Originally posted on pursuitof300.com
A 40-year-old irrigation technology is seeing newly realized yield value as drought conditions, economic factors and resource scarcity issues intensify.
Initially adopted by U.S. vegetable, fruit and nut farmers in the 1960s and 1970s, subsurface drip irrigation (SDI) technology has rapidly advanced in the last two decades and continues to gain precision agriculture momentum.
Today’s SDI systems apply slow, frequent applications of water into soil and surrounding plant root zones through a system of driplines and emitters buried 10 to 18 inches below ground. SDI systems are well suited to support crop production in arid, semi-arid, hot and windy growing conditions such as those experienced by farmers in the High Plains states.
According to Texas AgriLife Research, SDI’s frequent low-volume irrigation applications increase water absorption rates near roots compared to higher volume irrigation methods that disperse water at longer intervals creating non-irritation days. This can help reduce plant stress caused by low regional precipitation and water restrictions.
Since water is placed near the root-zone, farmers using SDI attain more uniform wetting patterns and can more easily water plants in what would be determined dryland corners in a circle-pivot system.
In some states, including Nebraska, federal agreements require field corners untouched by pivots to be watered as well. Failing to irrigate those areas would result in the loss of their irrigated status, meaning they could never be irrigated again. Subsurface irrigation addresses this potential obstacle.
Long-term benefits of SDI irrigation efficiencies may outweigh price
Subsurface drip irrigation saves water and improves yield by eliminating surface water evaporation and potential run-off. It can also reduce the incidence of disease and weeds. Some operations have also reduced labor costs a result of improved irrigation.
While long-term benefits are evident, SDI costs farmers an average of $500 to $2,000 per acre including installation needs and product variables like water sourcing, water quality, filtration, materials, soil characteristics and automation technologies. Though this cost is greater than typical center pivot systems, SDI compares competitively to pivot systems.
According to Chuck Burr, educator at the West Central Research and Extension Center in North Platte, well-managed drip irrigation systems function for up to 20 years. In comparison, typical full sized center pivot sprinkler systems last an average of 20 to 25 years. To maximize SDI system lifespan, Burr encourages farmers to regularly check and maintain SDI systems which can cost three to five times more than pivots to repair and maintain if neglected or damaged.
If you decide to invest in SDI, farmers can expect to reduce water application by as much as 60 percent according to Toro’s DripTips blog. Many farmers have also found cost-savings success through cost-share programs like that offered by the Environmental Quality Incentives Program (EQIP).
Subsurface irrigation is not for every acre. Some fields may be better served with alternative options. Farmers with sufficient precipitation or water availability might not see the economic benefits as those in more arid states do. For more information on various irrigation methods, read the Nebraska Farmer.
SDI can help farmers monitor, manage and conserve water—and experience a yield advantage
Today’s farmers are making great progress in implementing efficient irrigation systems and water conservation best management practices. While SDI drips water into the soil and root zones at a controlled rate, diligent monitoring and management is still needed to successfully reduce overall water use.
According to National Resource Conservation Service (NRCS) engineer, Greg Sokora, subsurface drip irrigation systems in accordance with NRCS technical standards and specifications are designed to meet a 96 percent efficiency rating.
“When properly designed and managed, subsurface drip irrigation systems can exhibit a yield advantage over other types of irrigation systems due to the crop response to daily irrigation and micro nutrient application,” he said in the NCRS publication, “Subsurface Drip Irrigation – Conservation Today for Water Tomorrow”.
What do you think about the benefits from subsurface irrigation systems? Let us know.