Standard nutrient extraction analysis: how to measure them

The Standard Nutrient Extraction Analysis is a very important indicator of the health of a plant variety, especially in sports fields because of the criticality of its maintenance. It is directly related to its fertilisation needs. That is why it is very important to measure or monitor the evolution of the nutrients available to the plant.

The plant under normal conditions has a water content between 75 and 80%. The rest is made up of mainly organic compounds corresponding to the dry matter. These organic compounds are formed from the elements essential to the plant. In addition to hydrogen, oxygen and carbon, these are essential nutrients on nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulphur (S), iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), boron (B), molybdenum (Mo) and chlorine (Cl). The plant is not able to absorb these elements in any chemical form, but needs them to be available in an assimilable form and only what is found in the soil solution will be available to the plant.

The standard nutrient extraction analysis measures the amount of nutrients available in soil solution.

Another test, called foliar analysis, is used to measure nutrient uptake, which will be discussed in another blog post.

The fertility of different soils in relation to available nutrients, whether macronutrients (Calcium, Magnesium, Potassium, Phosphorus, Sulphur) or micronutrients (Iron, Manganese, Zinc, Copper, Boron) is based on laboratory tests where samples are subjected to the action of different chemical extractants. The determination of the absolute total of the different chemical elements, as we have said, is not indicative of fertility, but will depend on the availability of these nutrients for the plants.

Availability will vary according to soil types, texture, structure, pHThe choice of extractant is therefore based on these criteria.

Different laboratories can use different extractants. Thus we have from the simplest, such as distilled water used in the saturated paste test, to simple acids, such as ammonium acetate, which is widely used in the standard analysis of sports surfacesmixtures of acids, bicarbonates, chelates or a combination of these. It is essential that the choice is the right one and that the results are expressed within fertility ranges adapted to the different plant varieties and species.

Tiloom has worked with the best certified laboratories in Spain and can in turn guarantee both that the procedures are adequate and guarantee the quality of their results through water and soil engineering software. We invite you to comment on their experiences through the comments on our blog, which is a professional community of greenkeepers specialised in these tests.