| I'd like to share a few pictures from my garden to illustrate a point. I put my hand in each picture so you can compare the size of each of the plants shown.
In the very front of our yard, outside our fence and along the road, we have terrible soil. It's heavy clay with many rocks in it and it doesn't have very much nitrogen. Lord knows what other nutrients it lacks as well. The soil is on a slope, as the bottom of our fence is about a foot or so above the top of the stone wall that runs along the sidewalk bordering this part of our yard. Because the soil doesn't absorb water very well, most water runs down the sloped soil, leading to erosion. The water that doesn't run off mostly evaporates. Here is a picture of a newly dead marigold plant I transplanted into this soil:
In another section of our yard, we've got slightly better soil, but I haven't done any work on it. It isn't on a slope, so at least the water doesn't run off and erosion isn't a problem. Here's a marigold I planted there:
As you can see, it's slightly bigger - and it isn't dead.
Last, here's an area where we did a LOT of work on the soil. We did a double dig to aerate the soil and we mixed in compost. Then I planted a nitrogen-fixing cover crop, hairy vetch, and let it grow until about 10-15% of the plants flowered, at which point I killed it and left it as a mulch. Here is a marigold I planted there:
I couldn't fit my hand into this picture, but the marigold is as high as my chest, and I'm 5'3".
These marigolds are planted from the same seeds. I planted them in the same potting soil and let them hang out in 5" containers filled with that potting soil until they reached a size large enough to transplant them. So it's not the genes in the marigold that makes the difference - it's the soil. And, while there are probably some minor differences in the amount of water I've given each of these plants, the soil determined how much of that water the plants actually received.
I've seen examples of this phenomenon over and over again this year. For example, here is a watermelon planted in my bad soil:
I started the watermelon seeds in late March. Then I planted this plant here in mid April. It hasn't grown much. Three other watermelon plants - started in the same potting soil from the same seeds at the same time - went to three other gardens I'm working on. One is in a large container and two are in the ground. The two in the ground are the largest - they are HUGE! - and the one in the container isn't quite as big but it's still much bigger than my little plant, and it has a watermelon the size of a baseball growing on it now.
I also planted chard in my bad soil:
Chard is one of those wonderful plants that you can continually harvest for weeks and weeks, so long as you don't kill the plant. But this plant, which I planted in February, STILL hasn't grown large enough that I feel comfortable harvesting any leaves. They wouldn't be big enough to make much of a meal anyway. Meanwhile, chard plants grown from the same seeds at the same time, started in the same potting soil, that I planted in another garden with better soil have grown to an edible size long ago. Months ago. Same with the beets, planted in both gardens at the same time.
Last, here are two eggplants, the same variety, planted with the same seeds at the same time in the same potting soil:
The large plant has nitrogen-fixing hairy vetch growing around its base. In the top right of the photo, another eggplant (much smaller) is in more or less the same soil but without any hairy vetch providing it with nitrogen.
Biotech companies say they can make plants that resist drought or salinity or other stresses. However, it seems to me that just as you can't make gold from a different element, you can't make a plant find and absorb nutrients that aren't in the soil, regardless of its genes. Genes certainly play a role. That's why my green zebra tomatoes are yellow-green with green stripes whereas my Matt's wild cherries are bright red and tiny. Genes did that. But while it would be wonderful to find a fix in a lab so that my chard, watermelon, and marigolds can grow in lousy soil, it just ain't gonna happen. And if it can - and maybe there are some things that can be done with genes in a lab - it's going to cost an awful lot more, take years longer, require taking more risks, and place more limits on biodiversity than simply focusing on the soil to help plants grow. |
