All steam ahead for alfalfa with sulphur

5 May 2016

The high feed value crop of alfalfa does so much for the farmers that grow it and for the livestock that eat it. Evidence just released from studies in North America show what farmers can do for their alfalfa with a top dressing with a sulphur-containing fertilizer.

The initial findings are yet another pointer to the value of using Polysulphate which not only contains sulphur, but also has the added bonus of valuable levels of potassium (K2O), magnesium (MgO) and calcium (CaO).

Appreciating alfalfa
Alfalfa spread from its Asian origins to be grown in many parts of the world as a fodder crop, whether grazed, dried for hay or preserved as silage. Provided that conditions, including optimum nutrition, are right then the deep-rooted legume performs incredibly well with yields of up to 20 tonnes per hectare. Good performance is only possible provided adequate plant nutrients are available, particularly sulphur.

Seeking the effect of sulphur shortage in alfalfa
In the US state of Michigan, in the area known as the Upper Peninsula, a team from the Michigan State University Extension have been investigating the limiting factors on alfalfa yield and decided to assess what impact the application of a sulphur-containing fertilizer could have on the alfalfa crop.

Tissue samples from side-by-side alfalfa fields with and without the addition of sulphur were analysed. Their findings, just released, show a top dressing of fertilizer containing sulphur resulted in a marked improvement in alfalfa production.

Dramatic results from addition of sulphur-containing fertilizer
The report quotes the experience of one farmer, from the county of Baraga. He told the team that he noticed how a top dress application including sulphur made such an improvement that he described it as “a ‘day and night’ difference in alfalfa yield”. He added that the additional cost of sulphur fertilizer was “paying off nicely”.

At ICL, we welcome this observation of the role of sulphur in soil and the plant and often hear farmers describe how cost-effective is the use of our sulphur-containing fertilizer Polysulphate.

Further work is required to establish what North American initial findings mean for alfalfa production in the US and elsewhere in the world. While this information cannot be subjected to statistical analysis, Jim Isleib, Michigan State University Extension’s Crop Production Educator, hopes that alfalfa farmers that grow alfalfa without sulphur fertilizer or manure should hear the strong hint and be aware of the potential need for additional sulphur on their crop.