氮素营养水平对小麦根际微生物及土壤酶活性的影响

在大田高产栽培条件下．研究了不同施氮水平对豫麦49-198根际微生物和土壤酶活性的影响。结果表明：豫麦49-198根系土壤蛋白酶活性和脲酶活性随生育时期推进均呈先上升后下降的变化趋势．蛋白酶活性、脲酶活性分别在拔节期和返青期达到最大值。在同一生育时期内，随着施氮水平的提高，蛋白酶活性呈先增加后降低的变化趋势．其中以N2（180kg／hm^2）处理的蛋白酶活性最高，但N4（360kg／hm^2）处理的蛋白酶活性仍大于对照N1（0kg／hm^2）；脲酶活性随施氮水平的提高呈上升趋势．以N4（360kg／hm^2）处理的脲酶活性最大。根际微生物总量随生育时期推进呈先增加后下降的趋势，在孕穗期达到最大值．开花期略有降低；在同一生育时期．随着施氨水平的提高，根际微生物数量呈先增加后下降的趋势，以N3（270kg／hm^2）处理的根际微生物总量最高．且各处理之间的差异都达到了显著水平。

Effect of Nitrogen Fertilizer on Soil Enzymatic Activity and Rhizosphere Microorganisms of Wheat

The effect of nitrogen fertilizer on soil enzymatic activity and rhizosphere microorganisms of Yumai 49 -198 root system was studied in this paper, The results indicated that the activity of the soil protease and urease of Yumai 49-198 increased with the growth period then descending, Protease activity reached its peak period up to jointing stage, Urease activity reached its peak period up to seedling establishment. The activity of the soil protease increased with nitrogen fertilize treatment and reached its peak on N2 level treatment. Urease activity increased with nitrogen fertilizer treatment and reached its peak on N4 treatment. Rhizosphere microorganisms increased with the growth period then descending and reached the peak up to flowering period. The results also showed that the population quantity of rhizosphere microorganisms increased with different nitrogen treatment then descending. On N3 level treatment, the quantity of rhizosphere microorganisms attained the highest value. The difference between treatments is significant.