Sweet Sorghum

Sweet Sorghum : Stem (Stalk feed), Leaves (Silage), Grains, bagase

Sweet sorghum is any of the many varieties of sorghum which have a high sugar content. Sweet sorghum will thrive under drier and warmer conditions than many other crops and is grown primarily for forage, silage, and syrup production.

The stem juice of sweet sorghum is rich in fermentative sugar and is a desirable alcoholic fermentation material. It is difficult to measure the juice Sugar content in the process of production. The sugar content is commonly expressed with juice brix degree, but the relation between sugar content and brix degree has not been very clear. The objective of this study was to find out their relation and tell the sugar content by means of the measurement of juice saccharine more accurately, which may provide a theoretical basis for crop breeding and fermentation. In addition to fermentative sugar, other kinds of sugars are also found in the stem juice of sweet sorghum. The acquirement of the contents of different sugars is beneficial to the enhancement of alcohol production rate. There are also some ammonia acids and minerals in the juice, measuring their contents enables us to use sweet sorghum better with multi-purpose.

  • Food (grain flour, malt, malt beverage, beer)
  • Feed (todder, tilage, crop residue)
  • Fuel (green energy in ethanol, bagase)
  • Industrial (fibreboard, paper, cardboard)

The current research determined the sugar content and brix degree of different varieties in different growth stages. The results gave a scientific basis for the arrangement in the varieties and their sowing dates, so as to prolong the fermentation period and increase efficiency of the alcoholic fermentation device usage. It also provides scientific uses for harvesting operations and feedstalk supply management to the crushing plant

  1. 1
    Location in Nigeria

    The present target of sweet sorghum production areas is the dry areas of Ondo State (Akoko North West and North East areas i.e Arigidi and Ajowa), Osun (Okuku area) and the northern parts of Oyo State Isehin and Ipokia area situated within the Southern Guinea Savanna agro-ecological zone or other places with distinct wet and dry seasons.

    The Northern part of Ekiti State is a semi-arid region, sparsely populated and normally described as the southern Sudan Savannah. The climatic conditions are suitable for sweet sorghum cultivation. This and the successful acquisition of nearly 10,000hectares of land within (10,000 square kilometers) of Oye Local Government area and around Ikole, Isan, Ayede, Igede, Omuo

    Other potential growing areas are in Niger, Adamawa and Taraba States where there are existing sugarcane mill-distilleries

  2. 2
    Vegetation cover and cropping pattern

    The North West portion of the Akoko area is a derived savanna zone with some semi-arid type shrubs. This southern Guinea Savannah vegetation supports the large scale cultivation of drought resistant crops like the Sweet Sorghum. This low human density area deteriorates into highly denuded impoverished soil zone in the North East of Akoko province.

    The potential of this portion of the total area under rainfed agriculture is limited as hydrologic ratios are low (0.5) leading to water deficit (>600mm) and occurrence of drought; but supports irrigation-supported plantation agriculture. Dams for irrigation agriculture, and use of legumes will improve cultivation of this area. The good thing about the North West and North East LGAs of Akoko in Ondo State is the relatively pen-plain characteristics which will ensure impoundment or harvesting of surface water

    “Sweet sorghum” is a special-purpose sorghum (Sorghum bicolor (L.) Moench) with a sugar-rich stalk similar to sugarcane. Besides having rapid growth, high sugar accumulation, and biomass production potential, sweet sorghum has wide adaptability (Reddy and Sanjana 2003). Given that water availability is poised to become a major constraint to agricultural production in coming years (Ryan and Spencer 2001), cultivation of sugarcane becomes difficult. Sweet sorghum would be a logical crop option in lieu of sugarcane in such situations.

    Sweet sorghum can be grown under rainfed conditions with less irrigation. Also less purchased inputs are needed compared to sugarcane. The sugar content in the juice extracted from sweet sorghum varies from 16-23% Brix. It has a great potential for jaggery, syrup and most importantly fuel ethanol production (Ratnavathi et al. 2004a). The stillage after extraction of juice from sweet sorghum can be used for co-generation of power.

