SASA

Biofuel Bonanza Should Benefit the Poor

December 2008

Overview

With the increase in global fuel prices in the past few years, there has been a growing interest in supplementing fossil fuel supplies with biofuels – fuels that come from plants. Working with national partners in the semi-arid tropics of Asia and sub-Saharan Africa, the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) conducts research on biofuels aimed at providing additional income to poor farmers while not compromising on food and environmental security.

ICRISAT’s Principal Sorghum Breeder BVS Reddy in a field of sweet sorghum.

To empower the dryland poor to benefit from, rather than be marginalized by the biofuels bonanza, ICRISAT launched a global BioPower Initiative. The BioPower research strategy focuses on feedstock sources and approaches with multiple advantages – they do not compete with food production but produce food as well as fuel, and this in a manner that greatly reduces greenhouse gas emissions.

Bioenergy crops such as sweet sorghum offer multiple benefits of food, fodder and fuel. The grain is used for food, sweet juice from stalks for ethanol production (to be blended with gasoline) and the bagasse (residual stalk material after juice extraction) and leaves as fodder. Sorghum is one of ICRISAT’s five mandate crops.

Sweet sorghum a smart crop

ICRISAT considers sweet sorghum as a SMART crop as it produces food, feed, fodder and fuel, without significant trade offs in any of these uses in the production cycle. Sweet sorghum can be grown in the dry or semi-arid tropics across the globe as a rainfed crop in areas with more than 700 mm rainfall. A crop of sweet sorghum takes about 4.5 months to grow, and can be followed by a ratoon crop (natural second re-growth from stubble after the first crop is harvested). Sweet sorghum requires comparatively less fertilizer, water, labor, and other inputs (Rao et al. 2004, Almodares 1997). The cost of production is US$ 217.5 for sweet sorghum and it gives 23% additional returns to farmers compared to grain sorghum (in India). Sorghum is planted from seed and some of the field operations such as sowing and harvesting, can be readily mechanized.

Thus, sweet sorghum is more accessible to poor farmers with limited access to capital in areas that receive a minimum of 700 mm annual rainfall. Secondly, sweet sorghum has a high net energy balance. Even though the ethanol yield per unit weight of feedstock is lower for sweet sorghum compared to sugarcane, the much lower production costs and water requirement for this crop more than compensate for the difference and hence, sweet sorghum still ends up with a competitive cost advantage in the production of ethanol in India (Rao et al. 2004). It produces three valuable products: food, fuel and feed, raising smallholder incomes by about 23% (in central India) while probably reducing net greenhouse gas emissions compared to fossil fuels.

The concern about the competition between first generation biofuels vs. food and feed crops for land can be overcome by growing sweet sorghum that has multiple uses. There has been much criticism recently of biofuels on the basis of food-fuel competition, economic impacts on the poor and environmental impacts, based on highly-publicized cases like US corn, Southeast Asian oil palm and European rapeseed.

By blending petrol (gasoline) with ethanol from sweet sorghum, developing countries can save on valuable foreign exchange spent on importing petrol. For India, this is potentially a saving of about a billion dollars per annum, increasing over time.

In India, the replacement of just 20% of the grain sorghum crop with sweet sorghum would meet the nation’s target for ethanol for a 10% blend of ethanol in petrol. This “crop replacement” strategy would not change current land use or push other food crops into ecologically sensitive frontiers, so it does not incur a startup “carbon debt” (release of greenhouse gases from the oxidation of cleared vegetation).

By connecting sorghum farmers to markets, sweet sorghum will likely trigger doubling or tripling of yields through the use of fertilizers, hybrid seeds and other technologies, increasing food, fuel and feed production rather than reducing it as has been the critique with corn.

Food-fuel trade offs

Food-fuel trade offs appear to be minimal for sweet sorghum since the plant produces both grain and biofuel. Although sweet sorghum grain yields seem to be about 25% lower than those of non-sweet sorghum varieties (in the postrainy season and about the same in the rainy season in India), the biofuel use of the crop may in practice leverage large increases in grain production by raising total productivity. Sorghum grown in the developing world is largely for local utilization, so it has little impact on international trade or food prices.

