Agricultural soils are tested to measure the soil quality and nutrient levels for monitoring fertiliser programmes and to assist with identifying nutrient deficiency or toxicity.
Why test soil?
Soil testing takes the guess work out of nutrient management and allows cost effective nutrient management. This is particularly important because most New Zealand pastoral soils are deficient in phosphorus, sulphur and to a lesser extent potassium and some trace elements can also be deficient. However, historical soil use will impact nutrient change with soils under intensive cultivation often having abnormal levels of some nutrients due to previous management practices and fertiliser programmes.
The value soil testing delivers
- Measure whether soil nutrient levels are high enough to sustain the desired level of plant growth.
- Indicate the existence of any deficiency, excess or imbalance of major nutrients.
- Provide a scientific basis on which to assess fertiliser and lime requirements of crops, pastures and turf.
- The Organic Soil Profile measures the soil quality, testing the soil organic matter, available nitrogen, total nitrogen and carbon:nitrogen ratio.
- The Hot Water Extractable Carbon test is recommended as a good indicator of microbial activity in the soil, as it is highly correlated with microbial biomass carbon and aggregate stability.
- A useful set of tests for assessing soil health would be Basic Soil, Sulphate-S, Anion Storage Capacity, Organic Soil Profile and Hot Water Extractable Carbon. Testing for heavy metal contaminants such as total cadmium and total copper may be important in some instances.
Soil tests measure only a fraction of the total pool of nutrients available to plants (immediate and long term) so it is important that standard New Zealand methods of sampling and soil analysis are used so the results are meaningful and can be related to plant growth under New Zealand conditions.
Choosing the right test option for your situation and interpreting the test data is important and you are best to contact your local fertiliser representative, rural merchant supplies store or consultant for advice. However, for Pastoral Soils: a Basic Soil Profile and sulphate-S test are recommended. Where reactive phosphate rock (RPR) fertiliser has been used, the resin phosphorus (RP) test should be added. For Arable Crops like Maize:a Basic Soil Profile, sulphate-S and available-N are recommended. Other Soil Tests include: organic sulphur, total sulphur, the organic soil profile for soil quality, aluminium, boron, EDTA trace metals, Mehlich 3 trace metals and more. For a more complete listing of our soil testing options and the associated test details, simply download our easy-to-read technical note specifically designed for soil testing.
Growing high-value horticultural crops comes with unique soil fertility management challenges. Understanding the soil nutrient profile can not only improve the yield of your crop but also improve storage characteristics and plant vigour. Hill Laboratories recommends that you get advice from your local fertiliser representatives, rural merchant supplies store or consultant to ensure that not only do you choose the right test for your situation but that you also maximise the value of the data generated. However, for Horticultural soils a Basic Soil Profile, sulphate-S and available nitrogen (AN) test are usually recommended. For Avocado Orchards a Basic Soil and Mehlich 3 trace nutrients test is recommended. For Kiwifruit Orchards a Basic Soil Profile and available nitrogen (AN) test is recommended. For Vegetables a Basic Soil Profile, sulphate-S and available nitrogen test is usually recommended. Other soil tests include organic sulphur, aluminium, boron, EDTA trace nutrients and more. Where reactive phosphate rock (RPR) fertilisers have been used, the Resin P (RP) test is recommended to measure plant available phosphorus. The Organic Soil Profile measures the soil quality and includes total nitrogen, available nitrogen, organic matter (total carbon) and the soil total carbon:total nitrogen (C:N) ratio. For a more complete listing of our soil testing options and the associated test details, simply download our easy-to-read technical note specifically designed for soil testing.
All Paddock Testing (APT) is a service provided exclusively through Hill Laboratories. A farmer using APT gets soil (in sample form) from the majority of paddocks tested, instead of the standard practice of testing only a few. As a result with the more comprehensive All Paddock Testing report you can optimise your fertiliser application by paddock (often for decreased cost). If you are interested in ordering an All Paddock Test then simply contact our friendly Client Service Manager team and they will help walk you through the process.
Whether you are a small block holder or large corporate farm, the value of understanding your plant health can be invaluable information when wanting to ensure that your animals are receiving a balanced dietary intake. As an independent testing laboratory we recommend that you enlist the support of your local merchant supplies store or other consultant to help guide you through a suitable testing plan and associated fertiliser recommendation plan for your lifestyle block.