Soil School: Rebuilding organic matter with Andy Kieraszewicz

Andy Kieraszewicz

Andy Kieraszewicz never thought the sandy soils on the former tobacco land he farms at Rodney, Ont., could ever average more than 200 bushels of corn per acre. But a fervent commitment to rebuilding organic matter in the drought-prone areas across the 1,000-acre operation has the farmer now consistently producing eye-popping yields he didn’t think possible 10 years ago.

On this episode of the RealAgriculture Soil School, Kieraszewicz shares what has happened to his soil over the past decade after he turned to a mushroom compost mulch to help rebuild badly eroded knolls. In just 10 years, he has increased organic matter from 1% to 2.6%.

In the first year of application, he applied 11 tons per acre of the mulch — consisting mostly of straw, chicken and horse manure, and micronutrients, including sulphur  — and boosted corn yield by 60 bu/ac. As more mulch has been applied over the decade he significantly increased the water-holding capacity of the soil and reduced the area of the farm suffering drought conditions from 30% to 10%. Average corn yield now pushes past 200 bu/ac across the farm. Before the mushroom mulch arrived, the farm averaged less than 150 bu/ac for corn and only 90 bushels on sandy knolls.

In the video, Kieraszewicz breaks down his approach, noting how he applies the mulch to lighter soils at a rate of 8 tons per acre, utilizing 4,000 tons annually from a nearby mushroom plant. (Story continues after the video.)

Kieraszewicz says there are pros and cons to using mulch to build organic matter. It’s labour and time intensive — a commitment he estimates at 18 days each spring. Specialized equipment is required to spread the mulch. He pegs the overall investment at $70 per acre more than it would cost for a conventional fertility program. But the yield boost more than pays for the investment and also makes the sandy soil resilient in stressful conditions and a more reliable crop producer.

Kieraszewicz notes that he uses commercial fertilizer across a good portion of the farm, which includes areas of highly productive black soil. But when it comes to sandy, eroded knolls, the ability to rehabilitate these areas and turbo boost yield certainly pays. He adds that mushroom mulch delivers high levels of phosphate and potash that also contribute to overall fertility. Adding 120 lb/ac of starter fertilizer and 120 lb/ac of nitrogen is enough to fuel bin-busting yields.

It all adds up to higher organic matter, better soil health, improved fertility and more cost effective crop production, says Kieraszewicz

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