Reclamation of dryland region in agriculture.pptx

Reclamation of dryland region in agriculture.pptx

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  Reclamation of dryland region A.SRIHARI U22AB034
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  Introduction • Dryland farmingis frequently defined as crop production in areas with less than 500 mm of annual precipitation • About 47 percent of the surface of the earth can be classified as dryland • Dryland Agriculture refers to growing of crops entirely under rainfed conditions. • Based on the amount of rainfall received, dryland agriculture can be grouped into three categories:
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  1.Dry Farming: Cultivationof crops in areas where rainfall is less than 750 mm per annum 2.Dryland Farming: Cultivation of crops in areas receiving rainfall above 750 mm 3.Rainfed Farming: Cultivation of crops in regions receiving more than 1,150 mm • Soil Reclamation is the process of reclaiming the soil's quality like lost fertility, minerals, nutrients and moisture to make it fit for intensive use again.
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  Water Resources • Waterprovision for crop growth requires the presence of water resources. • In arid and semi-arid areas water resources can be of three different types: they can come from remote catchment areas that involve extensive and costly conveyance systems • They can refer to local groundwater that requires the installation of pumping wells
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  • They canderive from special water harvesting techniques for collecting and optimizing the use of the limited rainfall,They are 1. Surface water 2. Groundwater 3. Water Harvesting • Efficient water use requires an optimal design based on crop water requirement, rooting depth, water application depth and time • Some irrigation water is lost as the result of conveyance losses and over-irrigation whether or not applied to limit soil salinity.
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  SURFACE WATER • Theannual potential evapotranspiration in arid and semi-arid regions is significantly greater than annual rainfall. • Rainfall in arid and semi-arid regions occurs often under the form of heavy rainstorms, followed by intense surface runoff and large floods that last only a few hours or days. • During the rest of the time, the riverbed is mostly dry.
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  GROUNDWATER • Groundwater reservoirsor water-bearing layers (aquifers) are geologic formations where water is stored by natural or artificial means • Most aquifers are sand or gravel layers • Poorly cemented sandstones and permeable limestone and basalt may contain large amount of water as well
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  • Groundwater reservoircontain water in volumes far greater than the largest surface reservoir • Groundwater is, therefore, one of the reliable water resources in arid and semi-arid regions. • The aquifer is not only a seasonal storage reservoir to overcome dry periods but also a a long-term storage reservoir to smooth out large fluctuations in groundwater • However, continuously increasing withdrawal, exceeding the recharge or over-exploitation of the aquifer by excessive use of pumping wells, depletes the groundwater resource (e.g. the Hebei Plain, China).
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  Water Harvesting • Waterharvesting deals with the collection of rainfall runoff and the water so gathered is of direct productive use to people, animals and plants, especially in drought-prone areas • Water harvesting is a rudimentary form of irrigation without any control over timing. • Water harvesting is not new and various systems have been used throughout the centuries
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  • Rainwater harvestingis the runoff from roofs and ground surfaces. Floodwater harvesting is the collection of water from intermittent or ephemeral watercourses.
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  Irrigation of Drylands IrrigationDesign Parameters • The water requirement, the application depth and time, and the irrigation frequency or return period constitute the basic parameters of an irrigation design. They depend on topographic, soil, crop and climatic conditions • Topography and soil determine the runoff and erosion hazard and will impose the application rate.
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  • The climatedictates the crop water use and the return period or irrigation frequency results from the total amount of applied water and the crop water use Water Requirements • Evapotranspiration (ET) is an important parameter in estimating the water requirement for irrigation. • It is the quantity of water that a cropped soil consumes both from the transpiration of crops and evaporation from the soil.
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  • The waterloss is generally given as a fraction or percentage of the total required amount of water Application Depth • The application depth is the volume of water applied at each irrigation. It depends on the amount of water stored in the soil over the rooting depth • Average rooting depth for a number of common crops is given in Table
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  Rooting depth (cm)crop Shallow (60 cm) Rice, Potato, Cauliflower, Cabbage, Lettuce, Onion, Moderately deep (90 cm) Wheat, Tobacco, Castor beans, Groundnut, Carrots, Pea, Bean, Chilies Deep rooting (120 cm) Maize, Cotton, Sorghum, Pearl millet, Soybean, Sugar beet, Tomato Very deep rooting (180 cm) Sugarcane, Citrus, Coffee, Apple, Grapevine, Safflower, Lucerne
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  How to improvesoil quality • Add organic matter: Improve the structure of your soil by adding organic material like tea compost, food peelings, or seaweeds. • Covers unused beds: Cover any beds that will remain unused during the winter months with cloth or net. This will help the soil to retain its structure.
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  conclusion • Planting moretrees - the roots of trees hold the soil together and help to reduce soil erosion from wind and rain. • Improving the quality of the soil - this can be managed by encouraging people to reduce the number of grazing animals they have and grow crops instead.