Written by the Gansu PPMO team
Plastic mulching is an agricultural technology used to retain soil moisture, reduce weeds and raise soil temperatures. Plastic is stretched over raised vegetable beds and holes are punched into the plastic sheeting to make room for seeds or seedlings. In Guanghe County, located between the Loess and the Qinghai-Tibet Plateau in Gansu Province, plastic mulching has been extensively adopted in upland crop farming.
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| Lan Cuiren, 71, is a farmer in Huinin County, Gansu Province, China. In this area, plastic mulching has not been used. ©IFAD/Qilai Shen |
The area suffers from limited rainfall and low temperatures during the spring planting season and plastic mulching has proved beneficial. In 2013, plastic mulching was used to cultivate over 356,000 mu (approximately 23,730 hectares) for 300,000 mu of corn and 56,000 mu of potato crops. According to the provincial agriculture department, the average yield of fully mulched corn reached 834.3 kg/mu, which is 36% higher than a half mulched cornfield, and the average yield of fully mulched potato registered 3085.3 kg/mu, an increase of 51.5% than growing potatoes in an open field. As a result of the widespread use of plastic mulching, the per capita income of farmers was increased on average by 1,272.7 CNY (approximately US$207) in 2013.
The increase in crop yield and farmers’ incomes also means farmers’ increased use of plastic sheeting – which is a source of environmental pollution. The Guanghe County Agriculture Bureau estimated that over 2,000 tons of plastic sheeting is used each year and this figure is increasing. Large amounts of plastic were discarded at the end of each harvest and this plastic was severely polluting the rural environment and the farming landscape. A substantial amount of plastic scraps were left in the soil, causing soil compaction and the resulting reduced land productivity. Some farmers even burned the used plastic, causing secondary pollution to the atmosphere. In 2011 there was no effective way of recycling the used plastic sheeting.
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Landscape view of terraced hillside where plastic mulching is used, Guanghe County, Gansu Province, China. ©Gansu PPMO |
The pollution caused by discarded plastic sheets became know as “white pollution” and it had become a big headache for farmers and local government officials. In 2011, the implementation of the IFAD/GEF project: Integrated Ecosystem Management Approach to the Conservation of Biodiversity in Dryland Ecosystems brought some light to the tunnel. Guanghe County, as one of the two counties that the project is working in, has been actively involved in public awareness building and policy studies to enhance ecosystems and environment protection of the project area. Leaders of the county government and the agriculture bureau who have participated in training and public awareness campaigns implemented through the project have been inspired by the integrated approach to ecosystem and environmental conservation.
With repeated debate and consultation, the county government issued a policy measure in late 2011 that included some county financing to support the collection of used plastics throughout the countryside. At the same time, a large-scale awareness campaign was launched to motivate farmers to participate in the program. Since then, the county has invested over 5 million CNY (approximately US$814,000) for the collection and recycling of 3,700 tons of used plastics, including 750 tons collected in 2011, 850 tons in 2012, 1,000 tons in 2013 and 1,700 tons in 2014. The collection rate of used plastics has increased from 46.9% in 2011 to 85% in 2014.
In this respect, the county government and its agriculture bureau adopted the following three measures. The first measure was awareness building and advocacy among farmers. Agricultural extension agents and county and township officials took every opportunity to educate farmers on the harmful effects that discarded plastic sheeting can have on the environment. Farmers are encouraged to participate in the program in an interest to develop sound, environment smart farming practices.
The second measure was to establish plastic collection stations that also provided a small reimbursement for the plastic collected. Each village in the county now has one functioning collection station and each township has a larger collection station. After detailed analysis, the county government decided on a standard buy-back price of 1.2 CNY/kg (Approximately US$ .20 per kilo) for the used plastic sheeting. The price was set high enough to motivate farmers to recycle their plastic sheeting without placing too high a financial burden on the county budget.
The third measure included a government-initiated negotiation process with private enterprises to establish a process to recycle used plastics. Lanzhou Golden Land Plastic Products Company Ltd. was identified and invited to enter into a partnership with farmers and the county government. The recycling process requires that at the main collection center soil is removed from the sheets, the material is pressed into bales and transported directly to the company and traded in for new sheeting. The company recycles the used plastics to produce sheeting and other products for agricultural use, significantly increasing the effective use rate of plastics while preserving the soil and landscape.
The second measure was to establish plastic collection stations that also provided a small reimbursement for the plastic collected. Each village in the county now has one functioning collection station and each township has a larger collection station. After detailed analysis, the county government decided on a standard buy-back price of 1.2 CNY/kg (Approximately US$ .20 per kilo) for the used plastic sheeting. The price was set high enough to motivate farmers to recycle their plastic sheeting without placing too high a financial burden on the county budget.
The third measure included a government-initiated negotiation process with private enterprises to establish a process to recycle used plastics. Lanzhou Golden Land Plastic Products Company Ltd. was identified and invited to enter into a partnership with farmers and the county government. The recycling process requires that at the main collection center soil is removed from the sheets, the material is pressed into bales and transported directly to the company and traded in for new sheeting. The company recycles the used plastics to produce sheeting and other products for agricultural use, significantly increasing the effective use rate of plastics while preserving the soil and landscape.
Guanghe County can now boast a significant reduction in white pollution with over 95% of collectible plastics now being recycled. Today, it is hard to spot scraps of white plastic mixed into the soil or blowing about in the trees and countryside. Plastic mulching, a farming technology that greatly increases yields while conserving soil and water, is no longer harmful to the environment in the long term.
Edited by: Bo Zheng, Liu Ke and Susan Beccio