Land Condition in the Tropical Tall Grass Pasture Lands. 2. Effects on Herbage Quality and Nutrient Uptake.

Herbage quality (in vitro digestibility, nitrogen and phosphorus concentrations) of plucked samples, and above ground nutrient uptakes (nitrogen and phosphorus) were compared on plots differing in land condition at 10 sites in northern Australia. Over all sites there was a significant increase in digestibility and nitrogen concentration, and a significant decrease in phosphorus concentration, as land condition declined. Both nitrogen and phosphorus uptake decreased as land condition declined. The results indicate that diet quality may be higher from land in poor condition. However, the large decrease in pasture productivity associated with declining land condition may more than offset this apparent improvement in feed quality.

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Pasture management in semiarid tropical woodlands: improving the herbage quality of stylos and grasses

Australian Journal of Experimental Agriculture ◽

10.1071/ea06291 ◽

2007 ◽

Vol 47 (11) ◽

pp. 1359 ◽

Cited By ~ 2

Author(s):

John G. McIvor

Keyword(s):

Phosphorus Concentration ◽

In Vitro Digestibility ◽

Stocking Rate ◽

Nitrogen And Phosphorus ◽

Pasture Management ◽

Buffel Grass ◽

North East ◽

Herbage Quality

The impacts of season and pasture management (tree killing, superphosphate application, stocking rate) on the herbage quality of stylos and grasses were measured at Hillgrove and Cardigan, north-east Queensland. Plucked samples of Verano, Seca and buffel grass (both sites) and a native grass (spear grass at Cardigan and desert blue grass at Hillgrove) were collected over a 4-year period and concentrations of nitrogen, phosphorus and sulfur and in vitro digestibility were measured. There were large seasonal variations in herbage quality of all species with high quality in the early growing season and low quality in dry periods. The stylos had higher nitrogen concentrations and in vitro digestibilities than the grasses, buffel grass had a higher phosphorus concentration than the other species and there were no consistent differences in sulfur concentration between species. Buffel grass generally had higher nitrogen and phosphorus concentrations and in vitro digestibility than the native grasses. Management had relatively minor impacts but where differences did occur, herbage quality was higher in plots with live trees than where trees were killed, on plots where superphosphate was applied compared with plots without fertiliser and was greater at high stocking rate. Oversowing native pastures with stylos had no effect on the herbage quality of desert blue grass which had similar quality in oversown pasture and native pasture.

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The effect of total water supply, and frequency of application, upon lucerne. II.* Chemical composition

Australian Journal of Agricultural Research ◽

10.1071/ar9720253 ◽

1972 ◽

Vol 23 (2) ◽

pp. 253 ◽

Cited By ~ 13

Author(s):

RW Snaydon

Keyword(s):

Water Supply ◽

Nitrogen Concentration ◽

Phosphorus Concentration ◽

In Vitro Digestibility ◽

Pan Evaporation ◽

Water Application ◽

Total Water ◽

Class A ◽

Class A Pan

Total water supply, expressed as a proportion of class A pan evaporation (Epan), and frequency of water application were varied independently during summer. The phosphorus concentration in the shoots of lucerne increased by 35% when the total water supply was increased from 0.1 to 1.0Epan; the nitrogen concentration was not significantly affected. The in vitro digestibility of leaf and stem fractions decreased with increasing total water supply, and the proportion of highly digestible fractions (leaf and flower) also decreased, so that total shoot digestibility decreased from 65% at 0.24 Epan to 55% at 0.58 Epan. Frequency of water application had no significant effect upon phosphorus or nitrogen concentration or in vitro digestibility. ____________________ *Part I, Aust. J. Agric. Res., 23: 239 (1972)

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The influence of water stress on nitrogen and phosphorus uptake and concentrations in Townsville stylo (Stylosanthes humilis)

Australian Journal of Experimental Agriculture ◽

10.1071/ea9800175 ◽

1980 ◽

Vol 20 (103) ◽

pp. 175 ◽

Cited By ~ 15

Author(s):

MJ Fisher

Keyword(s):

Water Stress ◽

Phosphorus Uptake ◽

Phosphorus Concentration ◽

Nitrogen And Phosphorus ◽

Growth Stresses ◽

Stylosanthes Humilis ◽

Influence Of Water ◽

Nitrogen Concentrations ◽

Townsville Stylo ◽

Nitrogen And Phosphorus Uptake

The phosphorus concentrations of Townsville stylo (TS) grown in the Northern Territory are lower than in Queensland, and fall below the requirements of grazing cattle for much of the year. An explanation was sought by measuring N and P in swards subjected to water stress at various times during growth. Stresses during early vegetative (EV), late vegetative (LV) and flowering (F) stages were compared with a well watered control. While nitrogen concentrations were affected little, water stress greatly reduced phosphorus concentrations, the relative effects being EV > LV > F. The EV stress depressed phosphorus concentration to 0.08% compared with 0.20% in the control. Phosphorus level recovered on the relief of stress to the same level as the control. Phosphorus concentration in stems was more sensitive to stress than that in leaves. These results show that if chemical analysis of plants is to be used to indicate the phosphorus status of the soil, the analyses will be unreliable unless the plants have grown without water stress for at least six weeks.

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