Dave Mengel and the Importance of Soil Tests

(Dr. Dave Mengel) Hi. I’m Dave Mengel, retired professor from K-State. Today we talked about fertilizer use for this coming year particularly in light of some of the financial implications of low commodity prices. Really we’re emphasizing soil testing and particular skills involved with soil testing in terms of the quality of the samples that we’re looking at and what really you can expect from soil tests. Which ones are very good and which ones may not be quite so good. That was one of the big keys to talk about. We’ve got about only about 50% of our acres in Kansas that are routinely soil tested on a regular basis, and because of that, it’s really an underutilized tool and one that can really help people allocate their input dollars more efficiently and more effectively. The other part of it that is very, very limited uses, the deeper soil samples that are required to use for nitrogen and sulfur in particular. That’s something that we utilize that information in making fertilizer recommendations and if they don’t have it, we do use a default value but we know that the default value is not very good and can either underestimate or overestimate the amount of nitrogen to apply. That’s probably the one place that they could really improve on their efficiency, is if they would take advantage of long-term soil testing for nitrogen. That was probably the biggest thing that we wanted to emphasize today. The ease of soil testing…how difficult a job is it? It’s not all that difficult. It is physically demanding particularly when you start talking about taking two-foot deep soil of course in dry soils but realistically, it’s the kind of thing that you have to pay attention to what you’re doing. Detail is the key. Make sure you take the same depth of soil sample every time for every core that goes in the bucket. Make sure that you take enough cores to get a good representative sample of that very heterogeneous, very variable material we call soil out there. The better job you do, it’s like anything else, garbage in, garbage out. To really get good quality useful samples to predict some major investments for fertilizer, we need to pay a lot of attention to detail. But it’s not something that is brain surgery by any means. Anybody can do it with a little training, a little thought. There are lots of labs that we can work with. Most of the labs that offer soil-testing services in Kansas and in surrounding states are certified. They go through quality assurance programs and we all use pretty much the same procedures or some minor variations, but the data is pretty much interchangeable. You could use labs located in Nebraska, Ward Labs, American Egg Testing in McCook, Midwest Labs in Omaha, University of Missouri, Servi-Tech, K-State, any number of places, you can get good numbers that you can use. Then the question is, what about the recommendations? One of the nice things available from K-State is that from the Agronomy Department, you can request a downloadable fertilizer recommendation program. You can take the numbers, even regardless of where you got them run, and run them through and look at K-State’s recommendations for either a nutrient’s efficiency or feed the crop type recommendation, for a longer term build and maintain type of recommendation. You can see where the differences in those are and both of those systems can give you comparable yields. There’s lot of resources available and something you really should consider.

No Comments Yet.

Leave a reply

You must be logged in to post a comment.