SITUATION

One of the services that Legend Seeds offers our customers through our Farmacology program is access to soil sampling services through Frontier Labs. Fertilizer is one of the highest input costs in an operation. Soil sampling is vital to ensure the RIGHT nutrients are applied at the RIGHT rate, at the RIGHT time, and in the RIGHT place of the field.

FACTORS TO CONSIDER

When deciding to fall soil sample, it’s best to have a plan in place before harvest. If you already have a plan in place, sampling can be done in a timely manner after harvest and your nutrient management plan can be in place for fall applications. Other factors to consider are:

• Sampling/application methods
• Field composition
• Tillage methods

ACTION PLAN

There are different methods to soil sampling. Which one is the best for you is determined by your fields and farming practices. The type of tillage you use on your operation affects the way the nutrients move in the soil. Taking that into consideration during testing will help you determine the right plan for you.

1. Composite sampling can be used when your field is very uniform. It consists of taking random samples throughout the entire field, then mixing them together for a field wide overview of soil nutrients.

2. Zone Sampling can be used when your field is somewhat uniform with zones of higher and/or lower production potential. This method is to take composite samples from each zone to determine what will improve your return on investment in each management zone.
3. Grid sampling is used when you want the most detailed report on what your soil conditions are like. Grids can be as large or as small as you feel most comfortable with. The most commonly used grid sample size is two acres. Each grid creates a data point that can then be used to variable rate the fertilizer.

SUMMARY

You need to determine the correct method of sampling for your fields and your operation’s goals. Grid sampling may cost more, but it gives you the best information of what the conditions are like in your fields. Being able to variable rate your fertilizer may save you money in the end and will give you the best opportunity to maximize the return from your investment.

RESOURCES

https://igrow.org/up/resources/03-5000-2016-21.pdf
https://cropwatch.unl.edu/site-specific-nitrogen-management-irrigated-corn
https://www.hullcoop.com/agronomy/fertilizer