Soil Health Services
What is Soil Health?
There are a few definitions of soil health out there in the media. Some are quite apt. The one we like and are guided by is a classic from the USDA:
Soil health is the capacity of soil to function as a living system, within ecosystem and land use boundaries, to sustain plant and animal productivity, maintain or enhance water and air quality, and promote plant and animal health. Healthy soils maintain a diverse community of soil organisms that help to control plant disease, insect and weed pests, form beneficial symbiotic associations with plant roots; recycle essential plant nutrients; improve soil structure with positive repercussions for soil water and nutrient holding capacity, and ultimately improve crop production. A healthy soil prevents pollution of environment and contributes to mitigating climate change by maintaining or increasing its carbon content.
(Doran and Zeiss, 2000; FAO and ITPS, 2015)
Farmers sometimes say that they can tell healthy soil by looking at it, so why measure it?
Soil is the engine of farm production. Just like human-made capital, the natural capital in the soil should be monitored regularly and maintained. While that makes common sense, there are sound specific reasons to do so:
- to ensure that soil physical condition fosters and supports soil biology especially mycorrhiza, and enables roots to reach out towards nutrients
- to avoid assuming that soil has not changed under human management. The slow decline of key attributes may escape attention until it reaches levels that affect productivity and reduce soil's resilence to stresses like heavy rainfall. Soil loss may increase step by step.
- to assess the costs and returns of investing in soil health. For example, investing in keeping soil pH at the optimal level will affect the nutrient use efficiency of the crop. If pH is significantly low, it will effectively raise the cost of fertiliser. In addition, appropriate levels of calcium will provide better soil structure which may reduce the incidence of soilborne diseases and resulting financial losses. It is false economy to think of soil as primarily a medium for plants to stand up in, or to buy fertiliser based on the cheapest price for the N or P that you are interested in.
- to ensure continuity of soil health practices when staff change.
- to ensure that the soil is not in ill health. We provide a 'soil ill-health report' based on our set of relevant indicators.
Check out the sections below for more details!
Learn MoreSoil Physical Condition
Taking a high level view, each component of soil health (physical, chemical, and biological condition) affects the others. Soil physical condition is the primary factor.
Soil structure affects plant growth by influencing root distribution and the ability to take up water and nutrients. Soil structure facilitates oxygen and water infiltration and can improve water storage. Increased water transfer through soil can reduce fertilizer retention in the soil matrix and fertilizer use efficiency in plants. Disturbance of soil structure through compaction or tillage can result in the rapid recycling of nutrients, crusting, and reduced water and air availability to roots.
2005 Bronick CJ and R Lal, Soil structure and management - a review
In short, soil in poor physical condition is going to be less fertile no matter what fertiliser you apply or how much. It will be less productive. This is because soil physical condition affects both the capacity of plant roots to reach out into the soil body, and because without the proper porosity or structure in the soil, the biology will not have the necessary conditions to act in the supportive way it should. In fact, the biology may turn antagonistic to plant growth.
The farm can measure soil compaction and porosity by using a soil penetrometer. If the soil resistance exceeds 300 psi, roots will struggle to get through the soil. The necessary gaseous exchange will be severely restricted. Water will not be able to move through the soil easily.
The solution will not be achieved by cultivation alone. Cultivation should be minimised, to preserve and foster soil health and productivity. Excess cultivation or cultivation under the wrong conditions, damages soil functioning.
Soil bulk density is one of the measures to monitor. Soil aggregate stability is another.
We can assist your progress towards soil healthSoil Chemical Status
It has been conventional to believe that soil fertility is entirely a case for adding fertiliser. Soil sampling is used to guide fertiliser recommendations. That is only one part of the soil processes that lead to soil fertility. The right levels of specific elements are a necessary thing, but they are not all it takes.
Soil structure and workability is affected by a number of factors. The amount of calcium and magnesium in the soil strongly influences soil structure. There is a reason for this: calcium fosters weaker bonds than magnesium does. It leads to soil that is more open. Some researchers theorised in the 1940s that there is an ideal ratio between these two elements, somewhere around seven calcium to one magnesium. Subsequent more detailed research demonstrated that the idea was partially true but no exact ratio applies in all cases. In general the sandier the soil, the lower the ratio can be. As clay becomes a bigger part of the soil texture, it has two important consequences:
- the soil has more capacity to hold on to nutrients and release them over time, and
- the soil becomes stickier as the magnesium proportion rises.
The calcium:magnesium ration must always be above 2:1. There are tables showing recommended ratios for given a given soil texture. They are a useful guide but not a rule.
None the less, ensuring that soil has more than the minimum calcium level to keep pH up is the least expensive way to foster soil fertility. Prefer lime to nitrogen.
