Physical properties and soil-water balance of key soils of the Opotiki region, North Island, New Zealand

Abstract

Abstract The soil pattern of the Opotiki region consists of alluvial soils and soils derived from volcanic ash. The soils range from recent soils to gley soils and yellow-brown loams and are discussed in terms of soil physical properties and water balance. Levels of available water are generally high to very high except where root depth is restricted by high ground water levels. Proportions of air, water, and solids are well distributed above ground water tables. Individual summer month moisture deficits of 3–67 mm occur in the soils under 1370 mm annual rainfall, despite storage capacities of over 50 mm of plant-available water for most soils. Imperfectly to poorly drained soils with low readily available water capacities are observed to compensate potential water deficiencies through capillary action.