Herbage and animal production from native pastures and pastures oversown with Stylosanthes hamata. 2. Modelling studies

1993 ◽  
Vol 33 (5) ◽  
pp. 571 ◽  
Author(s):  
MR McCaskill ◽  
JG McIvor
Keyword(s):  
Strong Relationship ◽  
Animal Production ◽  
Wet Season ◽  
Stylosanthes Hamata ◽  
Native Pasture ◽  
Utilisation Rate ◽  
Modelling Studies ◽  
Native Pastures ◽  
The Times ◽  
Stocking Rates

Data from a long-term grazing experiment were used to develop relationships suitable for modelling between-year variation in pasture and animal production. The experiment was conducted near Townsville in North Queensland and consisted of a factorial combination of 2 stocking rates (0.6, 1.2 steers/ha) x 2 pasture types (native pasture, native pasture plus Stylosanthes hamata cv. Verano) x 2 superphosphate rates (nil, 300 kg/ha.year). Cattle were weighed monthly, and the herbage presentation yield and stylo content estimated annually. Relationships between annual liveweight gain (LWG) and a range of climate-derived parameters including the number of 'green days' were calculated from a water balance and pasture growth model. When a different intercept was allowed for each pasture and stocking rate combination, there was a strong relationship between annual LWG and the number of 'green days' (R2 = 0.78). In a more general relationship, LWG was related to green days, stylo content, and utilisation rate (R2 = 0.58). No relationships was found that would enable reliable prediction of between-year variation in the pasture attributes of stylo content and the water use efficiency of herbage growth. The times of the year when daily rates of LWG changed could be predicted satisfactorily, but rate of gain within each phase varied considerably from year to year. Differences in LWG between stocking rates occurred when there would have been restricted amounts of new green feed, or of stylo in the late wet season.

Herbage and animal production from native pastures and pastures oversown with Stylosanthes hamata. 1. Fertiliser and stocking rate effects

1993 ◽  
Vol 33 (5) ◽  
pp. 561 ◽  
Author(s):  
CJ Gardener ◽  
MR McCaskill ◽  
JG McIvor
Keyword(s):  
Animal Production ◽  
Stocking Rate ◽  
Heteropogon Contortus ◽  
Stylosanthes Hamata ◽  
Stylosanthes Humilis ◽  
Native Pasture ◽  
Utilisation Rate ◽  
Native Pastures ◽  
Fertiliser Application ◽  
Stocking Rates

Native pastures dominated by Heteropogon contortus (speargrass) were sown to Stylosanthes hanzata cv. Verano in 1972, and herbage production and steer growth rates were compared with those of native pastures from 1973 to 1985. The native pastures also contained naturalised Stylosanthes humilis, but its contribution to pasture yield diminished rapidly, after infection by Colletotrichum gloeospoirioides (anthracnose) in 1973. The experiment was a factorial design of 2 pasture types (native, native plus Verano) x 2 stocking rates (0.6, 1.2 steers/ha) x 2 superphosphate treatments (nil, 300 kg/ha.year) x 2 replicates. Fertiliser application decreased the proportion of legume but had no significant effect on herbage or animal production on this comparatively fertile site (extractable P, 18 mg/kg). Annual liveweight gains at the high and low stocking rates, respectively, on the native pasture averaged 100 and 120 kg/steer. Sowing to Verano did not affect herbage yields but increased annual liveweight gains by 28 and 36 kg/steer at low and high stocking rates. The high stocking rate of 1.2 steers/ha was sustainable for the first 9 years of the experiment, when above-average rainfall was received. However, in the following 3 below-average years, there was a shift to less-desirable species, and a decline in pasture productivity. Relative to the low stocking rate, herbage production on the native pasture in the final season was reduced by 60% and on the Verano pasture by 26%. The highest annual herbage utilisation rate that appeared sustainable in the long term was about 45%, which corresponded to a utilisation rate of 30% during the growing season (about November-May). When oversown with Verano, speargrass tended to decline in favour of annual grasses, weeds, and the introduced grass Urochloa mosanzhicensis, which had been sown on an adjacent experiment. Urochloa appeared to be a more suitable companion species than speargrass for Verano.

