Must haves for Healthy Soil
Gardening can be a great delight - in fact, we are actually neurologically wired to get a dopamine (the reward neurotransmitter) hit when we harvest. It’s understandably frustrating when we tend our patch and it fails to give us the juicy harvest we’ve been daydreaming of.
Soil health can be remedied by some easy, cost effective steps - which is a great relief for many of our students lamenting failed or struggling garden beds. In our subtropical climate, and much of the Australian climate, water retention and infiltration (the rate at which a soil can ‘soak up’ rainfall). Luckily, these five principles rehabilitate soil and in doing so improve soil infiltration. So we have happier plants, and more effective use of our water resources.
Number 1: Maximise Soil Coverage
If you do only one thing after reading this we would say mulch like your life depends on it. Mulch, or any organic material covering top soil (read leaves, bark, branches etc), significantly improves the homely of soil for the squillions and billions of microbes essential for plant health. It creates insulation for the soil, humidifying in hot temperatures and protecting from cold.
Soil is made up of a matrix of particles and air. When rainfall occurs, air is pushed out to make way for water to infiltrate. Using soil coverage, slows this process and increases the surface area for water to soak in.
Number 2: Plant Roots
When it comes to roots and soil health - the bigger is the better! The larger and deeper a root is, the more effective it is in it’s role of nourishing soil. The practice of planting and maintaining roots in soil, even if they are the root of a weed, is crucial for cultivating healthy soil. Plant roots feed soil organisms and interact with mycelium - the matrix of fungal networks within soil. Roots exchange access to sugars from photosynthesis for release of soil nutrients via the network of fungus and microorganism. These fungus breakdown organic material into nutrients for plants, aid access to water and even create a communication service for plants. Yes, they are the wifi of the plant world - allowing plants to preferentially release nutrients or send ‘distress’ signals from one section of forest to another to warn of stressors, like disease or pests. Roots also form a substrate or tract, allowing water to flow more readily to deeper regions of the soil. Isn’t nature magical?
A rich matrix of mulch and cut green grasses cover the soil. Mushrooms are an excellent sign of soil health - as they spring to life when healthy fungal networks are present in soil.
Number 3: Green Manure
Green manure is a mixed crop planted for the purpose of fertilising or replenishing the nutrients within soil. Returning these crops back to the soil improves it’s structure, reinforces infiltration by the mechanisms discussed and draws up minerals through the soil profile, making them more accessible to the next crop or current plants. A green manure crop can be created out of any seed that will germinate at the time of season that you plant it. A green manure crop is an excellent idea when nutrient hungry crops have finished, like brassicas, or are about to be planted like corn. These crops are largely perennials meaning they provide years of fertiliser that is low cost and high nutrient density without any synthetic chemicals.
Some ideas for your Green Manure seeds:
oats: these grow prolifically and are excellent for crowding out weeds
grains: buckwheat and barley, great source of glucose to reinvigorate soil microbes
legumes: these help to recycle and balance soil nitrogen by drawing nitrogen from the air into the soil. A quintessential
mustard seeds: these are excellent soil fumigators keeping at bay nematodes. Another great crop for this is garlic!
Green manure rows grow between our Syntropic Forest to be cut back and placed over our crop rows.
Number 4: Foster Biodiversity
Growing various crops above or within the ground helps to foster varying microbes that preferentially cohabit soil with different plant species. Another key to soil biodiversity is using no-till or low till, which means the intricate mycelium and soil matrix is not disturbed in the process of planting. By protecting the soil matrix we improve water infiltration through the mechanisms discussed, which further helps to ensure crop longevity.
Let us know if you see a difference from mulching and removing bare, uncovered soil. This is one of the fastest ways to improve your soil and get your garden flourishing again.
