控释掺混肥对夏玉米氮肥利用效率和气态氮损失的影响

Effects of blends of controlled-release and conventional nitrogen fertilizers on nitrogen utilization efficiency and gaseous nitrogen loss in summer maize cropland

为阐明控释掺混肥对夏玉米产量、氮肥利用效率和气态氮损失的影响,本研究以郑单958为供试材料,设不施氮对照(CK)、常规施氮(FFP)、优化施氮(OPT)、含30%控释尿素的控释掺混肥(CRBF30)和含50%控释尿素的控释掺混肥(CRBF50)共5个处理,对比分析了不同处理的夏玉米产量、氮肥利用效率和气态氮损失(氨挥发和N2O排放)的差异。结果发现,控释掺混肥(CRBF30和CRBF50处理)较FFP处理夏玉米增产1.4%~2.9%(P>0.05),在减氮和一次性施肥的条件下实现了夏玉米稳产。与FFP处理相比,CRBF30和CRBF50处理的氮肥吸收利用率分别提高了8.4个和11.1个百分点,其中CRBF50处理差异显著(P<0.05);氮肥偏生产力分别提高了8.87 kg·kg^(-1)和9.86 kg·kg^(-1)(P<0.05)。与FFP处理相比,控释掺混肥(CRBF30和CRBF50处理)的氨挥发强度和累积氨挥发损失分别降低71.9%~73.5%(P<0.05)和71.59%~72.66%(P<0.05),N2O排放强度和累积排放量分别显著降低了34.5%~41.4%(P<0.05)和33.7%~37.5%(P<0.05)。综上,施用控释掺混肥可兼顾夏玉米稳产、氮肥高效利用并降低氮素气态损失。

Summer maize is an important staple food crop in China.The Huanghuaihai Plain is the main production area for summer maize,and stabilizing the planting area and yield of summer maize is of great significance for ensuring national food security.Adopting highefficiency nutrition management practices is critical for maintaining summer maize yields and for sustainable agricultural development.Controlled-release fertilizer is a novel nutrient-efficient and environment-friendly fertilizer that can provide available nutrients in the soil at controlled rates or concentration levels required for crop growth while maintaining the nutrients for a longer period.Controlled-release fertilizer can promote crop yield,simplify fertilizer application,save labor,improve nitrogen use efficiency(NUE),and reduce reactive nitrogen losses by better synchronization of nitrogen release and crop uptake.To determine the effects of the blends of controlled-release and conventional nitrogen fertilizers on summer maize yield,nitrogen utilization efficiency,and gaseous nitrogen loss,ammonia(NH3)volatilization was measured using the aeration method and nitrous oxide(N2O)emission was sampled using a static box and measured by gas chromatography.A field experiment was conducted using the summer maize cultivar Zhengdan 958,and five nitrogen fertilizer management treatments were established:no nitrogen fertilizer(CK),conventional nitrogen application(FFP),optimized nitrogen application(OPT),blends of controlled-release and conventional nitrogen fertilizers with 30%coated urea(CRBF30),and blends of controlled-release and conventional nitrogen fertilizers with 50%coated urea(CRBF50).For the CRBF30 and CRBF50 treatments,total nitrogen was applied simultaneously as basal fertilization.Summer maize yield,NUE,NH3 volatilization,and N2O emissions under different treatments were compared.The results showed that blends of controlled-release and conventional nitrogen fertilizers(CRBF30 and CRBF50 treatments)increased the yield of summer maize by 1.4%to 2.9%compared with FFP treatments(P>0.05),and a stable yield of summer maize was achieved under the conditions of nitrogen reduction and one-time fertilization.Compared with FFP,the nitrogen recovery efficiency(NRE)of the CRBF30 and CRBF50 treatments increased by 8.4 and 11.1 percentage points,respectively,with a significant difference in the CRBF50 treatmen(t P<0.05).Nitrogen partial factor productivity(NPFP)of CRBF30 and CRBF50 treatments increased by 8.87 kg·kg^(-1)and 9.86 kg·kg^(-1)(P<0.05),respectively.Compared with FFP treatment,NH3 volatilization intensity and cumulative NH3 volatilization loss of the blends of controlled-release and conventional nitrogen fertilizers(CRBF30 and CRBF50 treatments)were reduced by 71.9%-73.5%(P<0.05)and 71.59%-72.66%(P<0.05),respectively.The N2O emission intensity and cumulative emission were significantly reduced by 34.5%-41.4%(P<0.05)and 33.7%-37.5%(P<0.05),respectively.In summary,blends of controlled-release and conventional nitrogen fertilizers can help ensure stable summer maize yields,improve NUE,and reduce gaseous nitrogen losses.