Impacts of grazing management options on pasture and animal productivity in a Heteropogon contortus (black speargrass) pasture in central Queensland. 4. Animal production

2010 ◽  
Vol 50 (4) ◽  
pp. 284 ◽  
Author(s):  
W. H. Burrows ◽  
D. M. Orr ◽  
R. E. Hendricksen ◽  
M. T. Rutherford ◽  
D. J. Myles ◽  
...  
Keyword(s):  
Stocking Rate ◽  
Economic Returns ◽  
Management Options ◽  
Heteropogon Contortus ◽  
Native Pasture ◽  
Utilisation Rate ◽  
Native Pastures ◽  
Long Term Impact ◽  
Stocking Rates

Steer liveweight gains were measured in an extensive grazing study conducted in a Heteropogon contortus (black speargrass) pasture in central Queensland between 1988 and 2001. Treatments included a range of stocking rates in native pastures, legume-oversown native pasture and animal diet supplement/spring‐burning pastures. Seasonal rainfall throughout this study was below the long-term mean. Mean annual pasture utilisation ranged from 13 to 61%. Annual liveweight gains per head in native pasture were highly variable among years and ranged from a low of 43 kg/steer at 2 ha/steer to a high of 182 kg/steer at 8 ha/steer. Annual liveweight gains were consistently highest at light stocking and decreased with increasing stocking rate. Annual liveweight gain per hectare increased linearly with stocking rate. These stocking rate trends were also evident in legume-oversown pastures although both the intercept and slope of the regressions for legume-oversown pastures were higher than that for native pasture. The highest annual liveweight gain for legume-oversown pasture was 221 kg/steer at 4 ha/steer. After 13 years, annual liveweight gain per unit area occurred at the heaviest stocking rate despite deleterious changes in the pasture. Across all years, the annual liveweight advantage for legume-oversown pastures was 37 kg/steer. Compared with native pasture, changes in annual liveweight gain with burning were variable. It was concluded that cattle productivity is sustainable when stocking rates are maintained at 4 ha/steer or lighter (equivalent to a utilisation rate around 30%). Although steer liveweight gain occurred at all stocking rates and economic returns were highest at heaviest stocking rates, stocking rates heavier than 4 ha/steer are unsustainable because of their long-term impact on pasture productivity.

Animal production on sown and native pastures on brigalow land in southern Queensland during drought

1969 ◽  
Vol 9 (36) ◽  
pp. 47 ◽  
Author(s):  
JE Coaldrake ◽  
CA Smith ◽  
JJ Yates ◽  
LA Edye
Keyword(s):  
Dry Matter ◽  
First Year ◽  
Stocking Rate ◽  
Rhodes Grass ◽  
Buffel Grass ◽  
Native Pasture ◽  
Chloris Gayana ◽  
Native Pastures ◽  
Stocking Rates ◽  
Better Than

Liveweight gains of six yearling steers grazing on each of four introduced grasses, each with lucerne, were compared with those from native pasture and native pasture plus forage oats, on a weakly solonized brown clay loam of moderate fertility in the brigalow region of southern Queensland. The pastures were grazed continuously for three years (1963 to 1965) at set stocking rates during the worst drought known from 87 years of local records. At the height of the drought in 1965 the sown pastures supported animals as far into the drought as did the two native pasture treatments at half the stocking rate. Sorghum almum (CV. Crooble) and Rhodes grass (Chloris gayana CV. Pioneer) died late in the drought and did not re-establish after rain, whereas buffel grass (Cenchrus ciliaris CV. Nunbank) and green panic (Panicm maximum var. trichoglume CV. Petrie) survived. Standing dry matter in the pastures was less than 1,000 lb dry matter an acre for much of the life of the experiment. At a stocking rate of one bullock to 2.3 acres S. almm gave the highest average gain per head in the first full year of grazing (462 lb per head), but this was only significantly better (P<0.05) than the gain from buffel grass, and not significantly better than the gains (at one bullock to 4.6 acres) on native pasture (415 lb per head) and native pasture plus oats (390 lb per head). Rainfall in the first year was 18 inches. In the remaining two years, with 13 and 8 inches of rain respectively, there were no significant differences between the sown pastures until the S. almum and Rhodes grass died. Native pasture plus oats (681 lb per head) and native pasture (424 Ib per head) gave the greatest gain per head in 1964, but not per acre because of the lower stocking rate.

