Cultivation and soil structure
Our intent: To minimise direct and indirect losses of sediment and nutrients to water without being prescriptive about cultivation or soil management techniques used, as there are many agronomic considerations to take into account on a paddock-by-paddock and season-by-season basis.
GMP: Manage farming operations to minimise direct and indirect losses of sediment and nutrients to water, and maintain or enhance soil structure, where agronomically appropriate.
- Distance from surface waterways, effectiveness of buffers
- Slope of land (degree and length) in relation to waterway
- Soil type and texture, quality (e.g. pugging, or compaction susceptibility)
- Climatic and weather conditions to determine timing of cultivation
- Cultivation methods (pre-, during, and post-cultivation; contour, no- or low-tillage)
- Measures to prevent sediment and nutrients entering waterways (e.g. sediment traps or interception drains, headlands or diversion bunds, grazing techniques)
- Measures to prevent soil loss through erosion, overland flow and wind blow (e.g. space planted trees, windbreaks, cover crops)
- Measures to prevent or remedy soil damage
- Previous use of land, and future use of land
- Using sub-soiling or ripping to remedy compaction of soils
Leave grassed areas around rocks, gullies and riparian margins. If spraying out pasture, first identify areas that won’t be worked or re-sown e.g. gullies, runners, riparian margins and rocky areas.
In heavy soils, cultivate soil when conditions are dry enough to reduce compaction and pugging and improve drainage and soil structure.
Our intent: Reduce risk of erosion, overland flow and leaching associated with exposed soil.
GMP: Manage periods of exposed soil between crops/pasture to reduce risk of erosion, overland flow and leaching.
- Consider soil conditions and crop rotation.
- Areas that are harvested, grazed or stock damaged (resulting in bare soil) are re-sown as soon as practical to minimise periods of exposed soil.
- Rest and re-sow erosion damaged areas.
- Use cover crops (green feed, oats, mustard, other biological activates) to reduce losses and nutrient use; this also increases organic matter.
- When developing paddocks, retain native vegetation such as tussock and shrub habitat in gullies, steep and higher country as this will regulate run off of water, help retain water quality, reduce soil movement and provide filter areas prior to water entering streams (a significant co-benefit is that it also provides cover for newborn stock).
- Outdoor pigs: Maintain groundcover in accordance with the following.
- For dedicated outdoor units or those in a pastoral rotation the minimum ground cover is:
- For dry sows: at least 40% cover on 75% of the land (less than 40% cover permissible on 25% of the land);
- Each paddock to have on average more than 10% cover;
- For lactating sows: at least 70% cover.
- For outdoor units as part of an arable operation the minimum ground cover is:
- For dry sows: 25% cover (100-0% over 2 years);
- For lactating sows: at least 70%;
- Reduce fallow during and immediately after the pig phase of the rotation e.g. by planting a catch crop.
GMP: Retire all Land Use Capability Class 8 and either retire, or actively manage, all Class 7e to ensure intensive soil conservation measures and practices are in place.
Sediment, phosphorus and faecal bacteria
Our intent: Minimise transport of sediment, phosphorous and faecal bacteria to water bodies.
GMP: Identify risk of overland flow of sediment and faecal bacteria on the property and implement measures to minimise transport of these to waterbodies.
- Identify, record and manage risk to and from critical source areas such as wallows, bank erosion, pugging, trampling or slips on steep hillsides to minimise or eliminate sediment entering waterways.
- Where appropriate use methods to minimise or eliminate sediment entering waterways such as:
- vegetated buffer strips/riparian planting adjusted in width for slope, hydrology, bank stability, land use and proximity to critical source areas;
- sediment traps;
- paddock contouring;
- earth bunds;
- raised headlands.
- Deer - Fence pacing considerations:
- Maintain appropriate feeding levels to reduce stress and fence pacing.
- Identify the best stock class to fit the soil types to minimise the risk of soil erosion, as identified in the Deer Farmers Landcare Manual.
- Maintain pasture length in winter or wet periods, to prevent soil being washed off in heavy rain. In particularly vulnerable areas retain tussock cover or native vegetation to regulate water runoff and to reduce risk of soil loss particularly in gullies or along riparian margins.
- If fence pacing is bad, fill in area and re-sow or plant with trees and if damage is extreme, re-fence to remove the problem area. If fence pacing continues, review fence placement as this can be a contributing factor.
GMP: Locate and manage farm tracks, gateways, water troughs, self-feeding areas, stock camps, wallows and other sources of run-off to minimise risks to water quality.
- Locate and design laneways so that run-off is filtered by a vegetated strip. Design and manage laneways to minimise water ponding, excessive effluent build-up and erosion.
- In areas exposed to wind erosion, establish shelter belts with trees that will filter the wind and provide added shade and shelter.
- On tracks, allow for cut-offs and slumps that will take the run off away from streams.
- Deer - wallow considerations:
- Identify natural springs and wallows prior to cultivating paddocks and pipe or drain into retired areas;
- Provide a suitable area away from waterways for safe wallowing.
GMP: To the extent that is compatible with land form, stock class and intensity, exclude stock from waterways.
- Plan and prioritise waterway areas (including wetlands) to fence, based on the vulnerability of the land, significance of the waterway and potential to impact on water quality off-farm.
- Exclusion of extensively farmed stock from waterways in hill and high country areas may not be practical but rather a mix of mitigations and practices can be used to minimise sediment and faecal bacteria losses from farms.
- Actively manage stock, stock density and stock classes adjacent to waterways to reduce risks to water where fencing is not practical.
- Exclude stock from significant waterways, drains and significant wetlands.
- Locate and manage crossing of waterways so it will not result in degradation of those waterways.
- Provide alternative stock-water sources away from waterways where possible.
- Provide shade and shelter away from waterways where appropriate.
- Place salt blocks and supplementary feed away from riparian margins.
- Leave an appropriate buffer depending on slope, to filter runoff, even if only temporarily during vulnerable periods.
- During high risk periods for erosion e.g. winter grazing, fawn weaning, actively manage stock to prevent slumping, pugging or erosion.
GMP: Monitor soil phosphorus levels and maintain them at or below the agronomic optimum for the farm system.
- To determine the level of phosphorus fertiliser needed, conduct regular, on-going soil testing (Olsen P or an equivalent, recognised soil test) at the block scale to monitor trends, patterns and the impacts of nutrient management decisions.
- Leave an unfertilised strip as a buffer zone beside creeks, drains and storm water flood zones. Allow more distance as slopes become steeper.