There are some natural pesticides, such as neem, a substance that has been used for centuries in India. They are used to kill weeds that compete with crops for root space, nutrients, and water. Sometimes the unintentional effect of using herbicides is to kill the plants they were intended to save. Crops Choosing which crops to grow depends on many different factors, such as climate, prospects for selling the harvest, and type of soil. It is also one of the oldest known crops, and can grow in a wide range of soils and climates.
Soybean oil has many food and industrial uses.
Hazards Farmers must learn to negotiate many uncertainties that can have potentially disastrous effects on their crops. With great increases in population in this century, especially in the Third World, there has been growing concern that traditional agricultural methods would be unable to keep up with increased demand for food. In the 1940's, a handful of scientists, sponsored by the Rockefeller Foundation, were invited to Mexico to look into ways to modernize and improve the efficiency of Mexican farmers. The hope is that the resulting hybrid will have the most positive characteristics of all the crossed varieties. Hybrids are sterile, and must continually be reproduced by cross-breeding methods intensive irrigation intensive use of fertilizers This research found rapid success.