Rice growers generally use much more water than the crop actually needs. Estimates show that 40-45 per cent of the water used for irrigation goes to paddy alone. This, perhaps, is the result of the mistaken belief that paddy is an aquatic plant that needs standing water to thrive. The truth, however, is that though rice plants can survive in waterlogged fields, they do not necessarily need flooding all the time.
The key advantage of constant submergence is that it keeps weeds under check. But its disadvantages are many and far more serious. It causes loss of applied plant nutrients due to leaching, increases emissions of environment-injurious gases, especially methane, and encourages proliferation of pests and diseases. Unsurprisingly, nearly 10 per cent of the methane emission come from paddy fields.
The intensive rice-wheat growing belt in the Indo-Gangetic plain, particularly Punjab, Haryana, and western Uttar Pradesh, as also several other states where power and diesel used for running water-pumps are free or heavily subsidised, are notorious for splurging water. The water table is declining rapidly in all these areas, approaching the inaccessible depths in many of them. In Punjab, for instance, studies have shown that the water table is receding, on average, by about one metre every year. The state has already lost about 85 per cent of its subsurface water due to reckless exploitation. Such a situation cannot be allowed to continue.
There are chiefly two ways to address this issue. The first one is to replace paddy with another equally lucrative but less water-consuming crop. But this is hard to do as long as the policy of open-ended rice procurement at pre-determined prices continues. And this practice seems unlikely to change in foreseeable future. The second and more practical option is to promote economical and efficient use of water, for which technologies are now available. Direct sowing of paddy seeds, instead of taking the transplanting route, is the most convenient and time-tested method of doing so.
Direct seeding ensures a normal harvest with substantially lower water consumption by doing away with the labour and cost-intensive operations, such as nursery planting, soil puddling, and seedling transplanting. Under this system, dry or pre-germinated seeds are sown straight in the fields with the help of seed-drill machines. For best results, land needs to be perfectly even — levelled, preferably, with the help of laser land levelling equipment. The menace of weeds is tackled by spraying herbicides prior to sowing or after seed planting, according to the need.
This technique was originally commended by farm scientists for medium to heavy textured soils. But subsequently they found that it could be used even on relatively light-textured sandy loam and loam soils as well. This means that it can advantageously be adopted by farmers in a large part of the country. Rain-dependent areas can specially benefit from it. In fact, this system is now gaining popularity in unirrigated lands in many states. It got a major boost during the Covid-19 pandemic, when the reverse migration-driven paucity of labour forced farmers to look for less labour-intensive ways of growing rice. Many of them have preferred to stick to this method even after the normalisation of the situation.
In Punjab, where the bulk of the paddy crop is irrigated with groundwater, efforts to promote direct seeding of rice have started showing results now. About 600,000 hectares of paddy was planted with this method last year. This year, the state government hopes to double this area to around 1.2 million hectares by offering a cash incentive of Rs 1,500 per acre (Rs 3,750 per hectare) to the adopters of this technology. The farmers have also been allowed to start planting the crop from the last week of May instead of the middle of June, which is normal. The Haryana government has gone a step further by announcing a higher incentive of Rs 10,000 per hectare for direct planting of rice.
The advantages of direct seeding of rice are, indeed, many and of various types. It cuts down the consumption of water by 20-35 per cent and that of diesel and power by nearly 40 per cent. Besides, it helps save 35-40 mandays of labour for every hectare of cropland. Moreover, it improves soil health and fertiliser-use efficiency, resulting in higher crop output with lower cash inputs, thereby, raising the net profits. This apart, it allows the crop to mature seven to 10 days earlier than normal, leaving more time for farmers to appropriately manage paddy stubbles instead of torching them to cause air pollution. And, most importantly, it reduces methane emission from paddy fields.
Since the paddy-sowing season is now round the corner, it seems an ideal time to mount campaigns, and offer incentives, to promote direct seeding of rice in areas where agro-ecological conditions permit the deployment of this technology. The benefits of such an initiative would far outweigh the costs.
surinder.sud@gmail.com