Land Development Booklet - Ministry for Primary · PDF fileChapter 5 Undertaking land...

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Transcript of Land Development Booklet - Ministry for Primary · PDF fileChapter 5 Undertaking land...

  • AA guide for West Coast Farmers

    Disclaimer:Every care has been taken in compiling this book to ensure that the information is accurate and current; however the authors do not accept liability for any errors or omissions, or the results of any action taken on the basis of the information in this publication.

    Contents

    Foreword 2

    Chapter 1 Understanding West Coast soils 3

    Chapter 2 Deciding between flipping or humping and hollowing 5

    Chapter 3 Benefits of flipping and humping and hollowing 9

    Chapter 4 Preparation before development 12

    Chapter 5 Undertaking land development 16

    Flipping 16

    Humping and hollowing 19

    Chapter 6 Managing developed land 26

    Machinery safety 26

    Lime and fertiliser Pre-planting 26

    Pasture species 28

    When to sow 30

    Pasture sowing management 30

    Nitrogen 30

    Chapter 7 Financial cost / benefit of development 32

    Glossary of terms 37

    Appendices A. West Coast Regional Councils rules and regulations 38

    B. Further reading 39

    C. Land development checklist 40

  • 2 Land Development by Flipping and Hump and Hollowing

    This booklet has been designed to offer West Coast farmers the most up to date information on land development. Since the first booklet on humping and hollowing the alternative option of flipping the land has become well established

    The Buller Community Development Co. Ltd. recognised the potential significance of the new techniques for the local economy and was successful in obtaining a MAF Sustainable Farming Fund grant to investigate the benefits of flipping. From the information gathered, and experiences of farmers, contractors and corporate groups such as Landcorp, it was decided to present this information in a booklet together with up to date information on humping and hollowing.

    Acknowledgements

    This booklet has been prepared by Murray Craighead, Nutrient Solutions Ltd and Richard Reynolds, Dexcel and includes information from Westland Milk Products Hump and Hollow- A Guide for West Coast Farmers (1996).

    With respect to the flipping project, special thanks to the MAF Sustainable Farming Fund grant for assistance in financing this work, to Ross Bishop, Farm Management Consultant and Richard Reynolds for collecting farm data and running field days to Craig Ross Landcare Research for soil and infiltration data, to Stephen Belton, Ravensdown Fertiliser Co-operative Ltd for soil and plant testing and to Mark Burnett, Alex King, Jonno OConnor, Brian Hateley for access to their data and use of their properties.

    Contributors to the update of the information on humping and hollowing include the Regional Action Team whose membership is made up of farmer representatives, Westland Milk Products, Dexcel, the West Coast Regional Council, Federated Farmers, the NZ Landcare Trust, West Coast Fish and Game and the Department of Conservation. The West Coast Regional Council provided up to date information on the rules regarding land development. Thanks to all those individuals and organisations that assisted with the update.

    Photographs have been supplied by Craig Ross, Landcare Research, Murray Craighead, Nutrient Solutions Ltd., and from the West Coast Regional Councils photo bank.

    Westland Milk Products and the Buller Community Development Company have sponsored publication of this booklet.

    We hope this booklet will assist you as farmers and contractors in making decisions about land development.

    Jonno OConnorDirector BCDC

    Foreword

  • 3A guide for West Coast Farmers

    West Coast soils can be loosely categorised into three groups, Pakihi soils, Recent soils and Terrace soils.

    Recent soils include;

    alluvial soils such as Hokitika and Hari Hari soils along the rivers and those on young fans, eg. Rotomanu soils.

    Terrace (or Brown) soils include;

    the Ahaura and Ikamatua glacial terraces of the Grey Valley as well assome older fans eg. Eliot soils, andcoastal sands such as Okari soils.

    Pakihi (or podzolised) soils of which there are about 200,000 ha on the West Coast are more diverse. These include;

    low glacial outwash terraces such as Kumara and Mai Mai soils,

    intermediate and high glacial outwash terraces such as Okarito and Kini soils,rolling pakihi soils such as Waiuta soils (at Bell Hill) and

    pakihi soils on the coastal marine benches such as the Addison, Utopia and Charleston soils at Cape Foulwind. small areas of peat soils are also found usually associated with old swamp areas and behind coastal dunes.

