Use of Climate, Soil, and Crop Information for Identifying Potential Land- Use Change in the Hokianga and Western Kaipara Region Georgina Griffiths1 Andrew Tait2 2 David Wratt Murray Jessen3 Malcolm McLeod3 Jeff Reid4 John Anderson5 Noel Porter6 Stephan Halloy7 Annette Richardson8 March, 2003 1 National Institute of Water and Atmospheric Research Ltd, Private Bag 109695, Auckland 2 National Institute of Water and Atmospheric Research Ltd, Private Bag 14-901, Kilbirnie, Wellington 3 Landcare Research, Private Bag 11 052, Palmerston North 4 Crop & Food Research Hawke’s Bay, PO Box 85, Hastings 5 Crop & Food Research Pukekohe, Cronin Road, RD1, Pukekohe 6 Crop & Food Research Lincoln, Private Bag 4704, Christchurch 7 Crop & Food Research Invermay, Private Bag 50 034, Mosgiel 8 HortResearch, Kerikeri Research Centre, PO Box 23, Kerikeri 1 Notice of Copyright: The copyright for the data, figures and tables contained in this document and the copyright for the associated maps is held by NIWA, Landcare, Crop and Food, and HortResearch. Material may not be reproduced without the prior consent of the Kaipara District Council, the Far North District Council, NIWA, Landcare, Crop and Food, and HortResearch. Disclaimer: NIWA, Landcare, Crop and Food, and HortResearch staff have used the best available information in preparing this document and the associated maps, and have interpreted this information exercising all reasonable skill and care. Nevertheless, neither the Kaipara District Council, the Far North District Council, NIWA, Landcare, Crop and Food, nor HortResearch accept any liability, whether direct, indirect or consequential, arising out of the provision of information in this document. Reviewed by David Wratt, Principal Scientist, NIWA, Private Bag 14-901, Kilbirnie, Wellington Released by Andrew Laing, Regional Manager, NIWA, Private Bag 14-901, Kilbirnie, Wellington NIWA Client Report AKL2003 037 2 Contents Contents .............................................................................................................................3 List of Hyperlinked Maps ..................................................................................................7 List of Figures....................................................................................................................8 List of Tables ...................................................................................................................10 Executive Summary.........................................................................................................11 1. Introduction..............................................................................................................12 1.1 Project Aims.......................................................................................................12 1.2 How The Crops Were Selected..........................................................................14 1.3 General Climate and Soil Information...............................................................15 1.4 Summary of the Main Findings from the Crop Potential Maps.........................15 Peanut ..................................................................................................................15 Māori Potato........................................................................................................16 Manuka (For Oil).................................................................................................16 Banana .................................................................................................................16 Mate Tea ..............................................................................................................16 Avocado................................................................................................................16 Cherimoya............................................................................................................17 Fig........................................................................................................................17 Blueberry..............................................................................................................17 Hydrangea............................................................................................................17 2. Climate fluctuations and changes affecting the Kaipara and Far North Districts....18 2.1 Year-to-Year Climate Fluctuations in the Western Kaipara and Hokianga Area ..................................................................................................................................18 2.2 Climate Extremes...............................................................................................19 2.3 The Influence of El Niño and La Niña on the Climate of the Kaipara and Far North Districts..........................................................................................................28 Rainfall.................................................................................................................28 Temperature.........................................................................................................31 2.4 Climate Shifts - The Interdecadal Pacific Oscillation........................................32 2.5 Anthropogenic climate change ..........................................................................33 Changes in the Kaipara and Far North districts through the 20th Century ........33 Expected Climate Changes in the 21st Century....................................................34 3. Derivation of the climate maps....................................................................................37 4. Description of the climate variables and their main patterns.......................................38 4.1 Rainfall...............................................................................................................39 4.2 Frost-Free Period ...............................................................................................39 4.3 Growing Degree Days........................................................................................40 4.4 Soil Moisture Deficit..........................................................................................40 4.5 Air Temperature.................................................................................................40 4.6 Wind Speed and Direction.................................................................................41 5. Additional climate information....................................................................................42 5.1 Sunshine Hours ..................................................................................................42 5.2 Probability of Frost ............................................................................................43 5.3 First and Last Frost Dates ..................................................................................43 5.4 Soil Temperature................................................................................................45 5.5 Cool Season Chill Units.....................................................................................45 5.6 Climate References and Further Reading ..........................................................46 3 6. Description of the soil maps ........................................................................................48 6.1 Soil Terrains.......................................................................................................48 6.2 Soil Series, Types and Phases (the Soil Name) .................................................49 Soils according to soil terrains............................................................................49 6.3 Slope Class.........................................................................................................54 6.4 Subsoil Acidity (minimum pH over the depth range 0.2-0.6 m) .......................54 6.5 Potential Rooting Depth.....................................................................................56 6.6 Soil Drainage Classes ........................................................................................57 6.7 Profile Total Available Water............................................................................58 6.8 Soil References and Further Reading ................................................................59 7. Growing peanut............................................................................................................60 7.1 Why Grow Peanuts? ..........................................................................................60 7.2 New Zealand Experience Producing Peanuts ....................................................61 Weed control ........................................................................................................62 Infrastructure .......................................................................................................62 7.3 Aflatoxin, A World Wide Issue .........................................................................63 7.4 Basic Growing Requirements ............................................................................64 7.5 Conclusions........................................................................................................65 7.6 Information Sources...........................................................................................65 People ..................................................................................................................65