I am amazed that this article did not stress the importance of buying only organic straw. I'm all in favor of the prescribed deep mulch technique (Google "Ruth Stout"), and straw is a great choice for such mulching, but if you use straw from conventional grain fields you could well end up doing far more harm than good. The danger, which has been well-documented for years now, is the newer class of "persistent herbicides," including aminopyralid, clopyralid, aminocyclopyrachlor, fluroxypyr, picloram, and triclopyr. They affect broad-leafed plants (like your garden veggies!) and thus are sprayed onto grass crops (like the grains from which come your straw!) to suppress broad-leafed weed species. The problem is that these chemicals have half-lives of several years, so contaminated straw mulch could be poisoning your crops for a long time to come. Probably not enough to kill them outright, but enough to stunt their growth and leave you wondering why your veggies look so sad. And since the mulch decomposes into the soil (that's kind of the whole point), by the time you realize the problem there will be no remedy other than literally to replace your soil, or to let that land lay fallow for years before returning to it. Neither composting the straw nor feeding it to animals is a solution, as the herbicidal chemicals will pass through unchanged and, in fact, only concentrated.
I am amazed that this article did not stress the importance of buying only organic straw. I'm all in favor of the prescribed deep mulch technique (Google "Ruth Stout"), and straw is a great choice for such mulching, but if you use straw from conventional grain fields you could well end up doing far more harm than good. The danger, which has been well-documented for years now, is the newer class of "persistent herbicides," including aminopyralid, clopyralid, aminocyclopyrachlor, fluroxypyr, picloram, and triclopyr. They affect broad-leafed plants (like your garden veggies!) and thus are sprayed onto grass crops (like the grains from which come your straw!) to suppress broad-leafed weed species. The problem is that these chemicals have half-lives of several years, so contaminated straw mulch could be poisoning your crops for a long time to come. Probably not enough to kill them outright, but enough to stunt their growth and leave you wondering why your veggies look so sad. And since the mulch decomposes into the soil (that's kind of the whole point), by the time you realize the problem there will be no remedy other than literally to replace your soil, or to let that land lay fallow for years before returning to it. Neither composting the straw nor feeding it to animals is a solution, as the herbicidal chemicals will pass through unchanged and, in fact, only concentrated.