Paddy and the Price of Water

Why in News?

• So far, the southwest monsoon season (June-September) has registered 37.2% deficient rain. 
• With the looming crisis El Niño (which typically suppresses rainfall in India) to fully set in by this month-end, the outlook for the rest of the season does not look great.

 

Paddy Crop and the Impact of Monsoon 

• Paddy is the most important food crop of India covering about one-fourth of the total cropped area and providing food to about half of the Indian population.
• It a very high water-intensive crop and therefore a weak monsoon can impact the yield of paddy (rice and husk). 

 

Conventional Method: Transplanting of Paddy Crop 

• The cultivation entails preparing nurseries, where the seeds are first raised into young plants that are uprooted and re-planted around 30 days later in the main field.
• During the nursery stage, water equivalent to one round of irrigation is given.

 

Disadvantage of Conventional Method: Use of High amount of Groundwater 

• The real water consumption starts after the transplantation.
• The field in which the seedlings are transplanted is usually irrigated once, before being “puddled” or tilled in standing water. 
• Puddling churns the soil, making it softer for transplanting, and breaks its capillary pores through which water percolates down. 
• This operation alone consumes water equivalent to three irrigations.
• For the first two weeks or more after transplanting, farmers must irrigate every 1-2 days to maintain a water depth of 4-5 cm, necessary to prevent weed growth during the crop’s early stage. 
• In all, the conventional transplanting route requires some 28 irrigations. 
• It can go up if high temperatures force more frequent watering, and go down if there is enough rain.
• Each irrigation consumes roughly 5 hectare-cm or 500,000 litres of water (one hectare-cm is one cm of standing water in one hectare area, equal to 100,000 litres).

 

DSR (Direct Seeding of Rice): New Paddy Cultivation Method 

• Direct seeding of rice (DSR) is a new method. In Haryana and Punjab, farmers are being encouraged to use this method for their paddy crop. 
• In this method, Paddy is sown directly in the field without any nursery preparation, puddling or flooding.

 

Advantages and Disadvantages of DSR 

• Advantages
  • It is labour saving. This advantage is the main reason for its current focus in times of large-scale labour shortages. 
  • It is water saving. It requires 30-40% lesser water compared to the transplantation method.
• Disadvantages
  • The seeds required under the DSR method is higher. While transplantation method requires 4-5 kg of seeds/ acre, the DSR method requires double the quantity (8-10 kg of seeds/ acre).
  • Availability of herbicide is a major challenge.

 

Comparison of Conventional Method of Transplantation and DSR 

• In transplanting, the flooded fields basically deny oxygen to the weed seeds in the soil, preventing their germination. Water, thus, acts as a natural herbicide. In DSR, water is replaced with chemical herbicides.
• The total number of irrigations for a 155-160 days crop works out to 21-22 in DSR method, as against 28-plus in transplanting. 
• It takes 4-5 labourers working a whole day to transplant an acre of paddy. Whereas, a DSR machine can cover the same area in 1.25-1.5 hours. 

 

Why are Farmers Still Reluctant to Use DSR? 

• Subsidised or Free Electricity: A key reason is subsidised or even free electricity for irrigation, providing farmers little incentive to deploy water-saving technology. 
• Lack of Good Machines
  • The recommended spacing for paddy is 20 cm row-to-row and 15 cm plant-to-plant, allowing for a plant population of 33 per square meter.
  • The DSR seed drill machines mostly sow row-to-row and do not get the plant-to-plant distance right. 

 

Steps Taken by the Government to Encourage DSR:

• The Haryana and Punjab governments are offering farmers Rs 4,000 and Rs 1,500 per acre respectively to grow paddy using DSR, instead of transplanting.  

 

Way Forward - New Methods should be Explored:

• System of Rice Intensification (SRI):
  • It promises to save 15 to 20% ground water, improves rice productivity, which is almost at a stagnant point now.
  • Experts said that it gives equal or more produce than the conventional rice cultivation, with less water, less seed and less chemicals.
  • The net effect is a substantial reduction in the investments on external inputs.
• Fish-rice farming method
  • In this method, fishes are reared in the flooded rice fields. These fishes reduce methane emission from the rice fields and act as additional income source for the farmers apart from adding nutrients to the soil.
  • This reduces dependence on pesticides and fertilisers.
• Save and Grow method 
  • This method was introduced by Food and Agriculture Organization that seeks to ‘produce more with less’.
  • It focuses on aspects like conservation agriculture, proper crop selection, efficient water management, etc.
• Crop Diversification: Beyond Paddy, push for crops that pay: In a push for crop diversification, experts have recommended several Kharif crops (like Moong lentil, Mah lentil, Arhar lentil)to the farmers to avoid ‘over-sowing’ of the water-guzzling paddy (non-basmati) crop.

 

Conclusion 

• The traditional methods of rice cultivation are labour intensive and require a high amount of groundwater.
• The government must work with farmers to explore new methods to save the groundwater. 
• When farmers are not ready to shun paddy sowing, any technique that claims to save groundwater must be researched and promoted.

 

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Q1) How will climate change affect rice production?

Climate change will aggravate rice production under climatic variability. Rice growth is sensitive to temperature, where warm daytime temperatures provide ideal conditions, and extreme heat events over 35 °C for even a few hours can impair plant physiology and deteriorate rice quantity and quality. 

 

Q2) Why is the Rice cultivation called water guzzler? 

Rice as grown in India is a water-guzzler, because farmers use on an average 15,000 litres to produce one kg of paddy, though water technologists at the Indian Agricultural Research Institute in New Delhi say no more than 600 litres is needed if proper water management techniques are followed. Given that 45 per cent of the country's total irrigation water is used solely for rice cultivation, the need to improve farming methods is imperative.

 

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Source: The Indian Express