Laser Land Leveling

Summary

Production fields in parts of South Asia are typically uneven, posing a challenge to agronomic management of flood irrigation.  If fields are not level, significant increases in water and energy occur.  Laser land leveling offers a 'fail safe' and efficient approach to ensuring field uniformity.  Significant gains in profitability (ca. $150 per hectare per year) are achievable in rice-wheat systems through a combination of cost-savings and higher yields.

Challenge/Problem

Crop production costs have been steadily rising for farmers in South Asia over the last twenty years. This includes increasing land preparation costs, irrigation costs, and labor and input costs. In Bangladesh, India, and Nepal the majority of farmers’ fields are uneven, not level, or sloped the wrong way. This undulating topography leads to uneven irrigation water distribution, resulting in a decrease in water application efficiency and an increase in the density of weed species in locations that do not receive sufficient water. These weeds are also costly and labor-intensive to eradicate. Unlevelled fields of rice cause disease problems in the low-lying patches where water stagnates and causes water stress in the patches where water does not remain stagnant for some time. Even land allows irrigation water to reach every part of the field without runoff or water-logging waste. It improves yield because the crop stays uniform, synchronized, and matures simultaneously. Additionally, level land reduces wear and tear on harvesting machinery, saving time and cost in the long run. The LLL is much more effective and quicker in ensuring a flat table-top-like surface than traditional land leveling (TLL).

Solution

The LLL is a machine equipped with a laser-guided drag bucket that users tow behind a four-wheeled tractor. It is particularly relevant for flooded irrigation of rice and other grains. The International Maize and Wheat Improvement Center (CIMMYT), other Consultative Group for International Agricultural Research (CGIAR) centers, and several research organizations developed the LLL.

The laser land leveler helps increase water application efficiency and consequently reduces costs. Water-saving is not the only criteria for its use – it also improves yields as a consequence of more even crop stands. In addition, because irrigation can be applied more evenly, crop emergence is synchronized and maturation and ripening is more even.  Numerous studies have also proven that the LLL can also even out the distribution of soluble salts in salt-affected soils. As a result, use of LLLs can aid increasing cultivable land area due to a reduction in bunds and channels between farmers’ fields; LLLs also aid in reducing weed density and is associated with improved fertilizer use efficiency as a result of improved water management LLLs are beginning to become a widely accepted technology, with increasing commercial availability of equipment and LLL services in South Asia. While laser leveling needs to be carried out every two to three years to maintain effectiveness, adoption rates have been high among farmers.

Results

- Laser land leveling allows farmers to reduce irrigation water use by 20–30 percent by improving the uniformity of the surface of their crop fields.

- It lowers irrigation pumping costs by INR350 (ca. USD4.4) per acre, and has the potential to raise rice and wheat yields by 5–10 percent. Whereas traditional leveling methods – such as a wooden leveler attached to a tractor – level land with five cm-precision, laser land leveling uses a laser transmitter and an adjustable metal drag to level agricultural plots up to one cm-precision.

- Land leveling has also been shown to improve the production of direct seeding, which reduces labor requirements by 30 person-days per hectare.

- Laser land leveling also improves weed control by improving water coverage, reducing weeds by up to 40 percent and resulting in less time being needed for crop weeding (as much as 75 percent savings on labor costs). The laser leveler is attached to a tractor and generally requires two workers to operate the equipment in the field.

- Irrigation water savings have been up to 12 percent in rice and 10–13 percent in wheat. Rice-wheat system profitability increased by USD113 per hectare in the first year and by USD175 in the second year following laser land leveling. Reduced water use – and a reduction in the costs associated with it – increases profitability as well as contributing to resource conservation.

Lessons Learned/Potential for replication

LLL equipment can be scaled in irrigated farming systems, but may require access to finance or policy support to reduce capital entry costs. In India, more than 40,000 LLLs are now used on 7 million hectares, resulting in savings of over 10 m3 of irrigation water year–1. As a result, wheat production has increased by ~2.5 million tons in India. Evidence from the Cereal Systems Initiative for South Asia (CSISA), which conducted early research and supported LLL scaling, suggests that this technology could have wide applicability in irrigated, cereal based farming systems where energy or irrigation pumping costs are high, and where markets can be aligned to support technology and LLL services availability for smallholder farmers.

Next Steps

Policies that encourage the adoption of the laser land leveler need to ensure that the expected real water savings will accrue on a command area basis. Policymakers and the private sector need to work together to ensure the market availability of LLLs through incentives and cost-discount programs, with the private sector taking the ultimate responsibility to assure low-cost technology affordability at scale. Regional partnerships within the research and extension system are also important, as some of these interventions need scaling with different business models. Other products which can be bundled include zero tillage and bed-planting.