All experienced or less experienced gardeners face, sooner or later, the challenge of improving the soil where they grow. Not all soils are suitable for different crops, and their improvement is a common activity for farmers, whether they are involved in a small or a large project. In order to achieve effective results, it is necessary to be able to rely on specific skills and strategies. Here are some commonly recommended methods of improving the soil and increasing the actual yield of a piece of land.
Steps
Part 1 of 3: Enrich the Soil with Nutrients
Step 1. Find out what nutrients your plants need
There are three very important substances for gardening: nitrogen (N) for foliage and stem growth, phosphorus (P) for roots, fruits and seeds, and potassium (K) for disease resistance. and general health. Seedlings may need more phosphorus to focus resources on foliage growth, while adult plants typically need fewer nutrients outside the growing season. For best results, check the specific needs of the plants you intend to grow. These are usually expressed with three numbers indicating the percentage or total amount of "NPK", that is, in order, of nitrogen, phosphorus and potassium.
If you would like a detailed report on nutrients in the soil, send soil samples to local agricultural assistance centers or a testing laboratory. This is not necessary for most home gardens, unless the plants exhibit slow growth or color changes
Step 2. Choose fertilizers derived from organic sources
Plant and animal substances, such as suspended fish particles or hydrolyzed fish preparation, provide the best type of fertilizer for long-term microbial growth, which keeps the soil nutrient-rich and porous. Fertilizers synthesized in laboratories typically feed plants without improving the soil, and in some cases can even have negative effects.
Always protect your hands and face when working with soil additives, as these can contain bacteria and other substances that are harmful to health
Step 3. Consider using manure or other organic materials
Instead of an industrial product, you may find unrefined and less expensive solutions at a garden store or farm. Here are some common solutions:
- Manure should be left to decompose for at least a month before use, to avoid damaging the plants. Chicken or turkey manure is inexpensive, but can cause runoff problems in large soils. Cow, sheep, goat and rabbit manure is of higher quality and has a less intense odor.
- Add bone meal for phosphorus, or blood meal for nitrogen.
Step 4. Prepare the compost
New compost generally takes four to eight months to mature, unless you want to speed up the process by adding particular bacteria. This long-term solution will benefit soil texture and nutrients if you have the patience to complete the process. Prepare a large outdoor container, tightly closed to protect it from animals, but with holes to ensure airflow. Take care of it with these techniques:
- Start with about 20% soil, manure, or mature compost; food waste of vegetable origin from 10 to 30%; dry foliage, grass and mowings from 50 to 70%. Thoroughly mix all of this together.
- Keep the compost warm and moist, and add kitchen scraps - other than meat-based.
- Turn the compost with a pitchfork or shovel at least once every week or two to introduce oxygen that encourages beneficial bacteria.
- Look for worms in wet areas under stones and add them to the composter.
- Compost is ripe (ready to use) if it clumps when squeezed, but can easily be crushed. Vegetable fibers should still be visible, but the compost should be mostly homogeneous.
Step 5. Add the fertilizer material
Whatever fertilizer used, solid matter, mature manure or compost, most gardeners mix it thoroughly into the soil. Many crops grow well with 30% compost and 70% compost mix, however vegetables and fruit plants often grow better with smaller amounts of compost. The quantities of fertilizer vary considerably according to the concentration; follow the recommendations for different plants.
- Proponents of "zero tillage" or "without turning the soil" agriculture add the material to the surface, allowing it to gradually decompose in the soil. Practitioners consider this a more natural and less invasive way to improve the soil, although full results can take years and a lot of organic matter.
- Add in the fall for best results. Many plants benefit from a "top-up" every month or two during the growing season, but this varies by species and variety.
- If you think the manure or compost is not decomposed sufficiently, keep a circle of earth without manure or compost around the plants to avoid damaging them.
Step 6. Add trace elements
There are many trace elements that have a less important or less direct effect, but can cause plant health problems or deplete the soil, if they fall below the required levels. If you want to be sure to include them, mix green sand (contains glauconite), seaweed meal or Azomite © into the soil before planting. For small home gardens, this may not be necessary - unless the plants have health problems.
- The most important trace elements are iron, boron, copper, manganese, molybdenum and zinc.
- The additives listed here are suitable for organic and natural agriculture.
