NAICC: Fall is soil sampling time
There is little doubt that fall is my favorite time of the year. Of course, a lot of that has to do with the fact that the growing season is winding down and I am a huge college football fan. But it also means harvest time and a time to see what went right and what went wrong in the growing season. For my business, it means the beginning of the 2014 crop season. As soon as crops begin to be harvested, we are in the field collecting soil samples and making fertility recommendations for 2014.
I have often felt that this is the greatest service I offer my customers. In many instances, there is no single place that farmers can save more money than by soil sampling and applying the correct amount of fertilizer. The key to accurate soil samples is consistency. In other words, fields should be sampled at least every other year so that changes can easily be tracked.
Samples should be collected in a consistent manner using the same procedure for each field and the same procedure year after year. Furthermore, the same lab should be used year after year to ensure consistent results and eliminate variability from labs.
I utilize soil samples primarily as a way of tracking changes in fertility levels and fine tuning fertilizer recommendations for each individual field. When making fertilizer recommendations, I look at samples collected over the past several years rather than just one year’s worth of data to make my recommendation.
Over the past few years, I have started deep nitrate sampling. In other words, collecting a sample from 0 to 8 inches that will undergo a complete nutrient analysis and then collecting a sample from 8 to 24 inches that will be analyzed for nitrogen only. In west Texas, we generally get very little winter precipitation and in my particular area, we have clay loam soils. Therefore, we can expect very little nitrogen loss due to leaching throughout the winter months.
Deep nitrate sampling has proven to be a very useful tool in cotton production. High levels of soil nitrogen have been shown to greatly affect the quality of lint. Thus, it is important to manage nitrogen levels to match crop needs and avoid excess nitrogen to help ensure good lint quality. Certainly, discovering high levels of nitrogen in cores taken at 8 to 24 inches can represent the potential to reduce nitrogen rates applied during the upcoming season. In this instance, farmers can end up saving a significant amount of money. Therefore, deep nitrate sampling has proven to be useful for grain production as well.
There are many different types of deep sampling probes available that can be used to collect samples to 24 inches or greater. In my particular instance, I was able to lease a unit from a retired consultant to collect my samples.
His unit was mounted on a utility vehicle (UTV) that had a self-contained hydraulic unit. A local machine shop constructed a probe with a hydraulic cylinder to collect samples. This setup has proved to be a fast and efficient way to collect soil samples. Other consultants in the area, have mounted probes on tractors and pickups as well. No matter how you collect your soil samples, just remember to be consistent and sample at least every other year.