If you have a drip irrigation system installed in your blueberry field, then you are one of an increasing number of blueberry producers switching to this “micro” form of irrigation. If you don’t have such a system, you should consider it. Aside from the benefit of efficiency, it is an ideal way to apply nutrients to your field. It is a precise way to fertilize, and it should not be much more expensive than using granular fertilizer. Applying nutrients through your drip system is known as fertigation.
By now, you are probably aware that local research, and even non-local research, has shown that nitrogen fertigation provides bigger yields, and larger plants, on average, then applying the same amount of nitrogen as a granular split application*. This is not necessarily the same for the other nutrients. There is a lot of scientific evidence showing the benefit of nutrients applied via liquid vs granular. There is not a lot of science specifically in blueberries, but it is nevertheless increasing, and we will endeavour to inform you when we learn of it. In any case, here are some other things you should probably know about fertigation in blueberries.
Don’t forget – highbush blueberries can only efficiently take up the ammonium form of nitrogen from the soil. They are incapable of using the nitrate form.
When humic acids are used in conjunction with fertigated nitrogen, root growth in the first two years after planting is nearly twice that when nitrogen is applied without humic acids.
In coarse soils, such as sandy soils with low organic matter found in areas of the mid to upper Fraser Valley, highbush blueberries are more susceptible to potassium deficiency.
The root systems of highbush blueberries under drip irrigation typically do not expand as much as non-drip fields. Keep this in mind when supplementing fertigated nutrients with granular fertilizer. Make sure to apply granular fertilizer within the drip zone.
On average, it is the least expensive when macro nutrients are applied mostly in granular form, and secondary and micronutrients are applied via fertigation (foliar micronutrients are also effective to some degree). This is not to say macro nutrients shouldn’t be applied through the drip.
If you have questions please call TerraLink at the Abbotsford office 800-661-4559 or the Delta office at 604-946-8338.
References: *Potassium Fertigation in Highbush Blueberry. The Fluid Journal, Summer 2017. Bryla, D. and Orr, S.