Seeding With My Son

Our family owns a prairie about 15 minutes south of our house, and that ownership gives me some wonderful opportunities to share my enthusiasm about prairie ecology with my kids.  I don’t expect any of my three offspring to become prairie ecologists when they grow up, but I do hope they’ll always enjoy and appreciate prairies.  In addition, I want them to understand the importance of land stewardship and the conservation responsibility we all have – especially those of us with direct management control over land.

Daniel Helzer throwing prairie seeds at the Helzer prairie farm near Stockham, Nebraska.

Last weekend, I got to spend a couple hours with my youngest son (Daniel, age 7) overseeding of a portion of our prairie.  During the summer and fall, all three kids helped me harvest seeds from local wildflower species that are rare or missing in our prairie.  Since the end of the growing season, I’d been waiting for the right day to put together a nice family outing to throw the seeds out.  It’ll be a good bonding experience, I thought.  A great way to share in the process of restoring a piece of family land.  Something my kids can tell their grandchildren about.

So yesterday, I asked for volunteers to help me spend a beautiful afternoon at the prairie.  Not one kid wanted to go.

Fortunately, my wise (and beautiful) wife pointed out to me that asking for volunteers wasn’t always the best way to handle children.  Adjusting my tactics, I cornered Daniel and simply asked him what time he wanted to go to the prairie with me.  I then explained that we’d be working in very short grass (really tall grass can be hard on a 7-year old) and that we could quit if he got tired of it.  I also described the satisfaction he’d get next year from finding new wildflowers in the prairie and knowing that they were only there because of his work.  I’m pretty sure that’s what swayed him.  Or maybe he realized that his brother and sister were going with their friends for the afternoon and his other option was staying home with his mom – who was cleaning house.  Probably it was the satisfaction thing.

Regardless, off we went. 

The right half of this August photo is the area Dan and I seeded yesterday. A season of intensive grazing (which continued well into October) knocked back the vigor of the grasses and other plants in that part of the pasture, opening up root space below and soil and light space on the surface. The portion of prairie on the left had the same treatment the previous year, but was ungrazed and recovering this year. The majority of this prairie was converted from cropland to grasses in the 1960's by my grandpa. Some wildflower species have colonized over time, but its overall wildflower diversity is still a little low - but growing.

(I wasn’t kidding when I told Dan we were going to be working in short grass.  I’d set up the grazing on our prairie this past year such that about a fourth of the site was grazed very intensively for most of the season.  Past experience has shown me that season-long intensive grazing can lead to decent establishment of seeded plants – particularly at this prairie.  The grazing opens up bare ground for seed-soil contact, but also greatly reduces the root mass of grasses to allow new seedlings a chance to compete with those normally dominant plants.  Next year the overseeded area won’t be grazed at all, which will give the seedlings a chance to start and the existing plants a chance to recover their vigor.  I’ve never seen any long-term damage to existing plants, but this kind of grazing opens up temporary space for new recruitment.) 

When we got to the prairie, I handed Daniel a bucket of seed and explained my special technique for overseeding.  “Take this seed and throw it on the ground,” I said.  Being a very bright young man, he picked it up quickly.  Did I mention how smart he is?

We did have a brief minor issue with the wind, but that was really my fault for not including that in my explanation.  What I should have said was, “take this seed and throw it WITH THE WIND.”  After we dug a few seeds out of his eyes and he spit out the rest, things went very smoothly.

The first test throw helped us refine our methods.

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Throwing seeds with the wind is much more productive.

We spent more than an hour walking around and throwing seed on the ground (more or less strategically) – pausing now and then to look at tracks he found in the dirt.  “Those are deer tracks,” I explained.  “Yep, those too…  and those and those and those.”  Apparently, we have a lot of deer this year… 

As we worked, we also spent some time discussing the best ways Dan might try to break the ice on the pond without getting muddy.  Eventually, it dawned on me that his questions about breaking the ice were less theoretical and more like hints about what he’d actually like to be doing with the remainder of his prairie outing.  So we put the remaining seed back in the truck and headed down to the pond, where we had a great time chucking sticks and rocks onto (and occasionally through) the ice.  And, yes, he got muddy.

When we got home, I was proud to listen to Daniel explain to his mother – in great detail – the specifics of our afternoon’s conservation work.  In fact, he very precisely described both the kinds of sticks and rocks we threw at the pond and exactly how high we had to throw them so they would punch holes in the ice when they landed.  He even used the word “plummeted” appropriately.  (Did I mention he’s very bright?)  I’m sure he would have gotten around to describing the deep satisfaction he’d gained from personally participating in the restoration of prairie function and diversity, but he got challenged to a ping pong game and forgot. 

