What does plowing do to soil?

In the previous post, we learned about soil compaction. This is one aspect of soil structure. Another aspect is layering.

We all know about topsoil: it’s the valuable layer of soil closest to the surface, that is rich with nutrients and other resources. Below this are other layers, or horizons, which are primarily of interest to soil scientists.

The point we will focus on today is that layers should stay where they are. When each type of soil is at the right depth, the plant community living on top of the soil thrives. When layers are all mixed up, plants suffer.

Mixing within a layer isn’t good for plants either. A third aspect of soil structure is the very specific way that particles are arranged in the soil. When clumps of sand or clay, water droplets, air pockets, and microorganisms get jumbled out of their proper places, soil ceases to function in the way that it’s supposed to.

What can cause this kind of jumbling? Plowing, an agricultural practice familiar even to non-farmers, is the process of deliberately scrambling soil. In other words: plowing is bad for soil.

Why would farmers engage in a practice that damages soil? The answer is that plowing boosts plant growth in the short term. By turning over the first few inches of topsoil, farmers can introduce more air to the soil. While air in soil is good, this is a case where too much of a good thing is not better. Soil microorganisms gorge themselves on the extra oxygen, and start breaking down organic matter in hyperdrive. That makes lots of nutrients available to plants, which consequently grow very vigorously.

The problem comes when those voracious microorganisms run out of organic matter to decompose. Then the amount of nutrients available to plants suddenly drops, leaving them struggling to survive. Farmers start feeding their plants artificial fertilizers in an attempt to maintain their yields from the depleted soil, and the whole system becomes expensive, unproductive, and environmentally damaging.

The practice of rapidly wearing out soil was not much of a problem when there were few people, when the American plains seemed to go on forever, and when farmers could plan to just move to a new quarter-section every few years. Now that pretty much all the land is spoken for, farmers need to farm as if they intend to stay where they are. Plowing is not a form of sustainable agriculture – and, indeed, the practice of no-till farming is becoming increasingly popular.

But many gardeners still use residential-scale equivalents of plowing, like rototilling and double digging. Just like with plowing, these practices increase fertility in the short term, but result in damaged soil that can’t sustain plant life over the long term. Many gardeners now are adopting practices that involve disturbing soil as little as possible.

People today have different knowledge and different values than people in the past. Plowing was once an iconic practice in the agricultural landscape. Now we know better ways of sustainably managing our land.

Advertisements
What does plowing do to soil?

What is soil compaction?

In previous posts, That Blog has covered properties of soil, such as soil types and soil pH. One property not yet written about is soil looseness.

Good soil, gardeners say, should resemble chocolate cake – in both its color and its crumbliness. Good soil has lots of air in it. Why?

First, because these channels and pockets of air also serve as pathways and holding places for water. As discussed in the previous post, we want water to move down into soil. Loose soil structure helps that to happen. Soil that is dense and hard will resist water, leaving it pooled on the surface, where it will either cause flooding, or run off to cause flooding somewhere else.

Second, because the air spaces in soil provide room for roots. Plant roots grow easily through loose soil. Under these conditions, plants are able to find nutrients, absorb water, and anchor themselves securely. In contrast, roots struggle to penetrate soil without air, leaving the plants sickly and weak.

Soil without air is compacted soilSoil compaction is events and processes that lead to compacted soil.

What kinds of things cause soil compaction? One major perpetrator is development: covering soil with pavement is, of course, not good for the soil. Another cause is heavy vehicles. A bulldozer or brush hog may be the fastest way to clear a site of unwanted vegetation and prepare it for new plantings, but these huge machines also cause serious damage to the soil on the site, making it more difficult for the new plantings to get a start in life.

Even lighter vehicles are tough on soil. ATVs can cause compaction and damage, which is one reason some people oppose the use of ATVs in natural areas. And finally, a person on foot is heavy enough to squash down soil and destroy those crucial air pockets.

For this reason, treehuggers may want to curb their desire to hug trees. When we walk up to a tree’s trunk, we are stepping on its critical root zone – the area directly under the tree’s canopy, where its roots are most actively performing their vital functions. Compacting the soil in this area can be very detrimental to a tree’s health. While some tree species – such as those that have evolved to live in perennially soggy areas – are adapted to compacted soil and able to withstand those conditions, many other species suffer from the suffocation of their roots.

Humans like hugs. Trees are indifferent to them. In a few weeks, That Blog will look at simple things tree lovers can do that trees will really appreciate.

What is soil compaction?

What is the first principle of permaculture?

Observe and interact.

