Pasture Botanical Composition Research Articles

Establishment and persistence of surface-sown and resident grasses using three pasture development methods in relation to three stocking managements

The botanical composition of pastures improved by three different methods (viz. fertilizer only; seed and fertilizer; and herbicide, seed and fertilizer), were compared on the Northern Tablelands of New South Wales. After sowing, the pastures were grazed strategically for 6 months before three continuous stocking rate treatments (5.0, 7.5 and 10 Merino wethers/ha) were applied to each treatment. After 3 years, all paddocks were continuously grazed by 10 Merino wethers/ha for a further 4 years. The establishment of sown species was improved by herbicide application and the lowest stocking rate. Of the four species sown, Phalaris aquatica showed the greatest response to herbicide application, while the cover of Phalaris aquatica and Dactylis glornerata increased at the lowest stocking rate. These factors were less critical for Festuca arundinacea and Lolium perenne for which differences in level of cover between improvement methods disappeared within 12 months. The effects of the strategic management treatments were inconsistent. The resident pasture failed to recover from herbicide treatment and cover and growth of most grasses was depressed by the presence of sown grasses even in the absence of herbicide. The proportion of winter-active native species in the pasture increased with increasing stocking rate.

Effect of soil slip erosion on seasonally dry Wairarapa hill pastures

Abstract Production, botanical composition, and some soil fertility parameters of pastures on seasonally dry Wairarapa hill country subject to soil slip erosion were measured over 3 years, beginning in 1979. Measurement sites were on sunny and shady aspects of ‘uneroded’ areas of hillslopes, and slip scars of 4 ages (mean dates of slipping: 1977, 1961, 1941, and 1906). Average annual pasture production on uneroded areas was 8391 kg DM/ha. Pasture yields on the 1961, 1941, and 1906 sites, and the 1977 sites were about 77 and 20% of this level respectively. Uneroded sites were generally less steep than eroded sites, and this complicated interpretation of data. Correction for this slope discrepancy would increase the 77 and 20% values slightly. The results of this study suggested that pasture production on hill soils formed under pastoral agriculture was unlikely to return to the production levels supported by soils formed under the original forest vegetation. Botanical composition of pastures was influenced...

Seasonal control of gastrointestinal parasites among dairy heifers using two strategically timed treatments of fenbendazole

Sixty heifers aged 7-18 months, in their first grazing season, were randomly assigned to four groups: treated, continuous grazing management, 16 head; control, continuous grazing, 16 head; treated, rotational grazing, 14 head; control, rotational grazing, 14 head. Treated animals received fenbendazole (5 mg/kg orally) on days 22 and 50 after turnout and controls received a placebo. Monitoring was carried out on weight gains, faecal egg counts, herbage larvae and botanical composition of pastures. Effective grazing density of the continuously grazing groups was 3.2 animals/ha. Each rotationally grazed group was allotted one of ten 0.4-ha. paddocks, each paddock being grazed 1-6 days depending on available forage. There were no significant differences between treated and control heifers in daily gains on either continuous or rotational pastures during 140 days after treatment. Heifers on continuously grazed pasture gained more than on rotational pasture. Faecal egg counts from rotationally grazed groups showed significant differences between treated and control groups on days 78 and 106. There were no significant differences in egg counts between continuously grazed groups. There were significant differences in numbers of infective larvae recovered after day 100, with most collected from rotational paddocks. Samples for botanical analysis from continuous pastures contained more than 50% white clover, whereas the rotational paddocks never had more than 15%. The results can be interpreted from two propositions: first, the level of parasitism was too low to affect weight, faecal egg count or herbage larvae; second, the accumulation of high levels of pasture larvae in the system of rotational grazing occurred too late to affect weight gains.

Performance of 4 white clover populations in monoculture and with ryegrass under grazing

Abstract Herbage accumulation and botanical composition of pastures containing 4 morphologically-contrasting white clovers (Kent wild white, Southland uncertified, ‘Grasslands Huia’, and ‘Grasslands Pitau’) are described. The clovers were grown in monoculture and in association with either ‘Grasslands Ruanui’ or ‘Nui’ perennial ryegrass under grazing frequencies of 4 and 6 weeks. Clover production in monoculture and mixtures was least from the small-leaved Kent, intermediate for medium-leaved clovers, and greatest from the largeleaved Pitau. Kent was inferior in all seasons, whereas the superiority of Pitau reflected good autumn-winter growth. In all mixtures, the ryegrass and clover components showed improved production under infrequent grazing for all seasons. Within a grazing frequency, pastures containing Kent produced the lowest clover yields but had the largest associated grass yields, whereas pastures containing the larger-leaved Pitau showed the converse. This compensatory effect resulted in the p...