Future growth in demand for bioethanol could be met by raising yields and by further replacement of grain by sweet sorghum, as well as by additional crops, particularly when second generation technologies come on-stream. Of course, countries with smaller sorghum areas compared to ethanol demand will be able to meet only a portion of their need from the current area sown to grain sorghum, eg, the USA where the area sown to sorghum is only one-tenth of that sown to maize. Though in such cases, the adopting farmers would have no fear of “glutting the market” causing a price decline.

Livestock feed is a major value component of sorghum. The growing affluence in developing countries that is driving the sharp increase in food prices is also increasing the demand for and prices of animal products like meat and dairy. Sorghum stalk is in high demand for feeding livestock destined to serve those markets (Blümmel and Parthasarathy Rao 2006).

The feed value of the sweet sorghum bagasse is not less than the value of non-sweet stem that is currently the mainstay of this market (Blümmel et al. 2008). Therefore the addition of bagasse to the commercial marketplace would not cause a decline in feed quality.

If the stalks are crushed at the factory, the bagasse may either be burned to fuel the distillation process (climate-change friendly since the stalk is renewable energy), or it may be sold as livestock feed. Feed blocks made from the bagasse can be sold in India for about twice the value of the fuel equivalent needed to supply heat for distillation (Blümmel, personal communication); so feed may be the more pragmatic use in the future.

Sweet sorghum vs grain sorghum

To be truly pro-poor, sweet sorghum should not compromise grain yield for food and increased income. Preliminary research at ICRISAT indicates that sweet sorghum hybrids have higher stem sugar yield (by 21%) and higher grain yield (by 15%) than grain-type hybrids, and sweet sorghum varieties had 42% higher sugar yield and 18% lower grain yield than that of non-sweet stalk (grain type) varieties in the rainy season. On the other hand, both sweet sorghum hybrids and varieties had higher stalk sugar yields (78% and 53%) and lower grain yields (16% and 21%) in the postrainy season. Thus, there is no significant trade off between grain and stalk sugar yields of the sweet sorghum hybrids in the rainy season while the trade off is very limited in these hybrids in the postrainy season.

Yet, the need to have no compromise between sugar yield on one side and grain and fodder yield on the other side requires a careful look at the extent of light capture by sweet sorghum. Intuitively, sucrose accumulated in the stem could mean that starch/sucrose is not remobilized towards the grain. So far, across seasons, there appears to be little or no decrease in grain yield across varieties and hybrids in sweet sorghum compared to regular grain sorghum. This may be explained by the longer duration of the cropping cycle in sweet sorghum materials, and could be the case if these have higher photoperiod sensitivity. It could also be due to difference in radiation use efficiency (RUE). An assessment of RUE across sweet sorghum and non-sweet sorghum lines could be very important. Sweet sorghum genotypes tend to grow slightly taller. It has been shown that taller sorghum types possess higher RUE, because of a better light penetration in the leaf canopy. The comparison of the processes of light capture between sweet sorghum and non-sweet sorghum lines needs further study.

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Sweet sorghum vs maize (in the USA) and sugarcane

Maize grain in the USA has a greater productivity for ethanol. For comparison, the 9 ton per hectare average yield of maize in the USA (15% moisture) yields about 3,600 liters of pure ethanol per hectare. A tripling of sorghum yields (from 20 t/ha to 60 t/ha) would therefore be needed to approach the level of ethanol land productivity of US maize.

However, tropical crops usually yield significantly less than temperate crops; the difference with maize is roughly a factor of three. Experiments in the southern US have produced sweet sorghum fresh weight yields in excess of 80 t/ha, and exceeding maize biomass yields (Rooney et al. 2007).

Thus, it can probably be said that sweet sorghum is inherently as ethanol-productive as maize under similar high-input cultivation conditions, though the tropics will be constrained by poorer soils and warmer night temperatures. Such equivalent potential productivity is reasonable because sorghum, like maize and sugarcane, is a C₄ crop (more efficient use of light for biomass production), and is thus highly efficient in converting water and carbondioxide (CO₂) into energy in warm, dry tropical areas. If the breeding intensity applied to maize in the US is applied to sweet sorghum, there is little doubt that yields would be even more competitive.

