连续施用农业废弃物组合肥制种玉米田理化性质及酶活性和重金属变化特征

在甘肃省进行了连续4 a施用农业废弃物组合肥制种玉米田理化性质及酶活性和重金属变化特征研究。 结果表明：农业废弃物组合肥施用量比例为秸秆组合肥18 t·hm^-2∶畜禽粪便组合肥36 t·hm^-2∶废渣组合肥15 t·hm^-2。施用农业废弃物组合肥4 a与不施肥比较，制种玉米田容重、pH值和真菌数量分别降低6.77%、6.20%和26.19%；总孔隙度、水稳性团聚体、总持水量、EC值、可溶性盐和CEC分别增加6.63%、18.95%、6.62%、5.23%、5.36%和36.10%；有机质、有机碳、有机碳密度、碱解氮、速效磷和速效钾含量分别增加23.72%、24.10%、15.48%、28.44%、49.92%和27.97%；细菌数量、放线菌数量、蔗糖酶、 脲酶、磷酸酶和多酚氧化酶活性分别增加38.20%、86.60%、63.46%、38.89%、61.48%和58.82%；Hg、Cd、Cr、Pb和Zn含量分别增加21.74%、30.00%、24.49%、27.55%和31.81%。农业废弃物组合肥施用年限与制种玉米田容重、pH值和真菌数量之间呈显著负相关关系，与总孔隙度、水稳性团聚体、CEC、EC值、可溶性盐、总持水量、有机质、有机碳密度、速效氮磷钾含量、细菌数量、放线菌数量、酶活性、重金属含量之间呈显著正相关关系。 虽然连续4 a施用农业废弃物组合肥重金属含量比不施肥高，但重金属含量小于土壤污染临界值，说明研究区域农业废弃物组合肥重金属含量较低，不会对作物造成风险。

Characteristics of physicochemical properties, enzyme activities and heavy metal changes of seed maize field under continuous application of agricultural waste compost

Physical and chemical properties, enzyme activities and heavy metal changes in the seed production maize field of Gansu Province applied with agricultural waste compost for 4 years were studied. The results showed that the dosage ratio of agricultural waste was 18 t·hm^-2 in straw group, 36 t·hm^-2 in livestock and poultry manure group, and 15 t·hm^-2 in waste residue group. In addition, the bulk density, pH value and fungus quantity of maize seed production group decreased by 6.77%, 6.20% and 26.19% compared with that without the waste compost. Total porosity, water\|stable aggregate, total water holding capacity, EC value, soluble salt and CEC increased by 6.63%, 18.95%, 6.62%, 5.23%, 5.36% and 36.10%. The contents of organic matter, organic carbon, organic carbon density, alkali\|hydrolyzed nitrogen, available phosphorus and available potassium increased by 23.72%, 24.10%, 15.48%, 28.44%, 49.92% and 27.97%. The number of bacteria, actinomycetes, activities of sucrase, urease, phosphatase and polyphenol oxidase increased by 38.20%, 86.60%, 63.46%, 38.89%, 61.48% and 58.82%; The contents of Hg, Cd, Cr, Pb and Zn increased by 21.74%, 30.00%, 24.49%, 27.55% and 31.81%. Agricultural waste compost using fixed number of years with seed corn field bulk density, pH value and the number of fungi was significantly negatively correlated, and the aggregate total porosity, water stability, the soluble salt, CEC, EC value, the total water holding capacity, organic matter, organic carbon density, available N,P,K content, number of bacteria, actinomyces, enzyme activity, heavy metals contentwas significantly positively correlated. Although the heavy metal content of maize field with agricultural waste compost was higher than that without the waste compost for 4 consecutive years, the heavy metal content was lower than the critical value of soil pollution, indicating that the heavy metal content of maize field with agricultural waste compost in the study area was low and would not pose a risk to crops.