Nitrogen as an aid to pasture establishment and renovation in Northland

Abstract The use of urea and two slow release nitrogen fertilisers to manipulate pasture botanical composition and increase dry matter production after pasture establishment or renovation was investigated in 5 trials in Northland, New Zealand. Seven bimonthly applications of urea (50 kg N/ha/application) after pasture establishment on an undeveloped podzol increased dry matter production by 41%. The percent legume in pasture was reduced by nitrogen, but returned to a level similar to control when applications of nitrogen ceased. Lotus pedunculatus L. was a useful colonising plant for acid podzols, providing a more rapid ground cover and higher early dry matter production than Trifolium repens L. but it did not persist under the grazing regime used. Nitrogen fertiliser applied during pasture renovation increased dry matter production, nitrogen applied 2 weeks after pasture emergence producing the largest dry matter response of the single applications investigated. Multiple 50 kg N/ha applications were supe...

A comparison of levels of production and profit from grazing Merino ewes and wethers at various stocking rates in northern Victoria

Merino wethers and breeding ewes were grazed at various stocking rates on an annual pasture in the sheep-wheat zone of Northern Victoria from 1966 to 1973. There was considerable variation between years in botanical composition, the incidence of subterranean clover in the pasture plots varying by up to 80 percentage units between years. Total pasture production was measured in one plot during the last 4 years of the experiment, varying from 2.1 t ha-1 in the drought year (325 mm rain) of 1972, to 8.8 t ha-1 in the higher rainfall (883 mm) year of 1973. The large year-to-year variations in pasture production and botanical composition were reflected in differences between years in sheep production at various stocking rates. Wethers produced about 20% more wool than breeding ewes grazing at the same stocking rate, providing no supplements were fed. August-lambing ewes either lost weight in early spring or gained weight more slowly than wethers of the same age and flock background. The consequence of this was that maximum weights of ewes were consistently about 10 kg less than wethers at the same stocking rate. Both ewes and wethers had similar rates of weight loss from November to March. In one year ewes at 3.7 ha-1 were fed supplements in autumn, since they were lighter than the feeding weight of 41 kg, whereas wethers stocked at 11.1 ha-1, were not. An economic analysis of the experimental data indicated that the most profitable stocking rates of Merino wethers were up to 1.7 times that of August-lambing ewes. This ratio varies with season, and is also likely to vary with changes in lambing date or environment. The most sensitive determinants of optimal stocking rate were the rate of decline of fleece weight, and lambs born relative to ewes joined, with increasing stocking rate. Sheep liveweight at time of sale could also be important.

Effect of Fertilizers on the Yield and Botanical Composition of Pastures in South Sulawesi, Indonesia1

AbstractInformation on the nutrient status of soils of the outer Islands of the Indonesian Archipeligo is limited. Attempts are being made to establish a cattle industry based on legume pastures, and this work has created a need for detailed nutrient investigations. Legumes have generally failed to produce and persist in large areas of South Sulawesi which are presently covered by Imperata cylindrica. A series of field experiments were conducted to investigate the nutrient status of a Glossudalf soil. Such soils cover large areas of upland country in Sulawesi that are used for cattle grazing. P, K, S, Mo, Cu, and Zn containing fertilizers were broadcast onto field plots that were oversown with Centrosema pubescence. Nutrient responses were measured during a 1‐year period by cutting quadrats from the plots. Responses to S, applied as either elemental S (brimstone) or as sulfate (in superphosphate), and Mo were recorded. In one experiment elemental S, applied at 13 kg/ha, lifted the yield of Centro from 4,068 kg/ha (green) to 10,491 kg/ha (green) over a 17‐week period. The increase in Centro production lead to a decline in the production of Imperata cylindrica.

Aspect differences in an unimproved hill country pasture

Abstract Soil nutrient status, sheep dung deposition, pasture botanical composition, and productiyity were measured on north, south, east, and west aspects of a hill in the southern Ruahine Range, New Zealand. Differences among aspects were significant in all the above factors. Pasture productivity appeared to be related to available soil nitrogen levels. Botanical composition was also related to available soil nitrogen levels and to soil available phosphate status. The rates of nitrogen mineralisation of soil cores incubated in the field were closely related to tota soil nitrogen content, soil carbon:nitrogen ratio, and temperature.

I. Pasture production and botanical composition

Abstract Effects of superphosphate, lime, and stocking rate on pasture production were studied over a 5-year period on a central yellow-grey earth on the Wairarapa Plains at the Masterton Field Research Area. A high annual rate of superphosphate (500 kg/ha) did not increase pasture production above that obtained from a low annual rate (125 kg/ha), but lime (6300 kg/ha) increased pasture production. A high stocking rate (22 ewes/ha) decreased pasture production in 2 years. Point analysis of botanical composition showed that browntop (Agrostis tenuis Sibth.) cover increased to a maximum in the third year and then declined. Both the high rate of superphosphate and the lime significantly reduced browntop cover. Ryegrass (Lolium × hybridum Hausskn.) and white clover (Trifolium repens L.) cover increased linearly with time, the spring recordings being significantly correlated with the previous summer's rainfall.

