For each crop, there might be a different definition of fertile soil. What one plant needs isn’t exactly the same that another prefers when we speak of soil texture, pH levels and nutrient composition.
However, if we can agree on something that every plant will generally look out for as soon as it starts rooting, that would be a deep, fresh and light layer of rich soil. And this is a goal that many gardens aren’t even close to achieving.
But so what can be done to boost soil’s fertility by using whatever means we have?
Well, two principles are key in this equation: you need to enrich the soil while, simultaneously, slowing down or even inverting the natural tendency for a soil to be washed out of its nutrients and organic matter.
The secret is to be mindful that both phenomena ultimately have the same influence over how we achieve a more prolific and inexhaustible garden.
How to add value to the soil?
Add organic residues
Organic matter is a broad category that includes almost every residue produced in our daily lives, so long as it’s not glass, plastic or metal. Here are a few examples:
Egg Shells and Fishbones
What these ingredients have in common is their high content of calcium, an important nutrient to keep the soil’s structure and assure successful plant nutrition. Besides this primary mineral, phosphorus (another main macronutrient required by plants) is also present.
You’d better crush the shells and especially the fishbones so that their decay is accelerated. And since these detritus are tough and hard to decompose, you may take them to the oven for a while and break them down through heat. Then pulverise them and sprinkle the earth or the seedlings directly.
This practice helps in keeping leaf diseases at bay while nourishing the plants by absorption through their aerial parts, and also by the roots once you water it all down in the evening.
Fruit and Vegetable Peels, Coffee Grounds and Grass Clippings
These ones are the worms’ favourites and you really want to keep adding fresh organic elements like these right into your furrows and compost bin.
Very soon these residues start brimming with life: little larvae, flies, eggs and fungi, and there’s nothing better than that if you wish to spice up the biodiversity in a ground where you’re growing plants.
Human and Livestock Manure
The worse it smells, the better for your garden. Well, I don’t mean you should be collecting everything from the toilet to incorporate in the yard, but urine can certainly be used to add a concentrated dose of nutrients to the mix.
Any farm animals you own will make a fabulous contribution to maintaining the nitrogen levels soaring and your garden proudly smelling a tad more like a real farm.
Rotten Food and Animal Feed Remains
The high protein content of many of our foods as well as our pets’ makes them a great addition to the soil. Those fibres and nitrogen will help its texture and fertility in a free, eco-friendly way.
Still, the scentful remains may attract wildlife to your garden and that’s something you probably want to avoid.
Residual Waters and Oils
Whether it’s water in which something was left to boil, ferment, soak, dissolve, or even waters from pets’ aquariums and livestock trays, these will all be more or less filled with rich chemical elements that your soil would love to drink up, like nitrates and sulphates.
Every kind of organic oil that’s too burnt for another fry is also a nice incorporation. You can pour it down the pile, though you shouldn’t dump too much at once, as it’ll slow the composting process.
Add compost
A compost pile may very well consist of the sum of every element I now described. The only difference is that you can always buy compost or potting mix, while you won’t be able to acquire someone else’s leftovers.
So, if you choose to build your own compost box, it’s indeed a more effective way of dealing with whatever organic residues you have to dispose of, preferably in a way that’s beneficial to your plants.
Make sure to keep it on a sunnier spot for the pile’s internal temperature to remain higher than the ambient temperature during the cold seasons. You also need to have it moist for the organisms which, otherwise, won’t stay alive long enough to produce a stinky pile of nutritious rot.
Add soil correctors
The pH of the soil is relevant because it dictates how mobile or immobile the chemical nutrients in it are. Thus, pH interferes with their effective availability to the plants and, consequently, conditions the growth and yield of your crops.
Test your soil’s pH levels and based on what the number is and what you wish to grow there, you can add the right correctors.
For example, to make the ground more acidic, you can input acidifying fertilisers, sulphur, sphagnum peat, iron and aluminium sulfates, or you may more casually mulch and add compost to your garden. If you need to alkalize it, then limestone, wood ash and baking soda shall fix the current lacks.
Apart from soil correctors, there’s a vast category of fertilisers and additives that range from the more organic versions that we already went through — be them homemade or store-bought compost mixes — to other types of fertility enhancers, such as rock phosphate, azomite, fortified bone meal and many synthesized fertilisers.
Grow cover crops
Crops that cover an otherwise bare ground will benefit the system in several ways.
