Abstract:

【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.

Key words: double cropping rice, machine-transplanted rice, deep fertilization, nutrient uptake, nitrogen use efficiency

摘要：

【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。

关键词: 双季稻, 机插稻, 侧深施肥, 养分累积, 氮肥利用率