THE INFLUENCE OF ASPECT ON PASTURE ENVIRONMENT

Large differences in climatic, edaphic, and biotic variables were recorded among four aspects of a hill in the Southern Ruahine range over a twelve-month period. Productivity of the existing sward appeared to be strongly influenced by available soil nitrogen levels, and soil moisture status during the summer/autumn months. Pasture botanical composition was related to both these factors and also to soil available phosphate status. Some practical implications of the differences recorded are discussed with reference to farm subdivision, seeds mixtures and feriiiizer requirements.

Effects of Fertilization and Cutting Management on Yield and Botanical Composition of Permanent Pasture

Effects of Fertilization and Cutting Management on Yield and Botanical Composition of Permanent Pasture

Wool production, ground cover and botanical composition of pastures grazed by Merino wethers in central western New South Wales. 1. Natural pasture

A natural pasture consisting predominantly of Aristida, Stipa, Danthonia and Chloris was grazed by Merino wethers set-stocked at 2.04, 1.36 and 1.02 ha-1 at Condobolin in central western New South Wales. Throughout the four years 1965 to 1969, the pasture supported 1.36 wethers ha-1 without supplementary feeding. Wool production per ha increased with increase in stocking rate but wool production per head and liveweight decreased. Although there was a greater percentage of annual medics at the high compared with the low stocking rate, the high stocking rate reduced total ground cover and the density of Aristida.

Wool production, ground cover and botanical composition of pastures grazed by Merino wethers in central western New South Wales. 2. Barrel medic pasture

Two grazing experiments were performed between 1965 and 1969 at the Agricultural Research Station, Condobolin, to determine the carrying capacity of Jemalong barrel medic (Medicago truncatula) pasture. In each experiment the pasture was set stocked with Merino wethers at 3.1, 4.1 and 6.2 ha-1. An additional treatment stocked at 6.2 ha-1 was included in which two-thirds of the pasture area was saved during autumn or periods of feed shortage while stock were confined to the other one-third. In both experiments the pasture supported 3.1 wethers ha-1 under set stocking for three years with little supplementary feeding and regenerated successfully each year. No major changes in botanical composition were recorded, and Jemalong medic remained the major component of the pasture. Autumn saving at 6.2 ha-1 mitigated the effects of the high stocking rate on both animal and pasture, but did not result in worthwhile animal production increases.

The control of slender thistle, Carduus pycnocephalus L. and C. tenuiflorus Curt. (Compositae), in pasture by grazing management

The effect of grazing management on slender thistle populations and botanical composition of improved pasture was studied in two field trials in southern Tasmania. Deferring grazing until winter or spring reduced slender thistle populations in both trials. The reasons underlying these observations are discussed. Spring grazing favourably altered pasture botanical composition by increasing the frequency of perennial ryegrass and subterranean clover and reducing the frequency of weed grasses. These changes arc discussed in relation to thistle control. It is suggested that deferred autumn grazing may be incorporated into the farm programme as an economical method for the control of slender thistle in pasture.

Substation insulator failure prevention by ultrasonic corona detection : Frederick Jr, W. IEE Trans Ind Appl Vol 1A–8 No 1 (Jan–Feb 1972) pp 82–83

The interactions between botanical composition of pasture, quality of herbage grazed, performances of dairy cows and sensory and nutritional properties of dairy products were investigated using an integrated system approach. Two contrasting grazing systems were evaluated from May to September in two years. The treatments included a continuous grazing system (DIV) managed at a lenient stocking rate (1.0 LU ha−1) on a botanically-rich permanent pasture, and a rotational grazing system (PROD) set up at a higher stocking rate (1.7 LU ha−1) on a former temporary grassland presenting moderate biodiversity. DIV aimed to maximize biodiversity and obtain high sensory and nutritional quality cheese, whereas PROD was oriented towards milk production and herbage quality. In each system, 12 non-feed-supplemented Montbéliarde cows were used. The DIV system led to higher milk production per cow in the early grazing season than the PROD system (22.2 vs. 19.9 kg d−1). At the beginning of summer, this milk production pattern was inverted following a decrease in grass nutritive value in the DIV system. In parallel, DIV cows showed a more marked loss of body condition than PROD cows over the season. In terms of milk fatty acid profile, the DIV system proved very interesting early in the grazing season but lost its value over time as the herbage matured. Cheese sensory properties differed between systems only after a long ripening period (6 months). Regarding the ecological performances, the DIV plot showed greater botanical and entomological biodiversity than the PROD plot. This study provides evidence that the balance between animal performances, dairy product quality and biodiversity in dairy systems is more complex than previously thought, since the expected benefits of each system vary markedly over periods. The evolution of herbage vegetation stage during the grazing season combined with the botanical composition of the pasture is a key component for understanding these variations.

