| Activity |
Best management practices |
| Choice of fertiliser |
- Soluble phosphate fertiliser is used where:
Fact Sheets 6, 9, 13
- rapid plant response is required
- soil P levels are required to be increased rapidly
- plants are actively growing
- there is a low risk of runoff
- Slow release phosphate fertiliser is used when:
Fact Sheets 6, 9, 13
- there is a high risk of runoff and/or
- a rapid plant response is not required and/or
- soil P levels are adequate and/or
- soil pH is less than 6.0 and annual rainfall is greater than 800mm
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| Rate of fertiliser application |
- Nutrient application rates are determined using some or all of the following factors:
Fact Sheets 5, 6, 7
- soil and plant tissue analysis
- nutrient budgets (including any effluent and/or feed imported to the block)
- crop type, yield/quality/stocking rate targets
- the need for capital or maintenance applications
- previous crop and fertiliser history
- soil moisture conditions and expected future weather patterns
- local knowledge
- The amount of phosphate applied per application is limited:
Fact Sheets 6, 8, 13
- when high rainfall is anticipated or irrigation is planned
- on very sandy soils, particularly for soluble phosphate fertilisers
- when slope is greater than 25ยบ, and/or pasture is less than 25mm high (approx. 1000 kg DM/ha)
- during winter
- Soluble phosphate fertiliser must be applied in split dressings if the single application rate would exceed 100 kg P/ha.
Fact Sheets 6, 13
- Phosphate is applied in proportion to other nutrients, according to plant requirements. (Adding excessive P when other elements limit crop or pasture growth is inefficient and could lead to P losses.)
Fact Sheets 5, 6 |
| Application technique |
- Application equipment used is suitable for the conditions and fertiliser type.
Fact Sheets 3, 4
- Only Spreadmark accredited spreading companies (experienced operators and calibrated equipment) should be used
Fact Sheet 4
- GPS and GIS technology is used for precise application and for a digital record of fertiliser application locations.
Fact Sheet 3
- Non-target application of fertiliser is avoided by:
Fact Sheet 4
- using fertiliser with larger particle sizes and few or no fine particles (aerial application)
- application techniques that direct or specifically place the fertiliser appropriately
- application in bands when sowing crops or pasture seed
- applying fertiliser only when any wind is blowing away from sensitive areas
- apply fertiliser only under agreed conditions (e.g. wind speed of less than 15 km/h)
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| Frequency of application |
- Nutrient availability is matched to plant demand, particularly for soluble P products and liquids.
Fact Sheets 5, 6
- Split applications are used where the single application rate would exceed 100 kg P/ha for soluble P or liquid fertiliser.
Fact Sheet 6 |
| Timing of application |
- Pasture is at least 25mm high (approx. 1000 kg DM/ha) before P is applied.
- Phosphate fertiliser is not applied after a dry (drought) period until sufficient regrowth has occurred after rain.
Fact Sheet 5
- P fertiliser is not applied when the soil is saturated
Fact Sheets 5, 6 |
| Fertiliser use and management measures |
- P fertiliser is not applied to severely compacted soils. Soil aeration techniques are used on such soils before fertiliser application.
- To avoid fluoride toxicity to stock, pastures top-dressed with P fertiliser are not grazed for 21 days or until 25mm of rain has fallen.
Fact Sheet 12
- Only phosphate fertilisers which comply with the industry limit of 280mg of cadmium per kg of P are used.
Fact Sheet 12
- Vegetated riparian buffer strips of sufficient width (10m - adjust for slope) to filter any run-off are maintained adjacent to all waterways.
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