Extension Bulletin on

Laser Leveller for precision land levelling for judicious use of water in Punjab

Rajan Bhatt and Manoj Sharma

Krishi Vigyan Kendra,

Kapurthala

DIRECTORATE OF EXTENSION EDUCATION

PUNJAB AGRICULTURAL UNIVERSITY

LUDHIANA -- 141001

1. An Overlook to the Water scenario in the Punjab:

Water has been prioritized to be the most crucial resource. Agriculture uses almost 85% of the total water available in the country. Shrinking water resources owing to over exploitation of ground water in Punjab threatens the maintenance of agricultural productivity. As a result, the water table is falling in 90% area of the state. With the inception of Green revolution in the Sixties, the water table started declining and the area having water table below 30 feet depth has increased from 3% in 1973 to 90% in 2004. During 1993-2003, the average fall of water table in the Central Punjab was 50cm per annum. However, in some of the areas, the fall of water table is even more than 80- 100 cm per annum. Out of 141 blocks of the state more that 100 blocks are over exploited. It is projected that by 2023 in Central Punjab, the water table depth will be below 70 feet in 66% area, below 100 feet in 34% area and below 130 feet in 7% area. Correspondingly in each district, the percent area below 70 feet depth will be 100% in Moga & Sangrur, 80 % in Patiala, 70 % in Ludhiana, 60% in Kapurthala & Jalandhar. To arrest this dangerous trend of ground water exploitation, there is an urgent need to conserve irrigation water through various on-farm water conservation practices. Land Leveling through Laser Leveler is one such proven technology that is highly useful in conservation of irrigation water.

2. Need of the Laser levelling:

Unevenness of the soil surface has a major impact on the germination, stand and yield of crops through nutrient water interaction and salt and soil moisture distribution pattern. Land levelling is a precursor to good agronomic, soil and crop management practices. Farmers recognize this and therefore devote considerable attention in levelling their fields properly. However, traditional methods of levelling land are not only more cumbersome and time consuming but more expensive as well.

Fields that are not level have uneven crop stands, increased weed burdens and uneven maturing of crops. All these factors tend to contribute to reduced yield and grain quality which reduce the potential farmgate income. Effective land leveling is meant to optimise water-use efficiency, improve crop establishment, reduce the irrigation time and effort required to manage crop. It is a common knowledge that most of the farmers apply irrigation water until all the parcels are fully wetted and covered with a thin sheet of water. Studies have indicated that a significant (20-25%) amount of irrigation water is lost during its application at the farm due to poor farm designing and unevenness of the fields. This problem is more pronounced in the case of rice fields. Unevenness of fields leads to inefficient use of irrigation water and also delays tillage and crop establishment options.

Laser Land Leveling seeks to explain the benefits of land leveling in fields, particularly rice fields, and help develop skills of farmers and operators in using laser technology to achieve a level field surface.

It is also intended to enable the users to identify and understand the working of the various components of a laser-controlled land leveling system; undertake a topographic survey using a laser system; set up and use a laser-controlled leveling system and troubleshoot a laser-controlled levelling system

3. History:First of all, in Punjab laser leveller introduced on an experimental basis in the Sukhanand village of the Moga district on an area of 150 acres and around 300 farmers included in

Guiding the farmers regarding the setting of tripod and laser receiver mounted on laser leveller.

these demonstrations. It is reported that around 25 – 30% of irrigation water can be saved through this technique without having any adverse affect on the grain yield. Further even surfaced land helps in equal distribution of the pesticides, fertilisers, thus reduces these inputs too. Upto 400 units if electricity units can also be saved in one acre where the land is laser levelled.

Years Number of laser levellers in the Punjab2005 12006 82007 1502008 10002009 20002010 2585

Why Laser-level Land?Benefits of Laser Leveling

1. More level and smooth soil surface 2. Reduction in time and water required to irrigate the field 3. More uniform distribution of water in the field4. More uniform moisture environment for crops 5. More uniform germination and growth of crops6. Reduction in seeds, fertilizer, chemicals and fuel used in cultural operations

Improved field trafficability

The limitations include the following:

1. High cost of the equipment/laser instrument 2. Need for skilled operator to set/adjust laser settings and operate the tractor3. More efficient for regularly sized and shaped field

YieldResearch conducted by PAU has shown a large increase in rice yield due to proper field

leveling. The following table is self-explanatory:

Year Rice Yield(t h/a)

  Leveled Fields Unleveled Fields

1996

1997

1998

1999

Average

3.40

2.27

2.72

2.34

2.72

2.67

1.46

2.36

2.00

2.19

Source: PAU, Ldh

Study entitled “Comparison of levelled V/s unlevelled field plot in growing Paddy crop” carried out Krishi Vigyan Kendra, Kapurthala during the year 2007 shown the following resultsTreatments

T1 Laser levelled plot.T2 Control (levelled by farmer with ordinary leveller)

MethodologyLevelled land is a pre requisite for getting the optimum yield in paddy due to the fact

that Paddy requires sub merged conditions for the first 15 days to get it established after transplanting. Mostly some nursery seedlings die either lack or excess of water in the field. Thus, precision land leveling is a must for getting proper yield. Moreover, it takes more time to irrigate the field if it is unlevelled. Keeping this point in view, an on farm trial was conducted in which, 0.4 ha area was laser levelled and other 0.4 ha.area was ordinary levelled.

Soil Type : Loamy sand

Results:

Treatment

Variety Date of sowing

Date of harvesting

Tillers/hill 1000 grain wt.