In comparing sweet sorghum with sugarcane, it is important to note that a crop of sweet sorghum has about 4-5 months to fix carbon into energy, compared to 12 or more months for sugarcane; and sugarcane is usually grown on richer soils with ample water supplies. This gives a per-crop yield advantage to sugarcane of about 50% more sugar (and therefore ethanol) per ton of stalk (75 versus 50 liters/ton), plus higher stalk yield per hectare. Because of this large difference in crop duration, a fairer comparison of inherent productivity would be on the basis of average yield per day when grown under similar favorable conditions.

Also important is to compare ethanol yields per unit of production cost. Though less productive per crop, sweet sorghum appears economically competitive per liter of ethanol produced; however the current database behind this comparison is scanty and urgently needs to be improved.

Sugarcane is more expensive to grow, requiring good soils and plenty of water over a long time period (usually costly and requiring fossil-fueled irrigation in India, though not in Brazil). Sugarcane as an ethanol source is also in competition with its use as a refined sugar source for foods, a business that is usually subsidized and well established.

A flaw of maize bioethanol is that the starting substrate for ethanol is starch from the grain. Starch has to first be milled out of the grain, hydrated, and then enzymatically converted to sugar before it can be fermented. This conversion process is costly and energy-intensive.

Direct fermentation of sugary juice from sweet sorghum (or sugarcane) on the other hand is simple, like making wine (in the case of grapes done readily on the farm). Yeast is added to the expressed juice and sealed off from the air (anaerobic conditions). Yeast ferments the roughly 18% sugar solution to yield about 9% ethanol.

State of research

As the world center for dryland agricultural research, ICRISAT has over the years strengthened its studies on extracting ethanol from sweet sorghum. Harnessing its core competence in crop improvement, ICRISAT has developed improved sweet sorghum varieties and hybrids. Compared to maize and sugarcane, sorghum has received little attention in the past. This creates an opportunity for rapid improvements and growth in the industry (Kundiana et al. 2006, Reddy et al. 2005, Rooney et al. 2007).

The three main research issues being addressed by ICRISAT are:

Food supplies: do biofuels take land away from growing food, or divert foodstuff into gas tanks?
Economics: are biofuels a potential engine for economic development in poor areas, and for energy security in both poor and rich countries? Will former oil importation costs be transformed into investments in rural development? Or will only the rich benefit?
Environment: do biofuels truly reduce greenhouse gas emissions, or perhaps inadvertently increase them instead; and do they excessively damage land resources (soil, water, biodiversity)?

In line with ICRISAT’s pro-poor BioPower strategy, socioeconomic benefits, potential risks, and livelihood opportunities that result upon sweet sorghum’s cultivation in dryland areas is being studied in detail with the help of appropriate tools and models developed by the Institute. Preliminary ex-ante analysis conducted on sweet sorghum cultivation promoted by Rusni Distilleries through the Agri-Business Incubator (ABI) of ICRISAT in Andhra Pradesh, India, showed that the crop has potential to become a bioenergy crop. Some important lessons learned in the process are: timely harvesting and procurement of stalks, availability of improved genotypes suited for the location and that following recommended crop management practices.

Research to accelerate the realization of this vision is inter-disciplinary, involving system analysts with engineering and lifecycle analysis skills, agronomists, breeders, economists, and environmental impact experts addressing urgent knowledge gaps as listed below:

Agronomic research to improve yield, quality, nitrogen use efficiency, economic efficiency and greenhouse gas emissions,
Plant breeding research to optimize food, fuel and feed yields and quality, especially through hybrids and novel sugar-related genes, and improving plant type for more efficient harvesting,
Post-harvest processing research to overcome the harvest-time bottleneck, eg, through decentralized crushing and syrup-making units,
Socio-economic research and policy analysis to optimize coordination that engages thousands of smallholder farmers and other poor with the private sector, accelerating improved technology adoption while monitoring the distribution of benefits to ensure that pro-poor outcomes are realized, and
Energy and greenhouse gas lifecycle analysis to quantify greenhouse gas and net energy yields.

To begin with, Life Cycle Analysis (LCA) for energy analysis, emission analysis and resource requirements will be carried out on both decentralized and centralized systems of ethanol production in Asia. Similar studies will be taken up in ICRISAT’s Eastern and Southern Africa (ESA) and West and Central Africa (WCA) regions, as LCA varies widely from location to location, as do processing techniques and logistics involved in the value chain (crop production, processing and distribution).

