“B90” BENTONITE SULPHUR PRILL TRIALS

Back in 1990 we were using various types of sulphur products to overcome highly sulphur deficient soils in the Central Otago horticultural industry. We were not achieving the results we would have liked, so a new sulphur prill "B90" was imported and applied.

Within a three year period, we had lifted soil sulphate levels from 7-9ppm to   
20-25ppm. These excellent soil sulphate levels are being maintained with annual maintenance applications of “B90”, even with large amounts of frost fighting and irrigation water being applied.

This led us to look at how we could improve the soil sulphate levels for agriculture, especially for the Otago/Southland high country. We were aware that in a lot of cases, high country farmers with good soil “Olsen p” levels were applying a sulphur super grade of fertilizer just to obtain the sulphur. (not a cost effective exercise)

We organised "B90" sulphur trials on two separate Southland high country farms, Nokomai Station and Mount Linton Station. You will see from the graphs below that in both cases we started with low soil sulphate levels of 7 & 10ppm and over the three year trial period lifted these to 25 & 45ppm. The recommended range for soil sulphate levels is 12ppm (min) & 30ppm (max) and for total soil sulphur 450ppm (min) & 880ppm (max).

“B90” sulphur prills are made up of sulphur particle sizes in the 10-50 micron range coated with bentonite. When soil moisture is added the bentonite breaks down allowing these sulphur particles to release and disperse at around 8% per month. These particles have a greater residual effect than sulphur super fertilizers.

“B90” sulphur can be applied by aerial top dressing aircraft in its prill form without having to be blended with any other product. The Civil Aviation Authority has very stringent requirements when it comes to applying sulphur by aircraft and bentonite sulphur prills are the only sulphur product which currently meets these requirements.

For further information regarding these trials or B90 sulphur prills contact us.

			Sulphur Prill Applications
Recommended Soil Sulphate levels	12ppm (min)		Year	kg/ha
	30ppm (max)		Year 1	40
Recommended Total Soil Sulphur Levels	450ppm (min)		Year 2	40
	800ppm (max)		Year 3	25
			Sulphur Prill Applications
Recommended Soil Sulphate Levels	12ppm (min)		Year	kg/ha
	30ppm (max)		Year 1	40
Recommended Total Soil Sulphur Levels	450ppm (min)		Year 2	40
	800ppn (max)		Year 3	25