【摘要】 为了解耕作制度对北方农田-畜禽养殖系统氮素梯级流动的影响,文章运用STELLA软件构建氮素流动模型,估算河北典型县2000-2015年间农田生产和畜禽养殖系统的氮素输入和输出通量及其利用效率,探讨耕作制度对其的影响。通过情景分析研究耕作制度变化对氮素利用率的影响,提出氮素管理措施。结果表明:2000-2015年间,该县农田生产系统氮输入量增加了24.25%,氮肥利用率由24.26%增长至34.32%;畜禽养殖系统氮输入量增加了67.78%,饲料氮利用率由41.62%增至55.43%。研究发现:若改变现有耕作制度:氮肥施用量可减少50%;若提高10%饲料利用率,可分别使农田生产系统和畜禽养殖系统氮利用率提高44.69%和18.69%。研究结果对河北农业发展具有指导意义。更多还原

【Abstract】 To understand the influence of farming system on the nitrogen(N) flow in the crop production-livestock breeding system in county scale, Hebei Province, a N flow model was constructed with STELLA software. This model was used to estimate the N fluxes and N use efficiency in the crop production subsystem, and livestock breeding subsystem from 2000 to 2015, for exploring the influence of farming system on it. Several N management improvement practices were proposed and compared on the influence of farming system changes through scenario analysis. Results show that during 2000-2015, the N fluxes of crop production subsystem in the typical county increased by 24.25% and fertilizer N use efficiency increased from 24.26% to 34.32%. The N fluxes of livestock breeding subsystem increased by 67.78% and fodder N use efficiency increased from 41.62% to 55.43%. It was found that reducing purchased fertilizer N input by 50% and through increasing fodder use efficiency would increase the N use efficiency in the cropping subsystem by 44.69% and 18.69%, respectively. Therefore,reducing purchased fertilizer N input and optimizing the feed compositions could increase N use efficiency. Results will guide significance to the agricultural development in Hebei Province.更多还原