机插同步一次性精量施肥对双季稻养分累积及利用率的影响

【目的】为保证水稻施肥的准确性，揭示水稻机插与同步一次性侧深减量施肥的养分利用特征，为机插双季稻的氮(N)肥高效利用提供依据。【方法】在典型双季稻种植区，以测土配方施肥量为依据，结合精量施肥机，2017?2018年研究机插同步一次性精量施肥对双季稻养分吸收和利用的影响。【结果】与常规施肥处理相比，机插同步一次性减N 10%~30%处理早稻N、P、K累积量分别提高7.9%~11.7%、9.4%~25.9%和2.0%~6.5%(2017)，8.2%~15.0%、9.0%~12.1%和14.0%~18.1%(2018)；晚稻分别提高?0.6%~5.7%、9.1%~14.4%和3.7%~19.6%(2017)，6.1%~8.5%、9.4%~19.3%和18.7%~22.2%(2018)；早稻N肥吸收利用率(NRE)、N肥农学利用率(NAE)、N肥偏生产力(NPFP)分别提高38.6%~92.7%、49.9%~103.6%和29.5%~71.7%(2017)，35.4%~71.4%、46.0%~98.4%和20.7%~75.4%(2018)；晚稻分别提高20.8%~43.1%、31.3%~64.2%和18.3%~48.5% (2017)，26.8%~99.1%、60.0%~ 82.9%和26.6%~60.5%(2018)。其中，早晚稻以减N 20%~30%处理效果较好。水稻机插同步一次性精量施肥随着施N量的降低，双季稻NRE先增加后降低，NHI、NAE和NPFP呈上升趋势，而土壤碱解氮含量呈下降趋势。【结论】通过施肥技术和机插模式的集成与优化，能有效减少稻田N肥施入，利于N、P、K吸收积累，同步提高双季稻的产量和N肥利用效率。

Effects of Machine-transplanting Synchronized with One-time Precision Fertilization on Nutrient Uptake and Use Efficiency of Double Cropping Rice

【Objective】 Our aim is to ensure the precision in rice fertilization, and to reveal the nutrient utilization characteristics of machine-transplanted rice under one-time, one-side deep fertilization with reduced nitrogen (N) application level and to improve the nitrogen utilization efficiency for double-cropping rice. 【Method】Field experiments (2017?2018) were conducted using soil-tested formulated fertilization with precise fertilizer distributor to study the effects of one-time precision fertilization on nutrient absorption and utilization of double-cropping rice system in typical growing regions, and to investigate the relationships between nutrient contents and yield.【Result】As compared with conventional fertilization treatment, the accumulations of N, P, K in machine-transplanted early rice under one-time N application rate (reduced by 10%?30%) increased by 7.9%?11.7%, 9.4%?25.9% and 2.0%?6.5% in 2017, 8.2%?15.0%, 6.9%?14.1% and 13.9%?16.7% in 2018, in late rice by ?0.6%?5.7%, 9.1%?14.4% and 3.7%?19.6% in 2017, 6.1%?8.5%, 9.4%?19.3% and 18.7%?22.2% in 2018, and N recovery efficiency (NRE), N agronomic efficiency (NAE) and N partial factor productivity (NPFP) in early rice by 38.6%?92.7%, 49.9%?103.6% and 29.49%?103.6% in 2017, 36.9%?85.1%, 46.0%?98.4% and 20.7%?75.4% in 2018, and NRE, NAE, NPFP in late rice by 20.8%?43.1%, 31.3%?64.2% and 18.3%?48.5% in 2017, 26.8%?99.1%, 60.0%?82.9% and 26.6%?60.5% in 2018. The optimum treatment was obtained with a reduction of 20%?30% in N application rate．With the reduction of N application rate, NRE of double-cropping rice first increased then reduced, while NHI, NAE and NPFP were on the rise, and soil alkali-hydrolyzale N declined. 【Conclusion】The integration and optimization of fertilization technology and machine-transplanted technique can effectively reduce N application rate, facilitating N, P, K accumulation and utilization, which is conducive to raise grain yield and N use efficiency of double-cropping rice.