Effects of straw returning on brown soil properties and nutrient content
To improve the quality of brown soils and better achieve the straw recycling,typical brown soils in Liaoning was selected to explore the effects of 7 straw returning methods(including no straw addition,crushed-straw returning,biochar returning,cow manure returning,crushed-straw cow manure returning,crushed-straw & biochar returning,cow manure biochar returning)on the properties and nutrient content of brown soils.The results showed that soil pH and total nitrogen content increased significantly after 18 months post returning than those of 2 months post returning,while soil bulk density,total phosphorus,available nitrogen and microbial biomass phosphorus content decreased significantly by 7％,51％,88％and 86％,respectively.Compared with other returning methods,crushed-straw returning significantly increased the soil total nitrogen content;cow manure returning significantly increased soil total phosphorus,available nitrogen,microbial biomass phosphorus and soil water content;biochar returning significantly increased soil total phosphorus content,but decreased soil bulk density and total nitrogen content;crushed-straw & biochar returning significantly increased soil water content but decreased soil pH;crushed-straw cow manure returning significantly increased soil water content but decreased soil bulk density;cow manure & biochar returning significantly reduced the soil bulk density.The relationship between soil water content,pH and soil phosphorus components was closer after 2 months post returning.Only soil organic carbon had significant influence on soil total nitrogen content after 18 months post returning.This study indicates that short-term cow manure returning could have the greatest effects on soil properties and nutrient content,and could be used as an effective means to improve soil quality and increase soil nutrient content in the short term.
万方数据
维普
