Introduction

Against the backdrop of a growing global population and climate change, how to feed more and more people on limited land and water resources has become a major challenge for modern agriculture. As a key driver of agricultural productivity, agricultural chemicals - from fertilisers to pesticides to plant growth regulators - have not only greatly increased food production, but also caused a series of environmental problems due to improper use. In this paper, we will discuss the core role of agricultural chemicals, their application scenarios and the future direction of sustainable development from a scientific point of view.

I. Definition and Classification of Agricultural Chemicals

Fertilisers: mainly used to replenish the nutrients in the soil to support the healthy growth of crops, typical representatives such as urea, potassium dihydrogen phosphate and so on.

Pesticides: Used to control crop pests and diseases to ensure that the growth of crops is not threatened, common ones include propiconazole (CAS 60207-90-1), Paclobutrazol (CAS 76738-62-0) and herbicides such as glyphosate.

Plant growth regulators: optimise the growth of crops by regulating the physiological process of plants, such as gibberellic acid to promote fruit enlargement and chlormequat chloride to prevent crops from falling down.

Functional chemicals: These include soil conditioners and preservatives, which can improve soil quality and extend the shelf life of crops, such as humic acid for restoring saline soils and 1-MCP for extending the freshness of fruits and vegetables.

II. The core role of Agricultural Chemicals: yield enhancement and sustainable development

1. Increasing yields and ensuring food security

Nutrient supply from fertilisers: Fertilisers are considered to be an important driver of global food production, especially in developing countries, where their use has led to significant productivity gains. For example, foliar sprays of potassium dihydrogen phosphate can increase sugar levels in grapes and reduce fruit splitting, thereby increasing crop yield and quality.

Pesticides are the ‘defence against disease’: Globally, about 30-40 per cent of annual crop losses can be prevented by pesticides. Take propiconazole as an example, it can effectively prevent and control wheat rust, with a preventive effect of more than 85%.

Precise control of growth regulators: Plant growth regulators can precisely adjust the physiological process of crops to ensure the healthy growth of crops. For example, polyoxazole can effectively control the growth of rice, reduce the risk of collapse, thus improving the stable yield of rice.

2、Promote the sustainable development of agriculture

The Rise of Green Alternatives: With the enhancement of environmental awareness, the application of bio-pesticides and environmentally friendly fertilisers has gradually replaced traditional chemical pesticides. For example, Bacillus subtilis, as a kind of bio-pesticide, not only has significant disease prevention effect, but also reduces environmental pollution.

Innovation in pollution remediation technology: Agricultural chemicals play an equally important role in the remediation of soil and water pollution. Potassium thiosulfate can effectively passivate heavy metal cadmium in the soil, reducing the risk of contamination of crops and helping to restore soil health.

3. Addressing global challenges

Resilience: Crop resilience allows crops to hold up in extreme weather. Chemicals such as silicates can enable crops to grow in water-stressed environments by increasing their drought tolerance.

III. Specific applications of Agricultural Chemicals: from soil improvement to pest control

Potassium dihydrogen phosphate (CAS 7778-77-0): as an important foliar fertiliser, potassium dihydrogen phosphate can effectively enhance the sugar content of crops, increase the sweetness of fruits, and improve the market value of fruits by reducing the phenomenon of fruit cracking.

Phosphorous acid (CAS 13598-36-2): Phosphorous acid not only enhances the natural immunity of plants, but also effectively prevents and controls many crop diseases, such as potato late blight, ensuring the healthy growth of crops by enhancing their disease resistance.

Potassium thiosulphate (CAS 10294-66-3): As a synergistic fertiliser, potassium thiosulphate can not only reduce ammonia volatilisation but also effectively reduce cadmium contamination in the soil and heavy metal content in crops when used in combination with urea.

Biodegradable Agricultural Film: The starch-based biodegradable agricultural film used in tomato cultivation is able to decompose naturally in as little as 60 days, reducing the problem of long-term pollution of soil and environment caused by traditional agricultural film, and embodying the concept of sustainable development of green agriculture.

IV. Challenges facing Agricultural Chemicals: environmental and health considerations

While agricultural chemicals play a huge role in improving agricultural productivity and ensuring food security, their use also poses challenges that cannot be ignored:

Environmental risks: Overuse of fertilisers may lead to eutrophication of water bodies, and overuse of pesticides may also have a negative impact on ecosystems. In addition, residues of traditional agricultural films can cause microplastic contamination of the soil and harm the environment.

Health hazards: Certain highly toxic pesticides, especially high-risk pesticides used over a long period of time, may be enriched through the food chain, threatening human health and increasing the risk of chronic diseases.

Resistance problem: With the long-term use of single pesticides, some pests and diseases have developed resistance to pesticides, leading to a decline in the effectiveness of pesticide control year by year, bringing new challenges to agricultural production.

V. Future Trends: Green Technology and Intelligent Agriculture

1、Green chemical technology

Nano controlled-release fertilisers: the application of nanotechnology makes the controlled-release performance of fertilisers greatly enhanced, and the use of new types of fertilisers such as polylactic acid-coated urea has increased the utilisation rate of nutrients to 80%, significantly reducing environmental pollution.

Microbial fertiliser: Through the use of nitrogen-fixing bacteria and other microbial fertilisers, the reliance on chemical nitrogen fertilisers has been reduced, providing a more environmentally friendly alternative to fertilisers for agriculture.

2.Intelligent Management

Application of IoT and AI technology: IoT sensors can monitor soil nutrients and humidity in real time, and by analysing the data through AI models, farmers can accurately adjust fertiliser and irrigation programmes to achieve more efficient agricultural production.

Conclusion

Agricultural chemicals are the indispensable ‘invisible guardians’ of modern agriculture, which provide an important guarantee for global food security, but also face the dual challenges of environment and health. In the future, the application of agricultural chemicals will tend to be more precise and environmentally friendly, so as to realise the sustainable development of agricultural production through the balance of scientific and technological innovation and ecological protection, and to let agricultural chemicals ensure the survival of human beings while coexisting harmoniously with nature.