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GS3 - Agriculture

Introduction

India, with 4% of the world's freshwater resources, is already a water-stressed country due to a 78% decline in water availability per capita per year since the 1950s. 

The Food and Agriculture Organization (FAO) report highlights the importance of increasing water-use efficiency, which is a measure of the value of water to the economy and society. India's water-use efficiency is only USD 1.9/m3, a cause for concern.

What is WUE?

WUE is a measurement of a cropping system's ability to turn water into plant biomass or grain. It encompasses both the use of soil water and rainfall throughout the growing season.

WUE depends on:

• Soil's capacity to catch and store water; 
• The crop's capacity to access water held in the soil and seasonal rainfall; 
• The capacity of the crop to transform water into biomass; and 
• Harvest index, which measures how well a crop can transform biomass into grain 

Why is enhancing WUE important?

• In order to maintain life in the face of the challenges posed by climate change, improving water use efficiency in all sectors of water use, including irrigation, is essential.
• Increasing water-use efficiency has a substantial impact on long-term agricultural production, economic growth, infrastructure and industrialization, cities and human settlements, and consumption and production.
• With water resources becoming increasingly scarce, it is critical to use irrigation practices and systems that improve water usage efficiency so that the water saved may be used for increased irrigation or other beneficial purposes.

Comparison of the WUE in traditional canal distribution networks and micro-irrigation systems

India's agricultural distribution network has an overall efficiency of 35-50%, with a weighted average overall project WUE of 36%. 
Micro Irrigation techniques like drip and sprinkler can save up to 40% of water over conventional flood irrigation methods, enabling extended coverage and improved water use efficiency. These techniques also reduce water-logging, fertilizer usage, labor expenses, and other input costs, enhancing agricultural productivity and farmers' income.
An impact evaluation study found that improving water use efficiency helps cover more area under irrigation, bridging the gap between irrigation potential created and used.

Methods to Improve Water Use Efficiency 

The primary goal is to preserve and use a substantial amount of the available rainfall for agricultural production. 

The following practices must be implemented in order to enhance water efficiency.

• Maximum precipitation absorption into the earth, resulting in the elimination of surface runoff. The following practices have been implemented.

1. Runoff Control: Various methods should be used to control runoff.
2. Tillage: The use of instruments for mechanical manipulation in order to create seedbeds conducive to field crop development. This technique boosts the soil's water retention capacity and infiltration rate.
3. Water harvesting: The collection of rainwater for present and future usage.
4. Water Recycling: Water recycling (also known as wastewater reuse or water reclamation) is the process of transforming wastewater into water that may be used for other purposes. Irrigation of gardens and agricultural areas, as well as replenishment of surface and groundwater, are examples of reuse.

• The following practices are used to reduce unproductive moisture losses such as evapotranspiration, weed water consumption, and losses due to subsurface flow and deep percolation, among others.

1. Weed Control: Weeds are a significant cause of water loss due to evapotranspiration. These can be regulated using various mechanical, agronomical, biological, and chemical methods, among others.
2. Crop harvesting at the proper time: Crops should be harvested at the proper time to prevent water losses.
3. Mulching: Mulching is the use of any material like straw, plant wastes, leaves, loose soil, or plastic film put on the soil surface to minimize ET, and erosion, or to shield plant roots from exceptionally low or high temperatures.
4. Primary and Secondary Tillage: Using primary and secondary tillage lowers these losses.
   

• The following actions are taken to improve the effective utilization of rain and stored soil moisture.

1. Cropping System: Choosing an appropriate cropping sequence is critical to the correct and optimal utilization of precipitation and stored soil moisture.
2. Crop and Variety Selection: Crops and varieties should be chosen based on water availability.
3. Seeding and Fertilizer Placement Technique: Proper seeding and fertilizer placement are critical for rabi season crops that develop on stored soil moisture.

Which nations have enacted it?

Various nations, like Singapore and Australia, have attempted to increase water consumption efficiency by developing a market for water-efficient items. 

Australia

• It implemented the Water Efficiency Labeling and Standards Scheme (WELS) in 2005 with the goal of lowering water usage by promoting the use of water-saving goods and technology.
• Products are assigned a 'Water Efficiency Rating,' allowing buyers to use water efficiency as a criterion in their purchasing decisions. 
• This grading system has been used for water-using appliances and items such as showers, faucets, flow controls, urinals, dishwashers, and washing machines.

