Science News 09/05/2014

Water-saving innovations in Chinese agriculture

Scientists from China, Australia and Canada have published a critical review of China's freshwater shortage and associated agricultural production and environmental issues.

Featured in the prestigious journal Advances in Agronomy, the article was co-authored by Hackett Professor Kadambot Siddique and Winthrop Research Professor Neil Turner, both from The University of Western Australia's Institute of Agriculture.

"China faces severe freshwater shortages, especially in the north-west of the country where availability is 25 per cent below the internationally accepted threshold for water scarcity," Professor Siddique said.

Farming in China's Hexi Corridor, for example, largely relies on irrigation water from snowmelt off the Qilian Mountains. But snow is receding annually, groundwater is declining, some natural oases have shrunk or vanished and wells have dried up.

At the same time China, the world's second largest economy, is drastically increasing agricultural production to feed its 1.3 billion people and satisfy its industrial needs. From 2003 to 2011 the country raised cereal production by more than twice the world average.

In the next 20 to 30 years more grain must be produced to meet China's projected demands, adding to the nation's water crisis. Recent innovative research projects have dealt with water-saving issues in arid and semi-arid north-western China, to sustain the grain industry.

"In the paper we summarise key technologies developed from recent research projects, and we discuss integrated and innovative approaches for developing water-saving agricultural systems," Professor Siddique said.

"Our goal is to encourage the implementation of innovative technologies to reduce agricultural water use, increase crop water-use efficiency and improve agricultural productivity."

China's water shortage may be extreme but the situation is repeated to various degrees worldwide, with global demands for crops and, in particular grain, expected to double by 2050 due to increased needs for food, fibre and biofuel for the burgeoning human population.

Food production systems for the three largest agricultural producers - China, India and the USA - are under serious pressure, mainly due to over-pumping of aquifers (underground layers from which groundwater can be extracted). Comprehensive water-saving systems need to be established soon, Professor Siddique explained.

These water-saving systems entail several key actions and components, ranging from technical innovations, public and private investment to political and socio-economic considerations.

Implementation of the key actions could lead to a "water-saving society" Professor Siddique said, which would bring together universities, other research institutes, local service organisations, government bodies, market developers and farmers into one coordinated and cooperative system, with positive outcomes possible.

For full details of the publication see: Chai, Q, Gan, Y, Turner, NC, Zhang, RZ, Yang, Y, Niu,Y, and Siddique, KHM. (2014). Advances in Agronomy 126: 149-201.

di S. C.