Effects Of Different Organic Materials On The Soil Fertility Of New Terraced Fields In The East Of Jilin Province

It is an important measure to reduce soil erosion and nutrient losses in the field for changing the slope to terrace now.In order to rapidly improve the soil fertility of new terraces,optimal fertilization measures should be taken.This experiment was conducted at “changing the slope to terrace” farmland,applying 3 organic materials:biochar,crushed maize straw and decomposed chicken manure respectively,with planting maize,soybean and alfalfa to discuss its influence on the physical and chemical properties,microbial activity and composition in the soil,and select the optimal fertilization measures that could quickly improve the soil fertility of new terraced field in the eastern part of Jilin Province.The main results were as follows:1.All treatments could increase soil total nitrogen,total phosphorus,total potassium,available nitrogen,available phosphorus,available potassium,and organic matter content.There were the best effect on increasing total phosphorus,total potassium,available phosphorus,and available potassium content in soil by applying biochar,the best effect on increasing soil total nitrogen and organic matter content and reducing soil bulk density of applying crushed straw,the best effect in improving soil available nitrogen content by applying decomposed chicken manure.2.In the treatment of planting alfalfa,applying biochar had the highest bacterial richness in the soil,and the soil bacterial richness of the organic materials treatment was significantly higher than that of only applying chemical fertilizer treatment.In terms of the relative abundance of soil bacteria,the proteobacteria phylum by applying biochar was greatest,,while the acid-bacterial bacilli of biochar was the lowest among the four treatments.3.By a soil fertility evaluation system established for this research,the treatment of applying biochar with planting soybean was the highest soil fertilityquality index,and the planting soybean was the best desirable way to improving soil fertility for newly-built terrace.