Nutrient status of soils and pastures of the Kaiwera district, eastern Southland, New Zealand

Abstract

Samples from 96 sites in the Kaiwera district were analysed for available major and trace elements to determine if ‘ill-thrift’ of lambs could be related to the nutrient status of soils or pastures. Major elements were slightly lower in upland soils (above about 300 m) than in lowland soils but there were no differences in pasture concentrations. Levels of cobalt (Co) and copper (Cu) extracted with EDTA were lower in upland than in lowland soils and pasture Co and Cu concentrations showed a similar pattern. Pasture Co declined markedly in all samples from October to February and was below the minimum requirements for satisfactory nutrition of sheep in many samples in February. Some pasture Cu concentrations were marginal for cattle. It is concluded that pasture growth in the district is not restricted by any nutrient limitation although nitrogen concentrations were below optimum. Sheep are probably affected by inadequate Co intake particularly when grazing upland pastures.

Keywords:

• mineral composition
• trace elements
• soil tests
• plant nutrition
• animal nutrition
• cobalt deficiency
• copper deficiency
• ill thrift