Conservation Farming

Conservation agriculture, or conservation farming, resembles sustainable agriculture because it follows principles that conserve natural resources and minimizes the ecological footprint of raising crops or food animals. An ecological footprint is the amount of land and water needed to provide a population with resources to sustain life and dispose of wastes.

Conservation farming today includes four main aspects that work together to reduce ecological footprint: water conservation, soil conservation, efficient tilling methods, and low environmental-impact fertilization methods. Sustainable agriculture may be considered to be stricter than conservation farming with respect to ecological footprint because, unlike sustainable methods, conservation farming accepts the following:

» meat production
» some water-inefficient crops
» monoculture
» seasonal crops
» use of prime cropland
» some use of pesticides and herbicides

Conservation farming aims to convert traditional inefficient food production methods into methods that are both sustainable and efficient. For instance, traditional farming of 20 to 50 years ago often included the following characteristics: several passes over the fields with tilling equipment before sowing seeds; preemptory weed control with heavy doses of herbicide; fertilizer use at inefficient levels; and acceptance of any crop yields. Today conservation farming uses more efficient tillage and soil conservation methods. In the 1970s farmers cultivated their soils at least four times and often as 10 times before planting. Conservation farmers have found this overcultivation to be unnecessary, not to mention a waste of manpower, fuel, equipment, and soil. In weed control, conservation farming borrows from sustainable methods by using ground cover plants and natural methods (birds, small mammals) to combat weed growth.

Conservation farming uses both organic and inorganic fertilizers to return nutrients to the soil between each growing season. Organic fertilizers come from plant or animal materials such as manure. Green manure consists of cut crops that are plowed back into the soil to replenish some nutrients for the next crop. Green manure also includes compost, which is decomposed plant material that has been broken down by microbes on a site away from the fields, and may then be applied to fields like any other fertilizer. Brown manure consists of solid wastes from cattle, horses, sheep, or poultry, and even urine, which contains nitrogen in the form of urea. Inorganic fertilizers produced by chemical companies provide a set amount of nitrogen, phosphorus, and potassium to the soil with each application. Conservation farming makes use of both types of fertilizer; organic fertilizer provides a slow-release spectrum of plant nutrients, and inorganic fertilizer provides a fast-release influx of nutrients most likely to be depleted from soil each season.

Crop rotation conserves fertilizer by planting different types of crops on the same land every other year. Crops such as corn or cotton deplete nitrogen from the soil, so rotation with legumes the next year helps return nitrogen to the soil. Legume plants contain bacteria-filled nodules on their roots that draw in nitrogen from the atmosphere and convert it to a usable form for plants, a process called nitrogen fixation. In addition to recycling nitrogen, crop rotation reduces erosion by keeping a crop on each field rather than letting the field lie fallow (unplanted) for a season.

Drought and desertification put pressures on conservation farming, often in the issue of water conservation. Different irrigation systems offer more or less efficiency to watering fields, as already discussed. But what happens if there is no water at all? The “Desalination of Water” sidebar discusses one option in world water conservation.

Source of Information : Green Technology Conservation Protecting Our Plant Resources