Life cycle assessment models the complex interaction between a product (bioethanol, in this study) and the environment from start to finish. It is also known as life cycle analysis or “ecobalance”. Biofuels or biogenic fuels may help displace fossil fuels in developed and developing nations, providing a possible solution to the twin challenges of energy security and climate change. ICRISAT’s life cycle analysis will address the following for each of the three regions:

Comprehensive description of sweet sorghum production, processing and use systems,
Collate inventory data and analyze the experimental data for calculating energy (inputs and outputs) and greenhouse balances, and
Scenario analysis with popular models.

For better operational efficiency of distilleries, extended feedstock supply is a critical issue. Therefore, trait-based improvement of sweet sorghum will be a priority research issue in improving hybrid parents for improved sweet sorghum hybrids for release and commercialization. It also includes study of genotype × environment interaction, development of photoperiod-insensitive genotypes with varying maturity periods, Integrated Pests and Diseases Management (IPM) including host-plant resistance, sequential or staggered planting, ability to ratoon with supportive areas like seed production systems and farm mechanization. Water Use Efficiency (WUE), Nutrient Use Efficiency (NUE) and RUE of sweet sorghum will be studied in all three ICRISAT regions in comparison with competing crops such as maize, sugarcane and cassava.

With the help of modern technology of crop breeding [Marker-Assisted Selection (MAS) and Transgenics], photoperiod-insensitive genotypes that yield both sugar and grain will be developed. The ICRISAT program in Asia is more advanced in this area and two other regions are also being strengthened in areas of hybrid parents development and biotechnology.

Post-harvest losses in terms of juice quantity and quality were observed when crushing was delayed. Therefore, the strategy aims to minimize post-harvest losses using identified chemical sprays/physical measures. Studies will be conducted to identify measures of retaining the stalk sugar/bagasse quality after harvest and prolonging the shelf life of extracted juice. This research will be carried out initially at ICRISAT-Asia, and will later be extended to ESA and WCA.

To help the dryland poor, alternative ways of utilizing sweet sorghum leaves/bagasse will be studied carefully – bio-compost, cogeneration, feed block making, honeymaking, etc. Preliminary findings in collaboration with the International Livestock Research Institute (ILRI) indicate good digestibility coefficients for sweet sorghum bagasse.

ICRISAT-Asia, with its lead in commercializing ethanol from sweet sorghum, will continue to lead the path in research, followed by ICRISAT in ESA and WCA. This will be the same for second-generation (cellulosic) technologies.

The approach is thus designed in line with the ICRISAT BioPower research strategy to address the knowledge gaps mentioned earlier in all the three regions of Asia and Africa; and a number of issues related to extended supply of stalk to industry. The strategy will also address development of value chain models for backward and forward linkages of farmers with input suppliers and distilleries in the centralized model; or linkages between farmers and village crushing units who in turn would be linked to the distillery in the decentralized model appropriate to the region for use of sweet sorghum in the first generation ethanol production technology.

Moreover, farm-level profitability and risks of sweet sorghum production and processing are not as yet fully understood. The strategic role for ICRISAT is to identify the varieties and hybrids with high juice and grain yield and profitability for bioethanol production, and to identify the relative profitability and potential risks associated with adoption of these new varieties.

Thus, ICRISAT’s research will answer the following questions:

What are the payoffs to smallholder farmers from investment in sweet sorghum and what are the additional income benefits by switching from traditional grain sorghum cultivars to sweet sorghum cultivars?
Under which production and market environments does sweet sorghum production pay smallholder farmers?
What is the overall economic feasibility of sweet sorghum-based bioethanol production in the different regions?
Will sweet sorghum for bioethanol provide the long-awaited vehicle for commercialization of the largely subsistence-led sorghum production in sub-Saharan Africa?

Existing hybrids

The breeding of hybrid sweet sorghums presents a substantial opportunity to raise yields of all the desired components – food, fuel and feed – especially since hybrids are more responsive to fertilizers. At present, the sugar concentration in the juice of hybrids is lower than that of nonhybrids, but this deficiency should be overcome through breeding.

An exciting possibility is that the biofuels objective could serve as a stimulus for the emergence of a hybrid seed industry in Africa. The fuel processor would be motivated and would have access to the technical and financial resources to address the constraints that have prevented a hybrid industry from being sustained so far in that continent.

