Here’s How Agriculture Has A Plastic Problem

Sridhar Jayagouda, a young farmer in Alarwada village on the outskirts of Belagavi city in Karnataka, is preparing for the monsoon crop of paddy by clearing beds of capsicum his family recently harvested. Once the plants are uprooted, he pulls out thin films of plastic covering the raised soil beds. That’s about 40,000 feet or 12 km of single-use plastic mulching sheet from his five-acre farm, every season.

“What other alternatives do farmers have?” Jayagouda asks. Plastic mulching is economical, it suppresses weed growth and reduces cost of labour significantly. “Our production has improved,” he says. Like many other farmers in this fertile swath of north Karnataka, Jayagouda adopted plastic mulching and drip irrigation five years ago.

Agriculture today is awash with plastics. Used in applications such as mulch films, shade nets, polyhouses, irrigation pipes, pond liners, and storage silos, plastics are integral to food production, processing, marketing, and consumption. They are also found in polymer-coated agrochemicals.

Jayagouda represents a growing number of Indian farmers who have shifted from traditional methods of using biomass mulch and manual weeding to plastic films fitted snugly over raised beds. Mulching, which involves covering soil beds to suppress weed growth, evaporation, and improve the microclimate around the roots, boosts productivity.

The growth of plasticulture 

Plasticulture is the application of plastics in agriculture. Introduced in India in the 1980s, it has seen exponential growth in the last decade. Plastic mulch, along with drip irrigation, is used in about 90% of “protected agriculture”, the cultivation of high-value horticulture crops in greenhouses, according to the agricultural scientists Mongabay India spoke to.

Polymer mulch of 15 to 30 micron thickness is among the fastest growing technologies of plasticulture; it is now being applied in open fields across the country. For context on thickness, plastic carry bags with thickness less than 120 microns are banned in India, as prescribed by the Plastic Waste Management Amendment Rules, 2021.

A one-acre farm requires approximately 8000 feet or 2.4 km of plastic mulch, most of which is single-use plastics. In the long term, the degradation and breakdown of these agri-plastics into micro and nano-plastic particles (MNPs) poses a potentially irreversible threat to food safety and security.

Microplastic is everywhere

Recently, news of the presence of microplastics in sugar and salt sold in India made headlines. Although it has raised concerns about quality and regulation, the impact of agricultural production and consumption on microplastics in food is not widely discussed.

Food systems are a major driver of plastic pollution. Microplastics (diameter less than five millimetres) and nanoplastics (diameter less than one micrometre) are everywhere, accumulating in soil, water, and our food. Historically, micro and nano plastics in the deepest reaches of oceans have been under focus, but now researchers say that MNPs in soil, sediments and freshwater may be an estimated four to 23 times higher, depending on the environment. They have been detected in the tissues and organs of terrestrial and marine life. Researchers warn of potentially life-threatening effects from plastic pollution, with raised risk of stroke and heart attack linked to MNPs in blood vessels. Polypropylene fibres have been found abundantly in human lungs, pointing at inhalation as a route of microplastic exposure; its presence in human faeces has been linked to inflammatory bowel disease; and MNPs were found in all the human placenta tested for a study.

In 2019, agriculture value chains used 12.5 million tonnes of plastic and food packaging contributed to 37.3 million tonnes globally, according to the Food and Agricultural Organisation (FAO, 2021). It forecasts a 50% increase in demand for agriplastics by 2030. Moreover, only about five percent of plastics used is recycled.

India’s Ministry of Agriculture states that the agricultural plastic industry forecasts the global demand for greenhouse, mulching and silage films to increase by 50 percent from 6.1 million tonnes in 2018 to 9.5 million tonnes in 2030.

In India, the issue of plastic pollution in agriculture has largely been overlooked — plasticulture is being celebrated for its role in ushering in a “second green revolution” in food production. The Indian government supports this approach by offering 50% subsidies on various plasticulture applications, particularly to boost horticultural production.

Climate change as a driver

Adverse climatic events have increased the popularity of plastic use in India, say Indian agricultural scientists. “Plasticulture technology like micro irrigation with mulching helps farmers combat situations such as heat waves,” says Rakesh Sharda, project coordinator, All India Coordinated Research Project on Plastic Engineering in Agricultural Structures and Environment Management, ICAR-Central Institute of Post Harvest Engineering and Technology, Ludhiana.

However, plastics consist of a complex mix of over 16,000 different chemicals, with around a quarter known to be hazardous to human health. These chemicals can leach out throughout the plastic lifecycle, providing direct pathways for toxic substances to enter the food chain.

In plastics in agriculture, this process is influenced by factors such as sunlight, mechanical degradation, exposure to various chemicals and pH levels. Global warming could also exacerbate this. Studies indicate that heatwaves hasten polymer degradation and scientists are calling for a revision of polymer safety specifications, so they are more resilient against rising temperatures.

While plastic-based solutions may improve food production and farmer profitability in the short term, the challenge of retrieving and recycling it is enormous, and plastic waste management value chains are poor.  For instance, in the absence of an alternative, most farmers, including Jayagouda, burn the plastic mulch films after use, oblivious of the pollutants they are releasing into the air, soil and water in the process.