    Pakihi soils are the name for podzolised and gley podzolised brown soils which develop under high rainfall where high leaching accumulates iron and aluminium oxides, humus and sometimes clay in the subsoil leading to iron and humus-iron pans which impede drainage. High accumulation of litter, particularly in very wet and cool conditions leads to high acidity and leaching of nutrients such as nitrate nitrogen, potassium and sulphate sulphur. The high organic matter derived from the top litter also readily retains high amounts of water.

    Soils are mainly derived from greywacke and schist (with some sandstone and mudstones), so most tend to be low in the base cations calcium, potassium and magnesium. Nitrogen status is also low despite their high organic matter content. This is because the waterlogged conditions cause anaerobic conditions (lack of oxygen), which not only reduces plant growth but also the mineralisation (release) of nitrogen from organic matter. The wet conditions also lead to micro-organisms producing toxic compounds to plant growth such as sulphides.

    Understanding West Coast SoilsChapter 1

  • 4 Land Development by Flipping and Hump and Hollowing

    Recent and Terrace soils also generally lack nitrogen, phosphate and sulphur. Recent soils generally have reasonable levels of potassium due to their clay mineralogy, but many Terrace soils do not. Although both soils generally have sufficient magnesium for grass growth, magnesium is often required in spring for animal health purposes.

    Trace Elements. Pakihi soils are very responsive to trace elements, in particular copper and molybdenum are required in the development phase for pasture growth. Cobalt and copper are required for animal health, in particular on Pakihi soils. Pakihi and Sands also require selenium for animal health although it is generally applied on all soils as is boron, to improve Brassica growth. While the nutrient status of a soil can generally be rectified, the most productive farming is on Recent and Terrace soils simply because the majority of these soils are well drained. However on pakihi soils unless this issue is overcome they are destined for low quality dairy production or extensive sheep and beef production. In the past podzols (with the exception of peats) have only shown limited improvement after drainage and then mainly on sloping ground. This is because vertical drainage has not been adequately addressed by breaking up some of the subsoil pans. Therefore it is the pakihi soils that are most suitable for flipping or humping and hollowing, although some Recent and Terrace soils that are slow to drain may suit humping and hollowing.

    Sandy podzol suitable for flipping.

  • 5A guide for West Coast Farmers

    Land Development is a very expensive exercise and the process needs to be carefully planned before any land is turned over (see following chapters). Not all Pakihi soils are suitable for flipping. Their suitability depends on their parent material and soil texture, their degree of podzolisation, the amount of organic matter, wetness, the climate and the topography. A lack of vertical drainage is their common theme, usually caused by impervious subsoils of iron and iron-humus pans below cemented sands and gravels or subsoils of silt and clay. The key is to break the top pans and also mix the water saturated organic matter through a larger soil volume so that water drains away from the rooting zone.

    In flipping this is done by inverting and mixing the top layers to a depth suitable to release surface water, at least to 1 m and often to 2-3 m. Several pans may be broken to do this, and water generally drains away to appear again at some lower point or drain.

    With humping and hollowing the hollow where the pilot drain is, is usually at the depth of the top pan (to give a firm base) and the soil above this is mounded on the adjacent area so water then runs from it to the pilot drain and then away to a main drain. This sequence is repeated across the paddock.

    Details of these processes are given in the following chapters.

    What is soil texture?

    Soil texture is the proportion of sand, silt and clay in the soil, sandy soils have a high proportion of sand, relative to silt and clay; and silt and clay loams a higher proportion of silt or clay relative to the others.

    The easy way to identify what your soil is, is to wet some soil and roll it into a ball (about 20 mm across). Press it between your thumb and forefinger.

    If you cannot make a ball or either the ball collapses easily or is very soft, then the soil contains a high proportion of sand. It will also feel gritty and make a rasping sound when rubbed. Silty soils will feel smooth, more firm than sands and will crack nicely when you press the ball. Clay soils will easily form a ball but will be extremely sticky to work.

    Sandy soils generally contain at least 75-85% sand and are the coarser material. They pack less but dry out quickly so are therefore prone to wind blow during the development phase.

    Clay soils contain at least 35% clay and consist of the finest material. They pack the most and are the mo