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October 3, 2022

Optimizing Soil pH for Top Yields With Elemental Sulfur Fertilizer

Farmers hands with soil in them

Better start. Better harvest.

What’s the blueprint for top yield and quality every year?

It all starts with the soil, say experts, and right across North America elemental sulfur has a critical role to play.

While regular application of elemental sulfur as a soil amendment often doesn’t get the attention it deserves, producers, agronomists, and custom fertilizer applicators in the know understand it’s a game changer for better results and higher profitability.

The reason is simple: agricultural land can have a soil pH level that is too high and, as a result, is sub-optimal for crop growth. Left untreated, this becomes a hidden cost – a major limiting factor preventing crops from reaching their highest potential.

Elemental sulfur fertilizer is uniquely suited as a tool to amend soils by bringing alkaline soils back down to a more desirable acidic pH – with elemental bentonite S fertilizer typically being the most economical, reliable, and easy-to-manage option.

Soil pH 101.

The pH scale goes from 0 to 14, and the midpoint, 7.0, is neutral. Values below 7 are increasingly acidic, and values above 7 are increasingly alkaline. Crops generally require a soil pH between 5.5 and 7 for healthy growth. A pH of 6 to 7 is considered ideal for most plants because there is optimum availability of essential plant nutrients in this range.

Certain crops prefer acidic soils (4.0-5.5 pH). This includes potatoes, parsley, peanuts, tobacco, raspberries, blueberries, and blackberries. Others, such as cauliflower, pepper, and several members of the squash family, excel in slightly acidic soils (5.5-6.5).

How alkaline soils negatively impact crops.

When soil pH is above 7 many key crop nutrients, including nitrogen, phosphate, copper, iron, zinc, magnesium, and boron become chemically tied up and less available for crops to absorb. The result is less fuel for plant growth meaning yield and quality cannot reach their full potential.

Oilseed crops (particularly canola) and forage crops have a higher S requirement than cereal crops. However, many additional crops, including cereals, are negatively impacted at a significant economic level by alkaline and/or sulfur deficient soils.

Where in North America is soil pH a particular concern?

Across key growing regions of the US and Canada, there typically are significant areas with high pH (above 7.0). In America, alkaline soils are common in California, Washington State, Texas, Montana, and Idaho. In Canada, median soil pH levels tend to be higher in Saskatchewan and Manitoba.

Advantages of amending soil pH with bentonite sulfur fertilizer

1. It is extremely economical.

Elemental sulfur is one of the lowest-cost fertilizers on the market. With its high analysis (typically 90% S), bentonite sulfur fertilizers provide ample amounts of sulfur needed to lower pH to the desired level. Typically, a field amendment to lower pH using elemental sulfur will involve applying around 1 to 2 tons of elemental sulfur per acre.

That said, not all bentonite sulfur fertilizers are created equally. Those made with superior clays will provide more consistent degradability, ensuring the soil and subsequent crops get the sulfur they need. Pastilles made with inferior clay may never fully degrade, meaning you’re paying for sulfur that’s not being used.

2. Bentonite elemental sulfur fertilizers are effective and easy to manage.

Fertilizers made with elemental sulfur and bentonite clay are highly effective and easy to manage. Generally, it’s as simple as broadcasting the sulfur pastilles and incorporating them at a later date.

As they sit on the surface, precipitation and weather will cause the pastilles to swell, which in turn breaks down the sulfur into fine particles required for effective oxidation. At this point, incorporation is recommended.

Note: If you incorporate raw pastilles immediately after application, you will limit dispersion. The bentonite-sulphur will still degrade/disintegrate underground when activated by water, but the individual pastille is described as more “encapsulated.”

As an aside, higher-quality bentonite sulfur fertilizers are formulated to minimize dust for better, safer handling.

3. Slow and steady breakdown wins the race.

With elemental bentonite S fertilizer – the slow and steady breakdown that results throughout the growing season is ideal for keeping soil pH at the desired level, supporting consistency in the pH target zone. The application timing and slow release of elemental sulfur also means no leaching and strong crop safety.

It does require a small degree of planning, as applied elemental sulfur takes time to break down and impact[DN3]  soil pH and sulfur availability. Similar to lime (which is used to raise pH), it may take up to two years for the amendment to deliver the desired results.

Lock in your crop’s full potential

As a farmer or advisor recommending fertility solutions, everything that’s been invested in the crop year – seed, inputs, equipment, countless hours and more – can be undermined if the soil pH isn’t right. Therefore, understanding soil pH and the most effective amendment strategy isn’t just smart farming but also sound risk management.

Elemental sulfur can provide you with an invaluable insurance policy – keeping your soils on track to give your crop the best nurturing environment it needs for success. It’s an investment that can pay off handsomely every harvest.

Download free guide to uncover the secrets to building an effective annual sulfur plan.