Selection by grazing sheep of pasture plants at low herbage availability and responses of the plants to grazing

1986 ◽  
Vol 37 (5) ◽  
pp. 527 ◽  
Author(s):  
DM Broom ◽  
GW Arnold
Keyword(s):  
Dry Matter ◽  
Growth Form ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growing Season ◽  
Abundant Species ◽  
Ecological Implications ◽  
Wimmera Ryegrass ◽  
Erodium Botrys ◽  
Pasture Plants

Merino sheep grazing annual pasture at the beginning of the growing season when the amount of herbage on offer was small, preferred to graze Wimmera ryegrass Lolium rigidum or subterranean clover Trifolium subterraneum rather than capeweed Arctotheca calendula, and Erodium botrys was avoided completely. Behaviour observations showed that capeweed plants were usually avoided. When the plants were grasped they were sometimes pulled up by the roots and then dropped so that the number of capeweed plants in the pasture declined. Supplementation with oats reduced grass intake. Harvesting behaviour changed with pasture conditions: as grass height declined in the pasture, the rates of biting, stepping and head swinging increased. Pasture measurements showed that, whilst capeweed plants continued to increase in height during grazing, as did ungrazed controls, ryegrass and clover plants decreased or remained short. Herbage dry matter increased in all species, owing especially to basal growth. The proportion of shoots and petioles which were erect increased in ungrazed plants, but the proportion which were prostrate was much greater in grazed plants. Individual plants adapted their growth form in a way which counteracted the depredations of grazers. The ecological implications of these findings are important. Firstly, the sheep were not foraging optimally in terms of maximising rate of intake, since two abundant species were largely ignored even though food availability was low. Secondly, because of their selectivity the sheep were giving the capeweed and Erodium a competitive advantage which, in these pastures, will persist through the growing season.

Effect of spelling newly sown pastures

1973 ◽  
Vol 13 (64) ◽  
pp. 549 ◽  
Author(s):  
RCG Smith ◽  
EF Biddiscombe ◽  
WR Stern
Keyword(s):  
Growth Form ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growing Season ◽  
Lolium Rigidum ◽  
Beneficial Effects ◽  
Continuous Grazing ◽  
Seed Reserves ◽  
Wimmera Ryegrass

Newly sown pure swards of Wimmera ryegrass (Lolium rigidum) and subterranean clover (Trifolium subterraneum) were either grazed or spelled (deferred) for five weeks after emergence in autumn and then evaluated with young Merino wethers stocked at 10 sheep ha-1. Sheep on deferred pastures had higher intakes and liveweight than on plots continuously grazed. Spelling increased the availability of pasture for prehension due to a greater weight of herbage being offered and the more erect growth form. Under continuous grazing the animal productivity on clover was much lower than on ryegrass but following deferment, both species had similar productivity. The beneficial effects of spelling after emergence were manifest over the ensuing ten months by liveweight, fleeceweight and number of days of grazing. Spelling also increased seed reserves at the end of summer and the number of plants re-establishing at the beginning of the next growing season.

Responses of intensively grazed dairy pastures to applications of fertiliser nitrogen in south-western Australia

2007 ◽  
Vol 47 (8) ◽  
pp. 927 ◽  
Author(s):  
M. D. A. Bolland ◽  
I. F. Guthridge
Keyword(s):  
Western Australia ◽  
Dry Matter ◽  
Maximum Yield ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growing Season ◽  
Mineral Elements ◽  
Italian Ryegrass ◽  
Total N ◽  
Dry Matter Digestibility

For the first time, we quantified pasture dry matter (DM) responses to applied fertiliser nitrogen (N) for intensively grazed, rain-fed, dairy pastures on sandy soils common in the Mediterranean-type climate of south-western Australia. The pastures are composed of subterranean clover (Trifolium subterraneum L.) and annual and Italian ryegrass (Lolium rigidum Gaud. and L. multiflorum Lam.). Six rates of N, as urea (46% N), were applied to 15 m by 15 m plots four times during 2002 and after each of the first 5–7 grazings in 2003 and 2004, throughout the typical April–October growing season. Total rates of N applied in the first year of the experiments were 0, 60, 120, 160, 200 and 320 kg N/ha, which were adjusted in subsequent years as detailed in the ‘Materials and methods’ section of this paper. The pastures in the experiments were rotationally grazed, by starting grazing when ryegrass plants had 2–3 leaves per tiller. The amount of pasture DM on each plot was measured before and after each grazing and was then used to estimate the amount of pasture DM consumed by the cows at each grazing for different times during the growing season. Linear increases (responses) of pasture DM to applied N occurred throughout the whole growing season when a total of up to 320 kg N/ha was applied in each year. No maximum yield plateaus were defined. Across all three experiments and years, on average in each year, a total of ~5 t/ha consumed DM was produced when no N was applied and ~7.5 t/ha was produced when a total of 200 kg N/ha was applied, giving ~2.5 t/ha increase in DM consumed and an N response efficiency of ~12.5 kg DM N/kg applied. As more fertiliser N was applied, the proportion of ryegrass in the pasture consistently increased, whereas clover content decreased. Concentrations of nitrate-N in the DM consistently increased as more N was applied, whereas concentrations of total N, and, therefore, concentration of crude protein in the DM, either increased or were unaffected by applied N. Application of N had no effect on concentrations of other mineral elements in DM and on dry matter digestibility and metabolisable energy of the DM. The results were generally consistent with findings of previous pasture N studies for perennial and annual temperate and subtropical pastures. We have shown that when pasture use for milk production has been maximised in the region, it is profitable to apply fertiliser N to grow extra DM consumed by dairy cows; conversely, it is a waste of money to apply N to undergrazed pastures to produce more unused DM.

