One of the newest applications in hazelnut production is the installation of irrigation to water the trees. Jeff Newton, a longtime grower at Crimson West/Christensen Farms in McMinnville, Oregon, is a pioneer in using drip irrigation to produce higher nut yields. In partnership with Crop Production Services and the OSU extension service, Newton has recently achieved groundbreaking crop yields through innovative methods of hazelnut orchard irrigation.
In 2011, Newton experimented by installing drip irrigation in 100 acres of two-year-old Jefferson that released one-half gallon per hour through three foot emitter holes. Newton began this pilot project when the weather warmed up in June, and increased the water volume through the even hotter months of July and August, while also monitoring ground moisture to give him a better idea how much water his trees needed. The hotter the weather, the more moisture the leaves put out, and whatever is lost through the leaves must then be absorbed by the roots to maintain healthy growth.
Once Newton had his irrigation infrastructure set up, the next step was easy: fertigation. He began injecting fertilizer into the existing drip line, slowly at first so he could monitor the results. The first time he tried it, he used seven gallons of fertilizer per acre – just enough for his young orchard. Now, five years later – he uses 40-50 gallons per acre. The logic seems simple: the larger the tree, the more fertilizer needed. There are complications, however, such as variety of tree, stage of growth, and nut development, and Newton admits it has been a learning process. “If you don’t have enough nutrition in the tree, it’s not going to grow enough or produce enough,” he says. “If one thing is missing, you can have all the other elements, but it’s not going to work.”
The key to getting just the right mix of fertilizer is in regular testing of the leaves. Newton analyzes leaves every four weeks and with quick results in just three or four days, he can add the needed fertilizer right away, with no guesswork. So far, he’s been pleased with the results. “When you measure tree caliper on the trunk and branch size, you can tell. In one year we got bigger trees.”
Why should hazelnut growers consider installing drip irrigation in their own orchards? The rising price of hazelnuts has brought maximizing yields to the forefront of growers’ minds, now more than ever, and with an Oregon water shortage potentially on the way (according to Newton), drip irrigation is the most efficient way to water trees with minimum loss to evaporation.
Before installing drip irrigation, there are some issues growers should consider. For instance:
· You must have water rights granted to you by the state if you plan to draw water from an irrigation well or a river.
· Unless you are installing the system underground (an additional cost), you will no longer be able to drag sideways because the drip tubes get in the way.
· The tubes can be a nuisance when harvesting. Some farmers avoid this by removing the tubes altogether right before harvest.
· If the water isn’t filtered (it is an extra cost to install a filtration system), you must be careful what chemicals you combine as they can clog the emitters.
Hazelnut trees grow just fine on their own during the wet months early after planning, but with irrigation, Newton has found a way to get the same growth rate during the dry summer months. Without this additional watering, growers will see a noticeable decrease in growth, not only in the size of the trees, but also in the size of the kernel itself. In only a few short years since installing his drip irrigation, Newton has seen a huge improvement. “Before drip irrigation was popular, it used to be four to five years before a tree would start producing nuts,” he says, “but with new experimentation with watering, it’s now only three years.”
As far as Newton can tell, irrigating hazelnut orchards in Oregon has already caught on in a big way. In fact, all new large orchards are installing irrigation by default. With this new research, it begs the question – how will this change the hazelnut industry? Newton believes irrigation will change the whole Willamette Valley. “It’ll be wall-to-wall hazelnuts,” he says. “The more nuts we make, the more demand will come along with it. There are markets we can’t touch now because we aren’t big enough as an industry.” Newton is optimistic that everyone would benefit from installing drip irrigation and it will profit the whole hazelnut industry. “We don’t know where it can go, but we do know there’s a lot of potential. How much we can unlock, we have no idea.”