Pasture and the theory of diversification

2017 ◽  
Vol 57 (7) ◽  
pp. 1210 ◽  
Author(s):  
C. D. Lewis ◽  
C. K. M. Ho ◽  
B. R. Cullen ◽  
B. Malcolm

Diversifying farm activities can reduce the business risk of agricultural production. The aim of the present study was to investigate the effect of diversifying the types of dairy pastures sown on (1) the average seasonal growth rate (kg DM/ha/day) of pasture and (2) the variability of seasonal growth rate of pasture over time by diversifying the types of pastures grown on a dairy farm. This approach is similar to the approach used to assess the diversification of annual cropping activities, although repeated harvest of pasture by grazing animals and the seasonality of pasture DM production complicates the question. The question investigated was ‘How does substituting chicory (Cichorium intybus L.) or tall fescue (Festuca arundinaceae Schreb.) monocultures for a perennial ryegrass (Lolium perenne L.)–white clover (Trifolium repens L.) pasture in increasing proportions affect (1) the average growth rate (kg DM/ha.day) of pasture and (2) the variability of growth rate of pasture in each season?’. The biophysical model DairyMod was used to simulate 30 years growth of a mixed sward of perennial ryegrass and white clover and monocultures of chicory and tall fescue for two rain-fed locations in the high-rainfall zone of southern Australia. Including chicory in the pasture base had the potential to increase pasture growth rate during the summer–early autumn period compared with growing perennial ryegrass–white clover alone. This increase in pasture growth rate increased variability, and reduced growth rates in late autumn–winter and spring. The simulated growth rates of tall fescue and perennial ryegrass were strongly correlated in all seasons; hence, tall fescue did not reduce the variability of total DM. Further analysis would include price correlations and variability and consider the whole-farm implications. The analysis presented here for the high-rainfall zone showed that introducing alternative forages may have benefits in terms of increasing pasture growth rates at critical times of the production year, but the variability of the growth rate was not reduced.

2004 ◽  
Vol 55 (6) ◽  
pp. 625 ◽  
Author(s):  
Z. N. Nie ◽  
D. F. Chapman ◽  
J. Tharmaraj ◽  
R. Clements

An experiment was conducted on 2 contrasting soil types for 4 years (1998–2001) to determine the effects of plant species mixture, management inputs, and environment on sown species herbage accumulation (SSHA) and seasonal growth pattern of pastures for dairy production. Five pasture types, combined with 3 management treatments, were established in south-west Victoria. Three of the pasture types were based on perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.). One pasture type included short-term, winter- or summer-active species in the perennial ryegrass–white clover mixture. The final pasture type was based on the perennial grasses cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.), and phalaris (Phalaris aquatica L.). The 3 management treatments involved different levels of fertiliser input and weed/pest control. Pasture type had a significant impact on SSHA in 3 of 4 years. In the first year, the mixture based on cocksfoot, tall fescue, and phalaris had the lowest SSHA, but this pasture matched other types from 1999 onwards and yielded the highest in 2000, the year with the driest summer during the experiment. Ryegrass–white clover mixture based on old cultivars had generally lower SSHA than the other types except in the first year. Higher fertiliser inputs increased SSHA by 16–28% in 1998, 1999, and 2001. There was a significant site × pasture type interaction on SSHA in 2000. The mixture based on cocksfoot, tall fescue, and phalaris produced up to 1–2 t DM/ha.year more than the other types in summer and autumn in dry–normal years. The inclusion of short-term species, or more stoloniferous white clover cultivars, in the ryegrass–white clover mixture, had little effect on SSHA, or on the seasonal distribution of pasture growth. Pastures based on perennial grasses other than perennial ryegrass appear to have potential for altering the seasonality of pasture growth in south-west Victoria, although the benefits resulting from changing pasture type will depend on environment. Overall, increasing management inputs usually had a greater effect on SSHA than changing pasture type, but management responses were also affected by environment, particularly through the effects of a dry season on a sandy soil type.


