Sustainable Soil Management for Home Garden

At Holhab, we take a holistic approach to soil improvement, understanding that soil is not just a static medium, but a dynamic ecosystem. Our expectation is that the soil we cultivate will continue to increase in fertility and resilience each year, ensuring a sustainable future for the landscapes we work with.

What is Healthy, Productive Soil?

Before diving into the specifics, let’s first define what we mean by healthy, productive soil. In our approach, healthy soil is:

• Optimal structure proving ideal water infiltration and retention

• Biologically rich with a thriving soil food web.

• Balanced in nutrients, enabling plants to thrive.

  
  

Therefore, a sustainable soil management approach will focus on these key components when restoring and maintaining a healthy, productive soil.

The Role of Organic Matter

Organic matter (OM) plays a key role in soil health, improving both its physical and biological properties. Increasing OM helps:

• Improve soil structure, allowing better water and air infiltration.

• Enhance nutrient retention and increase the availability of essential minerals to plants.

• Creates an environment that supports beneficial microbes, fostering soil resilience.

  
  

We aim to build our soils to contain 10% organic matter. This is achieved by introducing organic material and encouraging biological activity and its outputs, including:

• Mulch: Straw, lucerne, woodchip, and forest mulch encourage an abundance of microbes and decomposers.

• Compost and Vermicast: Solid compost or vermicast is applied around the dripline of trees and throughout veggie gardens, helping to boost OM and humus content.

• Cover Crops: Grown between fruit trees, inter-seasonally within veggie gardens and in areas designated for future food production. Species should be mixed like a cover croptail.
  

Your cover croptail seed mix should include a diversity of species including grasses, legumes, brassica, radish and daisy to provide the full spectrum of benefits

Encouraging biology

Biology is the life of the soil, literally. There are approximately 1 billion bacteria, 5,000 protozoa, and 45 nematodes in each teaspoon of soil! Plants are healthiest, most resilient, and most nutritious when they live in symbiosis with the microbes and the broader soil food web. A thriving soil food web accelerates nutrient cycling, while intercellular fungal associations provide defense against parasitic microbes and nematodes.

Here are a few examples of the important players within the soil food web that we want to encourage:

• Nitrogen-fixing rhizobacteria: These bacteria live in partnership with legume roots, capturing atmospheric nitrogen and converting it into organic nitrogen that plants can use.

• Mycorrhizal fungi: These fungi produce chelates and convert inorganic, unavailable nutrients into plant-available forms.

• Ectomycorrhizal fungi: Form fungal sheath around plant roots, trading essential nutrients while defending plants from pests and diseases.

• Earthworms: These hardworking organisms travel up to several kilometers in search of decaying plant matter, microorganisms, soil, and animal waste. As they tunnel through the soil, they aerate and build organic matter.

As you can see, soil health quickly becomes a complex web of interactions. But don’t worry, here are three key actions you can take to ensure that you're doing your part of the symbiosis:

1. Incorporate nitrogen-fixing plants: Include legumes and cover crops throughout the garden and in your cover croptails to naturally boost soil fertility.

2. Inoculate with beneficial microbes: Seedling dips with trichoderma and mycorrhizal fungi, aerated compost and vermicast teas applied as a foliar spray, seedling soak or soil drench.

3. Minimise soil disturbance: Reduce tilling and mechanical intervention to preserve the natural structure of the soil and its microbial life.

If you’re working with sterilised soils, such as landscape soil or potting mix, it’s essential to inoculate them with beneficial microbes and bring the soil to life (or the life to the soil). This will help jump-start biological activity and accelerate the development of a soil ecosystem that will support your plants and bellies!

Left to right/ top to bottom: Fungal-rich compost, slashed cover crops, fungal mycelium throughout forest mulch, organic matter and worm macropores throughout naturally, clay-dominant soil

Balancing the Nutrients

One of the fundamental principles of soil health is ensuring a balance of nutrients that are available in forms plants can readily absorb. While organic matter plays a crucial role in enhancing soil structure and fostering microbial life, it’s also important to understand the specific nutrients that contribute to plant growth. These include primary macronutrients (nitrogen, phosphorus, and potassium), secondary macronutrients (calcium, magnesium, and sulfur), and micronutrients (iron, manganese, boron, etc.).

