Factors affecting the susceptibility of 3 soils in the Manawatu to stock treading

Abstract

Stock treading damage decreases farm productivity by affecting plant growth, soil properties, feed utilisation, and animal health. Three soils that differed markedly in susceptibility to treading damage were studied. Ramiha silt loam had a low susceptibility because of low stocking rates, a protective pasture cover, strongly developed soil structure, and good profile drainage. Tokomaru silt loam had a high susceptibility because of intensive stocking rates and poor drainage. Manawatu fine sandy loam was intermediate as it had weak structural stability but good drainage. In the field there was a loss of soil macroporosity which correlated well with field reports of treading damage. Soil bulk density and total porosity were not useful indications of treading damage and hence did not correlate with field experience. The similar relationships found between resistance to penetration and matric potential indicates that all 3 soils are susceptible to treading damage when very wet. However, differences in drainage characteristics influence the length of time during which the soil remains at high matric potentials. An efficient drainage system appears vital if treading damage in the Tokomaru silt loam is to be minimised.

Keywords:

• grazing intensity
• compaction
• soil permeability
• drainage
• soil properties
• sheep
• cattle
• stock
• penetration resistance