A study of phosphorus nutrition and water supply on the early growth and survival of buffel grass grown on a sandy red earth from south-west Queensland

Abstract

The influence of phosphorus application on the growth and drought survival of buffel grass on a sandy red earth in south west Queensland was studied in a series of pot experiments. An omission nutrient trial showed phosphorus was the principal nutrient limiting seedling growth, the severity of the deficiency increasing with time. A further pot experiment showed that at rates greater than 24 kg P ha-1 luxury consumption occurred. The critical phosphorus concentration for the plant was estimated to be 0.26 per cent. The available (0.01 NH2SO4 extractable) soil phosphorus concentration corresponding to this critical tissue concentration was 25 p.p.m. Beyond the 2-leaf seedling stage, the seedling depended increasingly on external phosphorus for growth. Under conditions of phosphorus deficiency, phosphorus absorption rates were insufficient to maintain tissue phosphorus at the concentrations necessary for healthy growth, and relative growth rates were low. In the presence of phosphorus, absorption and growth rates increased. Maturity of phosphorus deficient plants was characteristically delayed but with little yield loss. The addition of phosphorus increased seedling growth rate, root development and drought survival. The depth of root penetration is considered to be the major factor responsible for survival.

Enhancing buffel grass seed germination by acid treatment for rapid vegetation establishment on railway batters

“…This analysis results indicated that the clay soil test had adequate nutrient content and imposed no chemical limitations for buffel grass germination (Christine, 1975).…”

Seed and spike traits from remnant populations of Cenchrus ciliaris L. in South Tunisia: high distinctiveness, no ecotypes

“…In Tunisia, several authors mention the species is scarce and growth is stunted, because it is selectively overgrazed (Waechter, 1982;Ferchichi et al, 1991;ChamK eb et al, 1992), and because its typical 'flush growth', as a C -photosynthesizer in an arid Mediterranean environment, occurs when other grazing resources are scarce. Alternatively, C. ciliaris would need high available-phosphorus levels (Christie, 1975) so that continued soil exhaustion could have interacted with overgrazing to cause its decline. Cenchrus ciliaris can only complete a phenological cycle when high temperature is combined with adequate soil moisture.…”

Response of a perennial grassland to nitrogen and phosphorus additions in sub-tropical, semi-arid Australia

“…In Australia, evidence of nutrient limitations has been largely derived from pot experiments that are difficult to extrapolate to field conditions. For example, field responses of grasses to added P were either negligible (Friedel et al, 1980) or were not tested (Christie, 1975;Silcock et al, 1976), while growth in the glasshouse was increased with added P. Moreover, some pot trials were confounded by the addition of basal nutrients (e.g. N, K, trace) in combination with different rates of P (e.g.…”

“…N, K, trace) in combination with different rates of P (e.g. Christie, 1975;McIvor, 1984;Armstrong & Helyar, 1993).…”