When it comes to annual vegetable production, we ask a lot of our soils. This is the time of year when we give back, in the form of amendments and compost, and also cover cropping. This is also the time of year to till up the beds, creating a fluffy, well fertilized medium with lots of organic matter, oxygen and the right pH for baby plants to thrive and grow. Soil structure is a fragile thing that tillage destroys, so finding ways to reduce the amount of soil that gets flipped during bed prep is always a goal of intensive gardening. I have taken a few beds out of production, at least for the spring, and seeded them up with cover crop. Other beds got cover cropped last fall, and are now being prepped and planted. This winter for the first time I tried using occultation, where you cover the soil with a water proof and light proof tarp-this warms the soil, dries it out, and encourages weed seeds to germinate. They and any cover crop then die due to lack of sunlight, and are broken down by the microfauna and bacteria that live in the soil. This was the perfect winter to try this, as it has rained nonstop basically since last October-the tarps help protect the soil from getting beat up by the rain and keep them relatively dry. Here is a good picture of how the process works. At the left is a fully amended terrace that is being planted up with early crops like lettuce, dill, cilantro, turnips, kale, and spring onions. The middle terrace has been amended with lime to adjust the pH, kelp meal and stone dust to add micronutrients, zinc, gypsum for sulfur and more calcium and feather meal for nitrogen. This blend and the amounts added per bed is all determined by an annual soil test I have done in January. At the end of the row you can see a pile of compost that gets added next. If the soil stays dry enough, I would then pass over this with my rotary harrow-which instead of flipping the soil stirs it more like an egg beater. I set the harrow at a shallow depth so I am also not turning up any more weed seeds from below the area that was germinated and then shaded out. The third terrace here has just had its tarp removed, and then I ran over it with the rotary harrow to help break up any plant residue that was left and incorporate that into the soil. You can see how the plant matter that remains is all dead and brown-this is going to be a game changer in terms of weed management later in the season. This even gets most of the really challenging things like rhizome grasses and deep rooted thistles. I’ll still have weeds but I expect to have less of them, and the first flush is already dead and gone-giving my baby plants a chance to establish themselves before having to compete. The tarps are heavy but mine are 10′ wide by 50′ long-just the right size for me to move without too much effort. The tarps also kept the soil dry enough for me to work-though I learned the hard way that if the headland soils are still wet you can get the tractor stuck at the End of the bed…. proceed with caution. To further fluff up the soil, since I didn’t till very deeply, right before I plant I pass over the bed with the broadfork-this lifts the soil and adds oxygen, all without flipping it upside down. The dogs help me when I move the tarp by catching any voles that have camped out under there. This is big fun for dogs. The fourth and fifth terrace have been mowed and just covered with the tarps. They should be ready for amending in 3 weeks or so, depending on weather (the warmer it is, the faster weeds germinate, plants die and break down).
I did cover crop these terraces in the fall-not all terraces established a good cover but this is an example of what you’d like to see in the spring: this is a mix of cereal rye, vetch, and clover. Vetch and clover fix nitrogen, rye gives you better biomass and good structure for the vetch to climb. When I look at this bed at least, I feel like the farm is turning a corner in terms of getting the soil in balance and to a good level of fertility. It feels good. These plants are also discouraging any weeds by crowding them out. Mwahahaha!Here is some cover crop starting to germinate-peas, oats, vetch, and I threw in some flowers for pollinators since I will leave these terraces most of the summer-phacelia, borage, poppies, sunflowers, and buckwheat are all great for the bees. It can be hard for a microfarm like mine to incorporate cover crops into the mix-as my soil improves I can plant more intensively-actually using less space, which opens up some opportunities to take soil out of veggie production at least for part of the summer-and the tarps I think will also help especially for bed prep early in the year when things are often still really, really wet.
So, this feels like good progress against weeds and towards fertile soils! The battle against rodents continues…I have a new gopher trap that seems to be pretty effective, and I also replanted my garlic in a gopher proof raised bed, but we are still at war. I am seriously considering gopher snakes. I mean, I should have twice as much garlic as this. At Least. And then there is the chipmunk in my greenhouse. I don’t mind her, except for the fact that she buries oats in my tomato starts, waits for them to germinate, and then digs them and the tomato starts, up. She is a farmer too, and cute as a button, but I need those tomatoes! The intelligence of animals is pretty remarkable-she knows those seeds are at their most nutritious right when they sprout (the same reason sprouts are so good for you). Maybe I can train her to use empty pots. This is also how I have learned that my rodent proof cover crop storage cabinet is not rodent proof.
Hope you are getting a chance to get into your garden-looks like May may give us spring at last. Here’s hoping…..