The Relationship Between Nutrient Levels in Soil and Weed Growth

Much has been said and little studied on the relationship between nutrient levels in soil and weed growth/suppression.

A long time organic grower and agronomist (and friend) shared his experiences with calcium levels and the reduction of weed growth after planting.

  • One thing that is necessary is good functioning, highly biological soil.
  • The second necessity is highly available calcium.

2017 barley high calcium weed suppresion trial skip

The barley in these photos shows the crop 30 days after planting.

The barley was planted with equipment outfitted to apply a liquid biological (Purple Cow CX-1) right in furrow on the 24 run drill (see picture of planter: the CX-1 goes down on each row/run planted right in the double disc openers) at a rate of 5 gallons per acre.  The day after planting a highly soluble calcium product was spread at 500lbs per acre over the field and left on the open surface.

24 run drill

Purple Cow FortiCal could be an option pre-planting, but in this instance, to be more “tender footed” in application, a finer/drier product that would go through a fertilizer cart was used (vs needing a spreader truck or larger heaver equipment) because it was applied on the planted (not yet emerged) crop.

~James (Sandy) Syburg, Soilologist

As you can see even the area in the field that was skipped by the drill (where the bare soil is exposed), there is almost no weed pressure even 30 days after planting!


60 Days after planting

2017 barley high calcium weed suppresion trial skip60DAYS

The barley looks pretty good for how wet it has been. Probably still a few weeks until harvest but weed pressure is almost nonexistent. I took a picture of skip and still very little weeds even with all the rain. My guess is very little of the soluble calcium is still around but I say it did its job.

~James (Sandy) Syburg, Soilologist

Why does soil biology matter?

The take away is to insure you have biologically active soils by using a liquid biological at planting – at the genesis of plant growth and germination.  Also, balance soil minerals to make sure to have nutrients available to both soil microbiology and the plant.

Mineral form application

Nutrients in an organic form that require liberation via the soil microbial community – meaning in mineral form – are best.  But in planting situations when soils biological activity is low the soluble calcium is what is believed to suppress the weed seed germination.  In this instance I would have to say it worked.  Not all the calcium in the product that was applied is soluble, so the biology is now taking over the job of releasing it due to the soils being warmer and activity returning.

~James (Sandy) Syburg, Soilologist

Midday Fix: Tomato garden tips from Purple Cow Organics VIDEO

WGN channel 9 in Chicago

Ryan Hartberg visited Chicago’s WGN channel 9 news station and while the cameras were rolling, talked about planting tomatoes and increasing the health of soils. Watch the segment here.


Tips for growing from Purple Cow Organics

There are some considerations to begin with, when you’re planting the perfect tomato. Do you want to start from seed? Do you prefer to start with a plant? What kind of variety do I like to eat? Because it’s been a cold, wet spring, it’s not too late to start from seed. And because tomatoes are warm-weather plants, it’s optimal to start tomato plants when it’s no longer cold and rainy in the day and down into the 40s at night. It’s about being an observational grower – you don’t want to be the first one to plant tomatoes just to be first. Wait until the timing is right outside, and be patient.

You can have the best plant in the world, but if it’s grown in bad soil, it won’t be a good plant – or tomato. The good news is that gardening organically is easier than you might think – instead of loading soil with chemical fertilizers, you can replace them with organic matter, nutrients and microbes. Adding a couple of inches of compost brings nutrients back into the soil, and also makes your tomato plants require less attention, because it’s grown in a living, breathing, self-regulating ecosystem. Perfect tomatoes start with good microbiology. A single handful of healthy soil actually contains more microbes than there are people on earth.

organic fertilizer

You can look for organic tomato plants, which will have an organic tag on them. But if you have good, healthy soil, it doesn’t mean that a non-organic tomato plant won’t do well – it still well. Generally speaking, if you’re buying a tomato plant, look for plants that aren’t too tall and leggy – the “squattier” the better. I’d rather have a plant that’s shorter than a tall plant. look for thicker, larger leaves that are greener, versus smaller leaves or yellow leaves.  With seeds, you can buy organic seeds or heirloom tomato seeds.

Tomatoes are heavy feeders, so you have to be sure there is enough fertility in the soil.  If you use bad soil, then the plant is more susceptible to disease and blight, because the plant is defending itself against that, instead of using the energy for strong, healthy growth.  After tilling the soil, you can apply fertilizer, like compost tea, which is good because you can make a batch and add it to plants quickly. Basically, you coat the leaves with a small coating – I’ve gone out in my garden with a spray bottle to spray it on a plant. A good two-inch layer on op will do.

Screen Shot 2017-06-01 at 12.23.04 PMIf you have clay or dense soil, you can incorporate compost to escalate the microbiological elements for a better tomato that is not just healthy but nutrient-rich. Alternately, you can use a liquid biological.

People get excited in the early spring, because they’re doing all the work and are glad when the plants are in the bed or container. But later, when you get later into the season, you might get tired of weeding, or it’s hot outside or there’s a lot of mosquitoes. Still, if you want great tomatoes at harvest time, check to see how your plants are growing regularly – are they flowering? Are they distressed?

For watering plants like tomatoes, you want to water less often, but water more.  If you can go every third or fourth day with a good dousing, that’s better for the tomato plant.