SOIL HEALTH
WHAT IS SOIL?
Soil is the loose/fertile surface material of the earth which is able to nourish & support plant life. Soil is composed of four basic components: mineral solids, water, air and organic matter (including living biota).

Mineral Solids are stone fragments, sand, silt, and clay. It is the proportion of the latter three that determines the soil’s texture. For example, a soil that is composed of 70% silt, 20% sand and 10% clay can be classified as a silt loam using the soil texture triangle (see Figure 1). Soil texture contributes to the inherent soil quality, the characteristics of the soil that result from soil forming processes. These characteristics are difficult to change through soil management.

Water is essential for soil life. Water is the medium that facilitates nutrient transport through the soil and enables plant nutrient uptake. Water also enables and facilitates the movement of microbes such as nematodes and bacteria through the soil.

Air is constantly moving in and out of the soil. Air provides the oxygen required for cell functioning in aerobic organisms including plant roots. Both air and water occupy the pore spaces created within and between soil aggregates (clusters of sand, silt and clay particles bound together by particle surface chemistry and microbial and plant exudates).
Organic Matter is any material that is part of or originated from living organisms. Organic matter may be divided into three fractions, the living, the dead (active fraction) and the very dead (stable fraction).
The living soil organic matter fraction includes microorganisms, soil-dwelling insects, microarthropods, animals and plants.
The dead fraction consists primarily of fresh residues from crops, recently dead microorganisms and insects, sloughed-off root cells, leaf litter, and manure, etc. This fraction is considered active. The sugars, proteins, cellulose and other simple compounds are quickly broken down (degraded) by soil microbes and used as a food source which fuels the soil microbial population. The exudates (sticky substances) produced by the microbes (and roots) as well as the microbes themselves (e.g. fungi) help bind the mineral particles together to form soil aggregates.
Good soil aggregation is important for maintaining good (crumbly) soil structure and enabling adequate air exchange and water drainage. The very dead organic matter fraction is also called humus. Humus is very stable and resists further degradation. Although it is not an important food source for microbes, it is important for storing nutrients and water, binding toxic chemicals and contributing to improved aggregate stability.
WHAT IS SOIL HEALTH?
The terms soil health and soil quality are becoming increasingly familiar worldwide. Doran & Parkin (1994) defined soil quality as “the capacity of a soil to function, within ecosystem and land use boundaries, to sustain productivity, maintain environmental quality, and promote plant and animal health.” The three characteristics of soil health are physical, chemical and biological:

Physical Soil Health refers to the friability and hardness of the soil. A physically healthy soil does not have hard pans or hard setting surfaces. It holds water well, drains well and does not restrict root growth. You can assess physical health in the field using a spade; there also are a range of measurements that can be taken in the field or laboratory.

Chemical Soil Health means that nutrients are in balance and available to the crop, the acidity/alkalinity is in the desired range and there are no problems with salinity or sodicity. Chemical soil health can be measured by conducting a soil test.

Biological Soil Health refers to soil life. A healthy soil has more soil organisms than an unhealthy soil of the same type. Crop residues break down more easily and the chemical and physical health is better. You can assess biological health in the field by checking for organisms and comparing the smell and feel of the soil. A high organic matter or carbon content for your soil type usually means a healthy soil.

Understanding soil health means assessing and managing soil so that it functions optimally now and is not degraded for future use. Soil works for you if you work for the soil by using management practices that improve soil health and increase productivity and profitability immediately and into the future. A fully functioning soil produces the maximum amount of products at the least cost therefore maximizing soil health is essential to maximizing profitability.
You can get a Soil Health Assessment by conducting a laboratory soil test using a range of physical, chemical and biological indicators. To get your soil assessed Now please contact our offices for more details.