Hybrids can also be sources of photoperiod insensitivity, allowing a wider range of planting dates to spread out the supply of feedstock over a longer period. However, it must be kept in mind that varying planting and harvest dates under rainfall-limited conditions could considerably increase drought risk, insect/bird damage, and grain mold damage.

Hybrids are better target materials for feedstock development. To improve the hybrids, there is a continuous need to improve both the parents - female lines and male parents. Hitherto conventional breeding approaches were utilized, but we propose to integrate conventional breeding with new molecular tools for higher efficiency in selection. Attempts will be made to exploit landraces from other target areas in ESA and WCA.

Second generation ethanol production (cellulosic technology)

The bagasse obtained after juice extraction from the stalks contains a concentrated amount of cellulose. This cellulose is also a potential source of ethanol. The world community anxiously awaits the realization of second generation cellulosic fuels. Enzymatic digestion of cellulose into sugar could make it practical to derive large amounts of ethanol from a wide range of plant waste materials. Such methods are not economically viable as yet, but intensive research worldwide is expected to make the technology practical in the next 5-10 years.

If and when the technology becomes practical, cellulosic sources of feedstock will still be required. From an environmental standpoint, it would be desirable to produce much of this biomass from existing cultivated lands (as long as food supplies are not compromised) rather than clearing wild lands for cultivation. Since sweet sorghum is highly productive and inexpensive to grow with good processing characteristics and yielding additional valuable products (grain and fodder), it still plays a pivotal role in the second-generation bioethanol technology.

Research will be initiated at ICRISAT headquarters in India, to develop high biomass yielding brown-midrib (bmr) mutants while sustaining grain yield by breaking the nexus between low yield and the bmr trait as seen in many of the mutants. Depending on the progress in the efficiency of the second generation technology, which depends on biomass as raw material, research on high biomass (bmr) sweet sorghum improvement will be initiated in the two other regions, ESA and WCA.

The focus will be on developing improved brown midrib lines for high biomass with high grain yield; developing brown midrib hybrid parents with high levels of pest and disease resistance; and developing high biomass brown midrib hybrid parents for the stay-green trait.

Cytoplasmic-nuclear male sterility systems are available to mass-produce hybrid seeds. Furthermore, sorghum is a versatile crop and grows over varied tropical and subtropical conditions, so, it is considered a good candidate crop for second generation ligno-cellulose ethanol production as well. Therefore, the strategy also includes research on improving biomass quantity and quality.

Product and by-product quality

Quality considerations (related to sugar content in the juice, for example) might loom large in due course in determining buy-back price. Building on its experience of the past two years, ICRISAT will also determine other quality parameters that may fetch a higher price from distilleries. Stalks before harvest for supply to the factory, or juice making at the village level, need to be assessed for quality (sugar), ensuring a minimum brix of 15%. Farmers will be advised to harvest only after the crop has reached satisfactory maturity with adequate levels of sugar accumulation in the stalks. Local civil society organizations or farmer associations will be trained on this aspect in addition to crop management aspects.

Another important issue relates to the use of sweet sorghum bagasse after extraction of juice. In the centralized model, the sweet sorghum bagasse will be at the distillery. The distilleries have the option of either selling the bagasse for animal feed, using it as fuel to run the distillery, or converting the surplus into electricity for supply to the grid. These options need to be studied carefully to come up with an optimal mix that would maximize the profits of the firm. They also need to be analyzed from the energy balance standpoint through LCA.

Research at ICRISAT in collaboration with ILRI indicates that sweet sorghum bagasse and stripped leaves-based feed block (BSLFB) were nutritionally equivalent to the commercial feed block based on normal sorghum stover, since there was no statistical difference in dry matter intake (DMI) and live weight gain (LWG) between animals fed with the bagasse plus stripped leaf-based blocks (DMI of 3.7% of live weight and 0.73 kg/d of LWG) and those fed on original sorghum stover-based commercial feed block (DMI of 3.5% of live weight and 0.82 kg/d of LWG) (Blümmel et al. 2008). Research also indicates that sweet sorghum stover promotes higher feed intake than normal sorghum when fed to cattle and sheep directly. Also, its digestibility is higher than normal sorghum stover.

