Farm Table says:
What is the problem?
It is hypothesized that a.) species with greater acid soil tolerance have an increased capacity to utilize incipient rainfall and b.) liming increases the productivity and the ability of pasture species to utilzize available water resources in the profile of an acid soil.
What did the research involve?
A field experiment was established on a moderately acidic yellow Kandosol and monitored over 5 years. Five perennial pasture species including lucerne, phalaris ,chicory , tall fescue and cocksfoot , were sown in monocultures with and without 2.9 t/ha lime.
What were the key findings?
Both lucerne and phalaris were more persistent than chicory, tall fescue and cocksfoot under severe drought, despite both being considered sensitive to soil acidity. Surface liming increased the soil water deficit by up to 27 mm at 0.75–1.65 m under perennial pastures compared to unlimed treatments, despite lime having no physical presence at that depth. Lime increased lucerne, phalaris and cocksfoot cumulative herbage biomass by 150, 30 and 20 %, respectively, but had no significant effect on chicory or tall fescue biomass.
The two most acid-sensitive species, lucerne and phalaris, were more resilient under drought despite the acidic nature of the soil.It was contended that species sensitive to acidity can be a valuable addition to pastures on acid soils. Lime used in conjunction with deep-rooted perennial species is likely to maximize the ability of pastures to utilize scarce available soil water reserves.