All in all, it was a pretty great day.

Why are there stripes in my prairie restoration?

The photo below was taken in September 2008.  It shows a long stripe passing through a restored prairie at the end of its 7th growing season.  The site was seeded with a drop spreader in November of 2001 (seed was broadcast on top  of soybean stubble shortly after harvest).  There are at least half a dozen of these stripes running through the prairie.  They vary slighly in width from a 1/2 meter to about 2 meters.

One of the stripes in the prairie restoration, delineated by the light colored seed heads of Canada wildrye inside the stripe and the reddish-colored big bluestem in the surrounding prairie. The site was planted in November 2001, and this photograph was taken in September 2008.

I’m confident that the stripes are a result of the way we seeded the site.  The drop spreaders we use (photo below) are named because they simply drop the seed straight out of the bottom of the spreader.  We load them up with seed and pull them behind ATVs, and try to overlap our passes slightly so we don’t create long skinny gaps that don’t get any seed.  In this case, I’m pretty sure we were a little sloppy and that these stripes are a result of not overlapping our passes very well – they line up exactly with the direction we were driving.  Because we were seeding on soybean stubble, it was hard to see the tire tracks from the previous pass, but we followed the rows as we planted so we’d at least go in a straight line.

The spreader we seeded the restoration with was similar to this one except it was a different brand and was slightly wider. There is an agitator inside and holes in the bottom, and the seed simply drops onto the ground as the spreader is pulled along.

As interesting as the visual effect is, what’s really intriguing to me is the exercise of trying to figure out why the stripes are still so obvious after 7 growing seasons (actually 9 growing seasons, because the stripes were still obvious in the fall of 2010).  We seeded this prairie with a light seeding rate (around 4lbs PLS per acre) but by its fourth growing season it was already dominated by perennial native plants.  Even if the strips we missed with the seeding didn’t get prairie seed that first year, they should have been getting seed rain from native plants (like big bluestem, which is all around them) by the 4th season.  Two or three seasons later, you’d expect that plants like big bluestem would be filling in those stripes – but it’s apparently not happening.

The stripes seem to be dominated primarily by Canada wildrye, with a smattering of other species like Canada goldenrod, annual sunflowers, and other annual weedy plants.  I’m assuming the wildrye colonized from plants that established adjacent to the stripes and subsequently dropped seed.  I can understand that.  But why didn’t other species colonize the same way?  Did the wildrye come in first and fill all of the open root spaces below ground, preventing other plants from colonizing?  Surely not.  The presence of annual plants in the stripes shows that there is space available for new colonizers.  In addition, wildrye was dominant in the rest of the prairie during the 3rd and 4th growing seasons but soon gave way to big bluestem and other longer-lived plants.  Why hasn’t that happened in the stripes?

It sure seems like there should be plenty of seed falling into the stripes from plants along the edges, but those seeds either aren’t falling, aren’t germinating, or aren’t surviving seedlinghood.  It’s like the stripes are in a sort of suspended animation – they developed into a 3rd season restored prairie and just stopped.

I’ve seen this kind of striping in some of our other prairies as well.  The most apparent is in a prairie that was seeded by Boy Scouts in 1997.  The Scouts walked back and forth across 1 acre squares we’d flagged out for them and threw seed as they walked.  That particular site apparently had a lot of Canada goldenrod in the soil when we planted prairie there because goldenrod established well across the whole prairie even though we put very little (if any) seed in our mix.  Most of that goldenrod has diminished and has given way to native grasses and other wildflowers, but there are stripes of goldenrod that have persisted – and they line up exactly with what must have been strips that the Scouts missed as they walked back and forth.  The stripes are starting to become less stark now (14 seasons after planting) but are still visible.

I’m very interested to hear from others who have seen this phenomenon.  I’d be even more interested to hear good rational explanations of why it happens.  I’m guessing it could be related to the difficulty people have experienced establishing diverse prairie restorations in old fields that have been idle for a couple of growing seasons.  I’ve always assumed that in the old field situation, a year or two of weed domination of the plant community resulted in such a high density of weed seeds in the soil that prairie plants couldn’t compete during early seedling establishment.  Maybe there’s something similar happening in the restored prairie stripes?  I’m really not sure.  I’m not worried by what’s happening (I like the heterogeneity and there aren’t any nasty weeds in the stripes).  I just don’t understand why it’s happening.

Help would be appreciated!  Thanks.