等氮滴灌对宿根蔗产量及土壤氧化亚氮排放的影响

为得到合理的水肥管理措施,研究等氮量下不同滴灌施肥比例对宿根蔗产量以及不同生育期蔗田土壤氧化亚氮(N2 O)通量和无机氮含量的影响,并分析蔗田土壤N2 O通量与无机氮含量之间的关系.该文以自然降雨W0为对照,设置2种滴灌灌水量水平W1(田间持水量的75％)和W2(田间持水量的85％),等量氮肥(N 300 kg·hm-...

Effects of fertigation under equal nitrogen on ratoon yield and nitrous oxide emissions in soil

In order to get reasonable water and fertilizer management measures, the effects of different fertigation proportions under the same nitrogen(N)rate on the yield of ratoon and nitrous oxide(N₂O)flux and inorganic N content in soil at the different growth stages were studied, the relationships between soil N₂O flux and inorganic N content were analyzed. Taking natural rainfall(W₀)as the control, two drip irrigation levels, W₁(75% of field water capacity)and W₂(85% of field water capacity)and four fertigation proportions at the same N rate(N 300 kg·hm^-2), F₁₀(100% basal fertilizer), F₅₅(50% basal fertilizer, 50% fertigation topdressing), F₃₇(30% basal fertilizer, 70% fertigation topdressing)and F₁₉(10% basal fertilizer, 90% fertigation topdressing)were designed. Agronomic traits(stalk weight, plant height, stalk diameter and effective stalks per hectare)and yield of sugarcane, the N₂O flux and the contents of nitrate, nitrite and ammonium nitrogen in soils at the three growth stages were determined. The results were as follows:(1)The ratoon yields in W₁F₅₅ and W₂F₅₅ were higher, i.e. 102.4 t·hm^-2 and 97.8 t·hm^-2, respectively; Soil N₂O emission flux in F₅₅ was lower under the same irrigation amount.(2)There was a significant negative correlation between soil N₂O flux and ammonium nitrogen content, with a correlation coefficient of -0.497(P<0.05, n=24); A reasonable fertilization proportion with drip irrigation can effectively increase sugarcane yield and reduce soil N₂O emission. Therefore, the treatment with a fertigation proportion of 5:5 under the same N rate can not only have a relatively high yield of ratoon, but also reduce the N₂O emission from the sugarcane soil.