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Potash News

The Potash Development Association publishes both technical Potash News items and shorter Blog items. Potash News provides the latest up to date information on Potash and its use, while blog items are shorter and more timely.

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The Role of Potash in Plants

May 2015

Ian Matts, Company Agronomist, Yara UK Potassium is one of the major nutrients required by all crops and is present in large quantities in the plant in the form of the cation K+. It plays a major role in achieving the maximum economic yield, as part of a balanced approach to crop nutrition, as well […]

Soil Texture and pH Effects on Potash and Phosphorus Availability

January 2015

Dr Paul Hargreaves, SRUC, Crichton, Dumfries. The application, use, efficiency and loss of nutrients including K and P can vary with soil type. Soil type is generally determined by the texture of the soil, which is a measure of the proportions of the following three particles: sand, classified as having a particle size between 0.05mm […]

High Yields – are we keeping up with Potash offtakes?

September 2014

The Fertiliser Manual (RB209) gives recommendations for phosphate and potash applications for arable crops and grass based on that needed to replace the amount that will be removed from the soil by crop offtake at harvest. In addition, where soil analysis is below target, it adds a small amount to build up the soil reserves […]

Measuring potassium in soil and crop

June 2014

At a time when a crop is looking at its best, as is usually the case at this time of year, there may be little incentive to think about deficiencies. However crops can appear to be perfectly well fed yet still be deficient in potash. This ‘invisible’ deficiency is often referred to as ‘hidden hunger’, […]

Nutrient recycling by grazing cattle

October 2013

Grazing livestock return most of the nutrients they consume to the soil. This sounds good but a glance at any grazed pasture will show that the recycling is not done very well. There are many patches where dung or urine has been deposited but most of the field is unaffected. In paddock grazing systems where […]

Fertiliser base dressings and timing

July 2013

Nitrogen fertilisation for good yields can be effectively managed at SNS Index 0, because nitrogen fertiliser is applied each year to make good the supply from the soil and to meet the needs of the crop. But we cannot do this with potash (nor with phosphate) on P or K Index 0 soils because it […]

What are the effects of potash deficiency?

March 2013

We write ‘effects of potash deficiency’ rather than ‘symptoms of deficiency’, because so many of the negative effects of a shortage of available potash to crops are not clearly apparent, whereas ‘symptoms’ implies some visible effect. Of course severe deficiency has visible symptoms (Figure 1), but there can be many expensive negative impacts on the […]

Calculator for estimating nutrients needed to correct soil deficiency

October 2012

In the previous Newsletter it was noted that in many cases it could take between 10 and 20 years to change the nutrient status of a soil from Index 1 to 2 if only the additional 30 kg/ha as suggested in the Fertiliser Manual (RB209) is added to the crop offtake when making a phosphate […]

Standard recommendations cannot make a poor soil good overnight

July 2012

A crop receiving the rate of potash (or phosphate) recommended in the Fertiliser Manual (RB209) for a soil at Index 0 or 1 is still very unlikely to perform as well as it could on an Index 2 soil. The standard recommendation at phosphorus (P) or potassium (K) Index 0 or 1 is in two […]

Good soil potash reserves are required for efficient nitrogen use

March 2012

In the spring there is understandably much talk of nitrogen applications, growth regulators and how well crops have come through the winter. It is seldom accompanied by discussion of the importance of potash on the efficiency of nitrogen utilisation, on the ability of cereal crops to resist going down, or on the resistance of the […]

Balanced nutrition shown by nitrogen:sulphur ratios

November 2011

In a recent Newsletter the pattern of uptake of potassium and some other nutrients during the growing season was shown. The same French data-set also analysed the crops for the patterns of nitrogen (N) and sulphur (S) uptakes. The majority of the N and S in crops (other than the Brassicae, such as oilseed rape, […]

Potassium uptake requirements of some crops

July 2011

Fertiliser recommendations for potash (K2O) are usually based on removal or offtake of K2O at harvest. Some detailed results of measurements on K2O uptake during crop growth show that greater care is needed to ensure potash supply meets crop requirement. Difference between uptake and offtake The amount of a nutrient needed for full growth of […]