Step 7. Consider crop rotation
If you grow the same type of plant in the same spot every year, the soil's nutrients will deplete more quickly. Some plants use few nutrients and even release nitrogen to the soil, so an annual plant rotation plan will keep nutrient levels more stable.
- For home gardening, start with a simple crop rotation guide (you can find many online). For an agricultural business, consult an expert local farmer or a service center, because the rotation plan varies according to the crops available.
- Farmers may also consider winter "cover crops" to provide nutrients for the next crop. Plant a winter crop at least 30 days before the first expected frost (or 60 days before if the crop does not require severe cold). Mow or remove the crop at least three to four weeks before planting the next one, and leave the cover crop on the ground to rot.
Step 8. Consider adding beneficial bacteria or fungi
If the soil is kept well aerated and rich in nutrients, the microbes will grow on their own, breaking down dead plants into nutrients that the plants can reuse. To improve soil health, you could purchase bacterial or fungal additives at a garden store if they are suitable for your plant species. Soils where decomposition is rapid do not need these additives, although there are no sound and immediate rules for how much to use or when to stop.
- One of the most common additives is a type of fungus called mycorrhiza, which attacks the roots of plants and helps them absorb more nutrients and water. All plants, except those of the Brassica genus (including mustard and cruciferous vegetables such as broccoli and Chinese cabbage) benefit, unless the soil is already in excellent condition.
- Bacteria called rhizobium are often already present in the soil, but you may want to purchase an inoculant to be safe. These form a symbiotic relationship with crops such as potatoes and beans, enriching the soil with nitrogen.
Part 2 of 3: Improving Soil Composition
Step 1. Try to understand the triangle of the terrain
Specialists divide the particles that make up the soil into three categories. The sand particles are the most numerous, those of silt are less abundant, and those of clay even less. The relationship between these three categories of particles determines the type of soil, and is described in a graph called the "terrain triangle". For most plants, a "loamy loam" or approximately 40-40-20 composition of sand, silt and clay, respectively, is preferable.
Succulents and cacti on the other hand often prefer a "sandy loam" with 60 or 70% sand
Step 2. Try a quick composition test
Collect a small lump of earth from under the surface layer. Moisten it, try to shape it into a ball and then flatten it into a ribbon shape. This quick and approximate method can detect major problems based on the following diagnosis:
- If the web breaks before reaching 2.5 cm, you have sedimentary or loamy soil (if you haven't managed to form a ball or web, the soil is sandy).
- If the tape reaches 2.5-5 cm before breaking, you have clayey soil. The soil could probably benefit from more sand and sedimentary earth.
- If the tape exceeds 5 cm, the soil is clayey. It will then be necessary to add the main additives, as described at the end of this section.
Step 3. Prepare a soil sample for thorough verification
If you're still unsure, you'll be able to get more accurate information with twenty minutes of work and a couple of days of waiting. To start, clear the topsoil, then dig a sample of the soil to a depth of about six inches. Spread it out on a newspaper to dry and get rid of all rubbish, stones and other large debris. Break up the clods, separating them as much as possible.
Step 4. Mix the ingredients for a jar test
Once the soil is dry, pour it into a large pot to fill a quarter of its capacity. Add water up to ¾, then add 5 ml (1 teaspoon) of non-foaming dishwasher detergent. Cap the jar and shake for at least five minutes to further crush the contents.
Step 5. Mark the pot as the earth settles
Let it rest for at least a couple of days, marking the outside with a marker or tape at these intervals:
- After one minute, mark the jar at the top of the deposited particles. These are formed of sand, and are deposited first due to their largest caliber.
- After two hours, mark the jar again. By now, most of the silt will be deposited on top of the sand.
- Once the water is clear, it marks a third time. Soil with a lot of clay can take a week or two to settle, while loamy ones can clear the water after a couple of days.
- Measure the distance between the marks to determine the quantity of each particle. Divide each measurement by the total height of the particles to get the relative percentage of particles of each type. For example, if you have 5 cm of sand and a total layer of 10 cm of particles, the soil is 5 ÷ 10 = 0.5 = 50% of sand.
Step 6. Improve the soil with compost or plant debris
If you find that the ground is already loamy, there is no need to change it. Clay soils benefit a lot from mature compost, as described in the nutrient section. Other plant additions such as dry leaves or mown grass serve the same purpose.
