Irrigation investigations in Otago, New Zealand

Abstract

The brown-grey earths and yellow-grey earths of the Maniototo Plains are similar in physical properties to the soils of the same groups in the Ida Valley, the Arrow Basin, and the Upper Clutha Valley.

Irrigation increased the field capacity, bulk density, available moisture, and percent organic carbon of soils of both groups, and the properties of the irrigated brown-grey earths tend to be intermediate between those of the virgin brown-grey earths and the virgin yellow-grey earths.

Available moisture in the top 12 in. of soil ranged from 2 in. to 2t in. for the brown-grey earths and from 2t in. to 3t in. for the yellow-grey earths.