Precision Fertigation: How Deerpoint’s White Box™ Transforms Crop Nutrition

Automated system delivers precision nutrition

The key to economical, efficient and responsible crop fertilization in permanent or annual crops, can be found in Deerpoint Group’s ‘White Box.”

Developed 13 years ago by Deerpoint Group, the White Box is a continuous in-field nutrient delivery system that sits alongside your irrigation filter system. It injects precision amounts of fertilizer with every drop of irrigation water. It is fertigation with spot-on accuracy.

Jeff Carr, Deerpoint’s Director of Grower Relations, emphasizes that while growers can still maintain control of their fertilizer applications, the White Box ensures the best utilization of fertilizer inputs, delivered to the root zone at crop demand rates. The precision feed system can deliver up to 12 different nutrients at a time. The White Box continuously and automatically adjusts the feed rates of nutrients as required for each crop.

“The goal with continuous fertigation is efficient fertilizer use along with improved plant health and productivity. Reducing the amount of fertilizer applied while still delivering the nutrients the plant needs is a big part of the white box program. When fertilizer prices are up and commodity prices are down, it is a big feature.”

This is not just Deerpoint’s position on fertigation. Charles Burt, chairman and founder of the Irrigation Training and Research Center at Cal Poly San Luis Obispo, told California Farm Bureau’s Ag Alert publication that plants need different amounts of nutrients depending on the stage of production. To achieve uniform growth, you need uniform uptake and availability of nutrients. DPG Continuous Fertigation® fills that role.

For example, nitrogen demand is driven by crop yield, tree growth and removal of woody debris from the orchard. With continuous fertigation over the growing season, Nitrogen applications can be minimized and still meet crop needs. With less loss below the root zone, growers can still realize optimal yields, with smaller nutrient budgets.

Reduce fertilizer use

The white box automated system is installed on loan at the grower’s filter station, with minimal up-front cost to the grower. Carr explains that the optimization of fertilizer use with this automated system reduces total units of fertilizers applied over the growing season. Applied in amounts that match crop uptake, leaching below the root zone is minimized and total fertilizer amounts can be reduced. Continuous fertilization with the white box also meets the 4Rs principles – right time, right place, right source and right rate and industry best management practices.

Deerpoint Group’s white box set in an orchard or field next to the irrigation system is the command center for nutrient distribution and acts as an automated fertilizer plant controlled remotely for each field. The specific nutrients are delivered through the White Box based on the plants’ needs throughout the season. The nutrients and amounts delivered through fertigations are determined with plant tissue analysis done at Deerpoint’s highly efficient laboratory – done on a regular basis.

Carr said before this nutrient delivery system is installed in a field or orchard, Deerpoint collects a through history of the site’s production and conducts laboratory analysis of soil and plant tissue to determine the nutrient needs at the site and to detect any deficiencies. Soil and plant tissue samples are taken including hull samples at an almond site.

Plant and soil samples

The samples are analyzed at the Deerpoint laboratory and the results determine what nutrients will be delivered and the rate of delivery, correcting any imbalances. After the grower approves the fertigation plan the system is installed. All the grower needs to do is to operate the irrigation system.

Through the white box, the fertilizer applications are controlled automatically / remotely. DPG Field Technicians install the White Box, maintain equipment, check pH in the field, if required, and receive fertilizer deliveries. This service reduces the growers manpower needs.

Grower Advisors do visual inspections of crops, in conjunction with tissue sampling to make recommendations for adjustments throughout the season. Growers receive a weekly report of fertilizer use and have access to the DPG Grower Portal 24/7.

Carr notes that fertilizer needs may change over the growing season. Visual inspection and sampling by Deerpoint, particularly with row crops, happen on a weekly or two-week schedule to determine if any adjustments in fertilizer is needed. Weather conditions that may affect yields can also trigger a change in the fertigation plan.

The white box takes implementation of the 4Rs principle to a whole new level. There is no ‘estimating’ of crop needs as the continuous fertigations replaces ‘slug ‘ feeding where a large portion of the crop nutritional needs are dumped into the system and delivered over a few irrigation sets.. Sure, some of the nutrients are picked up by the plant but how much is lost when excess nutrients move below the root zone?

On-line information for growers, crop consultants

Growers will never be in the dark about what fertilizers are being delivered, the rate and timing. Carr said Deerpoint’s real time digital web portal allows them to receive an on-line look at their field or orchard anytime. Logging on to, growers access the amount of nutrients that are being delivered by the White Box, tank levels, water pH and other pertinent information. Growers can also access reports on their program summary over any specific time frame.