Abstract:In the cultivation,the essential material is soil,which plays a decisive role in the growth of the whole crop.Soil replacement and directional fertilization are the key technologies to improve soil nutrients.In order to study the influence of soil replacement and fertilization on soil nutrients of calcareous chernozem,this paper takes a certain block of Heilongjiang Province (calcareous chernozem) as the research object,and takes 0-20 cm soil and20-40 cm soil as the research object.After one year of soil replacement,three consecutive years of directional fertilization treatment was carried out to explore the effect of soil replacement on nutrient content and effectiveness of calcareous chernozem;with no soil replacement as control (CK),further soil replacement (T1),soil replacement+straw(T2),soil replacement+500 kg dried chicken manure (T3),soil replacement 40%theoretical phosphorus fertilizer application amount (T4) were carried out for calcareous chernozem.In order to study the effects of different fertilization conditions on the effectiveness of directional cultivation of soil layer replacement,four methods were used as experimental groups.The results show that the content of available N,P,K and TOC in calcareous chernozem will decrease after soil layer replacement only.In the comparison of soil layer replacement and directional cultivation,it was found that the effect of soil layer replacement+500 kg/667 m2 drying chicken manure was the best,and the content of available nitrogen,phosphorus,potassium and total organic carbon in calcareous soil increased the most.The application of soil replacement and directional fertilization technology can significantly improve the nutrient content of calcareous chernozem,improve the effectiveness of nutrients,and provide a good soil environment for crop growth.