Some effects of botanical composition of pasture on growth and wool production of weaner sheep

August-born Corriedale lambs were weaned at ten weeks old and, for the following 12 months, were grazed on 16 plots. Each plot had been sown six years previously, to one of eight pasture mixtures which differed in their grass component, but not in their clover component. Trifolium perenne, Phalaris tuberosa, Dacylis glomerata, Trifolium repens, T . subterraneum, and T. fragiferum were sown. Hordem leporinum volunteered in most plots. Where perennial grass species were sown, Trifolium repens (white clover) contributed less than two per cent to the pasture present on the plots. For the two plots where perennial grass was not sown, white clover contributed up to 31 per cent. The total for all sown clover species present in the pasture varied from approximately 100 to 1000 kg ha-1, or approximately 3-30 per cent. Apart from the two plots where perennial qrass was not sown, the clover species present was mainly Trifolium subterraneum (subterranean clover). Average fleece weights varied from 3.1-4.9 kg on the different plots. The amount of sown clover present in the pasture accounted for 77 per cent of the between-plot variation in fleece weight and 66 per cent of the between-plot variation in annual liveweight gain. Measurements of pasture growth were made for four pasture mixtures. Total pasture growth showed differences of over 50 per cent due to pasture mixture, yet, when grazed at 20 weaners per hectare, differences in annual liveweight gain and fleece weight (10 months wool), due to pasture mixture, did not exceed 10 per cent. Annual liveweight gain and fleece weight were not correlated total pasture growth. However, pasture growth rate measured at monthly intervals, accounted for 43 per cent of the variation in mean daily liveweight gain during these individual months.

Seasonal variation of phosphorus in soil and pasture

Abstract Availability of soil phosphate to pasture plants, as indicated by rate of growth and phosphorus concentration in herbage dry matter, is typically greater in spring than in autumn and winter. The hypothesis that this apparent higher phosphate status of soils under pasture in spring is due to a build-up of available phosphate during the period of slow growth in winter has been examined by measurement of pasture and soil properties at monthly intervals over 14 months on seven widely differing soils in the Hawke's Bay and Wellington districts. The experimental areas were on developed pastures under rotational grazing. Rate of pasture growth, botanical composition of pasture, and concentration of phosphorus in the pasture species all followed the normal seasonal pattern. Anion-exchangeable phosphate, concentration of phosphate in O.O1M CaCl2, and phosphate retention showed significant changes over the summer, but there was little variation over the winterspring period to indicate a build-up of availab...

Grazing Experiments at Ukiriguru, Tanzania: III. A Comparison of Three Stocking Rates on The Productivity and Botanical Composition of Natural Pastures of Hardpan Soils

Grazing Experiments at Ukiriguru, Tanzania: III. A Comparison of Three Stocking Rates on The Productivity and Botanical Composition of Natural Pastures of Hardpan Soils

Effects of treading by dairy cows on pasture production and botanical structure, on a Te Kowhai soil

Abstract The effect on pasture dry matter (D.M.) production and botanical composition of treading by dairy cows while grazing autumn-saved pasture in late winter was examined over three years. The silty clay soil was close to field capacity when trodden. Levels of treading were 60 and 120 cows per acre for one and two days. Plots treated in these ways were compared with controls from which the grass was cut and removed or cut and returned to the plots at the same time as the treading treatments were imposed. The effects of heavy treading on D.M. production were not great in any year, nor was there any evidence of cumulative effects when pastures were trodden for three years in succession. Differences between years in D.M. production and botanical composition were much greater than those caused by treatment effects within years. It is concluded that for this soil type a single period of severe treading when grazing off autumn-saved pasture in late winter will have little effect on animal production from su...

Liquid manure as a grassland fertilizer. III. The effect of liquid manure on the yield and botanical composition of pasture, and its interaction with nitrogen, phosphate and potash fertilizers

1. In an experiment conducted for the 3 years 1961-63 on a perennial rye-grass and white clover sward a split-plot design was used to investigate the effects of liquid manure (cow urine + water) and its interactions with various levels of nitrogen, phosphate and potash fertilizers on the yield of herbage and on the botanical composition of the sward.2. On the average the liquid manure contained 0.26% N, 0.44% K and had a pH of 8.6.3. The liquid manure treatments supplied 0, 50, 100, 200 and 400 lb. N/acre/year and 0, 87, 174, 349 and 697lb. K/acre/year. The fertilizer nitrogen treatments were 0, 100 and 200lb. N/acre; the potash treatments 0 and 166 lb. P/acre and the phosphate treatments 0 and 66lb. P/acre.