# Agrochemical

An agrochemical or agrichemical, a contraction of agricultural chemical, is a chemical product used in industrial agriculture. Agrichemical typically refers to biocides (pesticides including insecticides, herbicides, fungicides and nematicides) alongside synthetic fertilizers. It may also include hormones and other chemical growth agents. Though the application of mineral fertilizers and pesticidal chemicals has a long history, the majority of agricultural chemicals were developed from the 19th century, and their use were expanded significantly during the Green Revolution and the late 20th century. Agriculture that uses these chemicals is frequently called conventional agriculture.
Agrochemicals are counted among speciality chemicals. Most agrochemicals are products of the petrochemical industry, where chemicals are derivitatives of fossil fuels. The production and use of agrochemicals contribute substantially to climate change, both through direct emissions during production, and through indirect emissions created from soil ecology problems created by the chemicals.
Agrochemicals, especially when improperly used or released in local environments, have led to a number of public health and environmental issues. Agrochemicals and their production can be significant environmental pollution. Agrochemicals are responsible for significant damage to waterways through runoff, and inproperly stored agrochemicals and agrochemical wastes are responsible for spills, especially during extreme weather events. Following the publication of Rachel Carson's Silent Spring, increased global attention has been paid to these ecological impacts of certain classes of chemicals, both in terms of effects on ecosystems and biodiversity loss. Some farmers choose not to use agrochemicals, with sustainable agriculture approaches such as organic farming or agroecology, avoiding use of pesticides and industrial chemicals, in favor of naturally occurring chemicals.

## Categories
### Biological action

In most of the cases, agrochemicals refer to pesticides.
* Pesticides
** Insecticides
** Herbicides
** Fungicides
** Algaecides
** Rodenticides
** Molluscicides
** Nematicides
* Fertilisers
* Soil conditioners
* Liming and acidifying agents
* Plant growth regulators

### Application method

* Fumigants
* Penetrant

## Application process

Agrochemicals are typically applied to seeds or the field using a variety of different methods.

### Seed treatment

A seed treatment is a treatment of the seed with either chemical agents or biological or by physical methods. Usually done to provide protection to the seed and improve the establishment of healthy crops. Not to be confused with a seed coating.
In agriculture and horticulture, coating of the seed is the process of applying exogenous materials to the seed. Also referred to as seed dressing.
A seed coating is the layer of material added to the seed, which may or may not contain a "protectant" (biological or chemical pesticide) or biostimulant applied to the seed and possibly some color... By the amount of material added, it can be divided into:
* A Film coating, a layer of thin film applied to the seed typically less than 10% of the mass of the original seed.
* Encrustment, where the applied material is typically 100%–500% of the original seed mass, but the shape is still discernible.
* Pellet, where the applied material is so thick that the seed's original shape is not discernible.
Seed coating provides the following functions:
* For formulations with pesticides, direct application to seeds can be environmentally more friendly, as the amounts used can be very small.
* Color makes treated seed less attractive to birds, and easier to see and clean up in the case of an accidental spillage.
* A thick coating can improve handling, by hand or by machine. Thinner coatings may also help with characteristics like flowability.
* Thick coatings may accommodate additional features such as fertilizers, plant hormones, plant-beneficial microbes, and water-retaining polymers.

### Aerial application

Aerial application, or what is informally referred to as crop dusting, involves spraying crops with crop protection products from an agricultural aircraft. Planting certain types of seed are also included in aerial application. The specific spreading of fertilizer is also known as aerial topdressing in some countries. Many countries have severely limited aerial application of pesticides and other products because of environmental and public health hazards like spray drift; most notably, the European Union banned it outright with a few highly restricted exceptions in 2009, effectively ending the practice in all member states.

## Ecology

Many agrochemicals are toxic, and agrichemicals in bulk storage may pose significant environmental and/or health risks, particularly in the event of accidental spills. In many countries, use of agrichemicals is highly regulated. Government-issued permits for purchase and use of approved agrichemicals may be required. Significant penalties can result from misuse, including improper storage resulting in spillage. On farms, proper storage facilities and labeling, emergency clean-up equipment and procedures, and safety equipment and procedures for handling, application and disposal are often subject to mandatory standards and regulations. Usually, the regulations are carried out through the registration process.
For instance, bovine somatotropin, though widely used in the United States, is not approved in Canada and some other jurisdictions as there are concerns for the health of cows using it.

### Impacts of pesticides

The environmental effects of pesticides describe the broad series of consequences of using pesticides. The unintended consequences of pesticides is one of the main drivers of the negative impact of modern industrial agriculture on the environment. Pesticides, because they are toxic chemicals meant to kill pest species, can affect non-target species, such as plants, animals and humans. Over 98% of sprayed insecticides and 95% of herbicides reach a destination other than their target species, because they are sprayed or spread across entire agricultural fields. Other agrochemicals, such as fertilizers, can also have negative effects on the environment.
The negative effects of pesticides are not just in the area of application. Runoff and pesticide drift can carry pesticides into distant aquatic environments or other fields, grazing areas, human settlements and undeveloped areas. Other problems emerge from poor production, transport, storage and disposal practices. Over time, repeat application of pesticides increases pest resistance, while its effects on other species can facilitate the pest's resurgence. Alternatives to heavy use of pesticides, such as integrated pest management, and sustainable agriculture techniques such as polyculture mitigate these consequences, without the harmful toxic chemical application.

## History

Sumerians from 4500 years ago have said to use insecticides in the form of sulfur compounds. Additionally, the Chinese from about 3200 years ago used mercury and arsenic compounds to control the body lice.
Agrochemicals were introduced to protect crops from pests and enhance crop yields. The most common agrochemicals include pesticides and fertilizers. Chemical fertilizers in the 1960s were responsible for the beginning of the "Green Revolution", where using the same surface of land using intensive irrigation and mineral fertilizers such as nitrogen, phosphorus, and potassium has greatly increased food production. Throughout the 1970s through 1980s, pesticide research continued into producing more selective agrochemicals. Due to the adaptation of pests to these chemicals, more and new agrochemicals were being used, causing side effects in the environment.

## Companies

Syngenta was the Chinese owned worldwide leader in agrochemical sales in 2013 at approximately US$10.9 billion, followed by Bayer CropScience, BASF, Dow AgroSciences, Monsanto, and then DuPont with about $3.6 billion. It is still in the worldwide leading position based on sales of year 2019. Based on a statistics by statistica, In 2019, the agrochemical market worldwide was worth approximately $234.2 billion. This is expected to increase to more than $300 billion in 2025.