Yield (q/ha)

Time to irrigate the plot (hours/ha)

T1 PAU-201

08.06.07 24.10.07 7.7 2.59 70.3 11.25

T2 PAU-201

08.06.07 24.10.07 6.9 2.54 69.8 16.25

Discussion:From the data it was evident that it took 11.25 hrs. to irrigate one ha. area if plot is

laser levelled in comparison to 16.25 hrs. required to irrigate ordinary levelled plot. Similarly there was considerable saving in the quantity of water used for irrigation purpose in laser leveled plot than the ordinary leveled. However, there was no significant difference obtained in the yield of Paddy between two treatments.

Organising farmer’s meetings on Laser leveller in the village Blairkhanpur of district Kapurthala

Weed ControlLand leveling increases yield. A large part of this increase is due to improved weed control.Improved water coverage from better land leveling reduces weeds by up to 40%. This reduction in weeds results in less time for crop weeding. A reduction from 21 to 5 labor-days per hectare is achieved. A reduction of up to 16 person-days per hectare viz. a 75% decrease in the labour required for weeding in laser levelled field.

How Laser Leveller Works

The laser-controlled system requires a laser transmitter, a laser receiver, an electrical controlpanel and a twin solenoid hydraulic control valve.

Equipment Details

 Scrapper

 

 

The laser transmitter transmits a laser beam, which is intercepted by the laser receiver mounted on the leveling bucket. The control panel mounted on the tractor interprets the signal from the receiver and opens or closes with a laser-controlled bucket. The use of laser-controlled equipment results in a much more level field – up to 50% better than leveling using other techniques. Laser leveling systems are commonly used in agricultural applications in Australia, Japan and the United States. Increasingly, laser-guided systems are being used in lesser developed country contexts as well. Laser levelling results in a much more level field

How to Laser-level LandLaser leveling requires soil to be shifted from the high points of the field to the low points inthe most cost-effective way. In most situations fields will need to be plowed and a topographic survey undertaken before leveling commences.

Step 1. Plowing the Field

Plow the field preferably from the center of the field outwards. It is preferable to plow the field when the soil is moist because if the soil is plowed dry a significant increase in tractorpower is required and large clod sizes may result. If the soil is very dry a one-way disc may be required. Disc harrows or tine implements are ideal for second workings. All surface residues need to be cut up or removed to aid soil flow from the bucket.

Step 2: Conducting a Topographic Survey

Once the field is plowed, you should conduct a topographic survey to record the high andlow spots in the field. From the surveyed readings you can then establish the mean height of the field by taking the sum of all the readings and dividing by the number of readings taken. Then, using a field diagram and the mean height of the field you can determine a strategy to effectively move soil from the high to low areas. Lasers are now widely used to accomplish a topographic survey. They are very accurate, simple to use and readily available in most countries. Recordings can be taken up to a radius of 300 meters from the transmitter. One person can operate a laser level. The laser surveying system is made up of a laser transmitter, a tripod, a measuring rod and a small laser receiver. A major advantage of laser surveying is the accuracy, simplicity of use and only one person is needed. .Using a Laser Level

1. Open the tripod legs and adjust the individual positioning of the legs until the base plate is relatively level. Use the horizon as a visual guide to get the base plate level.2. Attach the laser transmitter to the base plate. 3. If the laser is not self-leveling, adjust the individual screws on the base of the transmitter to get the bubble into the center of both circles. Most lasers will not rotate unless the transmitter is level.4. Once the transmitter is level attach the receiver to the staff and activate the sound monitor.5. The laser is now ready to commence recording heights.All measurements should be recorded in a field book that can be easily carried in a shirt ortrouser pocket.

Step 3: Levelling the Field

Leveling a field involves the following steps:1. The laser-controlled bucket should be positioned at a point that represents the mean height of the field. 2. The cutting blade should be set slightly above ground level (1-2 cm).3. The tractor should then be driven in a circular direction from the high areas to the lower areas in the field.

Discussing the performance of four wheeler laser leveller in the field

4. To maximize working efficiency, as soon as the bucket is near filled with soil the operatorshould 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.5. When the whole field has been covered in this circular manner, the tractor and bucketshould then do a final levelling pass in long runs from the high end of the field to the lower end.

TroubleshootingProblem Cause/SolutionBucket will not raise or lower

1. Check the transmitter is working2. Check hydraulic connections3. Check electric connections on solenoid4. Check pressure relief valve setting on control valve5. Check for contamination in oil lines

Bucket doesn’t respond in certain parts 1. Line of vision between transmitter and receiver blocked of field2. Receiver the same height as tractor cabin3. Laser beam above or below the receiver height

Bucket will only move in one direction1. Check hydraulic connections2. Check electric connections on solenoid3. Check pressure relief valve setting on control valve4. Check for contamination in oil lines

On-farm discussion with the farmers regarding the performance of four wheller laser leveller

Bucket shudders when first started1. Oil cold or no load in bucket2. Check pressure relief valve setting

Other Equipment

Other equipment may be needed when using a laser system for topographic surveying. Thisincludes:

1. Tape: One 100-meter tape. White metal tapes are more accurate.

2. Staff: if a measuring rod is not available. The staff is preferred as metric, upright withan E-type, pattern. Check the accuracy of the scale on the staff using a steel tapebecause some staff faces may be out by one or more centimetres

3. Compass: If direction and bearings are to be recorded a compass will be required.The compass can be used to set magnetic north on the level and allow recordings tobe taken from it

4. Pegs/Hammer: Pegs, preferably painted white, are required especially for markingout a grid survey or temporary marks

5. Book: A notebook is required to record all measurements and other informationrequired to make sense of the survey work completed in the field.

6. Pencil/Eraser: A pencil and eraser are preferable to an ink or biro type pen in thefield.