Author(s):  
G.J. Goold

Three perennial ryegrass cultivars (L&urn perennr L.), Grasslands 'Ruanui', Grasslands 'Nui' and Yates 'Ellett' were sown in two experiments on different peat soils at Moanatuatua. Both experiments were alternately mown and grazed with Friesian cattle after an establishment period on each soil. Ruanui swards, grown with white clover (Trfolium repens L.) were the least productive one both a partially-developed and a well-developed peat. "Ellett' and 'Nui' swards produced 28% and 20% more total DM than 'Ruanui' on a well developed peat and 16% and 5%, respectively, on a partially-developed peat, over a 21 cut period from September 1976-September 1979. Pasture growth rates were generally lower on the partially-developed peat and cultivar differences were minimized in this experiment. Peak sward growth rates occurred in December-January on both peat soils. Whereas all three ryegrass cultivar swards reached a peak growth rate of approximately 70 kg DM/ha/day on the partially-developed peat, and Ruanui and Nui reached similar levels on the developed peat, Ellett swards attained higher growth rates (90 kg DM/ha/day) on the more fertile peat. Sward growth rates of Ellett and Nui pastures were consistently higher than those of Ruanui in the autumn. Ellett pastures contained more ryegrass and less white clover than Ruanui swards with Nui being intermediate in grass and clover composition. The value of Ellett and Nui on fertile, organic soils in the Waikato is emphasised.


Geosciences ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 187
Author(s):  
Rolf Vieten ◽  
Francisco Hernandez

Speleothems are one of the few archives which allow us to reconstruct the terrestrial paleoclimate and help us to understand the important climate dynamics in inhabited regions of our planet. Their time of growth can be precisely dated by radiometric techniques, but unfortunately seasonal radiometric dating resolution is so far not feasible. Numerous cave environmental monitoring studies show evidence for significant seasonal variations in parameters influencing carbonate deposition (calcium-ion concentration, cave air pCO2, drip rate and temperature). Variations in speleothem deposition rates need to be known in order to correctly decipher the climate signal stored in the speleothem archive. StalGrowth is the first software to quantify growth rates based on cave monitoring results, detect growth seasonality and estimate the seasonal growth bias. It quickly plots the predicted speleothem growth rate together with the influencing cave environmental parameters to identify which parameter(s) cause changes in speleothem growth rate, and it can also identify periods of no growth. This new program has been applied to multiannual cave monitoring studies in Austria, Gibraltar, Puerto Rico and Texas, and it has identified two cases of seasonal varying speleothem growth.


2010 ◽  
Vol 24 (4) ◽  
pp. 440-445 ◽  
Author(s):  
Daniel T. Earlywine ◽  
Reid J. Smeda ◽  
Travis C. Teuton ◽  
Carl E. Sams ◽  
Xi Xiong

Oriental mustard seed meal (MSM), a byproduct generated by pressing the seed for oil, exhibits herbicidal properties. In turfgrass, soil fumigants such as methyl bromide are used to control weeds prior to renovation of turf. Environmental concerns have resulted in deregistration of methyl bromide, prompting the need for alternatives. The objective of this research was to determine the effect of MSM on the establishment of selected turfgrass weeds as well as inhibitory effects on establishment of desirable turfgrasses. Greenhouse experiments were conducted in 2006 and 2007 at the University of Missouri. MSM was amended in soil at 0, 1,350 (low), 2,350 (medium), and 3,360 kg ha−1(high) concentrations. Weed species included annual bluegrass, large crabgrass, buckhorn plantain, white clover, and common chickweed. Turfgrass species included: Rembrandt tall fescue, Evening Shade perennial rye, and Riviera bermudagrass. All species were seeded into soil amended with MSM and either tarped or left untarped. All treatments were compared to dazomet (392 kg ha−1), a synthetic standard. Plant counts and biomass of all species were recorded 4 wk after seeding. Overall, tarped treatments suppressed weed emergence 27 to 50% more compared to untarped treatments, except for large crabgrass. High rates of MSM suppressed emergence of all weeds ≥ 63%. Compared to the untreated control, the density of buckhorn plantain, white clover, and common chickweed was reduced by ≥ 42% at low rates of MSM. Biomass of buckhorn plantain, annual bluegrass, common chickweed, white clover, and large crabgrass was reduced from 37 to 99% at high rates of MSM. MSM at high rates reduced stand counts of tall fescue and perennial ryegrass up to 81% and 77% respectively, compared to the untreated control. Regardless of MSM rates or tarping, suppression of common bermudagrass emergence did not exceed 30%; tarped treatments actually increased bermudagrass emergence by 22%. The biomass for tall fescue, perennial ryegrass, and bermudagrass was reduced by 85, 68, and 10%, respectively, at high rates of MSM. For tall fescue, MSM at all rates strongly suppressed seed germination by 7 d after planting (DAP) (up to 100%), with additional germination observed through 14 DAP, but not thereafter. In both trials, dazomet completely suppressed emergence of all weeds. MSM appears to suppress emergence and growth of a number of weeds common in turf, with potential selectivity for bermudagrass.


