• Problems and Solutions
  • Assessing Soil Condition
  • Managing Soil Biology & Carbon
  • Managing Soil Structure
  • Managing Nutrient Imbalance
  • Managing Soil Acidity
  • Pasture & Cropping Soil Health

• Why is it important to me as a farmer?
• Background information about fertilisers

• What is the best practice?
• How can you achieve this?

• Assess current soil conditions and identify key constraints to production before developing your nutrient management plan
• Farmers make soil and nutrient management decisions with imperfect knowledge. Decisions are based on the best available science and their own and other people�s experience
• The general approach is to take account of the main nutrients entering and leaving the farm and allowing for the influence of soil factors when working out what fertilisers are required
• The key to cost-effective fertiliser management is to make sure that the fertilisers you are applying match the nutrient requirements of your farming system
• Nutrient planning uses the concepts of capital and maintenance to determine the nutrient requirement on different areas of the farm

• Target levels of soil fertility should be set based on your production system
• Monitoring soil fertility with soil tests is a vital step in the nutrient planning process
• Approximately 10% of agricultural land managers in the Corangamite region regularly conduct soil tests to determine the nutrient input requirements for the soils
• Many land managers could potentially be applying insufficient or excessive amounts and/or the incorrect type of fertilisers to their soils
• Continued levels of agricultural productivity depend on good soil health, focusing on soil chemical, physical and biological condition
• Increasing soil organic carbon levels through the modification of management practices and complementing inorganic fertilisers with organic fertilisers will contribute to a more sustainable production system in the longer-term

• Maintaining a cost-effective balance of available plant nutrients is an important component of farm management. Sustainable land use requires the replacement of extracted nutrients. Nutrients can also be lost from the soil through leaching into the deeper soil profile, in run-off or through soil movement
• In some cases, nutrient extraction or deficiencies may be over-corrected through excessive fertiliser or trace element application leading to unnecessary expense for the farmer as well as unintended off-site impacts to the environment

• The key to cost-effective fertiliser management is to make sure that the fertilisers you are putting onto the paddock match the nutrient requirements of your farm and enterprise. If this is done, only the nutrients that are required for plant growth are applied
• Too often money is wasted on fertilisers that contain nutrients that are already at high levels in the soil. The rewards are there in either cost saving or improved productivity for those who take the time to work out their actual farm fertiliser requirements before they place the fertiliser order

• A fertiliser or soil conditioner is any material added to the soil or applied to a plant to improve the supply of nutrients and promote plant growth. This definition includes both inorganic and organic fertilisers and also soil conditioners, such as lime and gypsum, which may promote plant growth by increasing the availability of nutrients that are already in the soil or by changing the soil�s physical structure
• Most soils contain reserves of nutrients that would otherwise have to be applied in fertilisers
• Most soils throughout the Corangamite region are naturally deficient of the level of nutrients required for agricultural production
• In addition, the decline in soil carbon has resulted in a further decline in the natural fertility of the soils
• As a result dairy, cropping and broadacre grazing managers apply fertilisers to improve productivity
• Nutrients are replaced as they are removed from the soil by pastures and crops. The greatest susceptibility to soil nutrient decline is found along the ranges of the Otways

Figure 1 - Areas of moderate, high and very high soil nutrient decline susceptibility in the Corangamite region. � Source: CCMA Soil Health Strategy

• The nutrient requirements of a farm depend on many factors, including:
  • Soil type
  • Current soil nutrient status (affected by soil parent material, fertiliser history, climate, stage of farm development)
  • The target soil nutrient levels you have set
  • Your farm production system (class and number of stock to be fed, amount of milk to be produced, amount of fodder conservation or cropping, etc.)
  • Rainfall

• These factors must be taken into account when making fertiliser management decisions on your farm. As these factors are variable, nutrient requirements will vary from farm to farm, paddock to paddock and year to year on fertilisers that contain nutrients that are already at high levels in the soil. The rewards are there in either cost saving or improved productivity for those who take the time to work out their actual farm fertiliser requirements before they place the fertiliser order
• We often view fertiliser applications and the �build up� in soil fertility in terms of capital and maintenance applications. Simply put:
  • Maintenance applications are applied to keep the soil nutrient status at the same level while supporting pasture and animal production
  • Capital applications increase soil fertility to a target level. It is important to remember that capital applications are the nutrients that are applied in excess of the maintenance requirement for any given production system

• The concept of capital and maintenance nutrient applications is used to estimate your farm fertiliser requirements. If a maintenance application is spread annually, assuming stocking rate and other parameters do not alter greatly, soil fertility will remain at a similar level over time. If a capital application is made, soil fertility will increase over time

Table 1 - Fertiliser characteristics � manufactured and organic/natural. � Adapted from the Soil Knowledge Bank � Department of Agriculture, Fisheries and Forestry

1. Use of soil test and nutrient planning tools to develop a nutrient budget
2. Maximising root abundance and rooting depth (cropping)
3. Optimise fertiliser application
4. Encourage a healthy soil ecosystem

