随着世界各国政府为生物燃料研究和生产提供税收减免和激励措施，对生物燃料的需求持续增长，为全球农业提供了巨大机遇。制造商面临的一个挑战是，各国在生物燃料技术和战略的开发方面处于广泛的阶段，涉及许多不同的作物和工艺。
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我们： The US uses 140 billion gallons of fuel each year, a figure that’s expected to rise to 290 billion gallons by 2050. The 2005 Energy Policy Act encourages fuel suppliers to use 7.5 billion gallons of renewable fuels by 2012; starting the following year, they’ll be required to use an annual amount of 250 million gallons of cellulosic ethanol. Additionally, more than US $4.2 billion has been dedicated for loans, grants, and production incentives aimed at increasing research, development and production of cellulosic ethanol; the 2007 Farm Bill proposals provide for an additional $1.6 billion for research and $2.1 billion in guaranteed loans.
Corn-based ethanol makes up 95% of US biofuel production, using 15% to 20% percent of US corn’s 80 million acres. To prevent a decline in exports and feedstocks, US corn acreage will need to expand by at least an additional 10 million acres. However, land scarcity could become an issue, as more acres of cropland and even pastureland will have to be turned toward biofuel crops to produce enough to offset increasing world petroleum use. US corn must increase to 14 billion bushels each year to meet all market demands, while soybeans will have to increase to more than 2.5 billion bushels. With the US focus on corn ethanol driving corn prices higher, though, some farmers are dropping their corn-soybean rotation to grow corn-after-corn, making soil erosion and nitrogen depletion major concerns. High input double-crop corn requires massive amounts of pesticides and synthetic nitrogen fertilizer, which degrades topsoil, inhibiting future crop output. In drier parts of the US, additional corn crops grown for ethanol production require irrigation, drawing water from already strained aquifers that cannot bear the additional burden.
柳枝稷和其他用于生产纤维素乙醇的多年生草类可以在贫瘠的土壤中生长，根深蒂固，增加了有机质。玉米秸秆和其他玉米残渣也可制成纤维素乙醇。
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巴西： In 2006, Brazil became energy independent, thanks to a sugar-cane-based ethanol program which replaced 40% of the country’s gasoline use. Brazil’s long commitment to ethanol development, along with state and federal tax breaks and flex-fuel vehicles (introduced in 2003 and making up more than 70% of new vehicle sales by the end of 2005) have made it a leader in ethanol production and the world’s number one ethanol exporter. In 2006, Brazil exported 3.3 billion liters of ethanol, a 30% increase from 2005.
Brazilian corn prices have shot up to 10-year highs, creating estimated crop production for 2006/07 of 45.6 million metric tonnes (Mt), a 12% increase over the previous year. Of this record amount, 1.5 million Mt have already been sold — before they’ve even been planted.
While producers feel pressed to plant even more, the high corn prices precipitate higher ethanol production costs, causing producers to look towards new, non-food crops as biofuel sources. Soy — already shrinking due to producers cashing in on double-crop corn instead of a corn-soybean rotation — is also a high-cost ethanol source. Brazil’s long-term ethanol plans are centered around Jatropha curcas, palm oil, Araucaria angustifolia (from which the pinhao seeds, able to be harvested every three weeks, contain 40% oil) and cellulosic ethanol sources suchas switchgrass. However, in the next year or so, Brazil expects widespread consumption of its cheap sugarcane ethanol.
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欧洲： The EU produced 89% of the world’s biodiesel in 2005, and EU25 oilseed production reached record levels in 2006. Almost 80% of the EU’s biofuel production is biodiesel, coming primarily from Germany (with over half of the EU’s biodiesel production), France, and Italy. Harvests and prices of canola — the EU’s primary biodiesel crop — in Northern and Eastern Europe have been significantly higher for the past three years, with 2006/07 production estimates of 15.75 Mt. Sunflower harvests, while smaller than canola demands, have been reaching record highs and continue to grow.