The effect of sodium molybdate mixed in the lime seed pellet on nodulation, nitrogen content, and growth of subterranean clover

1969 ◽  
Vol 9 (39) ◽  
pp. 432 ◽  
Author(s):  
JW Gartrell
Keyword(s):  
Nitrogen Content ◽  
Dry Matter ◽  
Sodium Molybdate ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growing Season ◽  
Combined Nitrogen ◽  
Matter Production ◽  
Clover Seed ◽  
Ground Limestone

Sodium molybdate at l 1/2 oz, 3 oz, and 6 oz mixed with 6 lb ground limestone and pelleted onto 12 lb of Trifolium subterraneum cv. Geraldton inoculated with peat culture markedly reduced clover nodulation, growth, and combined nitrogen production compared with nil sodium molybdate. Mixtures of sodium molybdate l 1/2 oz, 3 oz, and 6 oz with l80 lb superphosphate drilled at 180 lb an acre with 12 lb an acre clover seed inoculated and pelleted with 6 lb ground limestone had no effect on nodulation, increased dry matter production by 70 per cent, and increased nitrogen per acre in tops by 110 per cent compared with nil sodium molybdate. The differences persisted into the second growing season.

Seasonal changes in the concentrations of copper, molybdenum and sulfur in pasture plants

1981 ◽  
Vol 21 (112) ◽  
pp. 498 ◽  
Author(s):  
GD Reddy ◽  
AM Alston ◽  
KG Tiller
Keyword(s):  
Soil Temperature ◽  
Water Content ◽  
Seasonal Changes ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Matter Production ◽  
Calcareous Sand ◽  
Matter Production ◽  
Wimmera Ryegrass

Seasonal changes in the concentrations of copper, molybdenum and sulfur in subterranean clover (Trifolium subterraneum), silver grass (Vulpia sp.), Wimmera ryegrass (Lolium rigidum), and capeweed (Arctotheca calendula) growing on lateritic podzolic soils were measured in glasshouse and field studies. The effects of varying soil temperature and water content on the concentrations of copper, molybdenum and sulfur in subterranean clover on a lateritic podzolic soil and a calcareous sand were also investigated. Similar seasonal patterns in plant composition were observed in the glasshouse and the field. The concentration of molybdenum tended to remain constant throughout the season, but that of copper and sulfur declined from autumn to spring; the decline was more rapid in the grasses than in subterranean clover and capeweed. Subterranean clover had higher concentrations of copper and sulfur but lower molybdenum than silver grass or Wimmera ryegrass. Capeweed contained more copper and molybdenum but less sulfur than subterranean clover. The concentrations of molybdenum and sulfur were similar in capeweed and the grasses. lncreasing soil temperature from 12 to 22�C increased the dry matter production and the concentrations of copper and molybdenum (but not sulfur) in subterranean clover on both soils. lncreasing soil water content slightly increased dry matter production and the concentration of molybdenum but had no effect on the concentration of copper and sulfur in subterranean clover. The results are discussed in relation to the health of grazing animals.

Factors affecting diet selection by sheep. V. Observed and predicted preference ranking for six cultivars of subterranean clover

1990 ◽  
Vol 41 (5) ◽  
pp. 957 ◽  
Author(s):  
WF Colebrook ◽  
JL Black ◽  
DB Purser ◽  
WJ Collins ◽  
RC Rossiter
Keyword(s):  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growing Season ◽  
Diet Selection ◽  
Preference Ranking ◽  
Factors Affecting ◽  
Freeze Dried ◽  
Two Stages ◽  
Good Agreement

