As spring starts to creep into the air in the northern hemisphere, it’s time to start planning for and preparing for spring plantings. In many places farmers have already been sowing and tending starts by growing in high tunnels or greenhouses, giving them an early start and a way to extend their growing season.
As growers are finalizing their spring planting plans and starting to prepare fields for planting we thought it would be helpful to share some common methods and approaches to getting a field ready for planting.
Till vs No-Till
Before we dive into the common soil preparation methods, let’s talk about no-till farming (zero tillage or direct drilling). No-till farming is a farming technique for growing without disturbing the soil through tillage. There are many benefits to no-till farming, including decreasing soil erosion, reducing irrigation needs, minimizing fertilizer and amendments, reducing weed pressure, and preserving soil biology, nutrients and health.
No-tilling typically occurs by either over-seeding or direct seeding through or over a previous cover crop. The cover crop acts as mulch and compost for the new planting and additional weed protection. In some cases farmers may apply an herbicide to the previous cover crop or can use silage tarps to prepare the bed for planting. Silage tarps are a large UV coated plastic that can be spread over a cover crop and within as little as 3 weeks can suffocate and kill the previous cover weed seeds laying dormant in that area. This process safely protects the microbiology and nutrients of the underlying soil. When complete, you're left with a bed ready to plant with minimal labor and high nutrient load.
Today tillage is the most common way that farms prepare their soil, but more and more farmers are seeing the benefits of no-till or low-till techniques that use minimal or shallow tillage, by using a disc harrow. There are different methods and equipment needs to pro and con in any type of soil preparation, so be sure to do your research to understand more what might work best for your operation.
Let the Soil Dry
In many areas spring means lots of moisture in the form of rain or snow, which is great for getting moisture to perennial plants and trees, but is not so great for soil preparation. Trying to work water-logged soils is difficult and also creates excess soil compaction which causes root impediments and nutrient loss. Before you start digging, plowing or tilling it’s important to make sure the moisture level in the soil has dropped to workable levels. To test if the soil is dry enough you can perform a basic soil test. Make sure to do this in a few different areas of the field you’re planning to prepare. Scoop up a handful of soil and squeeze it into a ball with light pressure, then drop the ball of soil on a hard surface like a rock or your boot, if the ball bounces (or forms a puddle) you should probably wait, but if the ball easily breaks apart, your soil is likely dry enough to start preparing.
Mowing & Incorporating Cover Crops
For farmers who used fall or winter cover crops to add nutrients, to change PH levels or otherwise stabilize and improve their soil health, mowing and incorporating the cover crops into the field is an important step before preparing beds and planting. The first step to this is to cut the cover crop, so whether with a tractor, walk behind tractor, heavy duty mower or old fashioned scythe you’ll want to cut down the cover crop to allow it to start to decompose. Once you’ve cut the cover crop down, let the plant matter settle in place for a few days before incorporating it into the soil through tilling (there are different approaches for no-till operations like rolling or crimping vs cutting).
After the cover crop or plant matter has settled for a few days the plant and root material should be fully tilled or plowed into the field. Fully breaking down the cover crop will help the nutrients be more easily absorbed into the soil and minimize the risk of re-growth from the cover crop. Ideally allow the field to rest for 3-6 weeks after incorporating your cover crop before preparing beds or sowing seeds to to allow for the maximum absorption of nutrients into the soil.
Check out some top cover crops that might benefit your soil.
Testing your Soil
While soil samples are often taken in the fall (to understand the soil health post-harvest), taking an additional solid sample in the spring (after the incorporation of cover crops) can help to provide details about overall soil health and any amendments you might want to consider.
Because soil is an active, diverse and dynamic biological system it’s a good idea to check in on the health of your soil in regular intervals. Think of your soil samples as a regular check-up for your soil - learn more about soil samples and testing.
Soil Amendments & Compost
Depending on the health, nutrients, structure or composition of your soil you may find yourself needing to add something or many things to it to create the ideal environment for your planned crops. In addition to the nutrient value, organic soil amendments also provide additional benefits like loosening clay and compact soil, improving water retention for sandy soils, increasing soil loom, and reducing labor for digging and tillage. When adding composts or other organic matter, it’s important to not add more than 3-4 inches to the soil.
There are numerous types of solid amendments and we can’t cover them all here in this article, but we’ll focus on some of the more common organic ones:
Plant Matter
As we mentioned earlier, incorporating cover crops into your soil is an excellent way to add additional nutrients to the soil. But you can also add other organic plant matter like leaves, straw or grass clippings. It’s ideal to add these types of amendments in the fall to allow them time to decompose over the winter.
Compost
Whether you make your own compost or buy from a local producer, compost is an excellent source of additional organic matter and nutrients to incorporate into your soil. Compost is also an excellent medium to integrate other amendments like gypsum, biochar, kelp, manures, azomite, humates, bone meal, sea minerals, boron, copper, or zinc, etc. It’s ideal to mix any additional amendments with your compost a few weeks ahead of time before you incorporate it.
