UK-China Agritech Challenge Zero-Waste Agricultural Mulch Films for Crops in China (ZEWAMFI)

该合作项目旨在改善中国农业的可持续发展，对农业社区产生积极影响，特别是通过减少水和农用化学品（氮肥和农药）的使用，不断提高作物产量生产力（和相关的农民财富），从而改善农场工人的安全。随着全球变暖的到来，预计亚洲和中东的半干旱地区降雨量将减少，这使得使用这种薄膜成为生产可耕地粮食作物的必要条件。该项目将开发用于可耕地作物的具有成本竞争力的农业覆盖薄膜，这种薄膜在使用过程中发挥作用，但之后会降解，并且在生产微生物量方面没有负面影响。农业塑料在中国用于提高粮食作物产量和水分利用效率，通过保护水，保持土壤水分，抑制杂草/鸟类造成的损失，提高温度和改善耐寒性。它们的使用导致粮食作物产量增加20-35%，经济作物产量增加20-60%。玉米、小麦、棉花和马铃薯产量分别提高33.7%、33.2%、26.1%和36.7%，相应的水分利用效率水平分别提高38.9%、30.2%、30.2%和37.8%。农用塑料覆盖物在农业中的典型应用时间仅持续几个月，并且由于物理破碎和化学老化过程，在暴露于冰雹和风暴等极端天气事件时甚至可以进一步缩短。这些产生了大量不可降解、难以回收的废物，这些废物通过焚烧排放、垃圾填埋或微塑料残留物污染环境。如果不从田地中清除，塑料废物会在环境中积累，进入食物链后，可能会对陆生和水生野生动物造成相当大的威胁。该项目的重点是新型塑料薄膜，这种薄膜将保持与提高作物产量有关的好处，但通过土壤可降解性，将消除土地中的微塑料污染，这是农业塑料覆盖物使用的不幸后果。微塑料污染对海洋的负面影响已经得到了很好的描述，最近的研究表明，在反复使用塑料覆盖物并将其翻回田地的地方，微塑料残留量从72公斤/公顷到260公斤/公顷不等。在这些水平下，植物生长受到抑制，累积的塑料残留物可能会影响土壤水分、养分运输和次生盐渍化。欧盟/美国市场已经推出了可堆肥聚酯地膜，但这些地膜价格昂贵，可用于高价值的园艺生产。该合作项目将设计具有成本竞争力的聚合物薄膜，可用于耕地作物（小麦、玉米）在使用过程中是稳定的，在使用结束时会被土壤中的微生物吃掉。最初的降解将由可氧化降解的添加剂催化，这将使材料破碎，然后具有适当配方的特定酶/微生物将代谢剩余的材料。可靠的科学数据来评估高性能农业聚合物材料的行为将支持对产品的要求，提供上述产品的主要财团包括威尔斯塑料，目前出口含氧生物降解树脂，并加入学术合作伙伴CAAS和班戈尔Uni开发的专有技术。卡斯是中国研究农业塑料的主要学术机构，班戈尔大学一直在研究生物塑料（用于食品），但也有多年来收集的独特微生物（来自海洋和林业）。

This collaborative project aims at improving sustainable agriculture in China with positive impacts on farming communities,specifically a continuous increase of crop yield productivity (and associated farmer's wealth) with reduced use of water, andagrochemicals (nitrogen fertilisers, and pesticides), therefore improving farm workers safety. With the advent of GlobalWarming, semi-arid regions from Asia and the Middle East are forecasted to receive less rainfall making the use of suchfilms a necessity for the production of arable food crops.The project will develop cost competitive agricultural mulch films for arable crops that will perform during use but degradethereafter and have no negative impact in terms of producing micro-plastics.Agriculture plastics are used in China to improved grain crop yield and water use efficiency through conserving water,maintaining soil moisture, suppressing losses due to weeds/birds, increasing temperature and improving cold tolerance.Their use has led to a 20-35% increase in grain crop yield and a 20-60% increase in cash crop yield. Maize, wheat, cottonand potato yields have increased by 33.7%, 33.2%, 26.1% and 36.7%, respectively, while their corresponding water useefficiency levels have increased by 38.9%, 30.2%, 30.2% and 37.8%. The typical application time of agricultural plasticsmulches in agriculture lasts only a few months and can be reduced even further when exposed to extreme weather eventssuch as hail and storms due to physical fragmentation and chemical ageing processes. These generate significant amountsof non-degradable, hardly recyclable waste, which pollute the environment either through incineration emissions, landfillleaching or microplastic residues. If not removed from the field, plastic waste accumulates in the environment where it maypose a considerable threat to terrestrial and aquatic wildlife when taken up in the food chain.This project focuses on novel plastic films that will maintain benefits related to increased crop productivity but will eliminatemicroplastic pollution in land, an unfortunate consequence of the agri-plastic mulch use, by being soil degradable. Negativeimpacts of microplastic pollution of oceans are well described and recent research has shown that where plastic mulcheshave been used and ploughed back into fields repeatedly, microplastic residue ranges from 72 kg/ha to 260 kg/ha. Plantgrowth is inhibited at these levels, and the accumulated plastic residue may affect soil moisture, nutrient transport, andsecondary salinization.Compostable polyester mulch films have been introduced in the EU/US market, but these are expensive and can be usedin high-value horticultural production.This collaborative project will design polymeric films that will be cost-competitive and could be used in arable crops (wheat,maize) will be stable during use, coupled with an end-of-life scenarios where they will be eaten by soil micro-organisms.The initial degradation will be catalyzed by oxodegradable additives, that will fragment the material, and specific enzymes/micro-organisms with suitable formulation will then metabolize the remaining material. Credible science data to evaluatethe behaviour of high performance agricultural polymeric materials will back-up the claims made on the productsA major consortium to deliver the above include Wells Plastic, currently exporting oxo-biodegradable resins and join knowhowdeveloped by academic partners CAAS and Bangor Uni. CASS is the main academic institution in China involved ininvestigating plastics in agriculture, and Bangor University has bee working on bioplastics (for food applications) but hasalso unique collections of microorganisms collected over years (both from marine, and forestry sources).