Under the decentralized model, where the juice is extracted at the village and the bagasse is available at the crushing unit, the options include use of the bagasse as energy source, returning the bagasse to the farmers for use as animal feed, or for composting.

Environmental impacts

Do biofuel crops protect the environment or add to greenhouse gas (GHG) emissions? This question is being debated thoroughly in scientific circles.

Crutzen et al. (2008) estimated that crops in general (including biofuel crops) create more GHG emissions than they save by replacing fossil fuels. Some dispute these findings, suggesting that more efficient processing techniques in recent years have reduced GHG emissions per unit of energy generated (Adam Liska and Ken Cassman 2008).

Considering that the nitrogen (N) emitted contributes to global warming, whereas carbon fixation by the same crop creates a counterbalancing cooling effect, Crutzen et al. (2008) estimate that the ratio of grams of (N)/kg dry matter, or r_N to grams of carbon (C) in the crop tissue is a quick and easy indicator of the fertilizer requirement of crops and therefore their global warming potential relative to the fossil fuels that they replace. High r_N crops are those that require high amounts of fertilizer and thus result in high N emissions. Low r_N crops are thus much preferred for biofuel use.

It is unclear without data where sweet sorghum fits on the r_N spectrum. Cultivation for biofuels would imply increased fertilizer use, and since grain-bearing is desired for sweet sorghum, N is needed to fill the protein sink in grain. Thus, sweet sorghum may well have a higher r_N than sugarcane. But sweet sorghum, like maize and sugarcane, is also a C₄ crop, and is physiologically more efficient in fixing atmospheric carbon per unit of nitrogen in the leaf than those crops.

Since it is suggested that N emissions from crops is much higher than previously thought, ICRISAT’s research would measure N use efficiency in sweet sorghum cultivation systems, and devise ways to increase it.

The other issue where research will be carried out is on the initial carbon debt. Both Fargione et al. (2008) and Searchinger et al. (2008) call attention to the massive release of CO₂ into the atmosphere caused by the oxidation of organic matter when natural lands are cleared for agricultural use. Such land clearing is being stimulated by the cultivation of biofuel crops. This initial “carbon debt” may negate the benefits of decades or even centuries of biofuel cultivation, relative to fossil fuel consumption.

Usually sweet sorghum can be grown only on lands that are already cultivated. This could still make a major contribution in many dryland tropical countries where the area of sorghum is large enough to more than meet the projected ethanol demand. The drylands, particularly those already cleared for agriculture, are also inherently lower in carbon storage, so the risk of carbon debt is lower.

The increased use of fertilizers to raise biofuel yields might increase the carbon in soils, but counterbalancing that may be the removal of stalks for crushing followed by burning to fuel the distillation process, or their use as livestock feed (soon re-entering the atmosphere through respiration). These counterbalancing aspects will be quantified through a life-cycle analysis of the entire process.

Sweet sorghum is estimated to yield 8 units of energy for each unit input, though this has not been measured in the field (personal communication from Dr Hosein Shapouri, USDA, based on sugarcane data); this is four times more energy-efficient than US maize.

State of technology utilization and commercialization

To translate ICRISAT’s research on ethanol from sweet sorghum, the Institute developed effective partnerships with the private sector, civil society organizations and farmers. Through innovative technology commercialization, the ethanol from sweet sorghum package was shared with poor farmers.

Agri-Business Incubator at the Agri-Science Park @ ICRISAT

The primary vehicle for ICRISAT’s technology commercialization is the Agri-Science Park at ICRISAT (ASP-ICRISAT) through its Agri-Business Incubator (ABI). Developed to incubate promising agri-business ideas into viable commercial propositions, ABI-ICRISAT worked on making the idea of commercially generating ethanol from sweet sorghum, in collaboration with Rusni Distilleries.

ICRISAT, Rusni Distilleries and sorghum-growing farmers have established the world’s first commercial distillery using sweet sorghum as a feedstock and a sweet sorghum supply network, in Mohammed Shapur village of Andhra Pradesh, India. Mr AR Palaniswamy, the entrepreneur who started Rusni Distilleries, brought in a patented technology to produce ethanol from sweet sorghum, and established a 40 kiloliters per day ethanol distillery at Mohammed Shapur village.This distillery demonstrated to the world that the idea of ethanol from sweet sorghum was a commercially viable proposition.

