Author: ANURAG PATEL
Vaugh School of Agricultural Engineering Technology, SHUATS, Allahabad (U.P.) - 211007
Water conservation is one of the biggest benefits-as a level field demands the same level throughout; if it is undulated, water would not reach everywhere and would accumulate at one particular spot giving too much water thereby damaging the crop; also prevents soil erosion. The laser land leveler can be play a major role was increasing agricultural production. It's controlled weed, seed, minimum farm operation and water use efficiency. Indian agricultural is diverse and complex with land area, capable of producing most of the food and horticultural crops of the world. Laser land leveling can certainly minimize yield variability at farm level, optimize input output relation and save resources like soil, water and energy. In most situations fields will need to be plowed and a topographic survey undertaken before leveling commences. Leveling is done for following purpose:
- To prepare a contour map for fixing sits for reservoirs dams, barrages etc., and to fix the alignment of farm field, roads, railways, irrigation canals and so on.
- To determine the altitudes of different important points on a hill or to know the reduced levels of different points on or below the surface of the earth.
- To prepare a longitudinal section and cross-section of a project (Farm field, roads, railways, irrigation cannel, etc.) in order to determine the volume of earth work.
- To prepare a layout map for water supply, sanitary or drainage schemes.
Component of Laser Leveler
Drag Bucket The leveling bucket can be either 3-point linkage mounted or pulled by the tractor's drawbar. Pull type systems are preferred as it is easier to connect the tractor's hydraulic system to an external hydraulic ram than connect to the internal control system used by the 3-piont-linkage system. Bucket dimensions and capacity will vary according to the available power source and field conditions.
Laser Transmitter The laser transmitter mounts on a tripod which allows the laser beam to sweep above the tractor unobstructed. With the plane of light above the field, several tractors can work from one transmitter.
Laser Receiver The laser receiver is an Omni-directional receiver that detects the position of the laser reference plane and transmits these signals to the control box. The receiver mounts on a manual or electric mast attached to the drag bucket.
Control Panel The control box accepts and processes signals from the machine mounted receiver. It displays these signals to indicate the drag bucket's position relative to the finished grade. When the control box is set to automatic, it provides electrical output for driving the hydraulic valve. The control box mounts on the tractor within easy reach of the operator.
Hydraulic Control System The hydraulic system of the tractor is used to supply oil to raise and lower the leveling bucket. The oil supplied by the tractor's hydraulic pump is normally delivered at 2000-3000 psi pressure. As the hydraulic pump is a positive displacement pump and always pumping more oil than required, a pressure relief valve is needed in the system to return the excess oil to the tractor reservoir.
Land leveling techniques
Laser leveling is a process of smoothing the land surface (Â± 2 cm) from its average elevation using laser equipped drag buckets to achieve precision in land leveling. Precision land leveling involves altering the fields in such a way as to create a constant slope of 0 to 0.2%. This practice makes use of large horsepower tractors and soil movers that are equipped with global positioning systems (GPS) and laser-guided instrumentation so that the soil can be moved either by cutting or filling to create the desired slope/level.
Laser leveling field
- Set the average elevation value of the field in the control box.
- The laser-controlled bucket should be positioned at a point that represents the mean height of the field.
- The cutting blade should be set slightly above ground level (1.0-2.0 cm).
- The tractor should then be driven in a circular direction from the high areas to the lower areas in the field.
- To maximize working efficiency, as soon as the bucket is near filled with soil the operator should turn and drive towards the lower area. Similarly as soon as the bucket is near empty the tractor should be turned and driven back to the higher areas.
- When the whole field has been covered in the circular manner, the tractor and bucket should then do a final leveling pass in long runs from the high end of the field to the lower end.
- The field should then be re-surveyed to make sure that the desired level of precision has been attained.
Principal of leveling:
Laser land leveling system includes three parts: laser transmitter and receiver, control system and scraper. It is actually like a scraper with rear wheels, which could automatically up and down according to the height of ground. The scraper goes up and down through the telescopic oil cylinder. The cylinder is installed between the rear axle and scraper. In the process of moving forward, when ground is higher, the oil cylinder will be shortened to make the scraper down then scraper blade cut soil there and goes forward with the soil. When the ground is lower, the oil cylinder will be extended to make scraper up, and then the soil in the scraper will be filled here. During the land leveling, soil in the higher places will be scraped to flatten the lower places to complete the land leveling.
Other equipment that may be required: Other equipment may be needed when using a laser system for topographic surveying. This includes Tape, Staff, Compass, Pegs/Hammer, Book, Pencil/Eraser etc.
Benefits of leveling:
- Conserves water by up to 45%.
- Protect top-soil erosion by rainfall and water runoff.
- Reduce the surface water contamination.
- Enhances water retention and storage.
- Increases productivity by up to 35 %.
- Increases cultivable area.
- Save fuel, electricity used in irrigation.
- Reduces fertilizer run-off.
- Uniform water distribution & helps in weed control.
Laser land leveling can minimize yield variability at farm level and save resources like soil, water and energy. If adopted on a large scale, the laser leveling would help in improving the quantity and quality of ground water because of improved water productivity and less accumulation and deep percolation of water-soluble pesticides and chemicals, especially nitrate. It is estimated that adoption of precision land leveling system to just two million hectare of area under rice-wheat system could save of irrigation water and improve crop yields.
Laser leveling of agricultural land is a recent resource-conservation technology. It has the potential to change the way food is produced by enhancing resource-use efficiency of critical inputs without any disturbing and harmful effects on the productive resilience of the ecosystem. In spite of several direct and indirect benefits derived from laser land leveling technology, it is yet to become a popular farming practice in the developing and the underdeveloped countries. For accelerating its popularization and large-scale adoption, it requires a number of well-considered and synchronized research, extension, participatory, economic and policy initiatives keeping in view the long-term sustainability of our production systems. Popularization of this technology among farmers in a participatory mode on a comprehensive scale, therefore, needs appropriately focused attention on priority basis along with requisite support from researchers and planners. The change in our vision of future agriculture in relation to food and nutritional security, environmental safety and globalization of markets demands improving resource-use efficiency considerably to reach the desired growth levels in food production and agricultural productivity. Laser leveling is evidently one of the ways by which we can address these issues to a great extent.
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2. Bell, Mark and Rickman, Joe. 2000. Land leveling and Improved Water Management, IRRI http://www.rdi.ku.ac.th/troprice_th/land% 20l evel.htm
3. Jat, M.L., Pal, S.S., Subba Rao, A.V.M. and Sharma, S.K. 2003. Improving resource use efficiency in wheat through laser land leveling in an ustochrept of Indo-Gangetic plain. In: National Seminar on Developments in Soil Science, 68th Annual Convention of the Indian Society of Soil Science, November 4-8,2003, CSAUAT, Kanpur (UP).
4. Jat, M.L., Sharma, S.K. and Gupta, Raj. K, Sirohi, K. and Chandana, P. 2005. Laser land leveling: the precursor technology for resource conservation in irrigated ecosystem of India. In: Conservation Agriculture-status and prospects (Eds., Abrol, I.P., Gupta, Raj K. and Malik, R.K.), CASA, New Delhi, p. 145-154.
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