  3. 3
    ``Sweet, Sweet`` Sorghum

    Most of the fuel ethanol around the world is produced from the molasses left over from the refining of sugar from sugarcane, but the supply of molasses is insufficient and not reliable enough for costly ethanol production facilities that need to keep working around the clock to pay off. Recent emphasis has shifted to the use of cassava and maize (Krishnader Calamur: “Analysis: Ethanol’s hurdles” UPI Energy Correspondent. Both of these crops are major food staples for Nigeria’s farm families. Their use for ethanol production could reduce their availability for food unless there are drastic increases in quantities produced. The constraint therefore is not the cost of ethanol production; it is the supply of raw materials for its production. This is where the work by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) and partners comes in. We, at Global Biofuels Ltd are excited about the potential of an erstwhile “orphan” crop, sweet sorghum, to help fill this supply gap for raw materials for ethanol production. ‘Sweet’ varieties of sorghum store large quantities of energy as sugar in their stalks, while also producing reasonable grain yields

    Before now, the major use for the stalk of sorghum for domestic purposes such as fencing and hut construction. What is not used for these purposes was usually left to rot away in farms or burnt. Thanks to ICRISAT, sorghum stalk will become much more valuable not only to the farmer but also to the world at large.

    Sorghum, like sugarcane and maize, exhibits C4 metabolism – making it more efficient at converting atmospheric carbon dioxide into sugar than most plants. As a dryland crop, sorghum requires far less water than costly irrigated sugarcane, making it more accessible to the poor. The juice squeezed out of sweet sorghum stalks contains about 15-20% sugar that can be fermented into ethanol more cheaply than from sugarcane molasses – and with even greater energy savings compared to maize grain, which has to be hydrated and converted from starch to sugar before it can be fermented.

  4. 4
    Best Alternative Raw Material

    In our attempt to invest in fuel ethanol production, we have decided to learn from the example of India. The Supreme Court of India early in 2001, informed the Government of India (GOI) to use Compressed Natural Gas (CNG) as an alternative to petrol and diesel for fuelling automobiles to reduce environmental pollution.

    However, considering the reduced output by the Oil and Natural Gas Corporation (ONGC), and thereby likely shortage of CNG in future (Anonymous 2001), the GOI has made it mandatory to blend petrol and diesel with ethanol (to reduce carbon monoxide emission in automobiles) initially up to 5% and gradually hiking it to 10% in the second phase.

    There are two objectives in this strategy: reducing both the environmental pollution and the fuel-import bill for the country. According to the Federation of Indian chambers of Commerce and Industry (FICCI), India could save nearly 80 million L of petrol annually if petrol is blended with fuel ethanol to a level of 10%. Burning quality of ethanol-blended petrol is more eco-friendly than that of CNG (Arbatti 2001). These environment and cost considerations triggered a debate on the availability of adequate raw materials for ethanol production able to meet the actual demand in the long run (Ratnavathi et al. 2004b).

    The requirement of ethanol in India to blend with petrol (10%) is about 1000 million L, and for blending with diesel (5%) another 3000 million L per annum. Total ethanol requirement including other purposes is 5000 million L per annum. The possible ethanol production from available sugarcane molasses (8.2 million t) and other sources is 2000 million L per annum.

    This leaves a deficit of 3000 million L of ethanol per annum. Further, the molasses-based ethanol distilleries operate only for 180 days (during sugarcane crushing season) because of the limited availability of the molasses to run the distillery throughout the year as well as the problems associated with the spent wash to comply with pollution control standards (Personal communication from Patil, Vasanthadada Sugar Institute (VSI), Pune, India).

    The existing distilleries therefore, operate at 50% efficiency and need alternative raw material(s) to operate at their full efficiency (Anonymous 2004). The underutilization of the existing molasses-based ethanol distilleries and the deficit in ethanol requirement can be made good if sweet sorghum cultivation is promoted for ethanol production.

    Global Biofuels Ltd. (RC 679588), a subsidiary of NeGSt Global Integrated Co. Ltd., is implementing a project to convert the juice from the stalk of sweet sorghum (Sorghum bicolor (L) Moench) to ethanol

    Our Partners

    ICRISAT India
    NNPC Corporation
    PRAJ Industry India
    IAR Samaru Nigeria
    OCEANIC Bank Nigeria
    SKYE Bank Nigeria
    Government Of Ondo State Nigeria
    Government of Ekiti State Nigeria
    Government of Osun state Nigeria