Post-Harvest Soil Tests Can Yield Results Next Season

by Darin Chapman, Precision Agronomy Advisor

Soil sampling and soil testing are best management practices to produce the highest yields. As margins narrow, farmers often look to reduce fertilizer as a way to reduce costs of producing a crop. Soil tests and precision ag technology can be the catalyst for reducing costs of fertilizer inputs without sacrificing yield or soil health.

The basic principles of soil sampling haven’t changed much over the years. Advancements in cropping practices, machinery and technology, new crop genetics and fertilizer application have resulted in advanced strategies for using that data.

Fertilizer recommendations historically have been based on average soil tests, area conditions and target yields. This method is good for the acres that align with the average, but it also means too little or too much fertilizer is applied to other areas impacting yield and profitability. It’s good practice to take soil samples every three years to monitor phosphorus and potassium. Soil sampling for nitrogen is imperative, particularly in years with unusual weather.

If reducing fertilizer costs is the goal, here are a few steps to consider:

1. Reduce broadcast applications in areas where soil tests show optimal levels. Routine soil tests in the years following with help make sure those nutrients are remaining at optimal level with this new practice.
2. Use Latham Hi-Tech Seeds’ Data Forward™ App to make grids that fit your operation whether it be 2.5-acre grids or zone sampling. Try to avoid these sampling areas: lime, sludge, or manure piles, animal droppings, areas near fences or roads, banded fertilizer rows, eroded knolls and low spots to ensure good data is included in your results.
3. Sample fields at the same time every year, so your analyses are more comparable over time. Post-harvest is a good time to sample for many crops. Taking samples three to six months prior to the next crop will allow enough time for any pH or nutrient adjustments.
4. Establish a dollar amount to spend on potassium, phosphorous, lime and nitrogen. Review the soil test grids to identify low producing areas and high producing areas of your fields. These newly identified zones can be a map for where to place more or less fertilizer for best return.

Low fertility and PH levels play a huge factor in your crop yields. We need to take advantage of the current technology to make crucial decisions on variable rate applications across the field. If we are not using our soil test results, yield monitors and yield maps to their full ability we are missing big opportunities to increase income.

Contact Latham Seed’s Precision Agronomy Advisors to perform a Needs Assessment. Phil Long and I can help you decide what is the best fit for your operations.