Environmental costs and benefits of growing Miscanthus for bioenergy in the UK.
Environmental costs and benefits of growing Miscanthus for bioenergy in the UK.
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DOI：
10.1111/gcbb.12294
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发表时间：
2017-03
期刊：
影响因子：
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通讯作者：
Clifton-Brown J
中科院分区：
文献类型：
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作者：
McCalmont JP;Hastings A;McNamara NP;Richter GM;Robson P;Donnison IS;Clifton-Brown J
在英国种植多年生生物质作物芒属可以抵消2-1300万吨石油/年−1，贡献了当前能源消耗的10%。政策制定者需要保证，可以可持续地扩大芒属植物的生产，而不会对基本粮食生产或更广泛的环境产生负面影响。这项研究回顾了大量的芒属相关文献，并将其简明扼要地进行了总结。多年生芒属植物的能量产出/投入比(47.3%±62.2)是一年生能源作物(4.7%±0.2%)的10倍，能源生产的总碳成本(1.12g二氧化碳-碳当量/−1)比化石燃料低20-30倍。在前耕地种植通常会增加土壤有机碳(SOC)，芒草固定0.72.2万亿mg/C4-C/ha−1yr−1。草原种植会导致土壤有机碳的扰动损失，这种损失很可能在作物的生命周期内恢复，并有可能通过化石燃料抵消而得到缓解。未施肥的芒属植物的N2O排放量可以比一年生作物低5倍，比集约化牧场低100倍。氮肥通常是不需要的，除非在低肥力土壤上。除草剂在除草剂建立后的几年内是必不可少的，在此之后，通过遮荫进行天然杂草抑制就足够了。杀虫剂是不必要的。水分利用效率很高(例如5.59.2g/−)，但高生物质生产率意味着与谷类作物相比需要更多的水。多年生的大自然和地下生物量改善了土壤结构，增加了持水量(增加了100-150毫米)，减少了径流和侵蚀。越冬成熟增加了野生动物的景观结构资源。减少管理强度会促进蚯蚓的多样性和丰富性，尽管较差的凋落物适口性可能会减少个体生物量。农田边界的化学淋溶低于可比农业，改善了土壤和水的栖息地质量。
Planting the perennial biomass crop Miscanthus in the UK could offset 2–13 Mt oil eq. yr−1, contributing up to 10% of current energy use. Policymakers need assurance that upscaling Miscanthus production can be performed sustainably without negatively impacting essential food production or the wider environment. This study reviews a large body of Miscanthus relevant literature into concise summary statements. Perennial Miscanthus has energy output/input ratios 10 times higher (47.3 ± 2.2) than annual crops used for energy (4.7 ± 0.2 to 5.5 ± 0.2), and the total carbon cost of energy production (1.12 g CO2‐C eq. MJ−1) is 20–30 times lower than fossil fuels. Planting on former arable land generally increases soil organic carbon (SOC) with Miscanthus sequestering 0.7–2.2 Mg C4‐C ha−1 yr−1. Cultivation on grassland can cause a disturbance loss of SOC which is likely to be recovered during the lifetime of the crop and is potentially mitigated by fossil fuel offset. N2O emissions can be five times lower under unfertilized Miscanthus than annual crops and up to 100 times lower than intensive pasture. Nitrogen fertilizer is generally unnecessary except in low fertility soils. Herbicide is essential during the establishment years after which natural weed suppression by shading is sufficient. Pesticides are unnecessary. Water‐use efficiency is high (e.g. 5.5–9.2 g aerial DM (kg H2O)−1, but high biomass productivity means increased water demand compared to cereal crops. The perennial nature and belowground biomass improves soil structure, increases water‐holding capacity (up by 100–150 mm), and reduces run‐off and erosion. Overwinter ripening increases landscape structural resources for wildlife. Reduced management intensity promotes earthworm diversity and abundance although poor litter palatability may reduce individual biomass. Chemical leaching into field boundaries is lower than comparable agriculture, improving soil and water habitat quality.