Evolving thinking on Agricultural Water Productivity: Lessons learned from 20 years of research

Meredith A. Giordano International Water Management Institute (IWMI)

Peter G. McCornickRobert B. Daugherty Water for Food Global Institute

World Bank Water WeekMarch 15, 2017

1996

Agricultural Water Productivity: Origins of water productivity research at IWMI

• Efficiency is a “tricky” concept in the field of water (does not account for capture and reuse of water)

• Scope for real water savings is often less than imagined

• New concepts are needed to address the “increasingly difficult problems facing water management”

• Water Productivity: Output (kg/$) in relation to water use (in terms of water withdrawn, applied or consumed)

> 300 journal articles, reports and other documents on water productivity:

methods, tools and applied research in diverse settings

Case Study: Water savings myths and realities

Background• Objective: Assess the impact of “resource conservation” practices on

water application, water productivity and real water savings• Location: Rechna Doab, semi-arid Punjab Province, Pakistan

Rice–wheat cropping zones in the Indus Basin of Pakistan and location of sample farms surveyed in and near Rechna Doab, the Punjab, Pakistan. Source: Ahmad et al. 2007, 2014

At field scale: Water application reduced

Field-scale impacts of laser leveling and zero tillage technologies (Ahmad et al. 2014)

At field scale adoption of resource conservation technologies led to• 24-32% reduction in water

application at the field scale• Increased farm level incomes

At system scale: Water consumption increased

Ahmad et al. 2007

Overall water consumption at the system scale increased by 59 million cubic meters/year following the adoption of “resource conservation” technologies.

Belief Reality

Transpiration Evaporation

Flood irrigation

Zero till

Transpiration Evaporation

Transpiration Evaporation

Flood irrigation

Transpiration Evaporation

Zero till

Some of the “wasted” water had actually been reused

Flood irrigation

Zero till

• Reductions on water applications at the field scale translate into reduced water consumption in the system (i.e., farmers won’t use the “saved” water).

• Net farm incomes increased.

• Increased profitability incentivized farmers to expand cultivated area and/or increase cropping intensity.

Belief Reality

Impact depends on physical setting

Groundwater quality in the Indus Basin, Ahmad et al. 2014

2017• Define terms carefully (e.g., water applied versus consumed) • Scale and context matter • Know your objective (i.e., improving

water productivity is not the end goal)• Be clear on the use and limits of

single factor measures

Agricultural Water Productivity Lessons learned from 20 years of applied research

Thank You

Ahmad, M.D.; Masih, I.; Turral, H.; Giordano, M.; Masood, Z. 2006. Opportunities and challenges in saving water and improving productivity through resource conservation technologies: Examples from Pakistan. In: International Workshop on Water Saving Technologies, Amritsar, Punjab, India, February 22-24, 2006. New Delhi, India: United States Educational Foundation in India. Pp. 120-139.

Ahmad, M.D.; Giordano, M.; Turral, H.; Masih, I.; Masood, Z. 2007. At what scale does water saving really save water? Lessons from the use of resource conservation technologies in Pakistan. Soil and Water Conservation 62(2): 29A-35A.

Ahmad, M.D.; Turral, H.; Masih, I.; Giordano, M.; Masood, Z. 2007. Water saving technologies: Myths and realities revealed in Pakistan’s rice-wheat systems. Colombo, Sri Lanka: International Water Management Institute (IWMI). 38p. (IWMI Research Report 108).

Ahmad, M.D.; Masih, I.; Giordano, M. 2014. Constraints and opportunities for water savings and increasing productivity through Resource Conservation Technologies in Pakistan. Agriculture, Ecosystems and Environment 187: 106-115.

Giordano, M.; Turral, H.; Scheierling, S. M.; Tréguer, D. O.; McCornick, P. G. 2017. Beyond “More Crop per Drop”: evolving thinking on agricultural water productivity. Colombo, Sri Lanka: International Water Management Institute (IWMI); Washington, DC, USA: The World Bank. 53p. (IWMI Research Report 169).

Seckler, D. 1999. Revisiting the" IWMI paradigm:" Increasing the efficiency and productivity of water use. International Water Management Institute (IWMI): Colombo, Sri Lanka

References