1999 ◽  
Vol 7 ◽  
pp. 19-26
Author(s):  
R.H. Watson ◽  
R.G. Keogh ◽  
M.F. Mcdonald

Two groups (n=39) of Romney breeding ewes were maintained under the same grazing management on either endophyte-infected (E+) or endophytefree (E-) perennial ryegrass pasture for two years (1997-1998) following a one-year equilibration period. The ewes were naturally mated in March each year and ovulation rate at 1st mating was measured, and conception and the number of lambs born and weaned were recorded. All ewes were weighed monthly and lamb growth rates were determined between birth and weaning. Mean mating date was delayed by 1.8 days (P


1990 ◽  
Vol 41 (6) ◽  
pp. 1083 ◽  
Author(s):  
AA McGowan

It is often claimed that improved pastures grow better in the early years after initial establishment than after many years of fertilization and grazing. A pot experiment was conducted to compare the dry matter production of white clover and perennial ryegrass when sown into soil from old established pastures and into soil taken from adjacent roadsides which had not previously been cultivated, fertilized, sown or grazed. On 8 out of 10 sites, white clover growth was consistently poorer when sown into the paddock soil than into the roadside soil. The average growth on paddock soil from these 8 sites was only 61% that of growth on the roadside soils. With perennial ryegrass there was no similar depression; in fact, the overall average growth of grass on the paddock soils was 121% that on the roadside soils. The explanation for this difference in growth of clover on the two soil types was apparently not due to any difference in the N status of the clover plants, as at no harvest was this difference significantly reduced when N fertilizer was regularly applied to the clover. The economic importance of these findings depends on confirmation of the results in the field. Possible, but untested, explanations may lie in different levels of soil-borne pests and diseases, or a residual allelopathic effect of improved pasture species on the growth of clover on the old pasture soil.


1982 ◽  
Vol 99 (1) ◽  
pp. 153-161 ◽  
Author(s):  
D. A. Davies ◽  
T. E. H. Morgan

SUMMARYHerbage characteristics of perennial ryegrass (Lolium perenne L.), cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.) and timothy (Phleum pratense L.) pastures were obtained whilst rotationally grazed by ewes and their single lambs at a fixed stocking rate of 25/ha on an upland site (305 m O.D.) in mid-Wales. Drymatter production of cocksfoot averaged 32·1 kg/ha/day over the 3-year duration of the trial (1975·7) and was 13·3 kg/ha/day lower than that of the other three grass species. This resulted in a 8 kg/ha/day reduction in dry-matter intake on cocksfoot; this was significantly lower (P < 0·05) than that achieved on the other grasses, which were similar to one another around 36 kg/ha/day.In vitro digestibility of the herbage ranked in the order perennial ryegrass > timothy = cocksfoot > tall fescue. Intake of digestible organic matter (DOMI) was lower on cocksfoot than on perennial ryegrass and timothy. Differences were also detected in crude protein, water-soluble carbohydrates and sodium composition between species.Dry-matter intake was positively correlated with herbage growth rates (r = 0·95, P < 0·001) but not to digestibility of herbage on offer (r = 0·18). Both ewe and lamb live-weight gains were positively related to intake of dry matter and DOMI.Reference is made to comparative yield data between the grasses obtained under cutting trials. In the 2nd and 3rd harvest years (1967–1967) growth rates in the grazing experiment were 76, 61, 81 and 80% of the 66·2, 66·7, 67·8 and 65·0 kg D.M./ha/day obtained under a cutting regime on perennial ryegrass, cocksfoot, tall fescue and timothy swards respectively. This illustrates the danger involved in assessing the potential of grasses based on such information.The results are discussed in relation to the value of the species for use under grazing in the uplands.