Manure
Manure is also an excellent source for additional nutrients. Effectively you’ve let cattle, goats, sheep or other livestock do the hard work of composting plant matter for you. Be sure to let manure age before using as fresh manure can damage and burn plants and can also introduce harmful bacteria. It’s typically recommended to add about 30-40 lbs of aged and composted manure for every 100 sqft of soil.
Green Manure
Green manure is a way of growing a nutrient rich plant, cutting it and leaving it so it can break down back into the soil and then tilling it in before you plant. Planting rye, oats or other cover crops in the fall after this soil preparation is an excellent way to incorporate additional organic matter and improve soil health. heck out the section above to learn more about Mowing & Incorporating Cover Crops in case you missed it.
Gypsum or Sand
For heavy clay soils, adding gypsum or sand can help to loosen the clay soil and make it more workable. Adding 3-4 lbs of gypsum per 100 sqft after your fall harvest can help improve the workability of heavy clay soils come spring planting time.
Tilling or Plowing the Field
If you choose to till you should try to till as deeply as possible, at least 8-10 inches. This loosens the soil, breaks-up existing plant matter and allows for deeper root depth for your crops. Regardless of if you till using a walk behind tractor, rototiller or a traditional tractor, be sure to till when the soil is dry, as working wet soil is not only difficult, but it causes additional compaction and damage to the soil. To make spring tilling easier you can also spade or fork the soil in the winter to prepare for spring planting.
Type of Plows for Soil Preparation
Digging in the dirt and preparing beds is hard work, but fortunately they are many mechanized solutions out there to help get your soil (in whatever condition it's in now) ready for planting. Depending on the field conditions and types of crops you're planting you may need to use different implements to prepare the soil. There are various different types of plows and configurations of plows that allow for various depths, aeration and impact on the soil. If you're shopping for a plow or tractor attachment we recommend talking to your friendly neighborhood farm equipment retailer and friends and neighbors to discuss your options and specific needs, soil conditions, crop plans, etc. We’ll try and provide an overview of different implements that you might use to prepare your soil.
Rototiller
Rototillers come in all shapes and sizes from your backyard garden front or rear-tined, to walk behind tractor attachments to heavy duty tractor mounted PTO driven Rototillers. In all cases they perform the same function to use rotating tines (discs) to dig into, loosen and break up the soil. Rototillers work well when breaking up compacted soils.
Moldboard Plow
Moldboard plows use a large curved blade that is pulled across the ground by a tractor. As it’s pulled across the ground it digs deep into the ground cutting a row and turning the soil. This type of plow cuts, lifts, breaks up and loosens soil. This process also loosens and aerates the soil and leaves behind a trough that can be used for planting.
Reversible Garden Plow
Reversible Plows are similar to a moldboard plow, but have a set of 2 or more reversible blades. These blades can be mounted in different positions and directions allowing for the creation of various space furrows or mounds. This is usually used for deep tillage to turn over the upper layer of the soil bringing up fresh nutrients.
Chisel Plow
Unlike a Moldboard, chisel plows use a curved chisel / rod that digs into the soil for aeration and loosening the soil without turning the soil. It leaves the crop residue on the surface of the soil. You can find chisel plows in various configurations, widths and with different types of chisels. Because they are not turning the soil, chisel plows are less damaging to the soil health as they cause less impact.
Disc / Harrow Plow
Disc plows are pulled behind a tractor and have multiple rows of rotating steel discs that turn as they are dragged. Disc plows work well to plow hard rough ground to pulverize and break up very compact soil.
Subsoil Plow
Used for breaking up the soil underneath a hardpan layer (typically caused by chemical treatments), a subsoil plow works by pulling lower layers of soil up to the surface without turning it. This action tills and aerates the soil and minimizes soil compaction. It also allows water to penetrate the soil to break up the hardpan layer.
Preparing Beds and Rows for Planting
Now that your field is dry, amended and tilled it’s time to prepare it for planting. Often fields are prepared into beds making planting, maintenance and harvesting easier and more efficient. Additionally, creating beds in your field allows for water to drain away from the plant roots, provides a trough for irrigation, and encourages air flow.
Before making beds it’s important to try and flatten your growing area. A level surface will allow for easier germination when direct sowing or a smoother platform to transplant into. To level you field, use a pull behind rake attachment or a good soil rake.
Once your ground is level you’ll want to try and create rows (furrows) about every 36” (if your garden is large enough). Beds (in the US) are typically 36” wide and often 100’ long. While straight beds are pretty to look at, they are not necessary. If you’re using any type of hoops or other crop covers be sure to consider the size of those when creating your beds. Also, planning for irrigation before creating beds and planting is important. We’ll cover more on irrigation in another post.
For smaller gardens you can mark your bed width using a board cut 36” long and use a hoe or other hand tool to dig a furrow along the length of the bed, typically about 8-10” deep. For larger areas you might choose to invest in a tractor attachment to help cut, level and shape your beds.
Once your beds are leveled and shaped it’s time to start planting on top of your beds.
Resources for Field Preparation
Summary
We’ve covered a lot in this post and hopefully you’ve learned a little more about different methods and techniques to prepare your fields for spring planting.
Happy farming out there!
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