Improvement in soil structure resulting from sown pastures on degraded areas in the dry savanna woodlands of northern Australia

Soil Research ◽  
1983 ◽  
Vol 21 (1) ◽  
pp. 83 ◽  
Author(s):  
BJ Bridge ◽  
JJ Mott ◽  
WH Winter ◽  
RJ Hartigan
Keyword(s):  
Soil Structure ◽  
Surface Soil ◽  
Northern Australia ◽  
Wet Season ◽  
Stylosanthes Hamata ◽  
Native Grassland ◽  
Townsville Stylo ◽  
Stocking Rates ◽  
High Infiltration

The structure of the surface soil under pastures sown on a former Themada australis native grassland and on degraded areas in the red earths of northern Australia was examined micromorphologically. Heavily grazed pastures containing the legumes Stylosanthes hamata cv. Verano and Alysicarpus vaginalis had more macropore space in the surface soil than arlightly grazed native grassland, while pastures containing S. humilis (Townsville stylo) had as little macropore space as degraded areas. Macropore space in a S. hamata pasture increased between the third and fourth wet seasons after establishment. Where macropore space was high, infiltration measurements showed that sorptivities were as high as those in the native grassland. Where macropore space was low, sorptivities were as low as those in degraded areas. However, all sown pastures showed low hydraulic conductivities equivalent to those in the degraded areas, and this was attributed to trampling during the wet season under the higher stocking rates involved. The improvement and maintenance of soil structure in the S. hamata and A. vaginalis pastures, together with their high sorptivities, indicates that they are stable in the long term.

Effects of fertilizer and stocking rate on pasture and beef production from sown pastures in north Cape York Peninsula. 2. Beef production and its relation to blood, faecal and pasture measurements

1977 ◽  
Vol 17 (85) ◽  
pp. 187 ◽  
Author(s):  
WH Winter ◽  
LA Edye ◽  
WT Williams
Keyword(s):  
Inorganic Phosphorus ◽  
Animal Production ◽  
Panicum Maximum ◽  
Stocking Rate ◽  
Beef Production ◽  
Wet Season ◽  
Fertilizer Rate ◽  
Guinea Grass ◽  
Stocking Rates ◽  
Phosphorus Levels

The animal production from two grass/legume pastures was measured over three years. The pastures were grazed at four stocking rates and annually received one of three maintenance rates of phosphorus fertilizer. The animals were given a phosphorus supplement at two rates. The grasses were either Brachiaria decumbens cv. Basilisk or Panicum maximum (common guinea grass) each sown with Stylosanthesguyanensis cv. Endeavour and Macroptilium atropurpureum cv. Siratro. The grasses had little effect on animal production although three Panicum pastures at higher stocking rates became overgrazed and required destocking during the experiment. Even though 73.5 kg ha-1 of phosphorus was used to establish the pastures, the maintenance rate of 40 kg ha-1 gave higher production than the 10 kg ha-1 rate in the first two years. In the third year, production was similar for each fertilizer rate. There was a concomitant rise in faecal phosphorus level with fertilizer rate but no such effect with blood inorganic phosphorus levels. Over the three years of the experiment the liveweight gain per hectare was similar (mean of 0.54 kg per day) at 1.7 and 1.9 beasts ha-1 but was significantly less at lighter stocking rates. In the last two years stocking rate did not significantly affect liveweight gain per head. At the highest stocking rate, gains were greater during the wet season and losses greater during the dry season than those at the lowest stocking rate. The phosphorus supplement did not affect animal production but increased blood inorgainc phosphorus levels. The relationships of animal production with blood and faecal compositions and with the pasture measurements described in a previous paper are discussed.