Weathered old wood chips, twigs or bark increase water and nutrient retention, both by creating porosity and by absorbing materials for slow release. Avoid new wood, as it can reduce nitrogen levels
Step 7. Consider manual land adjustment
If you have a soil with a lot of clay (more than 20%) or very sandy or sedimentary (more than 60% sand or 60% silt), you can mix it in other types of soil to get a fairly homogeneous mixture of sand and silt. and no more than 20% clay. This can be labor-intensive, but it's faster than making a specific compost. The goal is to create a porous soil that can hold a lot of water, air and nutrients.
- Note that only salt-free sand with many protrusions should be used.
- Perlite, available in garden stores, is useful for all types of soil but especially for clayey ones, essentially containing very large particles.
Step 8. Take on soil compaction
Limit pedestrian and vehicle traffic to a minimum to keep the terrain aerated. If the soil looks dense or crusty on top, you can use a pitchfork to turn it over and crush larger sods. For very compacted soil, use a tiller, or dig holes with a lawn aerator. While water retention is not a problem, densely packed soil can kill beneficial fungi and bacteria and promote harmful anaerobic ones.
- Mixing in organic material helps, as described in the section on soil nutrients.
- Dandelions and other tap-rooted plants can help prevent compaction and clod formation.
- Alternatively, you can follow the "zero tillage" or "without turning the soil" farming techniques to leave it undisturbed, and transform it into natural soil in a few years. However, limiting traffic is recommended for this method.
Part 3 of 3: Adjust the pH of the Soil
Step 1. Get a soil sample
For accurate results, remove the superficial part until you reach layers of uniform composition and color, usually about 5 cm deep. Dig a 6-inch hole. Repeat several times in the garden or field to get a representative set of specimens.
Step 2. Check the pH of the soil
You can send these samples to a local service center or testing lab, and pay to test the pH, or acidity of the soil. However, pH test kits are available inexpensively at garden supply stores or nurseries, and it's easy to use them at home.
Sending the samples to a professional is recommended for agricultural entrepreneurs, so you can get the exact prescriptions for how much additive to use. Home gardeners could use the cheapest and most practical kit, and go for trial and error
Step 3. Check the needs of the plants
Many plants prefer slightly acidic soil, so aim for a pH of 6.5 if you don't have any other information. You can still find your plant preferences online, or talk to an experienced gardener.
If you cannot find the exact pH levels, assume that "acid soils" have a pH between 6.0 and 6.5, while "alkaline soils" have a pH between 7, 5 and 8
Step 4. Make the soil more alkaline
If the pH is too low for your plants, increase it with these additives. Check at a garden store for silt, chopped shellfish, or other calcium supplements, or grind eggshells to powder. Stir a large handful of additive into the soil several times, and check the pH each time.
Step 5. Make the soil more acidic
If you need to lower the pH level, an acid addition is required instead. Mix in some aluminum sulfate or sulfur from a garden store, checking the pH after each handful.
There are no reliable home methods for increasing the pH of the soil. Scientific tests show that pine needles and coffee grounds do not have an effective effect on the acidity of the soil, despite the widespread belief to the contrary
Step 6. Take the tests every three years
Over time, the pH will gradually return to its usual levels, which are mainly determined by the type of minerals present in the area. Unless you experience problems with pH regulation or plants have growth problems, testing the soil every three years should be fine.
Advice
- Toxic chemicals in the soil aren't a common problem, but it's worth investigating if you live near an industrial estate, landfill, or toxic waste site, or if you grow edible plants by the side of the road. Send the soil samples to a service center for tests and advice. Dangerous chemicals may require professional interventions, while for others it is sufficient to dilute them with other soil.
- If there are cats that use the garden as a toilet, discourage them by scattering a thin layer of straw in the garden, and leaving uncovered circles around the plants. Straw will also increase water retention and soil temperature, which can be beneficial or harmful based on soil characteristics and climate.
Warnings
- Always protect your face, hands and other parts of the body from contact with the different substances you use to improve the soil. Read product warnings and learn about the safe use of soil improvement chemicals.
- When using any type of organic material to improve the soil, try to limit the inclusion of weed seeds. Too many of these seeds can sprout during the grow cycle and cause problems.
- Never use dog or cat feces as manure, because these can be the site of dangerous agents for human health.
- Citrus waste is not ideal for compost, as it takes a long time to decompose and reduces the activity of worms.
