关键词: 长期施用沼液, 土壤养分含量, 土壤酶活性, 养殖企业

Abstract: In order to find out the effect of different application years of biogas slurry on soil nutrient content and enzyme activity，11 treatments with different amount and years of biogas slurry applied were designed according to the source of biogas slurry（breeding enterprises），and the nutrients contents and enzymes activities of soil applied with biogas slurry and the control soil without biogas slurry were studied. The results showed that the contents of organic matter（OM），total nitrogen（TN），total phosphorus（TP）and total potassium（TK）of biogas slurry were relatively low，OM contents were 0.03—0.94 g/L，the average was 0.26 g/L；TN contents were 0.30—2.60 g/L，the average was 1.27 g/L；TP contents were 0.04—0.38 g/L，the average was 0.19 g/L；TK contents were 0.40—1.98 g/L，the average was 0.94 g/L；pH values were 7.40—8.59，the average was 8.11. Long⁃term application of biogas slurry changed pH value to be conducive to soil nutrient release，and increased the nutrients contents in the soil tillage layer.Compared with the control，the OM contents increased by 0.96%—367.11%，TN contents increased by 2.15%—600.00%，TP contents increased by 29.94%—663.27%，and the treatment with 900—1 050 t/ha biogas slurry produced by Henan Kanglong Industrial Group Co.，Ltd. applied for 21 years had the biggest increase range；TK contents increased by 1.14%—28.10%，and the treatment with 900—1 050 t/ha biogas slurry produced by Henan Youlin Industrial Co.，Ltd. applied for 5 years had the biggest increase range；available phosphorus（AP）contents increased by 26.76%—593.99%，hydrolyzed nitrogen（HN）contents increased by 7.49%—420.24%，and the treatment with 900—1 050 t/ha biogas slurry produced by Henan Kanglong Industrial Group Co.，Ltd. applied for 21 years had the biggest increase range；available potassium（AK）contents increased by 15.48%—103.30%，and the treatment with 900—1 200 t/ha biogas slurry produced by Henan Yifa Animal Husbandry Co.，Ltd. applied for 27 years had the biggest increase range. Long⁃term application of biogas slurry significantly increased the activities of soil hydrolase and oxidoreductase. Compared with the control，the protease activities increased by 9.20%—44.69%，sucrase activities increased by 6.41%—41.91%，urease activities increased by 14.47%—42.58%，acid phosphatase activities increased by 13.03%—44.44%，cellulase activities increased by 2.77%—44.65%，nitrate reductase activities increased by 22.00%—54.38%，nitrite reductase activities increased by 1.41%—42.17%dehydrogenase activities increased by 4.94%—47.44%，catalase activities increased by 1.42%—47.67% respectively. There were significantly or extremely significantly positive correlations between soil nutrients contents and enzymes activities. The contents of soil OM，TN，TP，TK，HN，AP and AK were extremely significantly positively correlated with the activities of dehydrogenase and catalase；the contents of TN，HN，AP were extremely significantly positively correlated with the cellulase activity；the contents of OM，AK were significantly positively correlated with the cellulase activity.

Key words: Long?term application of biogas slurry, Soil nutrient content, Soil enzyme activity, Breeding enterprise