Center for Resilient Communities, University of Idaho, Moscow, ID, USA; Scion (New Zealand Forest Research Institute), Rotorua, New Zealand.
Center for Resilient Communities, University of Idaho, Moscow, ID, USA.
Sci Total Environ. 2020 Feb 25;705:135817. doi: 10.1016/j.scitotenv.2019.135817. Epub 2019 Nov 28.
This paper applies a social metabolism framework and energy flow analysis for evaluating agroecosystem and land use transitions in food-energy-water systems using the Upper Snake River Basin (USBR), Idaho, USA as a case-study. The study area is one of the primary agricultural regions of the State of Idaho. Dairy products are the primary agricultural outputs of the region; therefore, we modified a biomass accounting framework to explicitly incorporate the role of manure in the agroecosystem. Despite the increase of cropland between 2002 and 2012 in the basin, a decrease in energy input was observed for crop production. An increase in the industrial energy inputs for dairy production, on the other hand, showed that the basin is a clear example of a metabolic industrialized farm system - an example of land use intensification. We compare the energy return on investments (EROIs) as an indicator of agroecosystem transition for both crop and dairy production during the period 2002 to 2012. Contrary to our expectations, the analysis suggests that livestock production is a relatively energy efficient process in land management in the basin. This is due to the reuse of nutrient by-products from livestock as well as the refuse and residues from crop farming. At the same time, the findings provide insights on the percentage of manure to be reinvested as compost that would improve energy production efficiency. However, the reuse of manure, as it is managed in the basin, may have a negative implication on the nutrient balance of the agroecosystem that needs further investigation. Nonetheless, there is market potential for the reuse and reinvestment of biomass to make energy production in the basin more efficient.
本文应用社会代谢框架和能量流分析，以美国爱达荷州上蛇河流域（USBR）为例，评估了食物-能源-水系统中的农业生态系统和土地利用转变。研究区域是爱达荷州主要的农业区之一。奶制品是该地区的主要农业产出，因此，我们修改了一个生物质会计框架，以明确纳入粪肥在农业生态系统中的作用。尽管 2002 年至 2012 年间流域内的耕地有所增加，但作物生产的能源投入却有所减少。另一方面，奶业生产的工业能源投入增加表明，流域是一个明显的代谢工业化农场系统的例子，即土地利用集约化的例子。我们比较了 2002 年至 2012 年期间作物和奶制品生产的投资能源回报（EROIs）作为农业生态系统转变的指标。与我们的预期相反，分析表明，在流域的土地管理中，畜牧业生产是一个相对节能的过程。这是由于牲畜的副产物以及作物农业的废物和残渣被重新用作养分。同时，研究结果提供了有关应将多少粪肥作为堆肥重新投资以提高能源生产效率的见解。然而，正如流域管理中那样，粪肥的再利用可能对农业生态系统的养分平衡产生负面影响，需要进一步研究。尽管如此，生物质的再利用和再投资具有使流域内能源生产更高效的市场潜力。
