Visual Soil Assessment (VSA) – A quick, simple and effective method to assess soil quality and plant performance
VSA is a quick and simple method to relate the performance of the plant to the condition of the soil and farm management practices. To the untrained eye, the difference in the quality of the soil on the left and right hand side of the hand is obvious. To the trained eye, the visual messages provide an immediate and effective assessment of the condition of the soil and the performance of the pasture or crop. Quite literally, the information appears at the speed of light. The trick is to train the untrained eye – that is partly the roll of the VSA. The VSA is a repackaging of the complexity of soil science and plant agronomy into a format that is more readily understood and applied beyond the farm gate. The VSA can be used by anyone, anywhere. Today, the VSA is widely used as the method of choice to semi-quantitatively assess soil quality and plant performance
Environmental and economic performance and sustainability of pastoral and cropping farms can be greatly influenced by soil quality. The Visual Soil Assessment method (VSA) described in the Field Guide provides land managers and environmental authorities with a simple tool to assess and monitor soil quality and pasture and crop performance. Visual soil properties are diagnostic of soil quality, and provide an effective and immediate way to assess soil quality quickly and cheaply in the field. The name “Visual Soil Assessment” is a bit of a misnomer because it is equally about the plant.
Assessing soil condition and pasture performance using the VSA
Assessing soil condition and crop performance using the VSA
Field Guides have been written for pastoral grazing, maize, wheat, annual crops, vineyards, olive orchards and orchards
Many soil physical, biological and chemical properties show up as visual characteristics. Changes in land use or land management
can markedly alter these. Research in New Zealand and overseas shows that many of the visual indicators are closely related to key quantitative (measurement-based) indicators of soil condition (see Further information – The science underpinning the VSA).
The VSA enables people to talk a common language to improve communication and information transfer to the farm gate and beyond
VSA provides an effective tool that allows farmers, consultants, environmental authorities and scientists to talk the same language
The strength of the VSA lies in its simplicity and ease of use, the provision of an immediate answer in the field, its relevance to farmers and environmental authorities, and the fact that it is essentially instrument free
“Any intelligent fool can make things bigger and more complex... It takes a lot of courage to move in the opposite direction.” – Albert Einstein
Graham Shepherd is the author of the Visual Soil Assessment (VSA) method and copies can be purchased directly from him or from a New Zealand Regional Council (Contact)
Learn more about the VSA method
Introduction to the VSA
Why the VSA can be used by anyone
Preface to the VSA
Why the VSA is an excellent educational tool
Field Guides available on the VSA
Learn more about the VSA Environmental Scorecards
Additional VSA information & links
How VSA works
VSA is based on the visual scoring of key bio-physical indicators of soil quality, and incorporated on an easy to use scorecard. The soil is scored by comparing the key indicators with three diagnostic photographs showing an example of good, moderate and poor condition. The soil indicators are supported by plant 'performance' indicators that link soil condition to pasture/crop production. The plant performance scorecard allows the plant to have its say as to what it thinks about the soil it is growing in. Plant scores will normally follow the soil score but if the two differ, the reason is usually because of the weather or farm management practices. Placing the spotlight on farm management is what the VSA is all about. The indicators are underpinned by extensive research and are linked to economic performance (see Further information). Soil indicators are generic and have the major advantage of being largely independent of soil type. That is, while soil type can influence the VSA score, the interpretation of what you see is largely independent of soil type.
For example, the interpretation from visual evidence that the soil on the right is poorly aerated and severely degraded holds regardless of the climatic zone, soil type, water content, land use, farm management, fertilizer use, analytical methods used to assess the soil, and location. The interpretation of severe degradation holds regardless of where the soil occurs in the world. With the exception of raw peat soils, this fundamental principle enables the VSA to be used almost anywhere.
In addition to New Zealand, the VSA has been applied equally well in 15 countries – Australia, France, Belgium, the Netherlands, Germany, Denmark, Norway, Sweden, Italy, England, Scotland, Canada, USA, Chile and South Africa.
