Destroying weeds in straw
Ammoniated straw is a weed-free mulch for strawberries and other horticulture crops.
Tom Ward, of the horticulture science department at the University of Saskatchewan in Saskatoon, has found that treating straw with ammonia destroys weed seeds.
He used a three percent application of anhydrous ammonia to control weed and grain seeds in mulching straw.
Applying ammonia to straw is easy with simple pipe structures and plastic coverings, he says.
The field trial strawberries showed no negative effects from the ammoniated-straw mulch, and were generally better in appearance due to reduced competition from weeds.
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“When compared to the cost of hand labor or the use of herbicides, the cost of controlling weed and grain seed growth in mulch is much more favorable. Also, by using ammoniation as a means of weed control, plus some hand labor, growers can promote their product as being herbicide-free,” Ward said.
– Saskatchewan Agriculture
Sulfur fertilizers tested
Jeff Schoenau, of the department of soil science at the University of Saskatchewan in Saskatoon, has explored different forms and application rates of sulfur fertilizers.
Two were experimental products. One was a combination of elemental sulfur and Saskatoon sewage sludge aggregated into pellets. Another was a by-product gypsum from a sodium sulfate mine.
The other two products were commercially available sulfur fertilizers.
“We found that the elemental forms were less effective than sulfate forms in increasing the supply of plant-available sulfate early in the growing season,” Schoenau said.
Producers with low soil sulfur levels who are seeding a crop that will need sulfer in spring should add a sulfate form to their fertilizer blend.
However, elemental sulfur, such as the sludge and gypsum, can help maintain sulfur fertility as a long-term, slow release source.
The low solubility of gypsum could be an advantage if applying it in the fall or in high-leaching conditions.
The project also found the amount of soluble sulfate in the soil in spring is not reliable as a predictor of how much sulfur will be available to growing canola.
This indicates the need to consider other sources of sulfur.
– Saskatchewan Agriculture
