抑制剂和水分对铵态氮肥在喀斯特地区土壤中迁移规律的影响OACSTPCD

The effects of urease inhibitors(NBPT)and nitrification inhibitors(DMPP)on the migration and transformation of four ammonium nitrogen fertilizers,including ammonium bicarbonate,ammonium sulphate,ammonium chloride as well as urea,in karst soils with varying moisture contents were studied by the means of indoor soil column incubation experiments.The results showed that compared to applying ammonium nitrogen fertilizer alone,the application of inhibitors had a significant impact on the migration of various ammonium nitrogen fertilizers in karst soil,and soil moisture significantly affected the distance of nitrogen migration.Ammonium bicarbonate,and ammonium sulfate,ammonium chloride,all showed the highest conversion rates under soil moisture content of 30%,reaching 16.42%,37.98%,and 40.41%,respectively.It can significantly increase the content of soluble inorganic nitrogen in soil and promote the migration of inorganic nitrogen to deeper soil layers.The conversion rate of urea combined with DMPP was the highest at 50%soil moisture content,with a conversion rate of 10.68%.The conversion rates of ammonium bicarbonate,ammonium sulfate,and ammonium chloride were 8.64%～16.42%%,24.32%～37.98%%and 27.91%～40.41%%,respectively.The conversion rates actually decreased with the increase of soil moisture content.The conversion rate of urea was 2.63%～10.68%%,which increased with the increase of soil moisture content.In conclusion,when ammonium nitrogen fertilizer was applied in karst soils,adding nitrification inhibitor could extend the migration distance of nitrogen fertilizer in the soil,increase the soluble inorganic nitrogen and the conversion rate,reduce nitrogen loss and increase soil nutrients.