马铃薯淀粉加工废水还田对土壤氮磷钾迁移转化的影响

Effects of Returning Potato Starch Processing Wastewater to Soil on Nitrogen,Phosphorus,and Potassium Migration in Soil

选取固原市某淀粉厂试验基地,对其有机废水还田种植作物后,连续2年采取土样分析土壤耕作层(0~30 cm)肥力变化和土壤剖面(30~60、60~90 cm)氮磷钾迁移规律。结果表明,施用马铃薯淀粉有机废水还田,还田量在600~900 m^3/hm^2时,能明显提高土壤耕作层中有机质、全氮、有效磷、速效钾含量,使土壤耕作层中全氮、有效磷、速效钾养分等级从Ⅲ级提高到Ⅰ级,有机质提高到Ⅲ级。有机废水还田量为600 m^3/hm^2时,30~60和60~90 cm剖面中氮元素无明显迁移趋势。超过900 m^3/hm^2时,在30~60和60~90 cm^2个剖面氮元素有明显迁移变化。随着还田量、还田和耕作次数的增加,氮元素向下迁移量增加。施用600 m^3/hm^2有机废水还田,土壤中磷和钾元素已经开始向下迁移。且随着还田量、还田和耕作次数的增加,磷和钾元素向下迁移越明显。在向下迁移过程中,有效磷和速效钾有逐渐转化为矿化磷和矿物质钾的固化趋势。

In this experiment,a starch plant test base in Guyuan was selected.After the organic wastewater was returned to the field,soil samples were taken to analyze the fertility changes of the soil tillage layer(0-30 cm)and the nitrogen,phosphorus,and potassium migration in the soil profile(30-60,60-90 cm).The results showed that when the potato starch organic wastewater was returned to the field and the return amount was in the range of 600-900 m^3/hm^2,the content of organic matter,total nitrogen,available phosphorus,and available potassium in the soil tillage layer could be significantly increased.The levels of available phosphorus,available phosphorus,and available potassium nutrients were increased from Ⅲ to Ⅰ,and organic matter was improved to Ⅲ.When the amount of organic wastewater returned to the field was 600 m^3/hm^2,the nitrogen element in the 30-60 and 60-90 cm had no obvious migration trend.When it exceeded 900 m^3/hm^2,the nitrogen elements in the 30-60 and 60-90 cm sections had obvious migration changes.With the increase in the amount of returning fields,the number of returning fields and the number of tillages,the downward migration of nitrogen increased.When 600 m^3/hm^2 of organic wastewater was returned to the field,the phosphorus and potassium elements in the soil began to migrate downward.And with the increase of the amount of returning fields,the number of returning fields and the number of tillages,the downward migration of phosphorus and potassium elements became more obvious.In the downward migration process,available phosphorus and available potassium had a tendency to solidify into mineralized phosphorus and mineral potassium.