Field Preparation for Spring Planting
As spring weather begins to work its way north, the growing season is coming alive for growers across North America. Greenhouses and high tunnels are filling up and fall sown, winter cover crops are getting worked into the soil after months of preventing erosion, stabilizing nutrients and soil life, and building biomass to feed future harvests. As growers finalize their plans for gardens and lay out their proposed bed feet of crops, we thought we'd highlight some of the many methods used by growers to prepare their soil for spring planting.
Let it Dry Out
In many regions, spring time is a season of excess moisture. Whether rains are more prevalent or snow and ice have been thawing as the temperatures have been increasing, growers are often forced to wait to prepare their fields until the moisture levels of the soil decrease. Working beds when water logged with equipment, especially heavy equipment like tractor implements, can result in smeared soil crumb. This smearing of the soil can create unwanted compaction, root impediment, and nutrient loss for future crops. It can establish an impervious layer that separates biological life from the important nutrients located in the subsoil. Working the soil when it has had a chance to dry out allows the soil texture to remain open and provide for healthy plants. A good old fashion test to see if the soil is dry enough to work is to take a small handful of soil, make a soil ball with light pressure, and then drop it on your boot. If the soil ball explodes, you're probably good to go. If the soil ball bounces off of your foot, it might be better to wait.
Mow Cover Crop
For those who have used a fall or winter cover crop to stabilize and rejuvenate their growing spaces during the dormant period of winter, mowing down or discing these semi-mature covers is the first step in bred prep. Whether you have a tractor, a BCS or other walk-behind tractor, a weed eater, scythe, or a simple lawn mower, getting the area cut is the first step in breaking down the materials. Allowing the materials a few days to settle before incorporating them into the soil will make the process a little easier for your equipment and can provide a nice mulch to help prevent emerging weeds. For no till operations, allowing certain cover crops to reach full maturity and cutting or crimping them when they have completely gone to seed can result in a great straw mulch that can be planted directly into after cutting it down, laying it flat, and allowing the root masses to die.
Incorporate Cover Crop
Once the cover crop has had a few days to dry out on top of the soil, incorporating this material into the bed is the next step. Plowing the cover crop in can be accomplished by using many different implements, but the goal is the same. The mowed cover and root masses should be incorporated into the soil fully. This will allow for the proper digestion of the materials by the soil and will suppress potential regrowth of vigorous cover crops. The incorporated cover should be left to digest for 3 to 6 weeks before the beds are prepared for sowing and transplanting.
Farmers have started using silage tarps to reduce tillage on the farm and as a great way to prepare a bed for planting without using any heavy equipment on the space. Silage tarps, also known as bunker covers, are large pieces of plastic that were originally used for covering silage throughout its fermentation and storage. These large pieces of UV-treated polyethylene tarps can create a stale seed bed in as little as 3 weeks. Weeds and cover crops are suffocated and killed and the soil is heated, encouraging weed seed to sprout and quickly die under the anaerobic conditions. Worms and decomposers gather under the tarp to incorporate the nutrients from the weeds and cover crops into the soil. What is left is a stale seed bed, ready to be planted into. This system is especially useful for permanent bed systems.
Build Your Beds
After your cover crops have decomposed or become mulch and your soil is ready to be made into a fresh seed or transplant bed, there are endless methods and tools for creating a happy home for crops. Whether you're running a team of draft animals through a field with old school, tried and true implements, using a tractor with a tiller, spader and/or bed shaper, or working with some of the newest, ingenious walk behind tractor implements that include tillers, spaders, and rotary plows, making your growing system work for you is the most important part. Along with finding the right tools to fit your personal work style, setting up the beds to work well with your farm plan is essential. Bed width and length are generally determined by the tools, the landscape, and the crop plan and making beds manageable will promote future success. Consistent bed length and size can make for easy planning, and this can often translate into more thoughtful and effective crop rotations.
Spring Soil Test
While many people will recommend getting your soil tested in the fall, taking a spring soil sample can be very beneficial. Taking a soil sample in the fall is a great way to see how the soil has weathered crop production and cultivation throughout the growing season. It can reveal what may be missing and what could be added as an amendment into the soil in the fall with the fall and winter cover crop seed. While that fall soil test is extremely useful and informative, it is important to remember that the soil itself is a diverse and changing community. Different organisms are more or less active at different times of the year and this can paint a very unique picture of the soil from one season to the next. Taking another soil test in spring is like taking the pulse of the farm. It provides a snapshot of what the soil is like for your crops in the present moment and gives you the opportunity to add or change up the nutrient inputs going into summer.
Amendments and Compost
When it comes to fertility, there are many options for getting your plants and soil life the nutrients they need for a successful yield. Whether you make your own compost or purchase it from a reputable local company, compost is an excellent resource for adding organic matter, bolstering soil life, and for encouraging humic formations in the soil. One method for applying specific amendments to soil (such as kelp, gypsum, manures, biochar, azomite, activated humates, feather and/or bone meal, sea minerals, specific nutrients such as boron, copper, or zinc, etc.) is mixing the amendments into compost and letting them sit for 2-3 weeks. This stabilizes the nutrients into the humic compounds of the compost and helps prevent them from leeching from the soil when applied to the landscape. Whether you apply the materials to the topsoil and let the soil life do the work or incorporate them into the first few inches of the bed, amending the beds just before or at the time of planting can help alleviate transplant shock and can serve as the nutritious icing on top of the cake of a freshly prepped and planted bed.
Lastly, the proper layout of the plants in the beds can provide for even harvests of uniformly grown crops. A good soil rake can be very useful when preparing a bed. A level surface on the top of the bed can make for even germination of direct seeded crops and the healthy establishment of transplants. There are so many new and exciting tools for creating even spacing of transplants, like gridders that lay out a grid over the bed. These and other rolling dibblers can be useful for spacing and for planting, making an incision in the bed where a transplant will be placed. Evenly spaced plants translate into uniform harvests, good air flow, and easy weed management.