施肥制度对川中丘陵区玉米不同生育期土壤反硝化酶活性的影响

Effects of Fertilizer System on Soil Denitrification Enzyme Activity at Different Growth Stages of Maize in Hilly Regions of Middle Sichuan

通过对川中典型紫色土区玉米坡耕地进行不施肥(CK)、单施氮肥(N)、单施有机肥(OM)、NPK肥配施(NPK)、有机肥+NPK肥配施(OMNPK)和秸秆+NPK肥配施(RSDNPK)6种施肥处理,测定了玉米拔节期、灌浆期和成熟期土壤硝酸还原酶(NR)、亚硝酸还原酶(NiR)和羟胺还原酶(HyR)活性。结果表明,在玉米拔节期、灌浆期和成熟期,N、OM、NPK、OMNPK和RSDNPK处理均提高了土壤NR、NiR和HyR活性,且RSDNPK和OMNPK处理的效果最好。这表明,秸秆+NPK肥配施和有机肥+NPK肥配施能有效提高紫色土区坡耕玉米地土壤NR、NiR和HyR活性,能有效提高作物对氮元素的利用率。

The six kinds of fertilizer system are as follows. N （N）, organic manure （OM）, mixture of N, P and K （NPK）, organic manure combined with N, P and K （OMNPK）, and straw combined with N, P and K （RSDNPK）. The fertilizer of each treatment was applied in the soil at different growth stages of maize. The experiment plots are located at the slope land of typical purple soil area in Middle Sichuan. The activities of soil nitrate reductase, nitrite reductase and hydroxylamine reductase at the jointing stage, the filling stage and the maturity stage of maize were determined. The results showed that the activities of nitrate reductase, nitrite reductase, and hydroxylamine reductase increased in the treatments of N, OM, NPK, OMNPK and RSDNPK, and the best treatments for enzymatic activity were RSDNPK and OMNPK. It suggested that RSDNPK and OMNPK could have better advantages to improve the activities of nitrate reductase, nitrite reductase and hydroxylamine reductase at the slope land of purple soil area in Middle Sichuan, and enhance the as similation rate of N by crops.