An old word game poses this challenge: animal, vegetable or mineral? If soil was the object of guessing, the answer might realistically be all three. Composed of rock and clay, rotted vegetation and earthworms, soil is as much a living thing as a panda or a maple tree.
Like any living organism, soil needs nourishment to sustain health, life and productivity. It also requires rest. Although fertilizer can boost soil’s ability to bring forth plants of all kinds, its long-term effects can lead to erosion and incapacity in the soil’s vitality. The following tips can help gardeners to limit fertilizer.
1. Identify Your Soil
It is helpful to think of soil as having different species. Scientist divide soil into three tiers. Closest to the bedrock is deep subsoil. The next strata up is subsoil. Finally, there is topsoil, i.e. the dirt we see and cultivate. Within these divisions are one or more sub-layers or “horizons.”
The make-up of each horizon – and their relation to each other – comprise a soil profile. As leaves fall and insects die and animals leave their waste, organic matter, aided by rainwater, permeates down through the horizons, adding uniquely to the strength of the soil. Accordingly, forest soil will differ from mountain soil; prairie soil from desert soil; and muck soil from volcanic soil.
Why is this important to learning how to enrich soil? It matters because different kinds of soil have differing acidity levels, salt content, moisture capacity and textures. It stands to reason that each “species” of soil will have its own nutritional requirements. Just as you will not feed cat food to a dog, neither should one soil receive food more suitable to another.
2. Use Alternative Nitrogen Sources
Nitrogen is a primary macronutrient for most every plant and a key in how to enrich soil. Without adequate nitrogen, discoloration and stunted growth will plague crops and ornamentals. On the other hand, an oversupply of nitrogen reduces plant immunity and produces weak and brittle stalks.
Furthermore, it will result in leeching and runoff when the rains come, affecting environmental quality and public health. Chemical, or mineral, fertilizers may be too high in nitrogen content, perhaps leading to such problems. Natural substitutes include livestock manure but even that might be too nitrogen-dense.
“Green manure,” like mustard, wheat, and borage dispense nitrogen – in lesser amounts – into the soil. Likewise, coffee grounds contain nitrogen-rich proteins that foster germination and growth in plants. Better still, when used as compost, the grounds impart antioxidant and antimicrobial properties to the soil. In addition, beneficial earthworms are attracted by coffee grounds, which they ingest as a food source.
Worth noting is the fact that coffee grounds do not increase soil acidity, as is sometimes suspected. Anyone interested in how to enrich soil should employ coffee grounds (at no more than 20 percent of total compost) and green manure to augment nitrogen presence without oversupplying.
3. Bone Up on Bone Meal
Bone meal is the finely ground bones and other tissues from animal carcasses. Its consistency is akin to baking flour. On its own, it amounts to a slow-release medium for phosphorous. While it aids in growth for every plant, root vegetables and bulb-generated flowers respond particularly well to its application.
Best when applied at 10 pounds per 100 square feet, bone meal assists plants in generating shoots and growing strong stems. Primarily, it supplies the necessary phosphorous to grow deep and extensive root networks. Moreover, phosphorous is responsible for robust fruit and flower presence, as well as a plant’s ability to convey and retain energy.
Bone meal is also a natural source of calcium supplementation. Calcium is a secondary but important nutrient for plants in that it strengthens cell walls and prevents blossom-end rot. An education in how to enrich soil should include knowing the power of bone meal.
4. Feel the Burn for Potassium
Fertilizers are often two parts potassium, and for good reason. Potassium manages the water balance in plants. Without it, cells grow squishy, less drought-resistant and more susceptible to diseases. As pioneers in North America burned and cleared forests, they combined the wood ash with water, creating a natural fertilizer they called potash.
Because of their potassium measure, wood ashes remain a potent plant food, but must be applied with restraint. Apply the ash to the soil well in advance of planting and—most importantly—never apply it directly to a plant. That is definitely not how to enrich soil. Also, never use ash from pressurized or pre-treated wood since toxic chemicals will be present in the ash.
5. Get Plenty of Rest
Those who wonder how to enrich soil without adding fertilizer have a time-free method that will not cost a cent – just leave the land alone… at least for a season. This is folk wisdom confirmed by science. A study on behalf of the Palo Verde Irrigation District in California determined that leaving land fallow for one to five years actually augments the amount of carbon, organic matter and nitrogen in the soil. Microbial activity increased and subsequent harvests were much improved over the years prior to the idle periods. Again, soil is a living thing thus needs rest for optimal health.
Although salinity levels were raised in the fallow land, the water saved in irrigation was more than enough to lower the salt content. Ancient scriptures call this technique agricultural sabbatical. Whether from revelation or experimentation, leaving land idle for a time is a case study in how to enrich soil.
Like many organisms, soil enjoys amazing recuperative powers of self-healing and fertility. Yet compaction, overuse and chemicals can take their toll on the health of the topsoil. Treating your garden gently with natural means of enhancement goes a long way to keeping it vital and sustainable. Beyond that, letting it be from time to time also gives it a stronger profile. Your soil will thank you and your plants will prove it.