Modern industrialized agriculture is based on very simplified ecosystems that are quite unlike the ecosystems that supported human-kind for millennia. They require large inputs of potential pollutants including pesticides and synthetic fertilizers to control pests and diseases and provide adequate nutrition for plants and animals. Organic farmers, together with scientists from around the world, are learning how to take a more ecological approach to managing productive farming systems. They are working in harmony with nature, rather than attempting to control nature. In organic agriculture, not only are synthetic inputs banned, but organic practices also focus on stimulating the biological processes in the soil, so that deterioration of the soil is actually reversed. Stringent organic standards require the producer to identify any potential environmental threats, and take action to address them, for instance by maintaining or establishing areas of native vegetation.
When synthetic inputs are banned, other methods must be employed to manage the nutrient and pest issues. More often than not, a combination of practices is needed to be able to deal with the issues at hand. Some examples are given by the UN Food and Agricultural Organization (2002).
Soil management practices include increasing humus content and biological activity as well as meeting mineral deficiency of soils, by means of:
- crop rotations, deep- and shallow-rooted plants, different crops requiring different nutrients
- growing green manure
- application of rock dust, manure, crop and agro-industry residues, household waste, compost
- appropriate soil tillage.
Pest, disease and weed management practices include:
- crop rotations to minimise survival of pests which can infest the next crop
- crop breeding for resistance to diseases and pests and enhanced competition against weeds
- strip cropping, to moderate spreading of pests over large areas
- manipulation of pH and soil moisture (with irrigation or soil surface management)
- manipulation of planting dates
- adjustment of seeding rates, to crowd out weeds or avoid insects
- use of appropriate plant varieties and livestock breeds for local conditions
- implementation of stock culling programs, emphasis on genetic resistance to certain diseases
- use of stock buying programs which minimise the import of diseases on to the farm
- biological control methods, to encourage natural enemies of pests by providing habitat or by breeding and releasing them in areas where they are required
- trapping insects, possibly with the use of lures such as pheromones
- biological pesticides in which the active ingredient is short-lasting, and which may be produced locally.