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How to understand fertilizer recommendation based on soil test reports? 

How to maximize your farm’s potential: Efficient and profitable farming depends on accurate soil testing, but fertilizer recommendations for the same batch of soil differ across the nation. Having healthy soil in your field results in healthy plants. Whatever you plan to plant, a soil test is the first thing to tick off the list. Once the soil analysis is done, you can find fertilizer recommendations based on soil test reports.

The soil analysis report you will receive from the lab should include all the attributes of the soil test you selected when you sent off your samples. This can consist of a fertilizer recommendation for achieving the commodity’s yield goal, which is usually based on local university research for your area. But each laboratory can adjust these recommendations based on your needs and expertise. The quantity and quality of vital information you receive for the analysis cost make soil testing a terrific value.

How do I understand the elements in my soil test report?

Elements reported on a very standard soil test include both macronutrients and micronutrients. Their saturation rates typically are reported in parts per million (ppm) but can vary based on the lab and the test. Except for nitrogen, multiplying ppm by two will equal pounds per acre of each nutrient. These details will help to carry out fertilizer recommendations based on soil test results.

1. Nitrogen

Nitrogen is tested in nitrate (NO3) form only if requested otherwise. By multiplying the analysis ppm by 0.3 per inch of soil sample depth, you can also determine the total soil nitrogen count.

For instance, 8 inches of soil sample depth that equals 0.3 X 8 = 2.4

If 12 ppm of NO3 is reported and then multiplied by 2.4 equals 28.8 pounds of nitrate nitrogen in the soil, which means the nitrogen applied should be effectively reduced by 28.8 pounds from the total N needed to grow your next crop.

2. Phosphorus (P)

Soils with 25 to 35 ppm P are typically adequate on most soils. There are also three common analysis methods to examine the presence of soil phosphorus:

Bray test: with neutral and low pH soils.

Olsen test: on high pH soils

Mehlich III test: on most pH values of cropping soils

3. Sulphur (S)

Sulphur is measured as sulphate, the available form of sulphur the plant can use. Sulphate is also subject to leaching. Soils ranging from 7-15 ppm S are considered adequate for most common soil types.

4. Zinc (Zn)

Soil tests can also predict whether adding zinc will impact plant health and crop yields. The desired ppm for zinc ranges from 1.0 to 3.0.

5. Iron (Fe)

Iron ppm of 10-20 is typical on most soils. Iron chlorosis is a problem with iron shortage and high pH issues, so applying additional iron could help alleviate any iron chlorosis problems you see.

6. Manganese (Mn)

Manganese at 8-11 ppm is usually sufficient. Mn availability is affected by soil pH, and less pH can increase Mn availability, while more pH can reduce it.

7. Copper (Cu)

Plants only require a small amount of copper. Copper at 0.8-1.0 is also adequate for most crops. A majority of copper deficiencies often occur in highly acidic soils.

8. Potassium (K)

The soil test examines the exchangeable potassium in the soil. Look out for a minimum of 165-220 ppm to supply the needed amounts of potassium to maximize production.

9. Calcium (Ca)

Calcium is typically plentiful in soils with a pH of 6.0 and higher; however, calcium can also be applied as gypsum and not impact soil pH. Calcium ppm of 1400 or more is generally suitable for most crops.

10. Magnesium (Mg)

Magnesium is often adequate in soils with a pH of 6.5 and higher, though magnesium at 100 ppm or more is acceptable.

11. Sodium (Na)

This part of the analysis is primarily used to repair saline or alkali soils. Sodium is not a soil nutrient— adding other elements, such as gypsum or elemental sulphur, will help with water infiltration to flush away the sodium you have present. The range for sodium in most common soil types is typically 80-120 ppm.

In conclusion

More information about your soil is on the other pages of the soil test report, but the lime and fertilizer recommendations are the most important. You can contact experts if you have any questions about your test results. Get in touch with our experts at SoilOptix® today!