When the planting high is over

Scott Fleming
Rock River Laboratory

Planting season is over! The crop is in the ground and for a short time, growers are breathing a sigh of relief and maybe even catching some time to see their family. But within a blink, the reality of low commodity prices, delayed planting, poor germination, denitrification, missing or late applications hit. And this list of in-season grower challenges goes on and on.

The crop is in the ground and for a short time, growers are breathing a sigh of relief...but the work continues out in the field.

These and many other problems have plagued the 2017 growing season thus far, leaving growers and agronomists scratching their heads searching for answers. Have we lost some of the nitrogen we applied to denitrification? If so, how much?  Does the crop have enough fertility to carry it through to yield?  Do we apply additional nitrogen to a crop with limited yield potential?  Do we need additional sulfur or boron to support yield? 

There are ways to fill in those blanks. Agronomic analysis offers a snapshot of what the plants are seeing, allowing agronomists and growers to know if enough nutrients are available to carry the crop to yield, rather than hoping enough fertility is left.

To guide agronomists and growers through some common in-season challenges,follow these recommendations:

Constant crop scouting

Crop scouting isn’t just about what meets the eye. Pest challenges and crop diseases can emerge throughout the growing season, so keeping a steady eye on all acres from emergence through dry down can help catch these vices early and keep them at bay before they spread and take down entire fields. However, not all challenges are visual. Denitrification and lacking plant-available nitrogen are unseen by the human eye. I recommend monthly PSNT testing, which takes a look at soil nitrate content at time of sampling, to assess and adjust for denitrification.

2. Set baselines for comparison and tailor applications

Running a soil nitrate analysis can help set a baseline to dial in the current nitrate levels in the soil and best administer only the nitrogen that is needed. In a wet year like 2017, nitrate levels could be lower than expected. One advantage of nitrate analysis is tailoring sidedress nitrogen application rates to soil test nitrate levels. Adding micronutrients to sidedress or post-emergence applications can help out a deficient crop. These methods also permit application of additional nitrogen to fields that would otherwise be maxed out in a Nutrient Management Plan.

Accurate samples

Growers or their agronomists, depending on who is pulling a sample for analysis, should take extra care to follow the specific sampling instructions for the crop at hand. Without an accurate sample, growers and their agronomists will be without an accurate analysis. Plant tissue sampling varies greatly between types of plants and growth stage, so look to your laboratory to provide the detailed instructions to follow for the plants you’re managing. I’ve included a link to the instructions we provide on our website, at the bottom of this post. Sampling is so important as it sets the stage for the interpreted results and the adjustments that will be eventually made in-field.

Assess all factors

As with any biological systems, many parts and pieces have to function together for the physiology to work correctly. Crops are a perfect example of this. Soil and the plants within it depend on each other, but sometimes, the soil makes certain nutrients unavailable to plants. In some instances, a soil analysis may show plenty of Nitrogen for the plant, but it’s not plant-available N. The beauty of submitting soil and plant tissue samples together is that a laboratory can analyze these together to showcase how they are or are not working together for optimal growth.

A good analogy is a truck’s speedometer and fuel gauge.  A plant tissue report is like the speedometer. We know we are in the sufficient range when we are following the speed limit. The problem is we may run out of gas shortly if we don’t look at the fuel. The soil is like our fuel gauge, it tells us what we can expect miles down the road.

When utilizing the specific agronomic analysis tools available, growers and agronomists can make refined decisions using sound data to assess challenges at hand or proactively avoid in-season challenges. At Rock River Laboratory, we offer an intuitive report when soil and plant tissues are submitted together. You can see an example of this report here: http://www.rockriverlab.com/file_open.php?id=40

Rather than hoping and praying after the relief of planting conclusion, the decision makers can incorporate scientific results when it comes to nutrient recommendations – saving both time and money. This 2017 growing season will be a memorable one, but by using a few convenient tools, 2017 can be remembered by growers as better than expected.

For information on how to sample additional crops or at growth stages not listed, visit: rockriverlab.com/pages/Sampling-Instructions.php.