Since water is essential to grow food, a drought situation can pose major problems for agriculture. Hence, farmers often face extreme poverty in drought-prone areas. Efficient water use techniques are very important in the face of climate change.
Irrigated agriculture is placing increasing pressure on finite freshwater resources, especially in developing countries where water extraction is often unregulated, unpriced and even subsidised. To shift to a more sustainable use of water in agriculture without harming the food security and livelihoods of hundreds of millions of smallholders, substantial improvement in water use efficiency is required. Here are some ways to do it.
1. Use of water efficient irrigation system
Drip and sprinkler irrigation systems are the most water efficient irrigation systems. They deliver water directly to a plant’s roots, reducing the evaporation that happens with spray watering systems. Timers can be used to schedule watering during the cooler parts of the day which further reduces water loss. Many places in Maharashtra, Haryana, Meghalaya and Rajasthan where water is scarce, drip irrigation is efficient. Properly installed drip irrigation can save up to 80 percent more water than conventional irrigation and can even contribute to increased crop yields.
2. Watershed development
Man and his environment are interdependent. The changes in the environment directly affect the lives of the people depending on it. Environmental degradation can be tackled effectively through holistic development of the watershed. Watershed provides a natural geo-hydrological unit for planning any developmental initiative. Watershed development can:
- mitigate the adverse effects of drought on crops and livestock
- control desertification
- encourage restoration of ecological balance
- promote economic development of village community
3. Irrigation scheduling
Modern water management is not just about how water is delivered but also when, how frequent and in what quantity. To avoid under- or over-watering crops, farmers should carefully monitor the weather, the moisture of both soil and plant and adapt their irrigation schedule to the current conditions. Some farmers water at night to slow down evaporation and to let the water seep down into the soil and replenish the water table.
4. Drought-tolerant crops
The drought-prone areas where water scarcity is a permanent problem, growing less water intensive crops like jowar, bajra, ragi and other millets, pulses and lentils, vanilla, black pepper etc can give very good returns with less water requirement. With the advances in biotechnology, many crop cultivars with less water requirement have been released.
5. Dry farming
Farming techniques like the use of mulches, residue management in crop fields, etc are helpful in retaining soil moisture for crop production. Farmers who are practising dry farming don’t use irrigation and depend on the available soil moisture to produce crops during dry season. Special tilling practices and careful attention to microclimates are essential. Dry farming tends to enhance flavours but produces lower yields than irrigated crops.
6. Rotational grazing
Rotational grazing is a method in which animals are shifted between fields to promote pasture regrowth. Good grazing management increases the field’s water absorption and decreases water runoff, making pastures more drought-resistant. Increased soil organic matter and better forage cover are also water-saving benefits of rotational grazing.
7. Mulch and compost
Compost, or decomposed organic matter used as fertiliser has been found to enhance water-holding capacity and improve soil structure. Mulch is a material spread on top of the soil to retain soil moisture. Mulch can be made from organic materials like wood chips or straw which can break down into compost. It further enhances the soil’s water-holding capacity. Compost and mulch can help to retain more water in the soil during dry season. Farmers may also use black plastic mulch as soil cover to suppress weeds and reduce evaporation.
8. Cover crops
Cover crops are meant to protect soil that would otherwise go bare. They reduce weeds and also increase soil fertility and organic matter. They also help to prevent erosion and compaction. Cover crops allow water to penetrate the soil more easily which improves its water-holding capacity. Certain research have found that fields planted with cover crops were 11 to 14 percent more productive than conventional fields during years of drought. Generally, cover crops are selected based on season and agro-climatic condition. In India, most frequently used cover crops are lentils, field peas, berseem, cowpea, soybean etc. It helps in less crop-weed competition.
9. Conservation tillage
Conservation tillage uses specialised ploughs or other equipment that partially till the soil but leave at least 30 percent of vegetative crop residue on the surface. Like the use of cover crops, such practices help increase water absorption and reduce evaporation, erosion, and compaction. Reduced tillage or no tillage is a very good option for environmental safety as it facilitates no burning of crop residue and enriches soil fertility by decomposing it.
10. Going organic
Recent research found that corn grown in organic fields had 30 percent greater yield than conventional fields in years of drought. In addition to keeping many of the more toxic pesticides out of waterways, organic methods help retain soil moisture. Healthy soil that is rich in organic matter and microbial life serves as a sponge that absorbs and retains moisture for plants. The trial also found that organic fields can recharge groundwater supplies up to 20 percent.
The authors are from Indian Agricultural Research Institute (IARI), New Delhi, an institute under the Indian Council of Agricultural Reseach (ICAR), Ministry of Agriculture.
The views and opinions expressed in this article are those of the author/s and do not necessarily reflect the policy or position of India Water Portal.