Organic soil fertility

I was asked a question the other day. A lady has a garden that she puts lots of time and effort into. The problem is that it is going downhill each year – low production, lots of pests, small produce. She was going to a large nursery in North County and buying some organic compost, thinking it was good soil fertility.

That is only one component of a broader program needed to build soil in a backyard garden or in any soil. We will begin a program of soil development in this and the next article to really send you on your way to having rich, alive and vital soil. Since this is an ongoing project in any garden, we will advise on a year-round basis how to keep making the soil stronger.

Before we get into the soil, let’s focus on this week’s gardens. Had you planted in the beginning of January you probably could harvest the outer leaves of spinach, lettuce, Asian greens and any number of soft greens. Things will keep growing at a steady pace now, so plant your favorite cabbage family plants and any of the soft greens for a succession – more onions, carrots or anything of this nature. If you started the zucchini, cucumber or basil they should have begun to germinate. Thin to one plant per pot and keep them where they are and happy.

Now, soil fertility. This is the most important aspect to an organic garden. We are trying to stimulate the soil microbiology to life. There can be more than a billion beneficial bacteria per teaspoon of soil. The other life forms are good fungus, mycorrihzae, soil nitrogen fixing bacteria and so many more it boggles the mind how abundant and varied they are.

Then we have earthworms and all the other critters that hang around with them. We don’t have to know their names, just know that they are important. By feeding the soil as well as the plants along the way and doing nothing that can destroy their existence the soil will grow strong. They will break down organic matter we add to the soil, dying plant roots and form humus. Humus is also known as carbon. This organic soil compound stops this carbon from escaping into the atmosphere and forming carbon-dioxide, which is 80 percent of all greenhouse gasses that cause global warming. It is also the basis of healthy plants and good tasting, high vitality food.

Plants and soil need this carbon to survive. When we achieve this we have accomplished a plateau that will allow us years of strong healthy plants in the garden. This will take a few years of working this area to create this live soil, depending on what we are starting with. Decomposed granite is rich but held in bond by its rock-like nature. Clay is extremely rich but has lots of physical limitations to being able to work it easily. Any soil can be made to be rich.

To understand how to feed our current crops, let’s study the basic needs of plants. The three most important needs are nitrogen, phosphorus and potassium.

Nitrogen (chemical symbol: N) is the nutrient that promotes general plant growth. It helps keep the plant green with chlorophyll that assists in photosynthesis (conversion of the sun’s rays into energy that the plant needs to live). The forms nitrogen comes in organically are chicken feather meal, cotton seed meal, blood meal and, to some extent, fish meal. These are all available locally individually or as part of a formula fertilizer.

Phosphorus (P) is vital to plant root development. It is necessary to the production of good and abundant fruit, flowers and leaf production in harvestable greens. Sources are soft rock phosphate (also a source of a lot of other minerals) and bone meal.

Potassium (K) is necessary to complete the photosynthesis process. It helps the plant to convert the sun’s rays to a glucose-type sugar. This is the food of the plant and helps create a sweeter fruit.

Look on packages of organic fertilizer for the N-P-K amounts. In organics, N (6), P (6 to 10), K (6) are high and good amounts since this is usually long-term and more bio-available.

Micronutrients are all the other minerals that help to feed the plant and represent a small percentage of the plants needs but are vital to its health and survival. Sources are kelp, most humates, soft rock phosphates, ground volcanic rock dusts and anything that comes from deposits in old ocean beds and the like.

In the beginning try to find an organic fertilizer that contains all the above ingredients for the ease of handling. Add this to a good quality compost and put on as per directions. Now is a great time to feed or side dress everything. Look to the local farm and garden stores that we have here in Fallbrook (a unique resource) for all the above types of organic fertilizers. It is so popular now their selections are terrific.

Next article I will go into more detail of how to create your own mixes, and the other resources beyond fertilizer that can help stimulate soil and plant growth even more.

How about this weather? Be sure to mulch, and happy spring gardening.