花椰菜残留物氮矿化及其对下茬蔬菜产量及氮吸收的影响

在3种不同施氮历史的露地菜田中，进行了花椰菜残留物翻压试验，对残留物中氮矿化及其对土壤无机氮含量、下茬蔬菜产量及氮营养状况等的影响进行了研究。研究结果表明，试验期间，3种不同施氮历史的处理中，残留物中氮矿化率分别达161．2％，78．8％和73．8％。残留物的施用不同程度地增加了土壤N win含量，但其对下茬苋菜产量、氮吸收的影响因氮处理的不同而有很大差异。在土壤氮水平高的Nt处理中，施用残留物对苋菜产量及氮素吸收量没有明显影响；而在土壤氮水平较低的Nt及Nr’处理中，残留物的施用显著提高了苋菜产量及氮素吸收量。

N Mineralization of Cauliflower Residues and It's Effects on Yield and Nitrogen Uptake of Vegetables

N mineralization of cauliflower residues and it's effects on soil mineral N content, N nutrition and yield of vegetable (Amaranthus spp. )was studied in field. Three nitrogen treatments were included, such on Nt, Nr and Nr'.The N mineralization of cauliflower residues were 161.2%, 78.8% and 73.8% respectively for the three nitrogen treatments. The application of cauliflower residues increased soil Nmin concentration. However, it' s effects on yield and nitrogen uptake by amaranth vary among differnet nitrogen treatments. In Nt treatment with high N level, the application of residues has no significant effects on amaranth yield and nitrogen uptake, but in Nr and Nr' treatment with low N level, the application of residues significantly increased the yield and nitrogen uptake by amaranth.