In the Midst of Drought, Subsurface Drip Irrigation (SDI) Helps Producers Flourish
As the worst drought in 50 years grips the nation’s farmland, some Nebraska producers are seeing increased yields using significantly fewer water resources. The trick, they say, is using Subsurface Drip Irrigation (SDI) to deliver water and nutrients directly to the roots of their crops. This is in contrast to applying water to the surface with gravity or sprinkler irrigation systems. As a result, SDI fields don’t lose precious water to scorching heat or dry winds – and crops are healthier, easier to irrigate, and deliver improved yields at harvest.
“Efficient subsurface drip irrigation is the future of irrigation,” says Ken Seim of Grand Island, Nebraska, who has farmed 1,400 acres of corn and soybeans for over 35 years. “Flood is about 40 percent efficient, pivots between 60-70 percent efficient, and drip over 90 percent efficient. We can manage our crops better with less using SDI and, as a result, be proactive – not reactive.” Seim has applied 9” of water to his SDI fields this year to achieve the same results as 20” of water to his center pivot fields and 22” of water to his gravity fields. “I can also build early season soil moisture with SDI after a dry winter,” notes Seim. His neighbor, Gary Greving, farms 1,100 acres and reports a similar water use scenario, and more. “We’ve achieved tremendous plant health with SDI and increased yields 40 percent. The stem of the plant was twice as thick, the leaf area larger, the plant taller, and the pod count over double. At the same time, we reduced water applications by 40 percent compared to our pivots. SDI is as close to 100 percent efficient as you can get.”
Don Anthony of Lexington, Nebraska, has farmed 1,300 acres in the Platte Valley for over 40 years. He also uses 2/3 to 3/4 the water and energy with SDI versus a center pivot, but takes SDI one step further. “With SDI, I can play chicken with the weather and sometimes take advantage of a rainfall event that I couldn’t otherwise.” Anthony explains that it takes 3 days for his pivots to complete an irrigation cycle, and over two weeks for his gravity fields. “With SDI, I can apply a small amount of water quickly and avoid plant stress. Therefore, I can wait longer for the rain and apply a short irrigation quickly if the rain doesn’t come. If the rain does come, I have saved myself an irrigation cycle.” Anthony is also using SDI to stretch limited water supplies so that all his land remains irrigated. “Since irrigated land has higher value, I have used SDI to avoid a balance sheet devaluation of my assets.”
All three growers agree that these advantages come with an investment cost. However, as water supplies tighten, the investment may spell the difference between farming and not farming. “If we are only allocated nine inches of water a year, as we already are in some parts of the state, we will have to irrigate with SDI in order to produce a crop,” Greving points out. “You can’t grow a crop with nine inches of water using pivots or gravity.” Seim explained that as aquifers decline, SDI works where a pivot can’t. This is because SDI blocks can be sized to match the available water source, while pivots require a minimum amount of flow to operate, and that amount is sometimes no longer available.
Investing in the farm is nothing new to Anthony. “Producers have enjoyed great crop production over the past ten years. In order to get through the tough times, we have always had to reinvest during the good times. I am investing in pivots and drip – both technologies have their place.”
This line of thinking is bearing itself out in the marketplace. While center pivot systems have been the primary irrigation choice in Nebraska, the adoption rate of SDI technology is rapidly rising. “My labor costs with SDI are about one-third compared with flood, but are about the same as pivot,” adds Seim. “With a pivot, labor is required to fix gear boxes in the middle of the summer when the corn is ten feet tall. But with SDI, the labor comes at a time in spring when it’s easier to perform and less detrimental to the crop.” Greving echoes this sentiment. “I adopted drip primarily to reduce my labor costs, which ended up being a wash, but have been pleasantly surprised to discover all the other benefits,” adds Greving. “On top of the water savings and yield increases, I have access to my fields 24/7. With pivots or gated pipe, there is always something in the way.” Anthony notes that fertigation with SDI is really fast, easy and efficient, too. “I have more options with SDI – I can fertigate a single block and easily track the results in a square sized block rather than a pie shaped block.”
For some, the learning curve is significant. However, Greving noted that once he mastered SDI, it was easier than pivots. “Acre for acre, I have to run my pivots 24/7 whereas my drip fields run from Sunday evening to Wednesday evening. This down time saves energy and water.” Seim noted that support from Toro and his dealer were great, and that “SDI was very easy to adopt. Anthony has had the same experience and says “there’s not much to it – I had good local support.” For Seim, the hardest adjustment was determining when to irrigate since the surface was dry. He uses soil probes and sensors, and will be experimenting with capacitance sensors in the future. “Producers will have to invest in technology to remain efficient and productive.” For these outspoken producers, SDI is a welcome addition.
