Should farms sell or chop straw with fertiliser prices high?

The worth of straw, whether or not for energy stations or conventional forage and bedding markets stays, buoyant, and plenty of growers will likely be trying to reap the benefits of that.

However, with excessive phosphorus (P) and potassium (Ok) fertiliser costs this season, the worth of straw as a cheap supplier of those vitamins, a better appreciation of the natural matter standing of soils and the significance of straw for soil well being, raises an rising variety of questions over straw elimination.

Rob Jewers, fertiliser and crop diet specialist for Hutchinsons, believes that with the intention to make an knowledgeable choice as as to whether to promote or incorporate, step one is calculating the worth of nutrient eliminated in baled straw.

See additionally: Tips to achieve successful long-term grain storage

Mr Jewers recommends wanting on the values of various straw varieties utilizing present market knowledge. “These could be discovered within the AHDB Nutrient Management Guide [RB209 Section 4 – Arable Crops, March 2022 edition]. These figures can be utilized the place the straw isn’t weighed when eliminated.”

He notes that because the potash content material of straw can range considerably relying on water availability throughout crop maturity and straw baling, it’s worthwhile figuring out the nutrient content material of consultant straw samples by laboratory evaluation.

Using present costs in June for trisodium phosphate (TSP) at £930/t = £2.02p/kg P and muriate of phosphate at £770/t = £1.28p/kgK, it’s doable to calculate that for a winter wheat crop yielding 10t/ha, if the grain and straw is taken off, this equates to 70kg/ha of phosphate elimination within the type of P2O5 and 105kg/ha of potash elimination within the type of K2O, he says.

“This works out at £64.87/ha of extra fertiliser worth in straw being eliminated. In comparability, finally yr’s costs this was solely £26.07/ha – that’s a distinction of £38.80/ha worth.”

“Looking at one other instance – say, a crop of winter oats with grain and straw taken off based mostly on a 8t/ha crop – there’s a lack of 77kg of phosphate and 132kg/ha of potash, so the extra fertiliser worth in straw eliminated is £112.86/ha, which is a distinction of £67.68/ha over final yr, when the extra worth was £45.18/ha.”

“The essential message right here is to reinvest a few of the cash made again into changing the diet that has been eliminated,” he says. 

Mr Jewers factors out that these values are purely the monetary alternative worth of the vitamins eliminated in straw solely.

However, there are different components to be considered similar to elevated site visitors and related soil compaction – it is a notably consideration in wetter areas of the nation the place additional site visitors will nearly actually trigger harm to the soil construction.

There can be the worth of natural matter almost about constructing soil construction.

Change in fertiliser worth of straw
Crop	Yield (t/ha)	Phosphate elimination (kg/ha P) P2O5)	Potash Removal kg/ha Ok2O	Current extra fertiliser worth in straw eliminated (£/ha)	Additional fertiliser worth in straw eliminated based mostly on June 2021 costs (£/ha)	Difference
Winter wheat grain solely	10	65	55
Winter wheat (grain and straw)	10	70	105	£64.87	£26.07	+£38.80
Winter barley grain solely	8.0	64	44
Winter barley (grain and straw)	8.0	68	84	£51.90	£20.86	+£31.04
Winter oats grain solely	8.0	64	44
Winter oats (grain and straw)	8.0	77	132	£112.86	£45.18	+£67.68
Spring barley grain solely	7.0	56	39
Spring barley (grain and straw)	7.0	60	84	£57.31	£22.80	+£34.54
OSR seed solely	4.0	56	44
OSR (seed and straw)	4.0	60	70	£36.03	£14.79	+£21.24
*Removal charges are taken from the AHDB Nutrient Management Guide (RB209 Section 4 – Arable Crops, March 2022 Edition). These figures can be utilized the place the straw isn’t weighed when eliminated.