We can assist your progress towards soil healthSoil Biological Status
Soil biology plays an essential part in soil fertility and plant resilience to pests. It is critical to building soil organic matter. Despite its importance, limited attention has been paid to it until recently.
Soil organic matter(SOM) is a key attribute of soil and environmental quality because it is an important sink and source of main plant and microbial nutrients. Moreover, SOM exerts an important influence on the physical, chemical and biological properties and functions of soil, because its depletion may reduce aggregate stability, resulting in crust ingand compaction, as well as nutrient supply. Moreover, organic matter increases the soil's nutrient cycling capability and provides a large pool of macro nutrients such as nitrogen, phosphorous and sulfur, which are very important for soil fertility. In addition, SOM has a positive influence on water retention capacity, porosity and cation exchange capacity (CEC)
The life forms that make up soil biology range in size from earthworms to fungi and bacteria. The most fundamental requirements for these life forms to flourish are
- pores in the soil for them to live in and breathe through
- water, but not too much
- leaf litter and the remains of other life forms in the soil, or organic sugars produced by plants and exuded around the roots, as food
Mycorrhiza fungi species grow around and into plant roots. They get the sugars that they need for energy from the plant and in exchange provide the plant with nutrients. It reaches out through a network far bigger than the root system, bringing back nutrients to the plant. It also holds on to nutrients, reducing leaching of nutrients as a result of rain.
Mycorrhiza mobilises soil P, helping to make it
Plans to manage and enhance the soil biome should be well researched, and well-structured.
- growing lots ground cover to yield lots of organic matter on the surface is a two-edged sword. On the one hand it moderates the impacts of weather condtions, such as erosion prompted by high intensity rainfall, and it helps maintain good soil temperature and moisture levels. On the other hand, putting more organic matter on the surface without providing supplementaty nutrients runs the risk of overstimulating soil biology and reducing softer soil organic matter. It could potentially lead to less sequestered carbon, and less soil organic matter, worsening things. Specific nutrients in a certain ratio really held build soil organic matter.
- Cultivation damages the soil biome. It may incorporate leaf litter but it exposes the soil biology to the surface conditions - drying winds and damaging UV. It breaks up the fungal networks.
- adding lots of leaf litter and plant trash requires careful assessment of how much supplementary nutrient is required to support the soil microbiome to do its work.
I have a report with these indicators??
Some measures of soil, especially of soil biology, are less helpful than they seem at first:
- counts of fungi and bacteria. The populations of these go up and down in response to food supply, temperature, and soil moisture. There is an annual cycle in the quantity, affected by conditions at your site. You have more in July this year, than in July last year? Without detailed information, and great expense, it's not useful to put a lot of value on this change. Counts are not a durable measure; they are too quick to respond to very temporary changes both ways in your soil.
- counts of species of fungi, bacteria etc. This could be described as a biodiversity measure but that is just very general information, with little potential to guide farm managers. In addition, some species can switch from beneficial to harmful under certain conditions. Its better to use soil texture/bulk density and soil aggregate stability, plus pH as an indicator. If the soil conditions are good for soil biology, there will be a higher likelihood of balanced biology and at levels that are appropriate for the conditions.
- I added some soil biology. How long will it last? How long until I need to add more? There is no certainty that adding any specific variety of soil biology will have a sustained benefit. Keep in mind the need for optimal conditions, which provide the best chance for long-term benefit. Your provider may be able to show you research results on persistence of the microbe family in the soil. One story about one farm is interesting, but not much help. Be sure to understand what the additional biology is intended to achive for the farm.
- The objective is to ensure that beneficial biology establishes itself in your paddock, and contributes to soil fertility, plant health, and soil resilience. Its not necessary to continuously "plant soil organisms" in your paddock if your soils conditions are sound.
Soil biology is an essential part of soil fertility and health. When you provide it good conditions, it gives a great return on investment.
Learn MoreStoring Data and Viewing it on Maps
Soil sample data provides better guidance when there is a trend line. Too much importance can be placed on the data in one soil sample report. It is best viewed as an indicator. Far better guidance comes from trends over time. That means storing the data and having ways of viewing it.
We can store your data in an industrial-strength SQL database. The SQL part means that the data can be easily analysed across time, across paddocks, and correlations tested and re-tested. From that your agronomist can give advice using a more complete picture.
It's a far better solution than spreadsheets. They get misplaced. Carrying out an analysis across multiple sheets is time consuming. You wouldn't run your business records on spreadsheets. Give the engine of your productivity better support by using our software.
Our software enables the user to easily see trends, to check values, download the data for that analysis and more. Its the solution if you use a soil-specific or precision agriculture approach.
Ask us about data storage and visualisation