生物炭和秸秆施用对复配土壤物理性状及团粒结构的影响

Effects of biological carbon and straw on physical properties and aggregate structure of compound soil

为了探明生物炭和秸秆施用对砒砂岩与沙复配土壤物理性状和团粒结构的影响,进而为复配土壤的结构改良提供理论依据。通过盆栽试验,选取砒砂岩与沙(1∶2)复配土壤作为研究材料,设置4个处理(CK:复配土;T1:复配土添加5%的生物炭;T2:复配土添加5%的秸秆;T3:复配土添加2.5%生物炭+2.5%秸秆),3个重复进行试验,对复配土壤的容重、田间持水量和团粒结构进行研究。结果表明:(1)各处理和空白对照CK相比,均显著降低了复配土壤容重,提高了复配土壤的田间持水量,其中T3对复配土壤容重和田间持水量的影响程度明显强于T1和T2;(2)各处理表层土壤R_(0.25)含量均优于空白对照CK,其中T3对复配土壤DR_(0.25)和WR_(0.25)含量影响显著,T1和T2仅对复配土壤WR_(0.25)含量影响显著;(3)干筛和湿筛下,各处理复配土壤平均重量直径(MWD)和平均几何直径(GMD)的大小顺序为:T3>T2>T1,T3处理对两者的影响程度均达到了显著水平。生物炭和秸秆还田混合施用更加有利于促进复配土壤结构的改善和团粒结构的增加。

In order to explore the effect of biochar and straw on the physical properties and aggregate structure of compound soil,and provide the theoretical basis for improvement of compound soil structure.We choose sandstone/sand(1∶2)compound soil as research material by pot experiments,setting four treatments(CK:compound soil;T1:compound soil with 5%biochar;T2:compound soil with 5% straw;T3:compound soil with 2.5% biochar and 2.5%straw)and three repetitions for studying.The results showed that:(1)Compared with CK,every treatment all reduced the bulk density and improved field water holding capacity of compound soil,among them,the effect of T3 was significantly higher than the treatment of T1 and T2;(2)Every treatment's content of R_(0.25) in surface soil was better than CK,and T3 had significant effect on the content of DR_(0.25) and WR_(0.25) in compound soil,T1 and T2had significanteffect on the content of WR_(0.25) in compound soil;(3)The order of mean weight diameter(MWD)and geometric mean diameter(GMD)of compound soil treated by dry sieve method and wet sieve method was T3>T2>T1,and the effect of T3 on both of them reached a significant level.The combined application of biochar and straw returning was more conducive to the improvement of soil structure and the increase the aggregate structure.