Themes/Questions

Congress Theme: ‘Tackling Water Scarcity in Agriculture’

Water use within agricultural systems, primarily irrigation, account for almost seventy to eighty per cent of global water withdrawals. With rising temperatures intensifying demand, in combination with more frequent and severe weather extremes impacting production, water scarcity in agriculture is posing a challenge to food security. Among other global trends, population growth and related increases in demand for agricultural and forestry products to provide food, fodder, fibre and fuel put further pressure on water resources.

Freshwater shortages have already begun to constrain socio-economic development in some regions. In many areas, competing uses for water from agriculture, industry, and municipal users further constrain the availability of water for agriculture. Bioenergy production and use put the additional onus on the water resources while an increased intensification of agriculture and water pollution poses an additional challenge. It is not surprising that seven out of seventeen Sustainable Development Goals (SDGs 1, 2, 3, 6, 13, 15 and 17) of UN Agenda 2030, are directly or indirectly influenced by the way we manage our agricultural water.

Increasing water productivity, within the agricultural water management domain, is analogous to achieving water savings (while maintaining yields), which can occur at the plot level and/or at the irrigation-system level, with or without adopting new technologies. With a diminishing share of water for agriculture, food security is feasible only with an increase in agricultural productivity, the efficient use of available water and increasing exploitation of new and non-conventional sources of water.

International Commission on Irrigation and Drainage (ICID) strives for a water-secure world free of poverty and hunger through its mission to facilitate prudent agriculture water management. “Enabling Higher Crop Productivity with Less Water and Energy” is the most cherished goal of ICID Vision 2030. Through its tri-annual Congresses ICID, provides a forum to exchange the knowledge, information and technology solutions that are needed to tackle water scarcity. The 25th Congress, therefore, focuses on the possible solutions of tapping alternative water resources and increasing water productivity through on-farm interventions to tackle agriculture water scarcity.

Question 64: What alternative water resources could be tapped for irrigated agriculture?

The spatial and temporal variabilities in precipitation and water availability call for harnessing the blue water component for different uses. Most irrigation systems operate at levels below the achievable efficiency and have enormous scope to improve their productivity and efficiency. Water use and management in agriculture cross many scales: crops, fields, farms, delivery systems, basins, and the nations. Farmers, as end-users and the main actors in on-farm water management, need enabling conditions in which they are willing to take initiative for improvement in productivity.

In addition to the water withdrawn from surface sources, irrigation requirements of plants can be met through rainwater, greywater, recycled wastewater, and groundwater. Rain-fed agriculture continues to contribute to about 40 per cent of global food production and most of its problems are often associated with high-intensity rainfall with large spatial and temporal variability. The dry spells need to be overcome through supplemental irrigation with the help of rainwater-harvesting systems. Adopting under-irrigation is also a strategy that can be highly beneficial in water-scarce conditions.

As one of the key alternative water resources, wastewater can be used in agriculture to compensate for water shortages, particularly in peri-urban areas. Wastewater irrigation has long development history and has undergone different phases in developing and developed countries that desires appropriate safety practices.

Subtopics:

64.1 – Reinforcing conventional sources of irrigation water.

  • Increasing the reliability of water supply in irrigation systems,
  • Rainwater harvesting and management, including rainwater conservation and on-farm storage,
  • Supplementing with sub-surface water through groundwater replenishment and recharge

64.2 – Tapping non-conventional sources of water

  • Water budgeting by farmers
  • Wastewater (treated and semi-treated sewage) in Irrigation with Good Agricultural Practices,
  • Managing saline and alkaline water for higher productivity

64.3 – Empowerment of farmers

  • Enabling participation through legal instruments – Coperatives, Water User Associations
  • Agriculture Extension Services for irrigation water management,
  • Capacity development through Information Education and Communication

Question 65: Which on-farm techniques can increase water productivity?

Substantially increasing productivity, not only in terms of physical outputs but also in economic terms is essential to meet the goals of poverty alleviation, food security and water security. Water productivity is dependent on, among others, water management practices and agronomic practices. Productivity at different levels of the irrigation system needs to be critically analysed to effectively guide policy interventions and practices vital to achieving the desired objectives. Interventions that close the “yield gap” between a farm’s current yield and its higher potential yield, are especially beneficial in regions where hunger is most acute.

There are several different approaches by which farmers can improve water productivity. Options include those related to plant physiology, which focuses on making transpiration more efficient or productive, agronomic practices, which aim at reducing evaporation, and on-farm agricultural-engineering approaches, which aim at making water application more precise and more effective. Resource conserving techniques such as laser land leveller for field preparation, and ridge-furrow method form part of such a wide spectrum of options. Emerging technologies present a vista of new opportunities such as precision agriculture, biotechnology, sensor technology, bioinformatics, climate-smart agriculture, robotics, drones, artificial intelligence, etc.

Subtopics:

65.1 – Improving management of existing facilities

  • A closer look into the concepts of Water Productivity and Irrigation Efficiency
  • Using real time forecasts on soil moisture, and Extended Hydrological prediction
  • Reducing water flows to sinks - irrecoverable deep percolation and surface runoff - and reusing return flows,
  • Efficient distribution of available water with minimum losses.

65.2 – Improved Agronomic practices

  • Timely application of irrigation water
  • Controlling non-beneficial evaporation
  • Minimizing salinization of return flows

65.3 – Efficient application of irrigation water

  • Reducing non-returnable losses of irrigation water
  • Pressurised irrigation through piped conveyance systems at farm levels
  • Using technologies such as SCADA, sensor technology and precision application