Soil Testing

At Holhab, we recognise that soil nutrient levels can vary, and our approach focuses on understanding and managing these variations for long-term soil health and productivity. The goal isn’t just to add fertilizer; it’s to create an environment where nutrients are naturally cycling and accessible to plants as they need them.

Soil testing is the first step in understanding your soil’s nutrient profile. Regular testing allows us to identify nutrient deficiencies or imbalances and tailor our soil improvement practices accordingly. It’s not about quick fixes or one-size-fits-all solutions; it’s about assessing the unique needs of your soil and adjusting inputs accordingly.

Your soil test should include a pH test as it is a critical factor in balancing nutrients and their availability to your plants. For instance, in more acidic soils (low pH), nutrients like phosphorus and calcium can become less available, whereas in alkaline soils (high pH), iron and magnesium might be harder for plants to absorb. The general range for a home garden is a pH between 6.0 and 6.4.

Fertilliser and Ammendments

While we advocate for building soil fertility through organic methods, there are instances where supplemental fertilisers or amendments can provide a needed boost. However, it's important to apply these selectively and responsibly noting that over-fertilsing can 'burn' (damage) plants and microbial life within the soil. Do not apply fertlisers with a concentrate greater than 10:10:10 (nitrogen, phosphorus, potassium (NPK)).

• Compost: Adding high-quality compost regularly is one of the best ways to naturally balance nutrients. It provides a slow, steady release of essential elements and boosts the microbial populations that help break down nutrients into plant-available forms.

• Mineral Amendments: Sometimes, soils may be lacking in specific minerals such as calcium or magnesium. In these cases, amendments like lime or gypsum can be used to correct deficiencies and rebalance pH without harming the soil’s microbial community.

• Organic Fertilisers: Organic fertilisers, such as fish meal or seaweed extract, provide a steady supply of nutrients while improving soil biology and increasing soil organic matter.

• Timing: Consider the plant habit and its life stage and fertilise accordingly. You want to help your plant grow roots and leaves during the vegetative stage, support the plants' defense and recovery during weather extremes and encourage flowers and fruits during the reproductive stage.

Incorporate the following actions into your fertilising schedule and give your garden the best chance to succeed:

• Soil testing: inform yourself and ensure that you're supporting and improving the nutrient profile of your soil rather than guessing and running the risk of exacerbating an imbalance.

• Foliar spray: Applying fertiliser as a foliar spray is like intravenous for your plant causing a rapid uptake directly through the plant bypassing any blockages that are caused by nutrient imbalances in the soil. Note that this is a short-term solution designed to fertilise your plant once and doesn't improve the soil.

• Combine fertilisers with humic acid, fulvic acid and microbes. This will increase the immediate uptake of nutrients whilst bind to the soil ensuring longer-term retention.

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Sustainable Soil Management for Home Gardens

In summary, your plants, garden and self are completely dependent upon the capacity of your soil to support your crops to thrive, survive and provide you with nutritious food, harvest after harvest. By taking a holistic approach that focuses on structure, biology and nutrition; you'll increase organic matter, beneficial biology and increase fertility each year. Finally, be sure not to get 'caught up in the weeds' and forget to observe,

“Be mindful, deliberate, and responsive to how your plants and garden react to both your management and the natural disturbance processes from season to season.”

At Holhab, we offer guidance and can prescribe a detailed program to implement sustainable soil management for your home garden and rural property. From soil testing to fertility guidance, compost and compost-tea recipes, microbial inoculation and cover crops. We'll simplify soil science and long-gone sustainable gardening solutions and show you how to build and maintain your soil, its biology and nutrients for seasons to come.

Learn more about our landscape design services and get in contact today!