When you weed, you allow the crop you planted to have more water and more of the soil nutrients. Yes you arrate the soil, lossening it up for the roots of another plant that you hope will soon provide you with food. But is weeding maybe harming the soil and therfore not the best for the crops? If you take the weed out, you are taking out a plant that has nutrients in it that it took from the ground and you are therefore taking nutrients out of the soil (just like it would be with any plant that is taken out of the soil, whether it is a "weed" or not). I think it would be best to take out the weeds that are crowding out the crops, and put them on top of the soil, acting as a mulch, both decreasing future weeds as well as evaporation. The weeds would then slowly break down and put their nutrients back in the soil. The weeds that are not near the crops I feel should be left alone because taking them out seems unnecessary. However, this also brings up a larger quesiton about "weeds" (plants that you did not plant and you do not want in that spot--did you know that lots plants people concider weeds are actually edible: dandylion is a prime example) and their regeneration. When you pull them out of the soil along with their roots, is it highly likely that if you put the on top of the soil as a mulch that they will "regenerate"? If you use grass clippings as mulch will you soon have grass growing where you mulched?
Anyone have any thoughts?
Do we weed because if we don't, it will reflect badly on us as gardeners (like having a messy bedroom that's on display)? Do we do it because it is human versus "nature" (though we are just as much a product of nature as the tress and the turkeys) and if we allow weeds in the garden that is a product of the human, then we are letting nature "win"? Do we do it because we think it's good for the soil and our plants or do we do it because we can't allow something to grow in an area that is supposed to be under our control?
Ah dios mio, this is great stuff.
ReplyDeleteSome studies significant decreases in yield for crops like corn and wheat as weed growth increases, since weeds compete for nutrients, sun, water, and space. But maybe that's part of the problem- that we think about gardening from a mentality of large-scale farming.
Many gardeners today use techniques that makes sense for large-scale monocultures, mostly because that's the predominant model of cultivating plants of which they know. The more you think on this, the more things you begin to find in gardening that are borrowed from monoculture approaches. They make sense for monocultures, but not for gardens. Like the weeding issue- is it worth pulling up the weeds in a garden, especially if some weeds are edible and/or not competing too much? In a field of wheat, where a certain density of weeds can wreck the entire harvest, it makes sense to weed like crazy. Another reason why large monocultures "weed" is that "weeding" is done at the same time as the soil is cultivated- a tractor drags a cultivator behind it and shallowly digs up the soil. This both kills weeds, aerates the soil, and, especially in dry climates/hard soil, opens up the soil so that water can seep in. Small-scale farmers/gardeners don't often have to deal with water seepage issues or soil compaction, so the "tear out the weeds" multi-purpose model used in monocultures may not best suited here. (Interestingly, another monoculture model used by gardeners is row-planting; European gardens were traditionally planted in blocks, since you can plant more if you have squares rather than rows of plants; rows are used in large-scale farming to make cultivation easier).
Then there's the extent to which "weeds" are a cultural construction. In the Mexican milpas, traditional 'cornfields' are less corn and more a little of everything: in addition to the Mesoamerican trio of corn, squash, and beans interplanting, numerous undomesticated and uncultivated plants are allowed to grow for dietary and medicinal (the imagined line between them blurs easily) purposes. In the milpas, one might legitimately say weeds don't exist. But in suburban American, weeds are every species except for that one lucky and largely useless variety of grass pounded into the heads of consumers by lawn culture. I think the 'control' issue is really what plays a key role, especially when you consider the neat, tidy gardens with perfectly laid out rows. I think that as a garden becomes more for food and survival, and less for pleasure/hobbying, the less one cares about appearance and so weeds are more greatly tolerated, even allowed- which brings us back to the Mexican subsistence farmers and their milpas, versus us in the industrialized West where we can always retreat to the supermarket if our garden fails.
Another issue you're raising is whether the actual act of weeding is in itself problematic. Perhaps it's better to leave the soil undisturbed rather than pull out weeds (unless you're cuting them off above ground, like hoeing). Aeration of the soil is a double-edged sword; it helps improve water entering the ground, rather than running off, but it also exposes the fine soil that once was around the roots to rainfall, and so can be washed away. Traditional Chinese farming makes fields sloped "inward" to a center point, so that if this happens, the soil washes into the middle of the sloped field. The weed mulch approach works great, and is ugly as hell for those inclined to a perfect, tidy garden. And then there's the issue you bring up of the weeds coming back to life, and if some already have seeds, you'd essentially aiding the weed seeds with mulched, disturbed soil. One option is to put the weeds aside to compost and then return the compost next season, and in the meantime mulch the heck out of the weeded patch (grass clipping are pretty harmless, since they're cut they're unable to re-root). You could also make compost tea with the weeds to return some of its nutrients immediately, and compost the leftovers.
ReplyDeleteA local urban farm, Fresh Spin Farms, recently posted an explanation of its weed-control techniques. They're pretty clever: http://www.freshspinfarm.com/blog/10637
Some photographs of the garden you're working on would be lovely : )