Desertification is a type of land degradation in drylands in which biological productivity is lost due to natural processes or induced by human activities whereby fertile areas become arid. It is the spread of arid areas caused by a variety of factors, such as overexploitation of soil as a result of human activity and the effects of climate change. Geographic areas most affected include the Sahel region in Africa, the Gobi Desert and Mongolia in Asia as well as parts of South America. Drylands occupy approximately 40–41% of Earth's land area and are home to more than 2 billion people.
Tillage is the agricultural preparation of soil by mechanical agitation of various types, such as digging, stirring, and overturning. Examples of human-powered tilling methods using hand tools include shoveling, picking, mattock work, hoeing, and raking. Examples of draft-animal-powered or mechanized work include ploughing, rototilling, rolling with cultipackers or other rollers, harrowing, and cultivating with cultivator shanks (teeth).
Crop rotation is the practice of growing a series of different types of crops in the same area across a sequence of growing seasons. This practice reduces the reliance of crops on one set of nutrients, pest and weed pressure, along with the probability of developing resistant pests and weeds.
Winter wheat are strains of wheat that are planted in the autumn to germinate and develop into young plants that remain in the vegetative phase during the winter and resume growth in early spring. Classification into spring wheat versus winter wheat is common and traditionally refers to the season during which the crop is grown. For winter wheat, the physiological stage of heading is delayed until the plant experiences vernalization, a period of 30 to 60 days of cold winter temperatures.
Soil erosion is the denudation or wearing away of the upper layer of soil. It is a form of soil degradation. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice (glaciers), snow, air (wind), plants, and animals. In accordance with these agents, erosion is sometimes divided into water erosion, glacial erosion, snow erosion, wind (aeolian) erosion, zoogenic erosion and anthropogenic erosion such as tillage erosion. Soil erosion may be a slow process that continues relatively unnoticed, or it may occur at an alarming rate causing a serious loss of topsoil. The loss of soil from farmland may be reflected in reduced crop production potential, lower surface water quality and damaged drainage networks. Soil erosion could also cause sinkholes.
Soil salinity is the salt content in the soil; the process of increasing the salt content is known as salinization. Salts occur naturally within soils and water. Salination can be caused by natural processes such as mineral weathering or by the gradual withdrawal of an ocean. It can also come about through artificial processes such as irrigation and road salt.
No-till farming is an agricultural technique for growing crops or pasture without disturbing the soil through tillage. No-till farming decreases the amount of soil erosion tillage causes in certain soils, especially in sandy and dry soils on sloping terrain. Other possible benefits include an increase in the amount of water that infiltrates into the soil, soil retention of organic matter, and nutrient cycling. These methods may increase the amount and variety of life in and on the soil. While conventional no-tillage systems use herbicides to control weeds, organic systems use a combination of strategies, such as planting cover crops as mulch to suppress weeds.
Contour bunding or contour farming or contour ploughing is the farming practice of plowing and/or planting across a slope following its elevation contour lines. These contour lines create a water break which reduces the formation of rills and gullies during times of heavy precipitation, allowing more time for the water to settle into the soil. In contour plowing, the ruts made by the plow run perpendicular rather than parallel to the slopes, generally furrows that curve around the land and are level. This method is also known for preventing tillage erosion. Tillage erosion is the soil movement and erosion by tilling a given plot of land. A similar practice is contour bunding where stones are placed around the contours of slopes. Contour ploughing has been proved to reduce fertilizer loss, power and time consumption, and wear on machines, as well as to increase crop yields and reduces soil erosion.
Soil conservation is the prevention of loss of the topmost layer of the soil from erosion or prevention of reduced fertility caused by over usage, acidification, salinization or other chemical soil contamination.
In agriculture, a living mulch is a cover crop interplanted or undersown with a main crop, and intended to serve the purposes of a mulch, such as weed suppression and regulation of soil temperature. Living mulches grow for a long time with the main crops, whereas cover crops are incorporated into the soil or killed with herbicides.
Worldwide more human beings gain their livelihood from agriculture than any other endeavor; the majority are self-employed subsistence farmers living in the tropics. While growing food for local consumption is the core of tropical agriculture, cash crops are also included in the definition.
Dryland salinity is a natural process for soil, just like other processes such as wind erosion. Salinity degrades land by an increase in soil salt concentration in the environment, watercourse or soil in unirrigated landscapes, being in excess of normal soil salt concentrations in dryland regions.
