Land is cleared of hedges and trees- to create more land for crops and make it easier for machinery to move around - destroys habitats, lack of roots can cause soil erosion Pesticides, herbicides, insecticides are used - to kill pests that compete with or harm crops- can kill useful organisms as well as pests Fertilizers are used - contain mineral salts that help plants grow and increase yield - can wash into streams and cause pollution so that organisms in water die Varieties - varieties of plants are chosen the produce the highest yield - the planting of huge areas of a single variety reduces biodiversity