分特征曲线,采用van-Genuchten模型拟合土壤水分特征曲线。试验以不掺加任何秸秆为对照,另设计分别掺加小麦或玉米秸秆的4个处理,掺加量分别为干土质量的1.0%、1.6%、2.25%、3.2%,比较各处理土壤水分运动参数和水分有效性差异。结果表明,掺加秸秆后模型进气值倒数值均小于对照;在秸秆掺加量为1%~2.25%时,形状系数值随着秸秆掺加量的增大而增大,当掺加量为3.2%时反而减小;秸秆的掺入还影响到土壤水分特征曲线的土壤残余含水率和土壤饱和含水率,掺加2种秸秆后,土壤饱和含水率均比未掺时小;土壤残余含水率变化规律与形状系数值一致,掺加小麦秸秆后,土壤残余含水率略低于对照,而掺加玉米秸秆后,土壤残余含水率略高于对照。掺加秸秆能减少土壤重力水19.3%~73.3%,在掺加小麦秸秆3.2%、掺加玉米秸秆2.25%时,土壤中易利用水比例系数最大,分别为26.3%、30.6%,所以通过掺加秸秆能显著提高土壤的保水性。研究可为阐明秸秆还田后土壤水分运动规律提供理论依据。

       

      Abstract: Abstract: To explore the impact of crop residues on soil hydraulic properties and water retention characteristics, a column experiment of soil water movement properties, which mixed crop residues into the soil, was carried out in August 2014, at Henan Key Laboratory of Water-saving Agriculture, North China University of Water Resources and Electric Power, Zhengzhou, China. There were 9 treatments with 2 kinds of crop residues, wheat straw and corn stalk. Proportions of mixed straw was calculated as the percentage of dry soil mass, which varied from 0 as control and 1.0%, 1.6%, 2.25%, 3.2%, respectively. Using a rice and wheat thresher, winter wheat straw and summer maize stalks were cut into pieces by once and third times. Those straw pieces in length less than 5 cm were collected and mixed with dry top-soil from test area in designated proportions. And then they were filled into the soil column as 1.4 g/cm3 soil bulk density layer by layer. First, water filled into soil column from its surface with soil infiltration instrument (Guelph) and lasted for 1 hour. Then, soil water retention was measured by the unsaturated hydraulic conductivity meter (Ku-Pf). It was implemented that the soil-hydraulic functions of van Genuchten, who used the statistical pore-size distribution model to obtain a predictive equation for the unsaturated hydraulic conductivity function in terms of soil water retention parameters. At last, the ratio of easily available water, which defined as easily used soil water content divided by saturated soil water content, was analyzed. Results showed that the van-Genuchten model was suitable for soil water retention under the condition of mixed wheat straw and corn stalk into the soil. For soils mixed with straw, soil moisture was lower than that of control in low suction section (soil water suction less than 150 cm H2O). In middle and high suction section (soil water suction more than 150 cm H2O), at a same suction, soil water content of mixed 1% wheat straw was lower than that of control, moisture of mixed 1.6% wheat straw was near to the control, and its mixed 2.25 %, 3.2% wheat straw was higher than that of the control. Descending order of soil mixed straw water content was 3.2%, 2.25%, 1.6% and 1%. For summer maize stalk, soil water content of soil mixed stalk was higher than that of the control in all treatments. Increasing the ratio of mixed corn stalk, soil moisture was increased firstly and then decreased. The highest soil water content appeared at 2.25% summer maize stalk mixed into soil. But soil water content of 3.2% treatment was lower than that of mixed 2.25% stalk. Soil moisture decreased from the ratio of stalk 2.25%, 3.2%, 1.6% to 1.0% treatment by sequence. Soil hydraulic parameters of van-Genuchten model were affected by mixed crop residue. Parameter α, reciprocal of intake air value was smaller than the control. The shape coefficient n increased with the mixing amount of straw from 1.0% to 2.25%, but it decreased at 3.2%. Mixed straw into soil affected the residual soil water content and the saturated soil water content in the soil-hydraulic functions of van Genuchten too. Soil saturated soil water content were smaller than the control after mixing two kinds of straw. The residual soil water content changed as the shape coefficient values. The residual soil water content was lower slightly than the control after adding winter wheat straw, while slightly higher than the control after adding summer maize stalk. The soil gravity water decreased and the easily available water increased after mixed crop straw. Soil gravity water reduced 19.3%-73.3%. The maximum ratio of the easily available soil water were 26.3%, 30.6%, which appeared at 3.2% winter wheat straw and 2.25% summer maize stalk mixed into soil, respectively. It could significantly increase soil water conserving properties by mixed straw into soil.

       

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