Deterioration of soil structure in the market gardens of the Pukekohe District, New Zealand

摘要

In the Pukekohe area, which lies about 30 miles (50 km) south of Auckland, vegetables for market have been grown for at least 30 years in some gardens on Patumahoe clay loam, a naturally well structured soil derived from volcanic ash. In some areas this soil now shows signs of structural deterioration.