Soils (for the boffins)

Like most vineyard soils of Central Otago, Georgetown's is of schist and quartz origin. The soil is officially (from dept of lands and survey map) known as Molyneux shallow loamy sand with a sliver of Waenga shallow sandy loam at one corner. More specifically the  Molyneux soil was initially laid down 339-362 thousand years ago after a glacial retreat. Over millennia the gravelly sandy sub layers were brought down from high above the Kawarau gorge by tributaries into gullies before being flattened and layered by the Kawarau river. This deep layer of sand to knuckle sized gravels was then covered with a shallow (~200mm) layer of loess, all the while different sized particles were pushed into place with small amounts of organic matter forming the soil (pedogenesis). The resulting soil is a coarse loam which has a low to medium water holding capacity. Presently about 50mm of irrigation is applied annually to supplement rainfall. It is reasonably high in calcium and therefore pH (6.5) and highish in Phosphorus. Although they have a low CEC (11me/100g) they are balanced, very permeable to roots and very giving, so deficiencies don't occur. To improve CEC and nutrient availability, compost is applied annually to weaker areas. Also a natural cover crop high in nitrogen fixing plants is regularly mown and cultivated into the soil every 5 years.