Soil compaction in permanent pasture and its amelioration by slitting

Abstract

SUMMARY In a field which had been grazed by dairy cows for 26 years, the bulk density of both total soil and fine earth increased rapidly with depth down to 10–12 cm, but decreased below this depth. The bulk density was approximately twice as great in the 10–12 cm as in the 2–4 cm layer. Total porosity in the 10–12 cm layer was only 22%. Slitting the soil to penetrate the compacted layer approximately doubled net herbage accumulation and the net uptake of N, P and K, raising herbage production and uptake of nutrients from a low level to an acceptable one. Slitting tended to increase the concentrations of nitrate-N and K in herbage, but had little effect on the concentration of total N. Slitting increased the weight of ash-free root in the 10–20 cm depth range.