Spain produces the EU’s largest amount of ethanol, with soybean production increasing throughout Southern Europe. Prairie grasses with rapid growth and high biomass yield such as giant Miscanthus offer future promise in cellulosic ethanol production.
EU policies and programs support Member States’ agriculture communities, as well as establish biofuels goals and standards. The European Commission has set a goal of 5.75% share of transportation fuel from biofuels by 2010.
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中国： 玉米和其他食用谷物价格上涨导致食品价格上涨和粮食短缺； 2005年以来，玉米秸秆价格飙升500%。到 2010 年，基于玉米的乙醇产量预计将增加两倍，达到 300 万吨，这可能迫使中国在 2008 年之前开始进口玉米。由于担心供应不足和耕地面积减少，中国已要求生产商寻找替代乙醇来源，例如木薯和甜玉米高粱。
甜高粱含糖量高，适应性强，生长迅速，一年两收。它具有很强的耐受性，可以填满中国西部和西北部超过 1.7 亿公顷 (Ha) 的干旱盐碱地。乙醇产量估计在每年每公顷 5,600 到 7,000 升之间，甜高粱相当于甘蔗（每年每公顷 6,500 升），并且生产更清洁、优质的乙醇。甜高粱随种子播种，每公顷仅播种 4.5 公斤种子，而不是每公顷甘蔗茎秆播种 5,000 公斤左右。
China’s government plans to increase domestic ethanol use from less than 2% to more than 5% of total fuel consumption, and will continue to provide subsidies, tax breaks, and other financial support for the expanding ethanol industry.
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印度： 大部分印度乙醇来自糖；生产商目前每年生产 13 亿升乙醇，预计 2007 年 6 月之后产量将增加，届时乙醇数量将需要翻一番，达到 10% 运输燃料。然而，印度大量的糖料作物导致地下水位下降。
Future production could see biodiesel from non-edible oils such as Neem, Pongamia pinnata and Jatropha curcas, which can grow on India’s 60 million Ha of wasteland. Pongamia and Jatropha, upon which animals will not graze, can grow in dry, degraded, or infertile soil unusable for food crops. Fast growing and hardy, they also produce an outstanding organic fertilizer after oil extraction. Within the next five years, India plans to replace 5% of its annually consumed 40 million tons of high speed diesel with a Jatropha biodiesel / petro diesel blend.
| 与基线相比，三种情景下世界原料价格的百分比变化 | |||||
|---|---|---|---|---|---|
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原料作物 |
场景 1* | 场景 2* | 场景 3* | ||
| 2010 | 2020 | 2020 | 2020 | ||
| 木薯 | 33 | 135 | 89 | 54 | |
| 玉米 | 20 | 41 | 29 | 23 | |
|
油籽 |
26 | 76 | 45 | 43 | |
| 甜菜 | 7 | 25 | 14 | 10 | |
| 甘蔗 | 26 | 66 | 49 | 43 | |
| 小麦 | 11 | 30 | 21 | 16 | |
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*情景 1：在没有技术改进的情况下积极发展生物燃料。 |
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未来的趋势
来自的预测 国际粮食政策研究所 表明存在三种情况。首先，在没有增加燃料节约或技术进步的情况下快速生产生物燃料；第二，纤维素生物燃料到 2015 年实现商业化生产；第三，生产力的提高、技术投资和智能农艺规划都发挥了作用。如图表所示，为了防止生物燃料的成本超过石油成本，使生物燃料成为可行的长期能源解决方案，必须有健全的农业政策和技术创新。
Given the geopolitical forces driving sustainable fuel development, it’s likely that biofuels will be a part of agriculture for a long time to come. Input-intensive corn should remain the main US ethanol source and a major biofuel crop in many other countries, requiring heavy loads of fertilizer and a variety of herbicides to avoid glyphosate-resistance from double-crop corn. Sugarcane and biodiesel crops ranging from canola to Jatropha require manual or irrigation–dripped nutrient and fertilizer application. As technology improves, large-scale biofuel farming will be a money-maker for the farm chemical industry.