I'm considering some ideas for growing vegetable crops on sites without water access. We get about 15 inches of rainfall, a bit less than half of what most vegetable crops need.
If sheets of plastic were laid on contour with open strips in between on a gently sloping field, would the catchment effect enable thirsty crops to be grown? I'm thinking that each sheet would end in an on-contour ditch to ensure catchment and infiltration of all the shed water. And of course, this would have to be combined with sensible mulching, weed control, varietal selection, etc.
What materials would be best for this, from durability, sustainability and cost perspectives? I've thought of everything from metal roofing to plastic sheets to pond liner to coated cardboard to concrete chunks laid like tiles.
Would it be better for the covered area to be covered permanently, or for the sheets to migrate up or down hill year by year? If they migrated, they could be used to terminate cover crops or kill weeds at the same time; I thought of having sets of three strips, sheet, crop and drought tolerant cover crop, with the sheet moving onto the crop area to kill weeds, bugs, and disease spores while the cover crop is rolled down for a mulch on next year's crop. Meanwhile the uncovered area would become the new cover crop area to repair it before the succeeding crop. Moving the sheets would also avoid a buildup of rodents or other pests underneath.
However, it would also increase labor and wear on the sheets.
Berry growers use a heavy fabric intended to last indefinitely. They cut openings with a sharp knife or box-cutter. Produce growers use plastic that is black on one side and white on the other. They put the black side up to warm the ground in cold areas and the white site up to not warm it too much in hot areas.
In both cases, there is a drip tube underneath down the middle. They are typically laid with a special attachment on the back of a tractor that rolls out the plastic or fabric and the drip tube at the same time.
Gail Gardner @GrowMap
Small Business Marketing Strategist, lived on an organic farm in SE Oklahoma, but moved where I can plant more trees.
I'm very seen something like this, using stones, directing water to a tree in depression.
Hardboard (think pegboard, without the holes) is made of compressed wood fiber, sheds water and lasts quite well in contact with the ground.
In a dry area, cardboard should last a long time as well, but would need stones to keep it in place.
If you can get it, it's usually taken up in strips.
It will decay in the sun, so wet it down and sprinkler it with Portland cement,neat,to protect it,and make it sheet water.
Burlap might work as well or better .
Soil-cement, as a permanent strip, or as tiles, could be cheap, durable and none toxic.