A natural yard is always a response to a specific place – there is no such thing as a one-size-fits-all natural yard plan. A plan may incorporate plants native to the region, and will certainly account for site conditions.

The only way to know the site conditions is to observe the site for a period of time. Permaculture experts urge practitioners to observe a site for a full year, if possible, before undertaking any major projects. Practitioners who don’t follow this guideline typically find that their impatience results in costly mistakes.

Many permaculture practitioners like to draw maps of their zones and sectors. Others simply absorb knowledge about patterns of sun and shade, water movement, animal behavior, and so on.

This observation is not passive, however. The second part of the principle is interact. While beginning major projects too soon is unwise, conducting small experiments is good. Bring in a few plants and see how they do. Dig a hole and watch how quickly it empties after a rain. Stroll around the yard and notice which areas you are drawn to.

The first principle of permaculture may seem simple, but it lays a crucial foundation for a successful natural yard.

What is the first principle of permaculture?

What is a patch?

A patch is an area of habitat.

Patches can come in any size. For example, balsam fir trees enjoy a huge patch of habitat across Canada’s boreal forest. But, a small Wisconsin yard with the right site conditions could also be a habitat patch for balsam fir.

If you own a yard – or even a balcony that could host a few flowerpots – then you have a patch. It is your choice what to do with it.

Some people choose to have a lawn, maybe with some non-native ornamental flowers or shrubs, and to prevent any other plant or animal from living on their property. Other people choose to make space for many species in their patch.

Even in a small yard, it is possible to have multiple patches. For example, one corner of the yard might include trees, along with plants that like shade. Squirrels may nest here, and forest birds might drop by. Another corner of the yard could host sun-loving plants, and the insects that frequent them. A third corner could feature a pond or rain garden, providing a habitat patch for wetland plants and birds that like to bathe.

Patches differ in quality as well as size. While a grouping of woodland plants in a corner of a suburban yard is not as good as a forest, it is better than a single aggressively-pruned tree standing in a lawn. Even relatively small, low-quality patches can provide critical resources for struggling species.

By taking small steps to improve the quality of our very own patches, we can enjoy seeing species not normally observed in the suburbs.

What is a patch?

What is Diggers Hotline?

Diggers Hotline is a free service that locates and marks buried utility lines on your property.

To avoid expensive and dangerous accidents that can result from striking underground pipes or wires, it’s important to know where these lines are before doing any kind of digging, including digging related to gardening.

Diggers Hotline can be contacted at their website or by calling 811. Within a few days, they will send someone to your property to mark the lines with flags or paint. After that, simply avoid the marked area when digging in your garden.

When making a garden plan, it’s also important to look up! Avoid establishing tall plants, especially trees, under overhead lines.

While utility lines aren’t usually considered a type of site condition, being mindful of what plants you put near them can save a lot of trouble in the future.

What is Diggers Hotline?

How do you get rid of dandelions once and for all?

The answer to this question is the topic of the previous post: natural succession.

Dandelions are the type of plants that characterize early stages of succession. As anyone who has battled with them knows, they prefer areas with lots of sun and little competition.

The secret of getting rid of them, then, is to eliminate these conditions.

Most lawns, if left to their own devices, would move away from these conditions by turning into forests. Mowing prevents this progression by serving as an artificial disturbance. By preventing any plants from growing more than a couple of inches tall, mowing maintains a site characterized by low competition for light and space at ground level – exactly the conditions that dandelions love! So  long as a yard is kept in an early succession stage, early succession “weeds” will continue to move in.

In a natural yard that mimics a prairie, with native plants adapted to grow 2-3 feet high and thrive in Wisconsin’s climate, dandelions have no place to squeeze in. They cease invading such a yard, simply because the conditions there are not inviting to them.

How do you get rid of dandelions once and for all?

When does spring arrive?

Astronomically, spring comes to the whole Northern Hemisphere around March 21. The date of the spring equinox is determined by the Earth’s movements through space.

Meteorologically, however, the arrival of spring is related to local climate conditions. Winter can be said to end when the temperature rises above freezing and stays that way. Winter returns when temperatures again drop below 32 degrees Fahrenheit.

The days on which these events are likely to occur are called frost dates. The time between the spring frost date and the fall frost date is the growing season. Because these phenomena were important to farmers throughout history, the average frost dates for each area are well known. In Madison, the growing season runs from about May 20 to September 21. Frost dates for other locations can be looked up here.

Because of climate change, however, estimates of frost dates based on past weather are becoming increasingly unreliable. In general, growing seasons are becoming longer. Because a late frost can kill plants, though, it’s often best to err on the side of caution when beginning the gardening season.

When does spring arrive?