K+S’s main focus at Cereals is to highlight the importance of potash and magnesium for optimum utilisation of applied nitrogen and maximising yield and quality of oilseed rape and cereal crops.


K+S will have the latest independent trial results demonstrating the benefit from ensuring sufficient potash, magnesium and sulphur is available to these crops throughout the growing season.

The four-year research programme focused on evaluating magnesium responses in arable crops in the UK. Jerry McHoul, technical manager for K+S UK and Eire, explained the aims of the work.

“There has been precious little quality field work done in recent decades on crop responses to magnesium. The idea therefore was to generate some quality replicated response data in modern crop cultivars and to compare the main sources of magnesium fertilisers available to farmers.”

The results collated from over 14 trials were very consistent year on year. said Dr Mike Armstrong, from independent research firm Armstrong-Fisher.

“We are now in a position where we can make some robust judgments from the findings, with a mean response to 400kg/ha ESTA Kieserite in both potatoes and sugar beet of 3.3t/ha, the benefit of applying adequate magnesium is clear,” he said.

“Large differences between fertiliser materials were observed with the mean response from calcined magnesite (Mg Oxide) just 0.7t/ha and 0.9t/ha in potatoes and sugar beet respectively.”

Mr McHoul added: “The results whilst surprisingly consistent were not altogether a surpris; kieserite is naturally occurring magnesium sulphate and in this form, the Mg is water soluble and therefore available for crop uptake. In calcined magnesite and hydroxide, the Mg is insoluble in water and therefore requires lengthy acidification to release Mg to plants.”

Responses to kieserite at some index 0 sites were approaching 5t/ha, which represent a return on investment of over 500% in potatoes.

Furthermore, consistent and cost-effective responses to applied magnesium have been seen in cereals and oilseed rape both on index 0 and 1 sites.

Mr McHoul said: “German farmers have long appreciated the benefit of supplying magnesium to crops and believes it is this attention to detail, particularly on oilseed rape which sets German rape growers apart and accounts for some of the ½ tonne/ha yield difference between UK and Germany.”

He stressed that the full reports have been made available to the committee responsible for the long-awaited new edition of the book of DEFRA fertiliser recommendations, currently known as RB209 and hoped to see more detailed guidance on magnesium recommendations as a result of this work.

K+S feel it is important to promote good practice for nutrient planning so farmers can get the most out of their existing resource and try to spend money on inputs where they really need to.

To this end, there will be a competition on both days of the Cereals event with a chance to win one of 40 soild stainless professional soil samplers at the stand.

Mr McHoul explained the idea for the free draw: “With the recent publication by the AIC of a huge number of soil analysis results, it was clear that P, Mg and particularly K levels in UK soils are falling dramatically to the point where the efficiency of applied nitrogen is seriously reduced.

“By regularly conducting soil sampling, fields below the target index for P, K and Mg can easily be identified and the appropriate quantity of nutrient can then be applied to restore and maintain soil fertility.”

It is basing its promotion at Cereals around the product Korn-Kali that was designed to deliver the right balance of potash, magnesium, sulphur and sodium to most combinable crops, replacing at least what is removed each harvest.

A Nutrient Deficiency Clinic will be on display, demonstrating clear crop deficiency symptoms and there will be four crop nutrition specialists on hand to offer advice to farmers on fertiliser usage and recommendations.

K+S has re-printed its unique waterproof nutrient deficiency Pocket Guide that proved very popular last year, which, along with a new crop growing guide for cereals and OSR, will be handed out at the event.

*Cereals 2010 exhibitor information as supplied by K+S.