Click to see how soil structure is rated
Click to see how earthworms are rated
Click to see how soil smell is rated
Click to see how the potential rooting depth is rated
Click to see how pasture quality is rated
Click to see how clover nodules are rated
Click to see how pasture colour & growth relative to urine patches are rated
Click here to see how root length & root density are rated
Potential rooting depth
Pasture colour and growth relative to urine patches
Root length and root density
Ease of Use
The VSA can be used by anyone and derive a similar score to an ‘expert’
Field trials at 25 sites throughout New Zealand indicated that laypeople with little or no background in soil science were able to assess the condition of their soil and plant performance with a similar accuracy to a soil scientist using the VSA method. The VSA scores at each site, as ranked by an expert, were often very close to, and usually fell within the standard deviation of the mean of the layperson’s assessment (Figs 1 & 2). The results also indicated strong agreement among farmers in assessing whether soils had a good, moderate or poor soil-quality ranking. This demonstrates that anyone, regardless of their background, can accurately assess the condition of the soil and plant.
Figure 1. VSA of the soil under pastoral grazing on flat to rolling country
-A comparison of soil ranking scores between 'expert' and lay people
Figure 2. VSA of the condition of 12 soils under cropping
-A comparison of soil ranking scores between 'expert' and lay people
VSA is an excellent educational tool
The VSA Field Guides contains all the information necessary to carry out VSA on your land. The Field Guide is self-explanatory and its use does not require special training or technical skills. The Field Guide contains a wealth of information about soil quality and plant agronomy and their fundamental importance to sustainable resource and environmental management. The information is expressed in a simple and concise way, and provides a useful educational and vocational training tool for those unfamiliar with soil science and agronomy. In particular, VSA can develop a greater awareness of the importance of soil physical and biological properties (such as soil aeration, earthworms and microbes) in governing soil condition and on-farm production. Accordingly, the VSA also provides an effective marketing tool for farm advisors.
Farming, and in particular dairying, is often portrayed as an industry with a high environmental footprint due, in part, to high emissions of nutrients, greenhouse gases, and the loss of soil carbon. While this can be the case, it is often the result of poor advice given to farmers by their advisers and fertiliser companies. The VSA provides simple to use scorecards that provide a guide as to the potential of a field or farm (under both pasture and cropping) to emit nutrients and greenhouse gases, and to be carbon positive (gaining carbon), carbon neutral, or carbon negative (losing carbon). Most of the information required is simply transferred from the Soil and Plant Scorecards of the VSA to the Environmental Scorecards.
The environmental footprint of many of our farming practices tend on be on the high side but it needn’t be this way. The Environmental Scorecards provide an assessment of the important drivers that enable the draw-down of the C and N in the atmosphere and how to minimise their loss into the environment.
The Nutrient Loss Scorecard provides a guide as to whether a site is likely to have a low, moderate or high potential for nutrient loss into the groundwater and waterways.
A farm near to the lake had a high Nutrient Loss Index and therefore a low potential for nutrient loss into the lake, despite having a coarse soil texture and rapid permeability. This was in accordance with the very low levels of nutrients in water samples taken from a stream entering the lake
The Carbon Sequestration Scorecard provides a guide as to whether a site is likely to be potentially carbon positive, neutral or negative.
This site has a medium Soil Carbon Index and therefore is carbon neutral, i.e. not gaining or losing carbon. The fact that the carbon is in steady state is supported by the fact that total C has remained at 5.2% over the last 30 years under the prevailing soil conditions and farm management practices
The Greenhouse Gas Emission Scorecard provides a guide as to whether a site is likely to have a low, moderate or high potential to emit greenhouse gases.
