Animal Production Systems group, Wageningen University & Research, P.O. Box 338, 6700 AH Wageningen, The Netherlands; Plant Production Systems group, Wageningen University & Research, P.O. Box 430, 6700 AK Wageningen, The Netherlands.
Plant Production Systems group, Wageningen University & Research, P.O. Box 430, 6700 AK Wageningen, The Netherlands.
Sci Total Environ. 2023 Nov 15;899:165540. doi: 10.1016/j.scitotenv.2023.165540. Epub 2023 Jul 18.
In many places on earth, livestock and feed production are decoupled, as feed is grown in one region and fed to livestock in another. This disrupts nutrient cycles by depleting resources in feed producing regions and accumulating resources in livestock areas, which leads to environmental degradation. One solution is to recouple livestock and feed production at a more local level, which enhances nutrient circularity. Recoupling livestock and feed production creates a natural ceiling for livestock numbers based on the feed producing capacity of a region. In this study we assess the consequences of recoupling livestock and feed production (i.e., by avoiding the import and export of animal feed) on ammonia and greenhouse gas (GHG) emissions, with and without feed-food competition. To this end, we used FOODSOM, an agro-ecological food system optimisation model representing the Dutch food system in this study. The Netherlands is one example of a region with high livestock densities and resource accumulation. We found that recoupling decreased livestock numbers (beef cattle: -100 %; dairy cattle: -29 %; broiler chickens: -57 %; laying hens: -67 %; pigs: -62 %; sheep -100 %) and animal-sourced food exports (-59 %) while still meeting the current human diet in the Netherlands. Consequently, ammonia emissions and GHG emissions decreased, and the nitrogen use efficiency increased from 31 % to 38 % at the food systems level. Recoupling alone was almost sufficient to meet national emission targets. Fully meeting these targets required further small changes in livestock numbers. Avoiding feed-food competition decreased livestock productivity and GHG emissions but did not improve nitrogen use efficiency. Total meat production could not meet domestic consumption levels while avoiding feed-food competition, and resulted in additional beef cattle. We show that recoupling livestock and feed production is a promising next step to enhance circularity while decreasing agricultures environmental impact.
在地球上的许多地方，畜牧业和饲料生产是脱钩的，因为饲料在一个地区种植，然后在另一个地区喂养牲畜。这通过耗尽饲料生产地区的资源和在牲畜地区积累资源来破坏营养循环，从而导致环境退化。一种解决方案是在更本地的层面上重新结合畜牧业和饲料生产，从而增强营养循环。重新结合畜牧业和饲料生产根据一个地区的饲料生产能力为畜牧业数量设定了一个自然上限。在这项研究中，我们评估了重新结合畜牧业和饲料生产（即避免动物饲料的进出口）对氨和温室气体（GHG）排放的影响，包括和不包括饲料-食物竞争。为此，我们使用了 FOODSOM，这是一个代表荷兰粮食系统的农业生态食品系统优化模型。荷兰是一个畜牧业密度高、资源积累量大的地区的例子。我们发现，重新结合减少了牲畜数量（肉牛：-100%；奶牛：-29%；肉鸡：-57%；蛋鸡：-67%；猪：-62%；绵羊：-100%）和动物源性食品出口（-59%），同时仍然满足了荷兰目前的人类饮食需求。因此，氨排放和 GHG 排放减少，粮食系统层面的氮利用效率从 31%提高到 38%。仅重新结合就几乎足以满足国家排放目标。要完全实现这些目标，需要对牲畜数量进行进一步的小调整。避免饲料-食物竞争会降低畜牧业生产力和 GHG 排放，但不会提高氮利用效率。在避免饲料-食物竞争的情况下，总肉类产量无法满足国内消费水平，因此需要增加肉牛。我们表明，重新结合畜牧业和饲料生产是提高循环性同时减少农业对环境影响的一个有前途的下一步。
