Every crisis produces its fall guy. This time, it is sugarcane that’s bearing the brunt of the blame for drought, especially in Maharashtra’s worst-affected Marathwada region.
Sugarcane, no doubt, requires 2,100-2,200 mm of water, more than the 1,400 mm or so for paddy, 900 mm for cotton, 600 mm for jowar (sorghum) and arhar (pigeon-pea), 550 mm for wheat, and under 500 mm for soyabean and chana (chickpea).
But then, sugarcane typically grows over 365 days, as against the 180 days of cotton and arhar, 130 days of paddy and wheat, 110 days of jowar and chana, and 100 days of soyabean. Besides, even the best Punjab farmer can harvest only six tonnes of wheat and nine tonnes of paddy per hectare, whereas cane yields rarely go below 40 tonnes, while averaging 80 tonnes for Maharashtra.
Simply put, sugarcane consumes less water on a per-day basis, and even less for every unit weight of biomass produced.
Moreover, the sugarcane farmer doesn’t merely grow cane stalks. For every 80 tonnes of cane produced from a hectare, an additional 15-16 tonnes of green ‘tops’ also get harvested. These green top leaves — roughly 20 per cent over and above the millable cane weight — meet much of the fodder needs of his buffaloes and cattle during the crushing season from November to April. The water being used for cultivating sugarcane, thus, also goes towards production of fodder, which the farmer would otherwise have had to grow separately.
But water used for sugarcane cultivation is only one part. Equally important is the fact that the end-product, or the crop itself, is some 70% water. This water — 700 litres in one tonne — is what mills actually use for production of sugar and much more. Out of the 700 litres, about 250 litres is utilised in boilers for generating steam and power, while an equal quantity gets consumed in the sugar manufacturing process. It still leaves a balance of 200 litres, which, after cooling in spray ponds and primary treatment, can be re-used for irrigation and other purposes.
That makes sugar a unique industry, which doesn’t require water from outside, and even generates its own energy from bagasse — the fibrous residue remaining after extraction of juice from the cane. The high-pressure boilers in most mills today use water from the cane and burn the bagasse to produce electricity. Around 130 kilowatt-hours can be generated from every tonne of cane, of which the mills’ own in-process and auxiliary consumption requirement is only 35-36 units, with the remaining 94-95 units being exportable to the grid.
Bashers of sugarcane will tell us how it takes 2,000-odd litres of water to produce one kg of sugar. But they won’t say that this water is consumed over 12 months, or that it goes towards production of fodder, electricity and alcohol as well. And if one were to also add that the mills themselves consume no additional water or electricity — they are surplus in both — it would virtually give a lie to the perception of sugarcane being a water-guzzler.
Incidentally, even the sugar accumulation in the cane takes place only in last 90-100 days of ripening and maturation. The crop’s 365-day duration also covers germination (40-45 days), tillering (springing of stems from the parent shoot: 90-100 days) and grand growth (development of millable canes from tillers: 110-120 days). Much of the water consumption happens in the tillering and grand growth phases that precede sucrose accumulation. This only reinforces the fact that this is primarily a biomass-cum-energy crop, with sugar only one of its constituents.
But for all this nuanced understanding of a much-maligned yet misunderstood crop, one could still ask whether a region like Marathwada, receiving an average annual rainfall of slightly over 820 mm, should be growing cane at all. The answer, on the face of it, might be no, given that a water requirement of 2,000 mm-plus is too much for any crop in a traditionally drought-prone belt.
However, even the above statement needs qualification in the light of the fact that the total area under sugarcane in the eight districts of Marathwada has ranged between 2.2 and 2.4 lakh hectares (lh) annually; in 2015-16, it fell to less than 1.9 lh. The accompanying table shows this to be way below the corresponding acreages under cereals (mainly jowar, maize and bajra), cotton, pulses (arhar, urad, moong) or oilseeds (soyabean).
It is difficult to see how a crop accounting for just over 2 lh out of Marathwada’s estimated 70 lh gross cropped area be the cause for drought, as many NGOs and drawing room experts are claiming. The drought and the accompanying rural distress in the region is the result of the monsoon’s failure in three out of the last four years. Period.
All this is, of course, not to argue against efforts to promote water use efficiency in sugarcane. Replacement of flood irrigation methods with drip irrigation has been shown to bring about water savings of 40-50 per cent, while simultaneously boosting yields by up to a third. The latter is on account of the water being delivered directly to the plant’s root zone (where it is really required) and the remaining soil area getting enough air to maintain an optimum air-water-nutrient balance. With drip irrigation and judicious use of canal water, it should be possible for even Marathwada’s farmers to realise the enormous food, energy, and fodder potential offered by a most versatile crop.
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