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The Basics of Soil Testing and Fertilizer Recommendations 

Soil testing and fertilizer recommendations should enable optimal crop management and help avoid the pitfalls of fertilizer mismanagement. While a soil test might reflect the chances of a positive crop response to the applied fertilizer, determining the amount of the required fertilizer requires that the soil is calibrated and interpreted correctly for specific crops. After the soil-test calibration and water management, understanding the philosophy associated with fertilizer recommendations is a crucial element of the fertilizer recommendation.

History of Fertilizer Use in Crops

Crop production in the early 20th century depended a lot on the native soils and its natural fertility. Certain minerals like rock phosphate, potassium silicate, sodium nitrate, and more were found to increase productivity. Organic nutrient sources like animal manure and guano were added to the soils. In the mid-20th century, synthetic and chemical nutrient sources came into wide use. These fertilizers were manufactured in large amounts and were inexpensive to use.

Fertilizers are applied in crop production to enhance crop productivity and increase farming profitability throughout the mid-20th century. Research played a crucial role regarding soil testing and fertilizer recommendations in the mid-20th century. The research was conducted mostly in the crop fields and provided guidelines for the amount of fertilizers used and how to apply it to the crop. Scientific methods were used to develop the means to effectively use fertilizers. These include soil testing methodologies, new fertilizer materials, and application technologies.

Water Management – A Basic Step Before Soil Testing & Fertilizer Recommendation

There is no denying that water for both irrigation and drainage must be managed efficiently. Any fertilizer recommendation will be useless if water is not managed correctly. Environmental problems occur when the movement of nutrients from the field is facilitated by water. If the grower can adequately manage water, the nutrients will be available for better yield and quality. Thus, it will improve the efficiency of the applied fertilizer and reduce the chances of adverse environmental consequences.

The Basics of Fertilizer Recommendations

Fertilizer research should follow the accepted scientific principles of randomly applying treatments, hypothesis testing, replication, unbiased interpretation, and statistical analysis. In all the fertilizer research, there must be a grower or on-farm component to work. On-farm or field testing fertilize research is crucial for several reasons. The scale-up nature from a small plot to field scale trials allows the researcher to test the results from the research plot in a farm environment with real-world practices.

Also, on-farm work allows the growers to view the research in the context of their farming management systems and conditions. Farm-scale testing allows complete economic cost analysis with real-world inputs. A soil testing fertilizer recommendation is a research-based set of guidelines to apply fertilizer to the crop for achieving optimal yield and quality goals in such a way that reduces nutrient losses to the environment. Typical soil testing and fertilizer recommendations include the following:

  • The rate – specifies the amount of fertilizer needed to supplement the nutrients supplied by the soil.
  • The different types of fertilizers to use – dry granular, soluble, fluid, controlled-release, and more.
  • Fertilizer sources for supplying specific nutrients. For instance – nitrogen might be supplied from urea, ammonium sulphate, ammonium nitrate, calcium nitrate, etc.
  • Placement method – The soil testing and fertilizer recommendations will include the placement method like ground or foliar, pre-plant, broadcast or band, and side-dressing in the season.
  • Timing – The recommendations will include the timing. For instance, whether it should be during planting, depending on certain growth cycles or growth stages in the season.
  • The soil testing and fertilizer recommendations include managing the irrigation system is crucial so that the water and nutrients stay in the root zone.

These principles are typically called the 4R Nutrient Stewardship Program, and is the cornerstone of sustainable fertilizer use.

If you are in search of the best and most effective organization to avail soil testing and fertilizer recommendations, get in touch with SoilOptix® today! Visit  for details.