First, they promote a greater infiltration of intense rain showers, seeing that when there are no ground-covering plants, the surface runoff will sharply increase. Also, without these crops, you’ll have an impoverished soil because there isn’t any biomass shedding and accumulating on the surface.
Leguminous plants are the best for covering a patch of soil because they’re not very competitive for nutrients, in case you’re implementing mixed cropping or even if you’re just filling in the empty spaces between orchard trees and shrubs. At the same time, they’ll improve the soil by fixing nitrogen and promoting symbiotic connections at the root level.
Grow nitrogen-fixing plants
Plants capable of fixating nitrogen are a great fertility booster, often with the bonus of producing their own fruits by the end of their cycle.
The symbiosis created between the roots of these plants and Mycorrhizal fungi allows for the fixation of chemical compounds in the subsoil that are advantageous not only for the present crops but for years to come over that same earth.
You need only to select the best species for each season while also seeing to your personal needs as the eater of your own garden. Everything you plant should be well integrated with your yearly cultivation plan, not just to keep the soil warmed up for your next crop but actually promote further functionality, regarding the interface between subterranean life and its aboveground counterpart.
Grow tap-root plants
Deep-rooted species will passively increase aeration and drainage of the soil. They also serve as biological accumulators of those nutrients that have been bleached to deeper layers.
By pumping them upwards to their leaves, fruits and seeds, plants basically mine for a richness that used to be buried underground and out of reach, but now, effortlessly surfaces and gets converted into either the produce that we eat or reusable residue to mulch your garden with.
How to stop stealing from the soil?
Reduce ploughing
Tilling the soil causes damage on various fronts and that’s why you should keep it to a minimum.
The consequences range from the destruction of beneficial underground and superficial biotic communities, powdering of the soil structure and natural porosity created by the root systems and organisms, as well as increasing the degradation of organic matter through oxidation and erosion.
What you must realise is that beneath the surface should exist well-established, living interconnections between the soil, the plant and every macro and microorganism belonging to the system.
Another thing to recognise is how important it is to only do the tillage at the right time. I mean that if you plough it when it’s too dry or too soggy, those interventions will do more harm the functionality of said soil. It becomes more susceptible to the formation of an impermeable hard layer in the subsoil called “ploughing pan” (when it’s soggy) or pulverization of its macropores and valuable biotic structures that had developed beneath the surface (if it’s too dry).
Start mixed cropping
One of the main causes of soil depletion and eventual desertification of what once were healthy patches of land is the production intensification allied to monocultures.
So, in mixing up the cultivated crops, we’re giving the earth some rest because each plant species will exploit a certain combination of nutrients, leaving time for the remaining chemical components to be replenished and bring the earth back to balance.
Do mulching and raised beds
With mulching, you’re paving the road to what can be a future around gardening using raised beds, or really any technique that promotes a more conservational approach to vegetable and ornamental growing.
For mulch material, use clippings of any sort (as long as they’re not too thick and ligneous), including vines, leaves and scythed weeds. Nettle, clover, borage and comfrey are good examples of nitrogen packed invasives that you should apply on the soil.
Just be sure you keep an eye on those sneaky roots these weeds might grow over time, for we know how resilient these plants tend to be.
Raised beds are the opposite of tilling, for obvious reasons. It’s a routine that consists in heaping up vegetable scraps, non-decomposed organic matter and substrate to then plant seeds or young plants on top of it. As it ages, the bed will come undone and degrade until it nears ground level.
When the crops are harvested, you can till the soil and incorporate everything into it, or keep piling up fresher mulch, potting mix and biomass in order to raise a new substitute garden bed.
More incorporation of crop residue
An impactful reason for the soil’s loss of fertility is the gradual degradation of organic matter. Years pass and the crops, the weather and the way you manoeuvre the earth will eat up all that richness your garden depends on.
For this purpose, as I’ve just suggested, you may either leave the straw from your dead crops on the ground as mulch or a starting mound for a raised bed, or you can bury it underground once you manually or mechanically plough the yard at the beginning of the new season.
Avoid biocides
Once again, if we kill a living soil, we are, in the long run, compromising the prosperity of our garden. Hence, everything should be done to foment the proliferation of friendly insects and microorganisms because they do a great job of establishing equilibrium on a phytosanitary level.
Always remember that less is more and that in starting naturally and without adopting measures that mean to kill biodiversity, whatever its form or function, the future will offer an easier path for life to grow on.
These benefits aren’t only yours but for everyone and everything on our green planet, so be wise, respect Earth’s suggestions and the fruits shall grow and ripen as they should, just in time for you to pick them up.