Selecting the right Potassium source

Selecting the right Potassium source

Potassium (K) can be added to soil in several forms. Crop residues often contain a significant amount of K that is recycled back to the soil as it decomposes. However, crop residues cannot replace the K that is removed from the field during crop harvest.

Soils in need of additional K most frequently receive applications of inorganic fertilizers. The most common K fertilizer sources are: Potassium chloride (KCl, Muriate of potash); Potassium sulfate (K2SO4, Sulfate of potash); Potassium nitrate (KNO3, Nitrate of potash); Langbeinite (K2SO4, 2MgSO4). All K-containing fertilizers provide the same K nutrition to crops, the main difference is in the elements that accompany the K.

Guidelines for selecting the most appropriate K source for plant nutrition will be one of many topics discussed at the January 2017 Frontiers of Potassium Science Conference
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#2: Selecting the right Potassium rate

Choosing the right application rate of K fertilizer is an important issue, though too frequently overlooked.

K fertilizers are commonly applied based on the results of soil testing, but specialists also advise to consider other procedures, such as: applying an amount of K fertilizer on crops equivalent to that removed during the harvest; relying on improved soil testing techniques, such as cation exchange resins, to determine soils’ need in K; taking into account soil differences, such as the presence of minerals that affect how K is made available to plants; and using organic crop residue.

These improved procedures on selecting the most appropriate rate of K fertilization will be an important theme of the upcoming Frontiers of Potassium Science Conference on 25-27 January 2017. Don’t forget to register! kfrontiers.org

#3: Timing the K fertilizer application

Choosing the right time to apply K fertilizer is important, but often planned with other field operation and therefore can occur before planting, following planting or as a foliar spray during the growing season. However, the uptake of K fertilizers by plants requires for plant roots to be healthy, and growing in soils that aren’t cold, compacted or waterlogged. It is therefore crucial to find the appropriate time to apply them. Determining that time requires a good understanding of soil factors, root dynamics and crop demands.

4R nutrient stewardship helps determine how crop demand for K changes through the seasons, and how to increase the amount of plant-available K in soils.

Improved procedures for choosing the best time to apply K fertilizers will be one of the key topics of the Frontier of Potassium Conference on 25-27 January in Rome. Register here: kfrontiers.org

#4: Choosing the right K fertilizer placement

K fertilizers can be applied to crops in many different ways: they may be broadcast or sprayed on the soil surface then either worked in or not with tillage implements, placed below the soil surface at various depths and distances from plants, or sprayed on crop leaves.

How K is applied to a crop depends on a variety of factors. For instance, for plant organs that have a high K demand develop rapidly, foliar applications of K can be beneficial. Matching K supply to water supply in the soil is a strategy used when crops are irrigated; and applying K in the same band as N or P increases the likelihood that the branching root system will access K too, as N and P are known to stimulate root branching.

Research suggests that placement of K appears to be less critical as the overall K supply in the soil increases.

However, there are many more considerations to explore in the placement of K, which is why it will be one of the topics of the Frontier of Potassium Conference on 25-27 January in Rome. Be sure to register: kfrontiers.org

#5: Potassium and Human Health

Is your K intake sufficient?

Though a daily consumption of K is essential for human heart and bone health , a great number of people lack an adequate supply of it in their food. K is now referred to as a “shortfall nutrient” due to its chronic absence from people’s diets.

The largest single food contributor to K is found in white vegetables, notably potatoes; other significant contributors of dietary K are milk, coffee, chicken, beef, citrus juices, and bananas. However, diets have gradually transformed, especially in modern Western countries, and it is now estimated for instance that only 3% of American adults consume enough K daily.

The Frontiers of Potassium Conference of 25-27 January 2017 will therefore challenge farmers, scientists, and educators to take a closer look at how they can work together to improve dietary health.

If you haven’t registered already, now’s the time! Go to kfrontiers.org today!