追施沼液对冬小麦根际土壤生物活性的影响

为给沼液的科学施用提供理论依据,在大田条件下用沼液作追肥,研究了不同沼液追施水平时冬小麦根际土壤微生物数量和酶活性的影响.结果表明,随着生育时期的推进,小麦根际土壤微生物数量及土壤脲醇和蛋白酶活性均呈"V"字形变化趋势,但不同指标处于谷值的时期存在差异.适宜沼液追施量能显著增加土壤微生物数量和提高土壤脲酶活性,且以120 kg·hm-2沼液追施量(均以沼液态纯氮计,下同)效果最好;蛋白酶活性以60kg·hm-2沼液追施量表现最高,其与120 kg·hm-2液追施量比较差异不显著.根际过氧化氢酶活性随生育时期呈"S"形变化,沼液追施量与过氧化氢酶活性整体呈负相关.

Effect of Topdressing Amount of Biogas Slurry on Soil Microorganisms and Enzyme Activities in Winter Wheat

To investigate the optimum topdressing rate of biogas slurry for good quality and high yield of winter wheat, an experiment was conducted using biogass slurry as topdressing fertilizer to study effect of different levels of topdressing rate on microorganism quantity and enzyme activity in rhizosphere of wheat field during 2008~2009. The result indicated that the quantity of microorganism and activities of soil urease and prolease changed in the form of V type during wheat growth, and there was an obvious difference in the stages with valley value for different indicators. Topdressing of biogas slurry could effectively increase the quantity of soil microoganisms and improve the activities of urease and prolease, with the optimum rate being 120 kg·hm^-2 for the quantity of soil microoganisms and the activities of urease, and 60 kg·hm^-2 for the activity of prolease. Moreover there was no significant difference between 60 kg·hm^-2 and 120 kg·hm^-2 of biogas slurry for activity of prolease. The activity of catalyse changed in the form of S type during wheat growth, and there was negatively correlation between activity of catalyse and topdressing rate of biogas slurry.