How do you control weeds in an annual pasture?
Question:
I want to plant annuals for grazing on 10 acres of established pastureland. We are looking at sorghum-susan grass, and maybe grazing corn. We have tried to do this a couple of times in the past using a no-till drill in existing pastures. Even when we mowed the pastures quite low, the annuals did not perform well. I do not want to use Roundup – and I am interested in doing a controlled burn of the fields where we will plant the annuals. I have contacted the local Fire Dept and they are interested in helping with this as an exercise for their members. Do you know anyone who has done this? Reading online, it seems the challenge of a burn is that the perennials will grow again, and may still be competition for the annuals. Any advice or suggestions you have would be appreciated.
Answer:
Establishing new crops into existing perennials (crops/weeds) is challenging because the perennials have such a head start. I haven’t heard of many success stories without the use of herbicides or tillage. Even with burning, perennials, like quackgrass, can reestablish more quickly than an annual plant starting from seed. If you don’t want to use herbicides, I’d recommend some form of tillage. You could try to reduce the intensity of that tillage, either by using shallow/skim plowing (followed by shallow seedbed preparation) or only tilling in strips (zone tillage). Both will likely result in some regrowth of perennials, depending on what species they are, but the tillage might give the annual crop enough time to get established to compete better with those perennials.