2011 ◽  
Vol 51 (8) ◽  
pp. 717 ◽  
Author(s):  
K. P. Golding ◽  
E. D. Wilson ◽  
P. D. Kemp ◽  
S. J. Pain ◽  
P. R. Kenyon ◽  
...  

The potential of mixed herb and legume pastures to increase post-weaning growth rates of lambs in comparison to ryegrass-based pastures was evaluated. Unrestricted allowances of pasture treatments were offered to weaned, Romney lambs in consecutive autumns of 2007 and 2008. In Experiment 1 (2007), 300 ewe lambs were allocated for 64 days to one of four permanent sward mix treatments; chicory, plantain, red clover and white clover [herb/clover (n = 75)]; plantain, perennial ryegrass and white clover [plantain/pasture (n = 75)]; tetraploid perennial ryegrass and white clover [new pasture (n = 75)]; or diploid perennial ryegrass, other grass species and white clover [old pasture (n = 75)]. In Experiment 2 (2008), the first three pasture treatments from Experiment 1 were re-used (‘old pasture’ not used) with 168 wether lambs allocated for 35 days; herb/clover (n = 56); plantain/pasture (n = 56); and new pasture (n = 56). Unfasted liveweights of all lambs were recorded at weekly intervals and before slaughter. A sub-sample of 78 lambs from Experiment 2 was slaughtered to obtain the carcass weights, tissue depth (11 cm from the spine over the 12th rib) and commercial meat percentages. At the conclusion of Experiment 1 the herb/clover treatment lambs were heavier than the new pasture and plantain/pasture treatment lambs, which were heavier than the old pasture treatment lambs (47.4 vs 41.5 vs 41.5 vs 39.6 ± 0.4 kg, respectively) (P < 0.05). At the conclusion of Experiment 2 the herb/clover treatment lambs were heavier than the new pasture treatment lambs, which were heavier than the plantain/pasture treatment lambs (35.6 vs 32.8 vs 28.8 kg ± 0.4, respectively) (P < 0.05). In Experiment 1 a higher percent of herb/clover treatment lambs grew faster than 200 g/day (P < 0.001) than of the pasture/plantain, new pasture and old pasture treatment lambs (87 vs 4 vs 3 vs 0 percent, respectively). In Experiment 2 only the herb/clover lambs (71%) grew faster than 200 g/day (P < 0.05). In Experiment 2 herb/clover treatment lambs had heavier (P < 0.05) final carcass weight (15.7 ± 0.20 vs 14.8 ± 0.38 vs 14.6 ± 0.27 kg) compared with the plantain/pasture and new pasture lambs, respectively. It was demonstrated that a herb/clover mixed sward can increase post-weaning lamb liveweight gains during unrestricted feeding conditions compared with traditional perennial ryegrass-based pastures.


1994 ◽  
Vol 42 (6) ◽  
pp. 723 ◽  
Author(s):  
MA Hindell ◽  
MM Bryden ◽  
HR Burton

Growth rates and changes in body composition of pups were monitored during the 3-week lactation period of southern elephant seals at Macquarie Island. Despite a slight decrease in weight in the first days post-partum, pups attained a mass of 114+/-16.6 kg (mean+/-s.d.) at weaning, representing an average growth rate of 3.53+/-0.80 kg day-1 over the entire lactation period. The proportion of body mass represented by fat was less than 3% at birth, increasing to 40.8+/-12.7% at weaning. Lean tissue mass altered little for most of the lactation period, but did show an increase in the last four days. The fat content of the milk reflected these changes, starting at 16.1+/-6.98% on Day 1 of lactation and increasing to 39.5+/-15.2% about the time of weaning. Fat content of the milk was, however, highly variable and at weaning ranged from 7% to 55%. Although the growth rate of the pup was correlated with mass lost by its mother during lactation, there was no relationship between maternal mass and weaning weight of pups. It is suggested that growth rates may be related to maternal condition and not simply mass, and, further, that differences in growth rates between populations of southern elephant seals are related to maternal energy reserves.


1967 ◽  
Vol 68 (1) ◽  
pp. 11-21 ◽  
Author(s):  
R. C. Grimes ◽  
B. R. Watkin ◽  
J. R. Gallagher

1. An experiment was conducted in which lambs grazed on pastures of cocksfoot, ryegrass and tall fescue grown with and without white clover, as well as on pastures of pure white clover.


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