Q: Does AquiMax® increase nutrient content in soil like it increases water content?
AquiMax® is a soil amendment. It does not contain any nutrients so applying it by itself will not add any nutrients to the soil. But what we’ve seen is that if we’re keeping more water in the root zone available for the plant, we’re also going to be holding more soluble nutrients that may be in the soil solution. So where normally we might have some leaching where we would lose some of those soluble nutrients, by keeping more moisture in the soil we are able to keep those nutrients available to the plant roots for a longer period of time.
Q: Is AquiMax® retained in the soil for a certain period of time and what's the residual effect?
AquiMax® has a reapplication interval of four to eight weeks and that’s going to depend on application rates. The effects of the product last for about four to six weeks and then start to fade. We’ve seen that with soil moisture data as well as sap flow data. Sap flow measurements we took in citrus really showed that after about six weeks those differences started to disappear, which is really valuable because you want control over the moisture in your soil. There are times toward the end of the growing season where you might want to dry out the crop.
Q: Is there a point where the water holding ability of AquiMax® competes with the plant's ability to access the water?
We have worked with the Soil Science Department at the University of Wisconsin-Madison. We have constructed water release curves with untreated soils and then soils treated with many different rates of AquiMax®. What that shows us is the amount of water that soil can hold at different levels of tension. Those different levels of tension can hone in and simulate the tension that the plant exerts to try to get water from the soil. What we’ve seen from that work is that the primary mechanism that’s helping us keep more water in the soil is that we’re not losing as much water to leaching and evaporation. What we’ve seen from the water release curves is that we’re not holding significantly more water at a given tension. That’s encouraging because it means that the product is not competing with the root for access to that water.
Q: Is there any evidence that the holding of water in the soil by polymers increases the potential for soil and root disease?
Any soil that’s too wet is going to be more predisposed to soil and root diseases that like lots of moisture. This product is a tool for managing water content of the soil. It is going to come back to management practices – this product will allow you to use less water and maximize the water that you’re using, but you’re still going to have to monitor and manage moisture just like you would normally to prevent excess water in the soil. In our field trials, we always monitor disease. In all of our trials work, we have not seen any cases where we had an increase in disease incidence from applying AquiMax®.
Q: Can you mix AquiMax® directly with fertilizer for fertigation in a pivot tank?
We have developed AquiMax® to be injected neat and so we do not recommend mixing AquiMax® with fertilizer in a tote or in a poly tank. We recommend using two separate pumps and applying them. You can apply them together. There’s no problem once they’re in the irrigation line, but we recommend applying AquiMax® as a neat material. We have done some work mixing in a ball tank, and if you have agitation, it works, but if it’s going to be sitting in that tank in the field for a long period of time, then we recommend applying the product neat.
Q: Can AquiMax® be injected along the whole irrigation event or just in a portion of it?
It depends on your irrigation system. If you’re injecting through center pivot, you probably don’t have a choice. You’ll have to run it as that pivot goes through the field to get the product out there. But if you’re using drip irrigation or microjet sprinklers, we recommend injecting during the first third or half of the irrigation run time to get the product out. After applying, continue running the water afterward to move that product down into the soil and get it evenly distributed.
Q: Is there any problem with the product remaining in the irrigation system without a complete flush, whether it's intentionally or unintentionally?
This is something we thought about a lot. With the old school long-chain polymer chemistry, that would be a huge problem. If your pump broke during an application and the product was in the lines, it would cause issues. We’ve tested it with AquiMax® – because of the lower viscosity that builds in this product, it doesn’t cause any problems if your pump would break in the middle of an injection. We did a really aggressive test where we injected the product mixed with water into a pump, created a really high viscosity, and then turned off that pump and let it sit for about a week. Then we turned the pump back on and it was able to get that product out and flush out with water after just a couple minutes. Because of the lower viscosity of this product compared to other long-chain polymers, we don’t anticipate any problems with the product remaining in the irrigation system without a complete flush out.