India

• The Government of India established the Bureau of Water Use Efficiency (BWUE) to promote, regulate, and control water efficiency in the irrigation, industrial, and home sectors. 
• In the irrigation sector, the Ministry of Jal Shakti is pushing various water-saving technologies like underground pipelines and micro-irrigation (drip irrigation and spray irrigation) as part of the Pradhan Mantri Krishi Sinchai Yojana (PMKSY) Scheme. 
• To improve water efficiency, the Bureau of Indian Standards (BIS) has issued Indian Standards for Micro-irrigation and Sanitary Products. The Government of India has also established other water conservation schemes such as Rain Harvesting, Catch the Rain, Jal Shakti Abhiyan, Amrit Sarovar, and soon.

Steps taken by the government to improve WUE

National Water Policy (2012)

• The National Water Policy 2012 addresses water efficiency concerns. 
• Aim: To assess the current situation and propose a national framework for conservation, development, and improved management of water resources.
• A drafting committee was formed in 2019 to revise the policy through consultation with stakeholders, including State Governments, to address emerging challenges. 

National Water Mission 

• The National Water Mission, which was unveiled on June 30, 2008, was one of the eight national missions created by the National Action Plan on Climate Change. 
• Its five objectives included increasing water use efficiency by 20% across all sectors by the end of the 12th Five-Year Plan, or by 2017.

Pradhan Mantri Krishi Sinchai Yojana (PMKSY) 

• It was established in July 2015 with the main goals of "Har Khet Ko Pani" (assuring water to every farm through assured irrigation) and "Per Drop, More Crop" (ensuring greater productivity through micro irrigation). 
• PMKSY offers a convergence of four components with the aid of three Central Government Ministries. 
• The Ministry of Agriculture, Cooperation, & Farmers Welfare is responsible for the "Per Drop, More Crop" component.

Idea of a Piped Irrigation Network to Prevent Land Acquisition Issues 

• When using the traditional open canal network system to transport and apply water, land acquisition is a problem in and of itself. 
• It is also the primary cause of the discrepancy between IPC and IPU. 
• In July 2017, the Central Water Commission published its ground-breaking "Guidelines for Planning and Design of Piped Irrigation Network" for water conveyance and application to increase irrigation efficiency and address land acquisition issues through a widely consultative process at a time when there are no ready-made guidelines or BIS standards available on this concept. 

Micro-Irrigation Micro-irrigation is a contemporary method of irrigation in which water is watered on the land's surface or subsurface using drippers, sprinklers, foggers, and other emitters.  The following are the major components of a micro-irrigation system. Water supply, pumping devices (motor and pump), ball valves, fertigation equipment, filters, control valves, PVC connecting accessories (Main and sub-main), and emitters are all included. Water is applied drop by drop closer to the crop's root zone region with this approach. The drippers are set based on crop spacing. There are several types of emitters on the market.  They are divided into four types:  Inline drippers On line drippers, microtubes Pressed compensated drippers Drip irrigation is best suited for crops with broader spacing. Micro Sprinkler irrigation is commonly used in sandy or loamy soils. This method works best with horticultural crops and tiny grasses. Water is sprayed from a lower height in numerous directions in this manner. There are also portable micro sprinklers available. They provide somewhat more water distribution than drippers and micro sprinklers. They spray water within a one-meter radius. It is used to prepare nursery and lawn soils with limited water retention capabilities.  Micro-Irrigation Fund The Cabinet Committee on Economic Affairs approved Rs. 5,000 crore for a Micro Irrigation Fund (MIF) under PMKSY, aiming to cover 10 million ha over 5 years by effectively utilizing resources and incentivizing micro-irrigation. Adoption by the states The Task Force on Micro Irrigation estimates 69.5 m Ha of potential, with 14% covered. States like Rajasthan, Andhra Pradesh, Maharashtra, Gujarat, Karnataka, and Haryana are adopting modern techniques to address water scarcity. Awareness through Krishi Vigyan Kendras and Melas The Department of Agriculture, Cooperation, and Farmers Welfare (DAC&FW) and the Indian Council of Agricultural Research (ICAR) are raising awareness about micro-irrigation through media coverage, leaflets, workshops, exhibitions, and farmer fairs, with over 10.8 crore farmers trained.

Conclusion

Improved water use efficiency through the persistent and coordinated efforts of individuals, groups/associations of individuals, and the Government implementation agencies/institutional mechanisms will go a long way in successfully coping with the challenges posed by climate change and the ever-increasing population on available water resources and will result in the optimum and efficient use of precious water, adding to enhanced productivity, prosperity, and sustainability.