腐植酸肥料对生姜土壤微生物量和酶活性的影响

设4个处理:空白对照、等量腐植酸、等量无机养分和腐植酸复合肥.通过小区试验,研究了腐植酸肥料在生姜不同生育时期对土壤微生物量和3种重要酶活性的影响.结果表明:与不施肥处理比较,施用腐植酸使前期的微生物量碳增加、脲酶活性降低,后期的微生物量碳减少、脲酶活性提高；施用腐植酸增加土壤活跃微生物量、提高酸性磷酸酶活性、降低蔗糖酶活性,全生育期平均土壤活跃微生物量和酸性磷酸酶活性分别提高17.34%和11.40%、蔗糖酶活性降低10.57%.与施用等量无机养分处理比较,施用腐植酸复合肥也使前期的微生物量碳增加、脲酶活性降低,后期的微生物量碳减少、脲酶活性提高；施用腐植酸复合肥增加土壤活跃微生物量、提高酸性磷酸酶和蔗糖酶活性,全生育期平均土壤活跃微生物量、酸性磷酸酶和蔗糖酶活性分别提高18.61%、10.07%和7.61%.

Microbial and enzyme activity in response to humic acid in soil with a ginger crop

This field study was conducted to investigate the effect of humic acid on microbial and the activities of three enzymes in the soil where gingers (Zingiber officinale Rose) were grown. Soil was subjected to four fertilizer regimes: control, humic acid only (19.6g/m2), inorganic nutrient (45.0 g N/m2, 15.0 g P2O5/m2, and 60.0 g K2O/m2), and humic acid compound (45.0 g N/m2, 15.0 g P2O5/m2, 60.0 g K2O/m2 and 19.6g humic acid/m2). Microbial carbon level was greater during the early experimental period, but lower during the late experimental period in humic acid only versus the control and in humic acid compound versus nutrient treatment. Urease activity level was lower during the early experimental period, but greater during the late experimental period in humic acid only versus the control and in humic acid compound versus nutrient treatment. When data were averaged over the entire experimental period, humic acid only treated soil exhibited a 17.3% higher active microbial carbon level, 11.4% higher acid phosphatase activity, and 10.6% lower invertase activity. than the control. Soil treated with the humic acid compound had 18.6% higher active microbial carbon level, 10.1% higher acid phosphatase activity and 7.6% higher invertase activity than inorganic nutrient treatment, when data were averaged over the entire experimental period.