Is your Soil Health Compromised?
Compost and manure may not be the whole solution for your soil.
If over the years of gardening in your yard, you have found that plants which used to thrive are no longer growing, your soil’s health may be compromised. Compost and manure may not be the whole solution for your soil.
Sadly, there is often a steady depletion of organic matter and soil minerals in modern methods of gardening. Namely, this is because so much of what is grown in a garden is taken away and never returned to it (neither in a digested or composted form). Often, new gardens that have been augmented organically will grow great for a few years; then, once soil health is compromised, some plants will stop growing well, or the garden may begin to suffer from increased weeds and/or pests. Nutrient deficiencies and excesses can diminish your garden’s productivity, but also- especially in the case of vegetables- can significantly decrease the quality of the food you are growing.
Robert Parnes stated that “the vegetable garden is an endless sinkhole for plant nutrients.” More than other types of gardening, vegetable gardens need their own organic matter returned to them. Sir Alfred Howard’s Law of Returns declares that that which is taken from the soil must be returned to it, or soil health will suffer. (Read the classic, Soil and Health by Sir Alfred Howard). Even a soil augmentation as virtuous as compost, needs to be selected carefully.
If your compost and animal manure is sourced locally, it is likely depleted in the same minerals that your garden soil is- since its organic components would have originated from the same parent rocks as your soil did. You must be choosy, and knowledgeable, in fertilizing your garden with organic matter so that you don’t end up amplifying deficiencies already present in your soil.
Don’t jump to the conclusion that your soil is acidic- especially in the Lower Mainland, where a lot of leaching might occur over the rainy winter months. Acidity in soil is usually treated with dolomite lime. Typically, these mixes have a 2:1 ratio, which might be okay for lawns, but is too much magnesium for garden soils. One should be sure to select a mixture that has a Ca:Mg ratio between 7:1 and 10:1. (High magnesium levels causes clay to bind to itself, turning your soil into a compacted, airless growing medium).
Soil has a finite amount of minerals and microbiology and these levels must be maintained in gentle, intentional ways. Remineralization guided by a soil test is your best course of action, leading you to make effective and earth-friendly augmentations in your garden this spring.
-Soil tests can be purchased from Pacific Soil Analysis Inc in Richmond BC-