Mulch for Outdoor Hemp Cultivation: Goodbye Plastic, Hello Straw
Last year was our first year farming hemp and we went with plastic mulch for our outdoor hemp cultivation because it was easy and everyone else was using it. While it does help retain moisture in the soil and keep weeds at bay, it adds to the greater environmental problem of plastic pollution and it may also have negative effects on microbes in the soil.
We knew there had to be a better way to retain moisture in the soil and it turns out that wheat straw is not only better in the fact that we’re not using plastic, it’s also better in that it helps plant growth by enhancing the soil’s microbiome, which in turn aids nutrient uptake. Plus, instead of having to pull up plastic mulch and drip lines at the end of the season, we can leave our drip lines in place and continue to build up our plant beds for seasons to come, which means we won’t have to disturb the beneficial microbes that are busy enriching our soil.
As we hadn’t used straw at this scale before, we weren’t sure how much we’d need. Thankfully, the USDA has a guide on straw mulching, which recommends applying 2 tons of straw mulch per acre. Since we’re doing 1.5 acres this year, we secured 3 tons of wheat straw.
While there are straw blowers that can carpet a hemp field with straw mulch, it made more sense for us to do by hand since we’re a smaller operation. We were able to complete the project with two people over the course of five days, and we're excited to see how the straw affects our soil and our plants.
Note, you want to use straw and not hay as straw is just the remaining stalk of an entire grain plant whereas hay is the entire plant or plant top, including the seed head, which may drop seeds in your field, meaning you’ll be doing a lot of extra weeding.