Abstract

Addressing the Millennium Development Goals on food and poverty over the coming decade puts enormous pressure on the world's finite freshwater resources. Without water productivity (WP) gains, the additional freshwater in agriculture will amount to 5,600 km(3) year(--1) in 2050. This is three times the current global irrigation use. This paper focuses on the underlying processes and future opportunities of WP gains in water scarcity prone and poverty stricken savannah regions of the world. The paper studies the consumptive (green) WP dynamics rainfed farming systems, and shows that the often assumed linear relationship between evapotranspiration (ET) and yield (Y) does not translate into constant WP over a wide range of yields. Similarly, crop transpiration (T) and Y show non-linearity under on-farm and low yield conditions. This non-linearity is validated against several on-farm research experiments in semi-arid rainfed farming systems. With integrated soil and water management, focusing on dry spell mitigation and soil fertility can potentially more than double on-farm yields, while simultaneously improve green (ET) WP and productive green (T) WP. Through the adoption of appropriate soil and water management in semi-arid smallholder farming systems, crop yields improve and result in improved livelihoods and WP gains.

Published in

Irrigation Science
2007, Volume: 25, number: 3, pages: 299--311
Publisher: Springer Nature

UKÄ Subject classification

Oceanography, Hydrology, Water Resources
Agricultural Science


Publication identifier

DOI: https://doi.org/10.1007/s00271-007-0062-3

Permanent link to this page (URI)

https://res.slu.se/id/publ/102548