Superphosphate and stocking rate effects on a native pasture oversown with Stylosanthes humilis in central coastal Queensland. 2. Animal production

1978 ◽  
Vol 18 (95) ◽  
pp. 800 ◽  
Author(s):  
NH Shaw
Keyword(s):  
Animal Production ◽  
Early Years ◽  
Stocking Rate ◽  
Heteropogon Contortus ◽  
Stylosanthes Humilis ◽  
Rate Effects ◽  
Native Pasture ◽  
The Difference ◽  
Stocking Rates ◽  
Main Factor

Liveweight changes of beef cattle were measured over eight years in a grazing experiment on a native pasture (Heteropogon contortus dominant) oversown with S. humilis (T.S.). The pastures were subjected to three levels of molybdenized superphosphate (F0 = nil; F1 = 125 kg ha-2 annually; F2 = 250 kg ha-1 annually plus an extra 250 kg ha-1 initially) in factorial combination with four stocking rates and two sowing methods for T.S. (ground sowing into spaced cultivated strips, or aerial sowing). Stocking rates were gradually increased during the experiment and for the last three years overlapping ranges were used for the three fertilizer levels; the overall range was then from 0.55 to 1.65 beasts ha-1. Superphosphate increased liveweight gain per head in all years. The main effect was in the period of weight gain and the difference between rates of gain on fertilized and unfertilized pastures increased over years. The mean for F, and F, ranged from 370 to 71 0 g head-1 day-1 compared with 270 to 470 g head-1 day-1 for F0. Except for the last year, there were liveweight losses in all three fertilizer treatments in winter; treatment differences then were mostly small, with significant effects in only three of the eight years. F, gave higher annual liveweight gains than F1 in three of the first six years, but by years seven and eight these two treatments were equal. Comparisons with pasture data described in a previous paper showed highly significant linear relations between annual gains per head and T.S. yield (log10 kg ha-1), and it is concluded that this is the main factor in the liveweight response to fertilizer. Increasing stocking rate depressed gain per head in F, in all years (mean of 35 kg head-1 for an increase of 0.5 beasts ha-1). A similar effect occurred in F1 and F2 in early years, but there was virtually no stocking rate depression in F2 in the last two years, and a significant increase for F1 in the final year. This effect is ascribed to the increase in T.S. yield in fertilized pastures at high stocking rates. Sowing method had no effect on animal production.

Diet selection and liveweight performance of steers on Stylosanthes hamata-native grass pastures

1980 ◽  
Vol 31 (2) ◽  
pp. 379 ◽  
Author(s):  
CJ Gardener
Keyword(s):  
Stem Elongation ◽  
Perennial Grass ◽  
Diet Selection ◽  
Similar Rate ◽  
Dry Season ◽  
Wet Season ◽  
Native Grass ◽  
Stylosanthes Hamata ◽  
Large Bulk ◽  
Native Pasture

Diet selection in S. hamata-native grass pastures was studied over 25 months at Lansdown, north Queensland, In oesophageally fistulated steers. The results were uscd to interpret the relationship between winter rainfall and liveweight gain of steers on pastures with and without S. hamata. Steers selected green grass leaf early in the wet season (December-February), but preferred S. hamata in March when stem elongation and flowering occurred in the native grasses. They then continued to eat a high proportion of legume during the dry season until rain fell. At Lansdown, this may occur from 4 to 23 weeks after the pastures hay off. After the rain, the steers ignored the large bulk of mouldy dry legume, selecting instead both green and dry grass. Seed and green leaf of S. hamata made their greatest contribution to the diet at the end of the wet season when retained on the standing plant and easily accessible to cattle. Small amounts of seed and dried leaf were licked off the ground before rain fell. The nitrogen content of the diet in the S. hamata-native grass pastures rose to a peak in April and did not fall below 1.0% during the study. The level in July was twice that recorded for the native pasture. Cattle gained weight during the wet season at a similar rate for all pastures. After March steers on S. hamata-native pasture continued to gain weight longer onto the dry season than those on native pasture in three out of four years. Much of the additional weight gains of steers on S. hamata were lost with the advent of winter rain, especially at the high stocking rate from which the perennial grass component had been lost. The value of S. hamata cv. Verano in the greatly differing climatic environments existing in northern Australia is considered.