Because of the management practices applied, this farm has a high Greenhouse Gas Emission Index and therefore a high potential to emit GHGs into the atmosphere
Introduction to the VSA
Environmental and economic performance and sustainability of pastoral and cropping farms can be greatly influenced by soil quality. The Visual Soil Assessment method (VSA) described in the Field Guide provides land managers and environmental authorities with a simple tool to assess and monitor soil quality and pasture and crop performance. Visual soil properties are diagnostic of soil quality, and provide an effective and immediate way to assess soil quality quickly and cheaply in the field.
VSA brings alive the study of the soil and plant sciences by presenting graphic images of soil, pasture, and crops in good, moderate and poor condition, and the effects of soil condition on plant performance.
VSA is based on the visual scoring of key bio-physical indicators of soil quality, and incorporated on an easy-to-use scorecard. The soil indicators are supported by plant performance indicators that link soil condition to the performance of the pasture/crop and farm management practices. In addition to assessing the condition of the soil and the performance of the plant, the VSA includes three environmental scorecards that help to assess the environmental footprint of a farm and its farming practices. The first scorecard addresses the potential for nutrient loss into the groundwater and waterways and whether a farm is likely to be a low, moderate or high emitter of nutrients. The second scorecard addresses carbon sequestration and whether a farm (or a field) is likely to be C positive, neutral or negative, and therefore in a position to claim C credits or pay C taxes. The third scorecard assesses the potential of a farm to be a low, moderate or high emitter of greenhouse gases.
The soil indicators are underpinned by extensive research and are linked to economic and environmental performance and sustainability. Soil indicators used are generic, and their interpretation has the advantage of being largely independent of soil type. This allows the VSA to be applied anywhere.
The VSA Field Guide is self-explanatory, and its use does not require special training or technical skills. While the Field Guides contains a wealth of information about soil quality and plant performance, and their fundamental importance to sustainable resource and environmental management, the information is expressed in a simple and concise way, and provides a useful educational tool. The VSA method also provides a framework that allows laypeople with little or no understanding of soil science or agronomy to assess the condition of their underground economy and plant performance almost as successfully as an expert.
For farmers, the VSA provides a practical farming guide, linking soil, plant, animal health, and environmental performance to farm management practices. The books also provide agricultural scientists, farm advisors, consultants, and regulatory authorities with a useful reference document on soil-plant-animal interrelationships and environmental management.
Confucius said “the best fertiliser for any soil is the footsteps of the farmer”. Spending time observing your soil, pasture, crop, weeds, insects, disease and the farm animals is part of the art of smart farming. The medical profession make their initial diagnosis of patients based on visual symptoms; we can apply the same principle to the farm.
Seeing is believing. Pick up a spade, and have a go!
Soil science is a complex subject incorporating soil physical, chemical and biological components. It is, however, a subject that can be repackaged into a format that is more easily understood by the layperson. This is achieved by simply showing a good, moderate and poor photographic example of key diagnostic indicators of soil quality and plant performance.
The environmental spotlight is firmly on agriculture and its effects on soil quality, nutrient loss into the groundwater and waterways, carbon sequestration, greenhouse gas emissions and climate change. While agriculture per se is seen to be a major contributor to soil and environmental degradation, many of the undesirable effects are more often a function of* specific farm management practices and the poor advice and mixed messages given to farmers.
While indicators of farm productivity and environmental performance have been developed across the globe, they are at a level that is not well understood by land users and farm advisors. Consequently, their ‘buy-in’ has been poor. The indicators are by and large based on measurements and while analytical measurements are essential, they are costly, limiting their spatial application and the number of sites that can be monitored. Measurement-based indicators also require technical expertise, experience and care in the interpretation of results. Most importantly, however, farmers/land managers are not involved in the assessment and monitoring process, with the result that ‘ownership’ and subsequent implementation of the information are generally poor. There is therefore a need for simple, quick and easily understood methods to assess and monitor the effect of agriculture and farm management practices on soil and plant health, farm productivity, nutrient loss into the groundwater and waterways, carbon sequestration, and GHG emissions. To meet this need, the Visual Soil Assessment (VSA) method was developed to provide a simple tool to assess and monitor soil quality and plant performance quickly, cheaply and effectively.
