Effects Of Biochar And Water Retaining Agent On Water Characteristics And Enzyme Activities Of Gangue Soil Matrix

The water resources in the arid regions of Northwest China are scarce,and the new soils in the drainage and drainage fields have poor water retention and fertilizer retention capacity,which restricts the process of ecological restoration.In order to investigate the effects of biochar and water retention agent on the soil water characteristics and enzyme activities of vermiculite soil,13 soil treatment experiments were carried out,which were blank control without adding biochar and cross-linked polyacrylamide water retention agent(CK),four biochar treatments of BI1,BI2,BI3,and BI4(the added mass ratio of biochar is 1%,2%,4%,8%),and four water retention agents treat CLP1,CLP2,CLP3,and CLP4(water retention agent)The added mass ratio is 0.01%and 0.02%,0.04%,0.08%),and four biochar and water retaining agent are mixed and added to process BC1,BC2,BC3,BC4.The research results are as follows:(1)The soil bulk density of the biochar-added vermiculite soil matrix decreased significantly,and the soil water content,soil organic matter and oxidizable carbon content increased with the increase of biochar addition ratio;the soil of the vermiculite soil matrix supplemented with CLP water retention agent The bulk density decreased,and the overall soil water content increased with the increase of the added amount.(2)The addition of biochar and CLP water retention agent can significantly increase the saturated water content of the vermiculite soil matrix,the capillary water holding capacity and the field water holding capacity.The cumulative infiltration of 4%and 8%biochar was 33%and 22%higher than that of the control group,which was beneficial to water infiltration.The addition of 1%and 2%biochar was more conducive to water retention.The cumulative infiltration of vermiculite soil matrix with 0.01%,0.02%,0.04,and 0.08%water retention agent was 18%,14%,26%,and 9.7%lower than that of the control group,which effectively inhibited the infiltration process of vermiculite soil matrix.Although the treatment with the added material was higher than the cumulative evaporation of the control group,the soil moisture content was still higher than the control group.In the cluster analysis,it is concluded that the effect of adding biochar and adding appropriate amount of water retaining agent on soil water retention and evaporation characteristics is equivalent to the effect of applying higher level of biochar.(3)Adding biochar and water retention agent can improve the soil enzyme activity of vermiculite soil matrix to a certain extent.Among them,8%biochar-added vermiculite soil matrix?-glucosidase,alkaline phosphatase and cellobiose hydrolysis The enzyme and dehydrogenase activities were increased by 19%,71%,59%,and 53%,respectively,compared with the control group.This is mainly related to a significant increase in soil water content,soil organic matter,and easily oxidizable carbon content.In summary,biochar and CLP water retention agents have certain effects on increasing the porosity of vermiculite soil matrix,increasing soil organic matter content,increasing soil water content and changing soil infiltration characteristics.In addition,biochar and CLP water retention agents can improve soil enzyme activity while improving the water characteristics of the vermiculite soil matrix.The addition of these two improved materials can improve the properties of the vermiculite soil matrix and have a certain guiding effect on the soil construction of the meteorite mountain ecological restoration.