Cheap eco-material could make China's arid land green
[BEIJING] Chinese scientists have developed an economical and environmentally friendly material they say can encourage the growth of vegetation in arid regions.
The biodegradable material's main component is a water-absorbent polymer. It also contains chemicals that improve soil quality, essential plant nutrients such as magnesium, iron and phosphorus, and mosses and algae to kick-start the establishment of plant cover.
The material, which is produced in the form of granules, will help restore degraded land and tackle desertification, says Yang Limin, chief scientist of the project at Lanzhou Institute of Chemical Physics in Gansu Province in northwestern China.
In the rainy season, the polymer in the material expands to store water. The water is later released in drier weather along with chemicals that neutralise soil acidity, and nutrients and microbes to revitalise degraded soil. The water itself moistens the roots of any vegetation planted.
According to Yang, the composite has been tested on 200,000 square metres of arid land in northwestern Gansu Province and the Inner Mongolia Autonomous Region over the past three years. The team found that it increased the density of vegetation in dry areas by up to one-fifth.
In China, people traditionally plant trees or grass in dry areas to prevent desertification. But this method is time-consuming and often involves high costs for transporting water. Also, if not irrigated properly, trees and grasses often fail to establish, Yang told SciDev.Net.
"The biggest advantage of the new material is that it combines materials that have a number of functions,” says Feng Zongwei, a scientist with the Research Centre for Eco-Environmental Sciences.
Feng, who chaired the scientific appraisal of the project, says the research has been proven to effectively prevent water outflow from dry land, improve soil structure, increase soil nutrition and correct the soil's acidity.
The Chinese Academy of Sciences and Gansu provincial government certified the composite for industrial production on 15 March.
Yang says that researchers in his team are working with local companies to start large-scale production, which could make it affordable for poor farmers.
China's traffic management departments have decided to test the material along highways through arid and semi-arid regions of the country.