Food security and environmental safety today face a range of conflicting challenges. “Some plastic applications, such as mulch, can reduce the use of water, pesticides, and herbicides in some cases, and are cost-effective for farmers. However, the impacts on soil health and the subsequent effects on food production, food security, and nutrition are only beginning to gain mainstream attention, and they are raising concerns among policymakers,” says Joe Yates of the London School of Tropical Medicine, who, along with fellow scientist Megan Deeney, is on the Working Group on Food Systems of the Scientists Coalition for Effective Plastics Treaty.

With mounting evidence of the adverse impacts of micro and nanoplastics, scientists are urging countries to take action. However, this global call to action to address plastic pollution is in conflict with national agendas focused on increasing food production and farmer income.

More plastics for food security 

Feeding a global population expected to reach 10 billion by 2050 exerts a great deal of pressure on the environment. Agricultural production has led to 70% of the groundwater extraction and 75% of deforestation, globally. In India, agriculture presents additional challenges of low productivity, improper use of natural resources, and now, increased frequency of climatic events. Precision agriculture, also known as protected area farming, a farming management strategy that uses technology to improve agricultural production and sustainability, poses a solution.

“Currently, 275,000 ha are covered by precision agriculture in India. Of this, over 90% is covered by plastic mulch, which has seen a steep rise in use in the past decade,” points out Rajesh Kumar Singh, head of department, Hydrology and Engineering, Indian Institute of Soil and Water Conservation, Dehradun. Singh was the former Project Coordinator of All India Coordinated Research Project (Plasticulture Engineering & Technology), ICAR.

The National Committee for Precision Agriculture and Horticulture (NCPAH, earlier known as National Committee for Plasticulture in Agriculture and Horticulture) has the mandate to promote plasticulture, and recommend suitable policy measures, through various central and state government schemes and mission programmes.

Its report on the Impact Assessment of Indian Precision Agriculture and Plasticulture Sector Post COVID-19, reveals that farmers who used plastic mulch reported a 20-30% increase in crop yields, with better quality produce that year. Farmers also reported a “reduction of 90-95% of manual labour for weeding and increase in irrigation interval”.

Drip irrigation for water conservation

Drip irrigation efficiency is 90% as opposed to 38% of surface irrigation, says Singh. However, drip irrigation uses HDPE (High-density Polyethylene) pipes. The main pipes are covered and buried in soil, for 10 to 15 years.  “Around 69 million ha of cultivable land has the potential for drip irrigation, which will amount to substantial water saving,” he adds. Similarly, greenhouses and polytunnels increase productivity up to four fold. In his 2018 report titled Status of Plasticulture Technologies in India, Singh says agricultural output can be increased by Rs. 74,000 crores through plasticulture.

The multifarious applications of plastics has spawned the growth of micro, small and medium manufacturing units for plasticulture products. About 50,000 plastic processing plants and 18,000 injection moulding plants are active across India. However information on the regulatory environment is hard to come by. As per a report by the NCPAH, India is the third largest user of plastic after the U.S. and China, even though its per capita consumption of 6 kg (to 9.7 kg in some reports) is lower than the world average of 26 kg.

While not all plastics may be replaced with safer and more sustainable alternatives, products like single-use plastic mulching replacing biomass raises the question of whether we are trading short-term agronomic benefits for long-term environmental damage.

“Once long-term plastic, microplastics, and nanoplastics pollution begins to threaten food security, there may be little chance of recovery. The harms caused by pesticides and herbicides are relatively well understood, but the role of these chemicals in many food system plastics is less recognised,” says Yates, explaining the pathways through which these chemicals of concern enter the environment.

The hidden cost of spotless choice

The political economy of agriculture and food policies plays a role in shifting practices. In Tamil Nadu’s Chengalpattu and Viluppuram districts, watermelon farmers began to adopt plastic mulch once traders began to prefer melons grown on plastic mulch.

Ajay T.M., joint managing trustee of Magasool, a Chennai-based trust that works on reducing farm inputs and improving farmer income says, “Ten years ago about 10% of the farmers used plastic mulch, today 60% to 70% have adopted it. Melons develop a discolouration where the fruit rests on soil bunds, which does not occur when bunds are covered in plastic mulch. These spotless fruits are preferred by export markets, and customers,” says Ajay, adding that unless consumer awareness and preference shifts from beautiful-looking produce to chemical-free produce, farmers will comply.

“Agricultural pollution needs the same kind of attention as industrial pollution,” says Soumik Banerjee, member of the Alliance for Sustainable and Holistic Agriculture (ASHA) Kisan Swaraj network. While it may not be possible to replace all plastic applications, Banerjee says that traditional agriculture provides alternative solutions to some. “Practices such as multi-cropping and intercropping are a good alternative to plastic mulching,” he says.

As Ajay says, farmers need suitable and sustainable alternatives that don’t impact their incomes or increase labour, and are as effective as plastic.

A sustainable solution is in linking agricultural intensification with ecosystem protection, backed by sustainable technological innovation. “Given the scale and magnitude of the plastics crisis, farmers and consumers cannot solve it alone. Responsibility for systemic change lies at a much higher level. When UN Member States resolved in 2022 to negotiate a legally binding agreement on plastics pollution, they recognised that the world needs systems-level, globally coordinated action,” says Yates.

(Published under Creative Commons from Mongabay-India. Read the original article here)