Dry season protein and energy supplements for beef cattle on native pastures at Katherine, N.T

1963 ◽  
Vol 3 (11) ◽  
pp. 280 ◽  
Author(s):  
MJT Norman
Keyword(s):  
Beef Cattle ◽  
Peanut Meal ◽  
Dry Season ◽  
High Protein ◽  
Wet Season ◽  
Protein Supplements ◽  
Native Pasture ◽  
Native Pastures ◽  
Sorghum Grain ◽  
Energy Supplements

Three experiments planned to gain information on the gross nutritive deficiencies of native pasture as a feed for beef cattle during the dry season were carried out at Katherine, N.T., between 1960 and 1962. Groups of local Shorthorn steers were grazed on native pasture from July to November and fed supplements of crushed sorghum grain and peanut meal at different levels of total digestible nutrients and digestible crude protein. The results suggest that up to the time of early storm rains, prior to the wet season proper, the dry standing native pasture is an adequate source of energy, which can be effectively utilized if cattle are given a small quantity of high-protein supplement. During the period of early rains, the pasture is not an adequate source of energy, and high-protein supplements do not prevent liveweight loss. High spring temperatures before the early rains did not appear to affect adversely the performance of supplemented cattle.

scholarly journals Sensitivity Analysis of Sentinel-1 Backscatter to Oil Palm Plantations at Pluriannual Scale: A Case Study in Gabon, Africa

2021 ◽  
Vol 13 (11) ◽  
pp. 2075
Author(s):  
J. David Ballester-Berman ◽  
Maria Rastoll-Gimenez
Keyword(s):  
Time Series ◽  
Sensitivity Analysis ◽  
Oil Palm ◽  
Time Interval ◽  
Potential Candidate ◽  
Initial Growth ◽  
Natural Forests ◽  
Wet Season ◽  
Radar Signatures ◽  
The Times

The present paper focuses on a sensitivity analysis of Sentinel-1 backscattering signatures from oil palm canopies cultivated in Gabon, Africa. We employed one Sentinel-1 image per year during the 2015–2021 period creating two separated time series for both the wet and dry seasons. The first images were almost simultaneously acquired to the initial growth stage of oil palm plants. The VH and VV backscattering signatures were analysed in terms of their corresponding statistics for each date and compared to the ones corresponding to tropical forests. The times series for the wet season showed that, in a time interval of 2–3 years after oil palm plantation, the VV/VH ratio in oil palm parcels increases above the one for forests. Backscattering and VV/VH ratio time series for the dry season exhibit similar patterns as for the wet season but with a more stable behaviour. The separability of oil palm and forest classes was also quantitatively addressed by means of the Jeffries–Matusita distance, which seems to point to the C-band VV/VH ratio as a potential candidate for discrimination between oil palms and natural forests, although further analysis must still be carried out. In addition, issues related to the effect of the number of samples in this particular scenario were also analysed. Overall, the outcomes presented here can contribute to the understanding of the radar signatures from this scenario and to potentially improve the accuracy of mapping techniques for this type of ecosystems by using remote sensing. Nevertheless, further research is still to be done as no classification method was performed due to the lack of the required geocoded reference map. In particular, a statistical assessment of the radar signatures should be carried out to statistically characterise the observed trends.

The design and interpretation of experiments to study animal production from grazed pasture

1968 ◽  
Vol 71 (3) ◽  
pp. 327-335 ◽  
Author(s):  
J. B. Owen ◽  
W. J. Ridgman
Keyword(s):  
Simple Model ◽  
Unit Area ◽  
Personal Communication ◽  
Animal Production ◽  
Stocking Rate ◽  
Grazed Pasture ◽  
Stocking Rates ◽  
Pasture Productivity

SUMMARYExperiments designed to assess differences between treatments in pasture productivity as measured by the production of animals are complicated by the stocking rates chosen. The paper attempts toderive a simple model relating production per animal and production per unit area to stocking rate for meat animals, based on biological considerations.A method is proposed which would allow meaningful grazing experiments to be carried out employing only one stocking rate, thus considerably reducing the expense of this type of experimentation.The model is applied to some recent data obtained by Hodgson (1966) and Appleton (1967, personal communication).

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