Abstract:

In order to explore the effects of straw and microbial fertilizer on the salt content of soil and crops in saline-alkali soil,the experiment was conducted in Dalat Banner,Inner Mongolia.Four treatments were set up:no straw and no microbial fertilizer(CK),single application of straw(G),single application of microbial fertilizer(F)and combined application of straw and microbial fertilizer(GF).Four crops,oat,sorghum hybrid sudangrass,proso millet and oil sunflower,were planted,respectively.The effects of straw and microbial fertilizer on salt ion concentration and salt content of soil and crops in saline-alkali soil were analyzed.The results showed that compared with CK,straw combined with microbial fertilizer could significantly reduce soil salt content,increase crop biomass and salt ion accumulation in crops,and the soil total salt content in the soil planted with oil sunflower was the lowest at 4 400.41 mg/kg,which was significantly reduced by 13.85% compared with CK.Crop biomass and salt ion accumulation of sorghum hybrid sudangrass treated with straw combined with microbial fertilizer were the largest,and the biomass and salt ion accumulation were increased by 68.32% and 108.28% compared with CK,respectively.In addition,straw combined with microbial fertilizer enhanced the selective absorption ability of each crop for salt ions.Under combined treatment,oat had stronger absorption ability for Mg²⁺,Cl^- and {{\mathrm{SO}}_4}^{2-},which were 50.51%,72.74% and 56.39% higher than CK,respectively.The selective absorption capacity of Ca²⁺ was 76.01% higher than that of CK.Oil sunflower mainly absorbed K⁺,and its content was 12.90% higher than CK.In conclusion,straw combined with microbial fertilizer could significantly improve crop biomass,salt ion accumulation and salt ion selective absorption ability,and could effectively reduce the total salt content of saline-alkali soil.Among the 4 crops,sorghum hybrid sudangrass and oil sunflower perform better.

Key words: Straw, Microbial fertilizer, Saline alkali land, Soil salinity, Crop salt ion