Surinder Sud: Sugarcane for the poor

FARM VIEW

Sweet sorghum can be grown purely as a rainfed crop as its water requirement is merely a fourth that of sugarcane.

Sugarcane may soon have a formidable rival for the production of ethanol, though not sugar. The contender is sweet sorghum, a special type of sorghum (jowar) that accumulates sugar in its stalks which can be converted into ethanol in a cost-effective manner. Realising the potential of this crop, some national and international agricultural research organisations have already begun promoting it. Several sugar and chemical factories, too, have started trying this plant out for producing ethanol for supplying to oil companies for admixing with petrol as mandated by the government's policy of selling ethanol-doped petrol in selected states.

As such, sweet sorghum can really be for the resource-poor tillers of unirrigated farms what sugarcane is for the resourceful farmers owning good quality irrigated lands. In fact, in some respects, sweet sorghum can be of more value to the farmers in distress as this crop produces both food and feed in addition to income-generating stalk juice for making biofuel. This apart, its grains can also be used for commercial production of potable alcohol and the bagasse obtained as by-product after juice recovery can be used for generating power as in the case of sugarcane bagasse.

Significantly, like sugarcane and maize, sweet sorghum is a C4 plant in terms of metabolism. This essentially means that it is a more efficient converter of atmospheric carbon dioxide into sugar than the plants belonging to C3 and C2 categories. Besides, sweet sorghum can be grown purely as a rainfed crop as its water requirement is merely one-fourth of that of sugarcane. Moreover, sweet sorghum is a relatively photo-insensitive crop and, as such, can be grown in kharif as well as rabi seasons in different parts of the country. It takes only around four months to grow, against 12 to 18 months taken by sugarcane.

The Hyderabad-based National Research Centre for Sorghum (NRCS), which is spearheading the research and development work on this crop, has already developed several varieties and hybrids of sweet sorghum suitable for Indian conditions. Some other public and private bodies are also engaged in this task. The improved varieties and hybrids developed in the public sector include SSV 84, CSV 11SS (RSSV 9) and CSH22 SS hybrid (NSSH 104). In the private sector, Advanta Seeds has come out with a hybrid PAC 52093 or Praj 1.

The NRCS feels that this crop is best suited for growing in the country's rainfed tracts of central and south India, besides sub-tropical areas in the Indo-Gangetic belt. Most the available strains yield around two tonnes a hectare of grain sorghum apart from 35 to 55 tonnes a hectare of fresh stalks (called sorghum cane). The juice content of the sorghum canes ranges from 16 to 18 per cent in kharif and 10 to 14 per cent in rabi season. The juice has a total reducing sugars (TRS) content of 10 to 14 per cent.

The production cost of ethyl alcohol from sweet sorghum juice has been assessed by the NRCS at around Rs 18.75 a litre, against the present ethanol price of around Rs 21.50 a litre being offered by oil companies for ethanol produced from molasses. In fact, taking into account the value of grains and that of other uses of this crop, the net profit for the sweet sorghum cultivators has been reckoned at around Rs 23,250 a hectare.

Among the global bodies, the International Crops Research Institute for Semi-arid Tropics (ICRISAT), located at Patencheru near Hyderabad, is taking up initiatives to bring together sweet sorghum producers and ethanol manufacturers. It has farmed public-private partnership with Rusni Distillery to set up a 40,000-litre per day capacity fuel-ethanol and extra-neutral alcohol re-distillation plant at Mohammed Shahpur village in Medak district. The objective of this initiative is to improve income and livelihood security of the poor by helping them to cultivate the high-sugar sorghum varieties identified by the NRCS and the ICRISAT for supplying to the industry. The other sugar and chemical factories which are experimenting with sweet sorghum production for ethanol manufacture on a significant scale include, among others, Sagar Sugars at Chittoor, Somaiya Organo-chemicals at Sakarwadi, India Glycols at Kashipur and Tata chemicals at Latur, Parbhani and Badau.

However, if sweet sorghum cultivation catches on, as seems likely in view of the promise this crop holds out, more players are bound to come forward for the manufacture of alcohol and gainful utilisation of other products and by-products.