不同肥力水平大棚土壤氮素转化的研究

取不同肥力水平的大棚土壤16份,同时取棚外粮田土壤作为对照,就土壤氮素转化速率、酶活性进行分析研究,探讨不同肥力水平大棚土壤氮素的矿化速率及土壤细菌数量和土壤脲酶、蛋白酶、转化酶的活性。研究结果表明,在0~7 d,处理2的矿化速率最高,达4.84 mg/kg,与处理1的矿化速率4.15 mg/kg相比,差异达显著水平;处理1的转化酶活性最高,达7.64 mg/g,与处理2的4.92 mg/g相比,差异达显著水平;处理2的细菌菌数最高,为10.76×108个/g,与处理1的8.57×108个/g相比,差异达显著水平。大棚土壤的矿化作用强烈,土壤酶活性较高,但有机质和速效养分过高时对氮素转化及土壤酶活性有抑制作用。

Study on Nitrogen Transformation of Various Fertilities Soil in Greenhouse

16 soil samples of varions fertilities from greenhouse for the comparison of soil from the outdoor crops fields to analyses the nitrogen transformation speed and the enzyme activity to study the soil nitrogen mineralization rates,soil bacterium quantity and urease, proteinase, invert enzyme activity in greenhouse soil of various fertilities. The results indicated that, in 0-7 d, mineralization rates were the highest in treatment 2 , which reached 4.84 mg/kg. Compared with 4.15 mg/kg in treatment 1, it reached the remarkable level. Invert enzyme activity in treatment 1 （ 7.64 mg/g ） was the highest, compared with treatment 2 （4.92 mg/g） ,which reached the remarkable level. Bacteria number in treatment 2 （ 10.76 × 108^8/g ） was the highest, compared with treatment 1 （8.57 × 10^8/g） , which reached the remarkable level. The soil mineralization and nitrification are intense, the soil enzyme activity is high, but when the content of OM and available nutrient are too much, the nitrogen transformation and the soil enzyme activity were inhibited.