In this summer’s series on soil health in the yard and garden, we’ve been exploring how often overlooked conditions can — with a little thought and effort — yield big benefits at home just as they do on working lands.

One reason farmers pay close attention to soil health is that in doing so, they can reduce the amount of chemicals they are applying to their land. This can translate into a direct cost savings much of the time, and when it comes to organic farming, can be of critical importance. Healthy soil can help combat pests and weeds, reducing the need for pesticides. It can also help free up and maintain nutrients in your soil.

Here in the Tualatin River basin, keeping nutrients like phosphorus and nitrogen out of our streams and rivers is important to preventing the growth of algae during summer months.

This in turn helps to keep oxygen levels in our waterways high enough for native salmon and trout. You might be surprised to know that home use of fertilizers can be a major source of nutrient runoff when they are washed away by the rain, but you no doubt know how much they cost each summer for your lawn and garden.

Let’s explore some of the soil health principles used around the farm that would help not only keep us from applying too much unneeded fertilizer but also can reduce costs and improve the health of your lawn and garden at home.

Know your needs

Most homeowners know that in addition to soil, water and sunlight, your plants crave some food from time to time. The major nutrients (macronutrients) needed by most crops, lawn and garden plants include nitrogen, phosphorus and potassium. Fairly large amounts of the micronutrients calcium, magnesium and sulfur are needed as well. Plants also use iron, manganese, zinc, boron, copper and molybdenum to a lesser extent.

The signs that your plant isn’t getting adequate nutrition can be relatively easy to spot, although diagnosing a nutrient deficiency from what you are seeing takes some practice.

Many nutrient deficiencies can look similar — you know something is wrong, but it is difficult to put a finger on what precisely. This is especially true where multiple nutrient deficiencies are occurring at the same time, or perhaps a plant pathogen is creating symptoms concurrently as well. The specific growing habits of the plant in question are important as well. For example, in nitrogen fixing plants like peas and other legumes, molybdenum is needed to complete the process of taking in nitrogen from the air.

If you didn’t realize this, you might misdiagnose yellowed or dry brown older leaves and add unnecessary nitrogen to your soil.

Understanding which of these nutrients might be missing from your soil is best assessed with a simple soil test. Home kits are available, or you can send a sample of your soil to a local lab. Basic soil testing is more affordable than you might think.

Ideas to try

So how does improving soil health help to manage nutrients? A healthy diversity of soil bacteria and fungi help to mobilize and deliver nutrients to the roots of plants, which exchange sugars for the nutrients unlocked by them. Since building good soil health means keeping a living root in the ground year-round, practices like keeping a cover crop on fallow gardens or moving towards permaculture in your yard can support this important relationship year round. They keep your soil’s vital microbiology well-fed and able to keep delivering those nutrients in a form available to your plants for use. Including a wide diversity of plants also helps to bolster the diversity of microbes in your soil, building their resilience to tough conditions in the future.

Another great practice for building soil health is adding organic matter to the soil. In addition to improving your soil’s structure and providing food and habitat for the microbiological community in the soil, added organic matter can directly increase nutrients available to your plants. Composted manure is a great source of nitrogen, and planting deep-rooted plants can help to bring up soil nutrients as well as improve the structure of the soil.

Got Questions? The Tualatin Soil and Water Conservation District provides educational resources and answers technical questions about soil health. See, write to This email address is being protected from spambots. You need JavaScript enabled to view it. or call 503-648-3174, Ext. 121.

Go to top
Template by JoomlaShine