Effect of bentonite on soil fertility and active organic carbon in Horqin sandy land
Bentonite has a large specific surface area and strong adsorption capacity,as so as has excellent water and fertilizer retaining and ion exchange capacity.The effect of bentonite types on the accumulation of active organic carbon and fertility in wind-sand soil is not clear.In this paper,in order to study the changes of soil fertility and active organic carbon components under different types and application amounts of bentonite,a pot experiment was conducted by using Poa pratensis L.as plant material,and Horqin sandy soils as the substrate,and then sodium-based bentonite and calcium-based bentonite in three application amounts were added on the basis of application of fertilizer and charcoal.The results showed that compared with control,bentonite with different application types and amounts significantly improved the soil integrated fertility index(IFI),total organic carbon content and contents of various components of active organic carbon,of which the best effect was achieved when the amount of bentonite applied was 3.Okg/m2.Correlation and redundancy analyses showed that the application of 3.Okg/m2 sodium-based bentonite and 3.Okg/m2,4.5kg/m2 calcium-based bentonite,is significantly positively correlated with soil IFI,total organic carbon content,and contents of various active organic carbon.There is a highly significant positive correlation between total organic carbon(especially microbial biomass carbon)and IFI.The above results indicate that bentonite can significantly promote the accumulation of active carbon in soil,improve soil fertility,and there by affect soil microecological environment and carbon cycling.The amount of bentonite is a key regulatory factor for ecological restoration of sandy soil,while the type of bentonite is not an important determining factor.
Na-bentoniteCa-bentoniteHorqin sandsoil active organic carbonintegrated fertility index
NETL
NSTL
万方数据
