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Soil Fertility Specialists Need Information to make Recommendations

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When you go to the doctor, he needs certain information to make a diagnosis. I'm no doctor, but soil fertility specialists also need information to make recommendations. This article outlines the information we need and why we need it. The more information we receive, the more accurate our recommendations will be.

First, and most basic, is contact information. We need your name, address, phone number and e-mail (if it's an option), so that we can contact you if needed.

We need to know the field or pasture identification. This can be any name or number as long as you know which soil sample came from which field. For example, you can name the sample the way you refer to the field when you tell your spouse or kids where you are going (back pasture, long field, the forty, Uncle Bob's, east half). However, it is helpful if the same field or pasture is referred to by the same name each time a sample is sent. That way, new results can be compared with old results to monitor trends in the fertility status. If the field or pasture has been mapped, use the name or number on the map. Also, indicate if a sub-soil sample has been taken.

Include the county where the sample was taken. This is especially important when recommending nitrogen fertilizer to meet a desired yield goal. No matter how much fertilizer is applied, it would be hard to produce more than five tons of non-irrigated bermudagrass west of I-35 due to the lack of rain.

Include the number or approximate number of acres sampled. If this number is more than 80, we may recommend that you take more cores per sample or split the field into more than one sampling area. As mentioned in previous articles, applying the correct blend of nutrients can make a difference in cost and production.

It is important to know if the property is leased or owned. Since the effective life of lime is several years but the up-front cost is high, many lease arrangements may make it impractical to apply lime.

Many pieces of crop information are important. Not only do we need to know the intended crop, but also the desired yield and if the crop is established. If it is not established, we need to know when it will be planted. Different crops require different amounts of nutrients. If plans change, we need to make a different ecommendation for the different crop. If the sample was taken in the last year or two, we can probably use the results on file and you will not need to resample.

The desired yield can be given in bushels, bales, pounds or animals per acre. If you use bales or animals per acre, be sure to include the weight of the bales or animals and the number of cuttings or months of grazing. If you know the bales or animals on the whole field but not per acre, include the acres in the field on which you're basing the count and we can calculate it for you.

"Maximum" is not a yield goal. However, there is a maximum potential for crops based on location and rainfall (see Figure 1). For information on setting a realistic yield goal, contact a soils and crops specialist.

If the crop is not yet established, we may recommend applying fertilizer at a different time or by a different method than we would if it is already established. Knowing the target planting date helps us know for what season of growth to fertilize. It may also help us recommend a change if your planting date is too early or late for the desired crop.

If the crop is not planted yet, it is important to know if starter fertilizer can or will be banded at the time of planting. Banded nutrients are more efficient. The broadcast rate of phosphorus for small grains is 1.5 times the banded rate.

Will the crop be irrigated? Again, the amount of rainfall and/or irrigation influences the yield potential of the crop.

Finally, we need to know something about the history of the field. This includes the date and rate of fertilizer, lime and other amendments applied during the previous year and the previous year's crop and yield obtained. Lime and some forms of nitrogen are slow to react in the soil, and if the soil sample was taken shortly after application the nutrients may not show up on the soil test results. Knowing the previous crop and yield obtained may allow us to adjust the fertilizer recommendation based on nutrient carryover.

All of this information should be provided on the Noble Research Institute Soil Sample Entry Form. However, if you don't have the form, you can write the information on a piece of paper and send it with the sample. For information on how to take a soil sample, request the Noble Research Institute video, "Unless You Test, It's Just a Guess."

Reminders from your soils and crops specialists:

  • Do not buy any pesticide without first seeing, reading and familiarizing yourself with the label.
  • Do not buy any pesticide from any unfamiliar source.