A study of Māori garden soil modifications and soil-landform relationships including a case study of the garden soils of Panau Pa, Little Akaloa, Banks Peninsula : A dissertation submitted in partial fulfilment of the requirements for the Post-Graduate Diploma of Applied Science in the University of Lincoln [Lincoln University]

Abstract

Oral history, archaeological and soil surveys, and ethnographic literature have all provided evidence to shown how sophisticated early Māori gardeners/agriculturalists were in terms of soil management involving texture and landscape modification, and the use of organic fertilisers. The manipulation of the soil involving the application of sand and gravel, was used to provide an improved medium on which to grow their crops. All the methods developed and employed made it possible to grow once tropical varieties in a temperate environment. Experimental work has recently been undertaken to verify the usefulness of these soil treatments. Although labour­ intensive, advantages included increased friability and improved soil aeration and porosity, and higher soil temperatures. Fertilisers such as wood ashes, fish meal, seaweed and compost, were also examined for chemical composition. Maori agriculture in Aotearoa and on Banks Peninsula, as well as avian-influences on soil chemistry and morphology is examined. The reasons for soil variability is also examined. A specific case study of Maori and possible avian-influenced soils is investigated for Panau Pa on Long Lookout Point, Banks Peninsula. Panau Pa has with it extensive areas of gardens with garden rows and stone rows still discernible. Five areas (named Tahi₁, Toru₁, Wha₁, Rima₁ and Ono₁) within the gardens were chosen to investigate variations between modified soils to ascertain the degree of modification. 10m x 3m grid plots were laid down within these areas. Colour, texture and other soil attributes were recorded, including presence of stones, aggregates and mottles. Three 1m x 5m pits (named Tahi₂ profile, Toru₂ profile, Wha₂ profile) were dug next to the corresponding grid plots to a depth of 1m for a detailed sampling of soils. At the beach front, a cutting (named Beach) was made into the face of the embankment and auger-samples taken to the depth of the water-table. For these sites, on-site soil profile description was undertaken to determine soil horizon, depth, colour, texture, consistency, structure, etc. Each soil profile was described according to the terminology of Soil Survey Field Handbook (1976). Chemical analyses of soil samples were conducted on some of the pit profile samples. Analyses of soil pH for the pit Wha₂ profile shows values decrease with depth from 5.6 to 5.1 (pH H₂0), and from 4. 7 to 4.0 (pH CaCl₂) . The percent carbon analyses of this pit has very high values (7.9-3.3) to a depth of 45cm with corresponding percent nitrogen values also very high. Phosphorus analyses was conducted on all the pits and on cemented rocks on the beach front. Accurate results were hampered by poor handling but findings may still be used as an indication of very high phosphorus trends. Morphological and chemical comparisons were made between these garden soils and similar soils located elsewhere in the Canterbury region. Morphological and chemical comparison were also made between these garden soils and avian­ influenced soils.