秸秆生物炭对黏壤土入渗规律的影响

Effects of Biochar on the Physical Properties and Infiltration of Clay Loam

为提高干旱半干旱区耕作土壤灌溉水的利用效率,采用秸秆生物碳对黏壤土进行改良,并用3种经典入渗模型进行入渗模拟,寻求适于描述研究区土壤入渗规律的模型及改良方案。采用双环入渗试验测定4种生物炭施用水平(10t/hm^2,20t/hm^2,30t/hm^2,50t/hm^2)的田间作物生育期内土壤含水率、入渗速率及累积入渗量,分别采用Green-Ampt模型、Philip模型和Kostiakov经验公式对试验组与对照组(CK)的入渗过程进行模拟。结果表明:施用量为30t/hm^2较CK效果最为明显,施用层(0—40cm)入渗速率增加44.6%,耕作层土壤含水率增加8.9%,累积入渗量增加45.45%。比较3种模型的入渗过程拟合结果,认为Kostiakov经验公式拟合的效果符合实测规律,可为研究区改良土壤水分入渗过程提供理论依据。

For improving irrigation water utilization efficiency of clay loam in arid and semi arid region,using biochar as soil conditioner to reformed cultivated soil at Hetao irrigation area,we simulate water infiltration process with three classical infiltration models to seek a suitable infiltration model to describe cultivated soil infiltration process and select a most effective proposal to improve the irrigation efficiency in semiarid climate area.There were four biochar application rates(10t/hm^2,20t/hm^2,30t/hm^2,50t/hm^2)and we carried out the double loop infiltration test under irrigated condition to measure soil moisture content,infiltration rate and cumulative infiltration amount during the crop growing period for the four applications.The GreenAmpt model,Philip model and Kostiakov empirical formula were used to simulate the infiltration process of experimental group and control group(CK).The results show that the effect of group of 30t/hm^2 was most significant and application layer(0to 40cm)infiltration rate increased by 44.6%,soil moisture content increased by 8.9% and cumulative infiltration volume increased by 45.45%.Compared with the infiltration process fitting results of three models,the Kostiakov empirical formula fitting presented better tendency and was close to the testing values,which could provide the theory basis for soil improvement in the study area.