Rusni Distilleries, India.

Sharing technology with farmers and the private sector

Like sugarcane but unlike compact and storable maize grains, extracting the juice from sweet sorghum requires rapid handling and transport of bulky, perishable plant material. This requires fuel, energy, and very good logistical organization.

One of the planks of commercialization of sweet sorghum involves linking private industries with farmers in the value chain of bioethanol along with other actors in the chain. The decentralized model deals with production of raw materials through linking farmer groups with micro-entrepreneurs (for decentralized juice extraction) and credit and input agencies. Further, micro-entrepreneurs are linked with private distilleries (ethanol), and the association of distilleries is in turn linked with policy makers. Through such a continuum and seamless integration of various actors at different stages of the value chain (including by-products), benefits can be maximized.

ICRISAT has created two platforms for a holistic, pro-poor approach in the sweet sorghum ethanol value chain to reinforce public-private partnerships so that the needs of industry for sustainable supplies of feedstock, and the poor for a fair share of the income are met for mutual benefit.

The ICRISAT-Private Sector Sweet Sorghum-Ethanol Research Consortium (SSERC), also a part of ASP-ICRISAT, has been established to meet current and future demands of the sweet sorghum-based ethanol distillery units, and this is being facilitated by ABI. If established, the distilleries will not only help widen the marketing opportunities for sweet sorghum farmers to get a higher income, but will also help to generate more employment. As of now, four companies are partners in this consortium.

The ICRISAT-Private Seed Sector Sorghum Hybrid Parents Research Consortium (SHPRC), another component of ASP-ICRISAT, operates with 22 members at present. The overall goal of this consortium is to strengthen sweet sorghum hybrid parents research at ICRISAT and share the products of this research with the seed industry, which in turn provides sweet sorghum hybrids to farmers.

A small juice-extraction unit in Mozambique.

ICRISAT proposes to exchange the materials and technology and test them in collaboration with partners across countries including India, China, Thailand, and the Philippines in Asia and countries in ESA and WCA.

Some private companies and public institutions in Kenya, Mozambique, Mauritius, Tanzania, Zambia, South Africa, Zimbabwe and Malawi have received germplasm for evaluation from ICRISAT. Likewise, Ethiopia and Namibia have indicated interest. To further streamline specific areas of sweet sorghum production, initial interest would be to focus on locations that are not farther than 50 km from the distillery. In WCA, Mali, Nigeria, Ghana and Burkina Faso are showing interest in biofuels (eg, Agri Biofuels Ltd in Nigeria).

Economic benefits for the poor

According to Mr AR Palaniswamy, Managing Director of Rusni Distilleries, a mid-sized plant such as Rusni costs about US$10 million to build. Running at full capacity, it produces 40 kiloliters of ethanol per day (the yield of about 40 hectares worth of crop at 20 tons stalk/ha), and employs 9,000 people part or full-time, including 5,000 farmers.

Rusni buys sweet sorghum stalk for Rs 600 per ton. Farmers who manage the crop well earn about 20% more than for competing crops (Rao 2007), providing a good economic incentive and reward. To avoid food-fuel competition, Rusni does not buy grain unless it is diseased (eg, fungus due to late-season rains) and therefore valueless for the human food market. By buying spoiled grain, Rusni provides a valuable element of livelihood security to its contract farmers. Grain spoiled for human or livestock consumption is still suitable for making ethanol.

The macro-economic value of bioethanol production could be measured by the value of petrol that it replaces. Alternatively, considering that the free market estimated value of bioethanol now is about Rs 29/liter in India, according to Mr Palaniswamy (the price of ethanol for non-fuel uses adjusted for the extra costs of processing of Rs 3), if India is to meet its goal of 1.5 billion liters of bioethanol, this would have a value of US$918 million per annum. Nearly a billion dollars per year formerly sent overseas would then be redirected into India’s agricultural economy to reach the 10% ethanol blend standard. Over time, the blend ratio will probably rise, the price of ethanol will probably rise, and transportation fuel needs will increase, raising these benefits steadily and significantly.