Intensive crop farming is a modern industrialized form of crop farming. Intensive crop farming's methods include innovation in agricultural machinery, farming methods, genetic engineering technology, techniques for achieving economies of scale in production, the creation of new markets for consumption, patent protection of genetic information, and global trade. These methods are widespread in developed nations.
Strip-till is a conservation system that uses a minimum tillage. It combines the soil drying and warming benefits of conventional tillage with the soil-protecting advantages of no-till by disturbing only the portion of the soil that is to contain the seed row. This type of tillage is performed with special equipment and can require the farmer to make multiple trips, depending on the strip-till implement used, and field conditions. Each row that has been strip-tilled is usually about eight to ten inches wide.
Agricultural sustainability in Northern Nigeria requires flexibility in both ecological management as well as economic activity. The population densities of the rural area in this region climbed from 243 to 348 people per square kilometer between 1962 and 1991, but the land area under permanent cultivation remained approximately the same. Increasing population results in high food demand among urban and rural dwellers, areas of cultivation, and reduced soil fertility. However, there are instances where frequent agricultural practices is not associated with degradation such as in Kano and neighboring region. Even though poverty and insufficient food exists in the region, it does not affect crop yield owing to sustained efforts to produce food in response to its high demand.
Farming systems in India are strategically utilized, according to the locations where they are most suitable. The farming systems that significantly contribute to the agriculture of India are subsistence farming, organic farming, industrial farming. Regions throughout India differ in types of farming they use; some are based on horticulture, ley farming, agroforestry, and many more. Due to India's geographical location, certain parts experience different climates, thus affecting each region's agricultural productivity differently. India is very dependent on its monsoon cycle for large crop yields. India's agriculture has an extensive background which goes back to at least 9 thousand years. In India, in the alluvial plains of the Indus River in Pakistan, the old cities of Mohenjo-Daro and Harappa experienced an apparent establishment of an organized farming urban culture. That society, known as the Harappan or Indus civilization, flourished until shortly after 4000 BP; it was much more comprehensive than those of Egypt or Babylonia and appeared earlier than analogous societies in northern China. Currently, the country holds the second position in agricultural production in the world. In 2007, agriculture and other industries made up more than 16% of India's GDP. Despite the steady decline in agriculture's contribution to the country's GDP, agriculture is the biggest industry in the country and plays a key role in the socio-economic growth of the country. India is the second-largest producer of wheat, rice, cotton, sugarcane, silk, groundnuts, and dozens more. It is also the second biggest harvester of vegetables and fruit, representing 8.6% and 10.9% of overall production, respectively. The major fruits produced by India are mangoes, papayas, sapota, and bananas. India also has the biggest number of livestock in the world, holding 281 million. In 2008, the country housed the second largest number of cattle in the world with 175 million.
Mechanical weed control is a physical activity that inhibits unwanted plant growth. Mechanical, or manual, weed control techniques manage weed populations through physical methods that remove, injure, kill, or make the growing conditions unfavorable. Some of these methods cause direct damage to the weeds through complete removal or causing a lethal injury. Other techniques may alter the growing environment by eliminating light, increasing the temperature of the soil, or depriving the plant of carbon dioxide or oxygen. Mechanical control techniques can be either selective or non-selective. A selective method has very little impact on non-target plants where as a non-selective method affects the entire area that is being treated. If mechanical control methods are applied at the optimal time and intensity, some weed species may be controlled or even eradicated.
Soil compaction, also known as soil structure degradation, is the increase of bulk density or decrease in porosity of soil due to externally or internally applied loads. Compaction can adversely affect nearly all physical, chemical and biological properties and functions of soil. Together with soil erosion, it is regarded as the "costliest and most serious environmental problem caused by conventional agriculture."
Melesse Temesgen is an Ethiopian agricultural engineer, hydrologist and businessman. He was born on 7 July 1964 in Gojjam, Ethiopia. He is the CEO of Aybar Engineering PLC.
This glossary of agriculture is a list of definitions of terms and concepts used in agriculture, its sub-disciplines, and related fields, including horticulture, animal husbandry, agribusiness, and agricultural policy. For other glossaries relevant to agricultural science, see Glossary of biology, Glossary of ecology, Glossary of environmental science, and Glossary of botanical terms.
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