施用猪粪对油麦菜产量、硝酸盐含量及土壤养分的影响

Effects of applying pig manure on lettuce yield and nitrate content and soil nutrients

应用盆栽试验方法,研究了施用猪粪对西南地区黄壤和紫色土中油麦菜产量、硝酸盐含量及土壤养分的影响.结果表明:施用猪粪能显著提高油麦菜产量,且黄壤中油麦菜增产幅度大于紫色土;油麦菜中硝酸盐、氮磷钾含量与土壤类型及猪粪施用量密切相关,以中国农业科学院制定的蔬菜中硝酸盐污染程度评价标准为依据,在紫色土对照(CK)及1倍猪粪(相当于施纯N 200 kg.hm-2)处理下油麦菜硝酸盐含量较低,符合一级标准(≤432 mg.kg-1,轻度污染);其他处理多超过二级标准(≤758 mg.kg-1,中度污染),但均未超过三级标准(≤1440 mg.kg-1,重度污染);黄壤中除化肥和8倍猪粪(相当于施纯N 1600 kg.hm-2)处理下油麦菜硝酸盐含量超过二级标准外,其他各处理均符合一级标准;黄壤和紫色土中表征磷素淋失风险的有效磷临界值分别为96.3和107.7 mg.kg-1.黄壤的猪粪环境安全容量较紫色土高.施用猪粪能显著提高两种土壤的有机碳和全氮含量.

A pot experiment with two representative soils （purple soil and yellow soil） in Southwest China was conducted to study the effects of applying pig manure on the lettuce （Lactctuca sativa L. var. capitata L. ） yield and nitrate content and the soil nutrients. Applying pig manure increased the lettuce yield significantly, and the increment was higher for yellow soil than for purple soil. The nitrate and total nitrogen, phosphorus, and potassium contents in lettuce plants were closely related to soil type and pig manure application rate. According to the evaluation standards of the nitrate pollution level of vegetables formulated by the Chinese Academy of Agricultural Sciences, the nitrate content in lettuce plants growing on purple soil was lower than the grade Ⅰ （≤432 mg·kg-1 , slight pollution） in treatments CK （no pig manure application） and M1（ applying 200 kg N·hm-2 of pig manure） , but generally higher than the grade Ⅱ （≤ 758 mg·kg-1, moderate pollution） while not exceeded the grade III（≤1440 mg·kg-1, heavy pollution） in other treatments. The nitrate content in lettuce plants growing on yellow soil was lower than the grade I, except that in the treatments of chemical fertilizations and of Ms（ applying 1600 kg N· hm-2 of pig manure） where the plant nitrate content was exceeded the grade II. The critical value of Olsen-P characterizing the apparent leaching risk level of phosphorous in yellow soil and purple soil was 96. 3 and 107.7 mg·kg-1 , respectively. The environmental safety capacity of pig manure was higher for yellow soil than for purple soil. Applying pig manure increased the organic carbon and total nitrogen contents of the two soils significantly.