According to the 2025 Global Organic Agriculture Statistical Yearbook released by FiB and IFOAM in February 2025, by the end of 2023, the global organic agricultural land area reached 98.9 million hectares, an increase of 2.6% from 2022. One of the key factors driving this trend is the widespread use of natural agricultural chemicals, which provide organic farming with pest management, nutrient supplementation and soil improvement solutions.

Definition and classification of natural agricultural chemicals

Unlike chemical agents synthesized in laboratories, natural agricultural chemicals are strictly derived from animals, plants or minerals and are completely degradable in nature. The USDA Organic Certification Manual divides them into five categories:

Botanical pesticides and pest control

Pyrethrins:

Conventional pesticides are prohibited in organic farming, while pyrethrins extracted from the petals of Asteraceae plants are permitted high-efficiency natural compounds.

Studies have shown that a 0.5% concentration of extract has a 24-hour knockdown rate of up to 89% for whiteflies, and it decomposes naturally within 48 hours to avoid harming pollinating insects.

Neem oil:

Another widely used natural pesticide is neem oil. Neem can simultaneously block the pest’s feeding desire (by inhibiting neurotransmitters), interrupt the molting process (interfering with molting hormones), and reduce the egg hatching rate (damaging embryonic development).

In a comparative test of greenhouse tomatoes, weekly spraying of 1.5% emulsion can reduce the density of thrips by 78%, and has no significant effect on the beneficial insect community.

Mineral-based natural fungicides

Bordeaux mixture:

A traditional fungicide made from a mixture of copper sulfate and lime, it is a “blue shield” for crops such as grapes and citrus.

In organic vineyards in France, Bordeaux mixture (containing 0.6-1.2g/L of copper) is sprayed 4-6 times a year. Copper ions achieve prevention and control by destroying the cell membrane potential of pathogens. The concentration of 0.6-1.2g/L can control the incidence of downy mildew within 5%, and meet the EU’s annual application limit of ≤6kg/ha for copper elements.

Sulfur powder:

In addition, sulfur powder (Elemental sulfur) is also a certified fungal disease prevention and control product.

This light yellow powder interferes with the pathogen enzyme system by releasing SO₂ gas, and cooperates with precise meteorological monitoring (applied only when the humidity is <70%), successfully suppressing the incidence of black spot disease below 10%.

The essential difference between natural agrochemicals and traditional synthetics

Although natural agrochemicals and synthetic agrochemicals have similar functions (such as insecticides/fungicides), the essential differences between the two determine their irreplaceability in organic agriculture:

• Mechanism of action: synthetics mostly act intensively through a single target (such as neurotoxins), while natural products often use multiple pathways in synergy (such as neem oil affecting feeding, molting, and reproduction at the same time)
• Environmental fate: synthetics can have a half-life of several months (such as neonicotinoid pesticides), while natural products are usually completely degraded within a few days
• Ecological impact: synthetics are prone to “non-target accidental injury” (such as imidacloprid causing bee colony collapse), while natural products are mostly ecologically selective (such as pyrethrins are extremely low in toxicity to mammals)

These characteristics make natural agrochemicals more in line with the sustainable development concept of organic agriculture, but also directly lead to special challenges in their application

Challenges in the application of natural agricultural chemicals

Although natural agricultural chemicals have significant advantages, they still face three core challenges:

① The rapid effect is weaker than chemical synthetics (e.g. neem oil takes 3-5 days to show effect, while pyrethroids take effect within 2 hours);

② High environmental sensitivity (Bordeaux mixture needs to be applied repeatedly after rainfall);

③ The cost is 30-200% higher than conventional chemicals.

• Current technological breakthroughs are concentrated in two directions:
• Nano-encapsulation technology: encapsulating pyrethrins in chitosan-sodium alginate nanoparticles to extend the effective period from 48 hours to 120 hours
• Combined synergistic strategy: Bt bacteria and potassium silicate are used together to enhance the insect resistance of the leaf wax layer and provide an alkaline environment for microbial reproduction

Conclusion: Natural agricultural chemicals help the transformation of sustainable agriculture

Organic agriculture is not “completely free of chemicals”, but to ensure crop health and soil ecology through environmentally friendly natural agricultural inputs. Choosing the right natural agricultural chemicals can not only increase yield and quality, but also promote soil carbon sequestration, reduce pollution, and achieve a balanced development of green planting and economic benefits. With technological advancement and regulatory optimization, natural agrochemicals will inevitably play a more critical role in global organic agriculture.