• �Nutrient budgets�, together with soil tests, are recognised as prime indicators for improved nutrient management
• Soil tests should be used to identify whether topsoil nutrient levels are at, above or below the target ranges
• It is not practical to soil test every paddock on the farm but it is reasonable to expect that different parts of the farm will have quite differing soil test results at any one time. We need to think of the farm as a grouping of soil management areas, where a representative soil sample would be taken from each area
• On areas where nutrients are below the target levels, capital applications of nutrients are required
• Once target levels are reached, maintenance fertiliser rates should be applied
• The aim of nutrient budgeting is to balance inputs and outputs, so that levels are maintained at the optimum for production
• Maintenance nutrient requirements will be different on different areas of the farm due to variations in soil type and fertility

• Differences in other imports and exports, such as differences in production levels or where brought-in fodder is fed out, will also result in a variation in maintenance requirement between paddocks across the farm
• Nutrient budgeting on a whole-farm basis gives only the big picture of what is happening at a farm gate level. It is very useful for indicating whether some nutrients are being overapplied or underapplied. For example, is more P or K being brought into the farm than is required for production? However, the farmer must ultimately be able to manage the nutrient balance down to individual paddocks or at least areas
• Farmers need to understand how to calculate the rates of fertiliser or individual nutrients to be applied and how to calculate the cost of various fertiliser options. Although this can be carried out by the fertiliser company, farmers who can do their own calculations can check the company�s recommendations or can make their own recommendations

• NutriMatch (for dairy farms) � See section 11.10 - Nutrient Planning - Department of Primary Industries, Victoria

Table 2 - Summary of the fertiliser planning process. Nutrient Planning - Department of Environment and Primary Industries, Victoria

• One way to optimise plant uptake of nutrient reserves in soil is to maximise root abundance and rooting depth. This means that crop roots can explore more soil and ensures they can follow nutrients and water down the profile
• This is especially important for leachable nutrients such as nitrogen and sulphur and nutrients with significant reserves in the subsoil
• Root abundance and rooting depth can be increased by maintaining optimum soil pH and minimising soil compaction and plant root diseases

• The rule to remember with soluble fertilisers is to apply small amounts regularly, rather than a large amount occasionally. Plants can use only a fraction of any large amount applied, so most will be leached away or react with the soil (P, Cu, Zn, etc). This is not only a waste of fertiliser and money, but it may also pollute ground water and surface waters and may contribute to the development of algal blooms
• Organic fertilisers can be applied in larger amounts less often, as they release nutrients more slowly, but you still need to be careful how you use them

• Non-mobile nutrients such as P stay close to where they are applied, and are moved only by cultivation and seeding. Fertiliser placement should be used to ensure optimum plant uptake during growth and development, and P should be positioned where it is likely to be in moist soil for longer
• Fertilisers should NOT be applied to:
  • bare soil (except when sowing)
  • waterlogged soils
  • drainage lines, riparian buffer areas and waterways
  • stock camps
  • paddocks or drainage depressions when rainfall that could result in runoff is expected, (e.g. when summer storms are anticipated in the next few days)
  • some native grass species

• Increase soil organic carbon
  • For example you could use manure, plant debris and composts. Some of these recycled organics also contain significant amounts of nutrients and can act as organic fertilisers and soil conditioners

• Use soil friendly agronomic practices
  • When sowing use direct drilling
  • Reduce soil compaction

• Increase soil biodiversity

• What are the optimum nutrient targets for pastures?
• How can I assess the health of my soil?
• How do I sample soil to ensure my soil chemical test results are reliable?
• Who are the accredited labs for traditional soil chemical tests?
• What natural soil conditioners work?

• What organic fertilisers work?
• How do dung beetles improve my soils?
• How should we manage our soils to increase soil biology?
• How should we manage our soils to increase soil carbon?

• Introducing Fertilisers - Department of Environment and Primary Industries, Victoria


• Fertilisers - Department of Environment and Primary Industries, Victoria


• What Nutrients do Plants Require? - Department of Environment and Primary Industries, Victoria


• How to Calculate Fertiliser Rates and Costs - (Dairy) - Department of Environment and Primary Industries, Victoria


• Nutrient Planning - Department of Environment and Primary Industries, Victoria

• Optimising Soil Nutrition - factsheet - Soilquality.org.au


• Build and maintain soil fertility - Module 7.1 (Grazing) - Making More from Sheep, MLA


• Managing Soil Fertility - Chapter 3. Sustainable land management practices for graziers, Department of Primary Industries, NSW


• How do I manage soil fertility? - Soil Health Knowledge Bank � Department of Agriculture, Fisheries and Forestry

• Introducing Fertilisers. Department of Primary Industries, Victoria.
• How do I manage soil fertility? - Soil Health Knowledge Bank � Department of Agriculture, Fisheries and Forestry.
• Clarkson T, Department of Primary Industries on behalf of the Corangamite Catchment Management Authority (2007) Corangamite Soil Health Strategy. Corangamite Catchment Management Authority, Colac, Victoria.

• Sustainable land management practices for graziers. 3 Managing Soil Fertility, Department of Primary Industries, NSW.
• Optimising Soil Nutrition. factsheet - Soilquality.org.au.
• Greenwood,K., Rees,D., Davey,M. and Brown,A.(2008) - Final report to Dairy Australia on DAV 12222, HDLN Soil and Water Dairy Action Program - Soil Assessment Component. Department of Primary Industries, Victoria

Page Updated: September 2013
Produced by AS Miner Geotechnical