The VSA is based on fundamental principles of soil and plant science and underpinned by extensive laboratory and field measurements. Some of the information given in the books will, however, challenge commonly held paradigms, and will, it is hoped, encourage debate and a re-evaluation of some of our commonly applied management practices. The VSA contains much useful and practical information on the physical, chemical and biological condition of the soil, and its effect on pasture/crop performance, animal health, farm profitability, and the environmental performance of the farm.
Each soil and plant indicator is considered as a separate stand-alone entity. For this reason, a number of soil and plant properties common to two or more indicators are repeated in the text. For example, the fate of nitrogen and sulphur under anaerobic and waterlogged condition is relevant to, and therefore repeated under, Soil porosity, Soil mottles, Soil colour and Surface ponding.
To the untrained eye, visual messages provide an immediate and effective assessment of the condition of the soil and the performance of the pasture and crop. To the trained eye, visual images provide extremely insightful semi-quantitative information regarding the condition of the soil and pasture/crop performance. The trick is to train the untrained eye. This is the ultimate purpose of the VSA, which will, in turn improve farm management practices.
The absence of soil structure and visible pores in the topsoil opposite, along with the pale soil colour and many large grey mottles, indicates the soil is extremely degraded and poorly aerated. The interpretation of poor aeration and severe degradation holds regardless of soil type, location, water content, land use, farm management practices, fertiliser use, and analytical methods. While we can spend a lot of time and expense measuring the air permeability, oxygen diffusion rate, redox potential, saturated and unsaturated hydraulic conductivity, pore-size distribution, and dry bulk density of the soil, the end conclusion is still the same − the soil is severely degraded. Put simply, “Soil physics is the quantification of the obvious” (Prof. Ian White). “Man does not have to measure everything before him to prove that everything has length” (anon).
The VSA is a ‘road map’ to better farm and environmental management.
VSA Field Guides are available for eight different land uses
Pastoral grazing & cropping
Pastoral grazing on hill country
VISUAL SOIL ASSESSMENT
Pastoral grazing on hill country
Cloy, J.M., Ball, B.C., Shepherd, T.G., 2015. Evaluating land quality for carbon storage, greenhouse gas emissions and nutrient leaching, in: Ball, B.C., Munkholm, L. R. (Eds), Visual Soil Evaluation: Realising Potential Crop Production with Minimum Environmental Impact. CABI, Wallingford, UK, pp. 103-121.
Ball, B.C., Guimarães, R.M.L., Cloy, J.M., Hargreaves, P., Shepherd, T.G., McKenzie, B.M. 2016. Visual soil evaluation: a summary of some applications and potential developments for agriculture. Visual Soil Evaluation ‒ ISTRO Special Issue
Shepherd, T.G. 2003. Assessing soil quality using Visual Soil Assessment. In: Currie, L.D. and Hanly, J.A. (ed.) Tools for nutrient and pollutant management: Applications to agriculture and environmental quality. Occasional Report No. 17. Fertilizer and Lime Research Centre, Massey University, Palmerston North. pp. 153−166.
Shepherd, T.G. and Park, S.C. 2003: Visual Soil Assessment: A Management Tool For Dairy Farmers. In: Brookes, I.M. ed. Proceedings of the 1st Dairy3 Conference. Continuing Massey University Dairyfarming Annual (Volume 55) Dexcel’s Ruakura Dairyfarmers’ Conference, April 7–9, 2003, Rotorua. pp 111–123.
Shepherd, T.G. 2017. Visual Soil Assessment – a simple method to assess soil quality and plant performance. Visual Soil Evaluation ‒ ISTRO. Submitted.
VSA - A management tool for dairy farmers
Science underpinning the VSA
Evaluating land quality