南方红壤旱坡地花生植株对施用氮肥的响应

选用多年夏花生-冬蔬菜种植制度下的典型红壤旱坡地,通过田间试验,研究了5种氮肥水平下花生根系的形态特征、固氮能力、植株生物量以及荚果产量。结果表明:不同氮肥施用量对花生植株生物量及荚果产量影响均不显著(P=0.091);而不同处理的土壤固氮酶活性与氮肥施用量间呈极显著的负相关(R2=0.88,P=0.005);单株花生根系总长度、总表面积、总分叉数及根尖条数均随氮肥施用量的增加而减小,且与单株花生根瘤生物量呈极显著(P<0.001)正相关。

Responses of peanut plants to chemical N application rate on sloping upland red soil of southern China

A field experiment was conducted on a typical sloping upland red soil to study the root morphology,nitrogen fixation,biomass,and pod yield of peanut plants under five levels of chemical N application rate.On this soil,the cropping system summer peanut-winter vegetable has been carried out for many years.The results showed that N application rate had no significant effect on the total biomass and pod yield of peanut plants(P=0.091),but had significant negative effect on the special actetylene reduction in soil(R2=0.88,P=0.005).The total length,total surface area,and the numbers of branches and tips of peanut roots decreased significantly with increasing N application rate,and had significant positive correlation with nodule biomass(P<0.001).