Difference and assessment in microbial characteristics of lime concretion black soil affected by long-term fertilization Biological factors influencing nitrogen transformation in wheat fields of lime concreted black soils and their response to different nitrogen supplications Study on fertilization techniques for strong gluten wheat in lime concretion black soil Effects of combined straw and N application on the physicochemical properties of lime concretion black soil and crop yields Effects of fertilization and straw incorporation on bacterial communities in lime concretion black soil Effects of different stable organic matters on physicochemical properties of lime concretion black soil and maize yield