Pretend you’re constructing a new building. Even if you have all your materials, you need to prepare the site. Level it, build up the foundation, make it solid, and make sure it’s prepared to support your construction.
It’s the same with growing crops. Even if you have great material, you still need to form a strong foundation. Crop development is in part dependent on nutrients available in the spoil, and nutrient interactions happen when one influences the uptake and use of another. They can have beneficial interactions, or if not done correctly – negative ones.
You’d expect that fertile soil will give crops the nutrients they need…but some nutrients can interfere with the utilization of others. For instance, higher rainfall will cause potassium to move down in the soil. In dry climates, high evaporation keeps cations on the surface. When crops are being irrigated, the irrigation water carries other nutrients, and the soil can take on the properties of the water. The result may be a great potassium level…but it could actually limit your production. All of these variables affect crop nutrition.
The only way to really know what’s happening is to perform a soil test. Let’s look at what you could find:
- Cation exchange capacity – The higher the number, the more water and nutrients it can hold.
- Calcium – A Calcium base saturation range of 60-75% makes sure that other nutrients aren’t being crowded out.
- Phosphorus – Phosphorus is very reactive with calcium. Since zinc, iron, manganese and copper are cations, they can be displaced by high levels of calcium.
- Magnesium (Mg) – Look for Mg to be between 10 and 20%. Over 20, and compaction is more of an issue. Under 10% and deficiencies begin to occur.
- Potassium (K) – Go for between 3- 8%. It’s rare to go over 8%, but this would restrict water infiltration.
- Hydrogen (H) – The higher the hydrogen number, the more acidic the soil, so it’s best to keep soil near the neutral level of 7.
- Sodium (Na) – A base saturation of sodium over 2% can limit production when temperatures rise and water is demanded by the plant to cool itself.
Cation management has a big influence on the productive capacity of soil, and a balance is important for nutrients to give the maximum return. Is it always possible to have a perfect balance? No. But in an ideal world, we would like calcium in a range of 60-75%, magnesium between 10-20%, potassium between 3 and 8%, hydrogen less than 10% and sodium less than 2%. These ranges will provide the most consistent yields through a variety of environmental conditions.
For more information, visit: Improving Crop Yields and Fertility
You’ve calculated, you’ve done the work, and now that your foundation is complete, you’re ready for the next steps in growing a high yielding, quality crop. Contact one of our crop nutrition experts to get started.