菜地土壤氮素矿化和硝化作用的特征

采用培养试验对南京郊区 6 对菜地土和水稻土的土壤 N 素矿化和硝化作用特征进行了研究。菜地土为相同类型水稻土改种蔬菜约 20 年的土壤。结果表明,培养 28 天期间,6 对供试土壤中有 4 对土壤都是菜地土壤矿化 N 量低于相同类型水稻土,其日矿化速率也低于相应的水稻土,而其他 2 对供试土壤之间无明显差异。大多数菜地土的土壤硝化率低于相应的水稻土。培养28 天时的矿化率和硝化率与土壤 pH、速效 P 呈显著相关。

CHARACTERISTICS OF NITROGEN MINERALIZATION AND NITRIFICATION IN VEGETABLE GARDEN SOILS

Characteristics of N mineralization and nitrification in six pairs of garden soils and paddy soils gathered from the suburbs of Nanjing, were investigated in a 28-day incubation experiment. The garden soils were formerly paddy soils about 20 years ago. Results show that after 28 days'' incubation, in four of the six pairs, garden soils were lower than the paddy soils in N mineralization, both quantity and rate, and the other two showed little difference. Following urea application, in 5 of the 6 pairs, garden soils were lower than paddy soils in N nitrification rate. Moreover, soil N mineralization and nitrification rates were significantly related to soil pH and soil available P content.