Some soils of the Southern Island of New Zealand with special reference to their lime requirements

Abstract

1. The Hutchinson-MacLennan method for determining the lime requirements of soils, when practised under suitable standard conditions, gives more reliable indications than are obtainable by the ordinary methods of chemical analysis.2. The method gives indications which appear to be uniformly in excess of the actual requirement of the soil for lime as judged by economic standards: hence a correcting value seems advisable.3. The correcting value for the soils of Canterbury Plains is about 0·10%.4. The greater acidity and higher lime requirement of soils of the Southland Plains appears to be due to a combination of lack of natural under-drainage and high rainfall, which prevents aeration and oxidation of organic matter, so that “sour” humus accumulates in the soil.