Tuesday, September 2, 2008


Last fall we planted cover crops in two of our paddocks, a mixture of clovers, cow peas and annual rye. The intention was to put something in the ground that would compete with the weeds that were sure to otherwise take over a fallow, recently tilled field. These plants have now all died and gone to seed.

Actually, they went to seed quite some time ago. I have left them standing for a reason, and that is I know field sparrows often use tall grasses to hide their ground nests and young. I found this fact out the hard way last year when I was readying a field for a second planting. One less field sparrow nest.

The tall dead grasses serve another purpose as well. A lot of seed-eating birds have been feeding off of the rye for a month or more. We try to provide birds with food. Every year we have sunflowers that volunteer, and when I’m mowing or tilling, I avoid these plants. The finches love the seeds in the fall. We also let our fencerows grow a little wild to provide the birds more food and some cover, and to give beneficial insects such as lacewings and mantids a place to live.

This late in the season all of the birds have fledged, so I figured it was safe to mow and till under the plants with the hope that the seeds would do a repeat performance. I use a bush hog to mow the fields. For you city slickers, think of a regular lawn mower blade and multiply it by about five in size and girth. This blade is housed in a piece of equipment that is put on the back of a tractor and is also propelled by the tractor’s power. It cuts about a five-foot swath. Pretty heavy-duty.

A soon as I started mowing, I noticed a milky white substance on a dead leaf of a taller plant. It looked like it might be a freshly-placed Praying Mantis egg cluster. I love mantids and would rather not have mowed it down, but too late, a front tire took the plant down and ran over it. Indeed, the field had numerous mantids, both the indigenous and imported varieties. Hopefully, they had been preying on the multitudes of grasshoppers I was also seeing.

The grasshoppers avoided the bush hog more readily than the mantids and for a moment I thought that perhaps I should just let the field be. I really didn’t like killing a beneficial insect. They eat a fair amount of the nasty ones. Of course, the ducks and the guinea also love grasshoppers and eat their fair share. But they also eat mantids. As I was mulling all of this over, I saw a vole. And then another. And another.

Voles are small rodents, like a cross between a mouse and a gopher. They burrow shallow tunnels and eat plant roots, including vegetables like carrots and potatoes. Every few years their populations grow to such a degree that they destroy large percentages of crop yields. The upside of these infestations is that the owl and raptor populations also grow. (We have installed barn owl nesting box just for such an occasion.) We’re about due for another one of those years, and this field already had its fair share. I would have to keep mowing, if for no other reason than to displace them. Perhaps the hawks and owls would benefit over the next couple days, but just in case they couldn’t get them all, I began chasing the varmints down with the tractor.

In the end, I left about a tractor’s width of the field unmowed. Some of the mantids escaped, and perhaps they will use what I didn’t take down to lay their eggs. Of course, there is another eight acres that I am certain is just as full of these wonderful bugs, so all is not lost. But there are voles out there too.

1 comment:

PAPro_SandMan said...

Sounds like Darwin's hard at work in the Great Northwest...