Ahhh…spring has finally arrived and that means the soil is warming up. And this change in temperature is the indicator to plants everywhere that it’s time to sprout up and bloom, bringing forth an abundance of flowers, leaves, and for the gardener in us, home-grown vegetables.
And as experienced gardeners know all too well, the foundation for a bountiful harvest is contained within the underlying soil in which we plant our seeds. To a novice green thumb, soil just looks like like plain old dirt. In fact, good gardening soil is an intermingling of various elements that all function together to produce a healthy, stout plant.
Still, the unfortunate truth is that most gardeners are not blessed with having ideal soil in their designated planting areas. This defect is usually due to having clay or sandy type soils which cause drainage, aeration, and soil structure issues.
The Dirty Facts About Soil
Soils are usually composed of some proportion of sand, clay silt, and organic matter known as humus.
Humus is composed of decayed leaves, dead insects, and decomposed plant and animal materials and it is very beneficial to soil because it holds nutrients and water, buffers the pH, and improves the overall soil structure.
Additionally, good soil is akin to marbles filling a jar. There will be lots of space between particles for water and nutrients to sift through.
Of course, different regions have different soils. This primarily depends on four factors:
The mineral content in the rocks and plant litter that formed the soil, the amount of rainfall a region gets because minerals will eventually wash out of the soil; how intensively plants were grown on the site in the past; how much fertilizer has been applied.
When you scoop up rich, vibrant soil you’ll find a mix of sand, clay and humus. This mixture is also composed of small pores filled with water, oxygen, and dissolved nutrients. This is known as the “soil solution” and the soil’s viability is dependent on the percentage of each component.
You can check your soil by picking up a handful and squeezing it in your palm. If it sticks together in a ball then it is primarily clay. If it will not stick together then it is considered to be sandy.
Clay soil is composed of small particles that are tightly bound together and therefore tends to be clumpy. Clay holds water nicely, but sometimes too much so, which causes it to be a poor drainer, makes it heavy to move around, hard to dig, and inhibits vigorous root movement through the soil.
What makes clay particularly attractive in soil is that its particles are negatively charged and many nutrients are positively charged so that they effectively bind together making clay soils very fertile.
Sandy soils are very light, drain well and are easy to maneuver your shovel around. But they’re not very fertile and don’t maintain a solid foundation for your plants to root in.
Good Soil Comes From The Right Mix
The ideal soil type you want to target is a mixture called loam. It is basically the proper proportions of clay and sandy soil combined with with humus, or organic matter, thrown in to make it especially suitable for plant growth because it holds nutrients, drains adequately, it’s easy to dig and work, and it’s amenable to root penetration.
As noted before, not everyone is so lucky as to have perfect loamy soil, so soil modification is often necessary to compensate for this. To encourage good soil structure, simply add organic matter such as compost or manure before each planting season. Organic matter helps to bind soil particles and ensure the soil solution is just the right density and make up.
Another good practice is to till the soil, ideally with a roto-tiller – but don’t overdo it. Excessive tilling can actually break down the soil structure, making it powdery and less amenable to vigorous, healthy plants and a bountiful harvest. Essentially, what you want is soil that you can form it into a loose ball but also falls apart when you poke it.
Proper pH Is Critical To Nutrient Uptake
Another important feature of good soil is its pH level, or how acidic or alkaline the soil is with 1 being most acidic and 14 being most alkaline, and the ideal level being between 6.0 and 7.5, which is considered neutral and is the level of pure water.
The pH is critical because it plays a major role in how much nutrients are available to plants. Too far along the scale one way or another and your vegetation won’t be able to “take up” nutrients even it they are present in the soil.
Determining the pH of soil is best accomplished by taking a soil sample to the local “extension center”. They’ll conduct a test and give you recommendations on what to do, if anything.
If the soil is too acidic, then an application of lime is required. If it is too alkaline, then sulfur is used. Sometimes this condition is difficult and expensive to rectify, so adaptable plants or raised beds where soil is brought in may be the best solution.
Soil Is Bullish On Manure
Finally, adding organic matter encourages healthy population of worms and microorganisms that break down the soil, releasing nutrients for plants to use. When doing so, add it to the entire planting bed, not just locally to the holes in which you’ve placed your plantings.
Mix the organic matter into the upper 6 inches of the soil if you do it before planting, or lay a 3 inch layer around existing plants and let it work into the bed. The longer this is done before hand, i.e. several months, the more it will have time to decay and work itself into the soil.
Take Care Of Your Soil
So there you have it. Some of the essential basics of soil characteristics and preparation. Paying attention to the requirements and constitution of your planting soil will have a profound effect on your harvest of heirloom tomatoes and large heads of lettuce in your straight-from-the-garden salad.