To enable farmers who are located away from the distilleries to participate in the sweet sorghum to ethanol value chain, a decentralized crushing and syrup making unit is proposed involving farmers from a cluster of three to four villages. The sweet sorghum syrup from the decentralized crushing-cum-syrup making units located in the villages will be transported to the distillery. ICRISAT`s strategy is to examine the feasibility of applying any one or more of these measures to mitigate the yield losses and help supply raw materials (stalks or syrup) to the distillery over an extended period in a year.

Outlook

Several entrepreneurs in India are coming forward to establish multi-feedstock ethanol distilleries that include sweet sorghum as one of the feedstocks. Other than Rusni Distilleries, whose plant is already operational, there are Sagar Distilleries in Andhra Pradesh and Tata Chemicals Ltd. in Maharashtra. Various key research issues on marketing, integrating farmers’ input suppliers and ethanol industry, and commercial cultivation of the crop will be addressed involving these distilleries and farmers in a coalition mode that would include researchers from NARS and government officials.

Similar studies will be facilitated in China, Thailand and the Philippines involving ABI-ICRISAT in Asia. In this context, the Hybrid Seed Consortium at ICRISAT involving the private seed sector, and Ethanol Research Consortium linked with distilleries will be strengthened to transfer the products to small-scale farmers and thereby enhance their livelihoods and to help capacity building of the personnel of seed companies and distilleries.

In Kenya, Spectre International is piloting bioethanol production with Ochuti, a farmers' variety that also has acceptable grain yields and sweet stalk. Agrochemical and Food Co. (ACFC) in Kenya is also using sweet sorghum stalks for ethanol production to supplement other feedstocks. Eco Energia Co. in Mozambique, SAKEB Bioenergy International Co. in Tanzania, and Mozambique Principle Energy in Mozambique are at different stages of establishing distilleries.

When these take shape, the key research issues in marketing, integrating farmers with industry and value chain economics will be addressed as was done in ICRISAT-Asia. Considering the poor connectivity of the roads and transport support, the decentralized model of syrup making is more applicable in ESA. Therefore, ICRISAT-ESA will initiate steps to set up these units and study the market and value chain economics.

Collaboration with advanced research institutions in life cycle analysis and utilization of brown midrib mutants in developing high biomass sorghums, biological nitrification inhibition (BNI) and identification of QTLs for stalk sugar-related traits, and physiology of sugar accumulation will be forged to capitalize on the synergies.

Potential collaboration is with the national agricultural research system of Brazil, the Empresa Brasileira de Pesquisa Agripecuaria (EMBRAPA), whose sorghum program has good leads in Aluminium tolerance and Phosphorous acquisition and use efficiency in sorghum, which can be successfully extrapolated for sweet sorghum improvement.

As with Brazil, closer partnership between CGIAR and USA scientists could accelerate progress in sweet sorghum research. The crop is currently grown on a small scale as a food sweetening agent, ie, for pancake syrup, but there is keen interest in its possible expansion for bioethanol.

Sweet sorghum is being studied for potential bioethanol use in a number of southern Midwest states – Oklahoma State University (in-field fermentation potential); Purdue University with the University of Florida (brown midrib genes); Texas A&M University (crop breeding and agronomy); University of Nebraska (lifecycle analysis); and the University of California, Berkeley (sorghum grain quality enhancement biotechnology).

ICRISAT also proposes to collaborate with the Japanese International Research Centre for Agricultural Sciences (JIRCAS), to study the (BNI) process for sweet sorghum. Nitrification releases fertilizer-N into the environment, contributing significantly to the greenhouse effect and NO₂ pollution of surface and groundwater. JIRCAS scientists pioneered an assay system to detect and quantify BNI ability in plant roots. Genetic exploitation of this attribute would lead to development of the next generation crop with a built-in ability to self-regulate nitrification, causing a dramatic impact in minimizing nitrogen losses.

Variability for BNI was observed among sorghum genotypes. Sweet sorghum genotypes with high BNI ability perform better in some high rainfall areas such as in the Philippines and also in irrigated sweet sorghum areas. Therefore, we propose to undertake studies on BNI ability of newly bred improved cultivars in collaboration with JIRCAS.

ICRISAT is presently collaborating with the Centre de coopération internationale en recherche agronomique pour le développement (CIRAD) of France on the “Sweetfuel” project with the objective of producing highly drought tolerant and high grain yielding sweet sorghum lines. The proposal is to take up modelling studies on sweet sorghum with the help of CIRAD.

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