Direct Draw vs Slurry Treating

- Jason Kaeb

Just as each farm is unique, so too are the retailers and seed companies that service them. I’m often asked if keg direct draw treating is better than slurry treating, but the answer isn’t cut and dry. It depends on a number of factors, including operator knowledge and expertise, resources and flexibility, or farmer choice, in services and products offered.

When slurry treating, products can be received in any type of package or container. This method requires the operator to mix different products together into a slurry tank. The slurry is then agitated to achieve product homogenization and plumbed to the treater inlet. At that point, the entire liquid product is metered and monitored from a pumping station. Here, the recipe is entered in the control panel as a total application — you’re using the entire mix.

Unlike slurry treating, products for direct draw are received in a keg and are directly withdrawn from and mixed together at the treater through a static mixer, or some continuous mixing device. The individual liquid ingredients all come into contact with each other at the point of application. In this process, the product application rate is entered in the control panel and defined on a per stand (product) basis.

Factors to consider include operator expertise, safety and stewardship, flexibility in product offering and capital costs.

Expertise/Knowledge. For slurry treating, operators must be able to calculate the proper ratios and pumping volumes for the seed to be treated. Additionally, products must be properly mixed and agitated. Direct draw treating takes human error out of the equation, as users don’t need to worry about mixing liquids on site or product compatibility.

Safety and Stewardship. Furthermore, direct draw treating employs a closed-loop system with a direct draw coupler from the keg and does not expose operators to the chemicals or ingredients being applied to the seed. If there is leftover product, it can be drawn back into the container and recirculated or agitated without having to worry about cross contamination. However, with slurry treating, operators must wear proper safety protection as they are handling and pouring ingredients. Additionally, the shelf life of a slurry is shorter than the shelf life of a single product or pre-mix.

Flexibility in Product Offering. This is where slurry treating excels. Operators have the flexibility to add in products that may not be offered in a keg, or container that allows direct draw. In general, with direct draw treating, there’s less flexibility in product offering. Also, with slurry treating micro additives can be included in the treatment; whereas, if the rates are too low to pump in by itself, direct draw treating does not allow for the inclusion of such ingredients.

Capital Costs. When compared to slurry treating, setting up your system for direct draw treating requires more capital upfront to get the proper number of pumping stations needed. A pumping station is needed for each product included in the mix.

While there is a general shift in the industry toward direct draw treating, that doesn’t make it the right decision for everyone. Evaluate your operation and your needs; there are pros and cons of both, and both can work for your operation.

Remember: In most situations, some combination of direct draw and slurry building is appropriate and desired. Some products, such as water, are good to have on their own pump stand without mixing into a slurry, as it provides the flexibility of simply adjusting the rate of water to compensate for seed size or coverage on the fly.