Samples from six cultivars of subterranean clover (Trifolium subterraneum) were harvested at two stages of maturity (vegetative and senescent) and one cultivar (Dinninup) at two additional stages. The samples were freeze dried to 90% dry matter, cut to 25 mm length and offered in pairs to trained sheep to determine their preference rankings. Within each stage of maturity, each cultivar was compared with every other cultivar. The vegetative clovers showed only a small (non significant) range in mean per cent preference (57-41), but the senescent material showed a much larger range (87-20). Preference for a forage was determined as the intake of that forage expressed as a per cent of the total intake of both forages on offer. Preference ranking changed with maturity and did not appear to be related to either oestrogenicity or length of growing season of the clovers in the vegetative stage. However, with the senescent material, clovers with a long growing season tended to have higher preference rankings (except for Dinninup). The 'palatability' of each cultivar of senescent herbage was quantified by comparing it in separate tests with a standard hay cut to several lengths. The preference ranking of the six cultivars predicted from this comparison with the standard hay was in close agreement with the observed rankings from the two-way preference tests. The agreement between the predicted and the observed rankings indicated that the method of establishing preference for forages relative to a standard hay (cut to several lengths) could be used to predict preference ranking between forages without performing a direct comparison. Seventeen of eighteen individual comparisons showed good agreement between predicted and observed preference. Preference ranking within the cultivar Dinninup decreased with maturity, and its ranking relative to the other clovers decreased markedly in the senescent stage comparisons. 'Palatability' and preference ranking may have major implications in the establishment and persistence of pastures, as well as influencing diet selection and subsequent nutrient intake by grazing animals.

The influence of seed size and depth of sowing on pre-emergence and early vegetative growth of subterranean clover (Trifolium subterraneum L.)

1956 ◽  
Vol 7 (2) ◽  
pp. 98 ◽  
Author(s):  
JN Black
Keyword(s):  
Leaf Area ◽  
Seed Size ◽  
Vegetative Growth ◽  
Dry Matter ◽  
Relative Rate ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Total Leaf Area ◽  
Pot Culture

Changes in the pre-emergence distribution of dry matter in subterranean clover (Trifolium subterraneum L.) variety Bacchus Marsh were followed at 21°C, using three sizes of seed and three depths of sowing, ½, 1¼, and 2 in. Decreasing seed size and increasing depth of sowing both reduce the weight of the cotyledons a t emergence. Seed of the three sizes were sown a t three depths in pot culture a t staggered intervals so that emergence was simultaneous. Dry weight in the early vegetative stage was proportional to seed size, and total leaf area and leaf numbers showed similar trends. Plants of each seed size grew at the same relative rate. No effect of depth of sowing could be detected, and this was shown to be due to the cotyledon area a t emergence being constant for any given seed size, regardless of varying depth of sowing and hence of cotyledon weight. It was concluded that seed size in a plant having epigeal germination and without endosperm is of importance: firstly, in limiting the maximum hypocotyl elongation and hence depth of sowing, and secondly, in determining cotyledon area. Cotyledon area in turn influences seedling growth, which is not affected by cotyledon weight. Once emergence has taken place, cotyledonary reserves are of no further significance in the growth of the plants.

Response of defoliated swards of subterranean clover and yellow serradella to superphosphate applications

1991 ◽  
Vol 31 (6) ◽  
pp. 777
Author(s):  
MDA Bolland
Keyword(s):  
Field Experiment ◽  
Sandy Soil ◽  
Dry Matter ◽  
Maximum Yield ◽  
Subterranean Clover ◽  
Soil Surface ◽  
Trifolium Subterraneum ◽  
Herbage Yield ◽  
Ornithopus Compressus ◽  
The Relationship

The effect of superphosphate applications (0, 25, 50, 75, 100 and 125 kg P/ha to the soil surface) on the dry matter (DM) herbage production of dense swards of subterranean clover (Trifolium subterraneum cv. Junee) and yellow serradella (Ornithopus compressus cv. Tauro) was measured in a field experiment on deep, sandy soil in south-western Australia. The swards were defoliated with a reel mower at weekly intervals from 88 to 158 days after sowing, to a height of 2 cm for the first 9 cuts, 4 cm for the tenth cut and 5 cm for the eleventh cut. Yellow serradella was more productive than subterranean clover. Consequently, for the relationship between yield and the level of phosphorus (P) applied, yellow serradella supported larger maximum yields and required less P than subterranean clover, to produce the same DM herbage yield. Maximum yields of yellow serradella were 12-40% larger. To produce 70% of the maximum yield for yellow serradella at each harvest, yellow serradella required about 50% less P than subterranean clover. However, when yields were expressed as a percentage of the maximum yield measured for each species at each harvest, the relationship between yield and the level of P applied was similar for both species, and they had similar P requirements.

Pasture legume species differ in their capacity to acidify soil

1998 ◽  
Vol 49 (1) ◽  
pp. 53 ◽  
Author(s):  
C. Tang ◽  
L. Barton ◽  
C. Raphael
Keyword(s):  
Acid Production ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growth Stages ◽  
Total Acid ◽  
Ash Alkalinity ◽  
Ornithopus Sativus ◽  
Excess Cations ◽  
Pasture Legume

The capacity of subterranean clover (Trifolium subterraneum L. cv. Clare), medic (Medicago murex Willd. cv. Zodiac), serradella (Ornithopus sativus Brot. line SP1/13), biserrula (Biserrula pelecinus L. line Mor99), and woolly clover (Trifolium tomentosum L.) to acidify soil under N2 fixation was compared in a pot experiment using a poorly buffered sandy soil. The amount of acid produced per kg shoot dry matter (specific acid production) varied betweefin species and with growth stages, ranging from 44 to 128 cmol/kg shoot. Subterranean clover and serradella acidied soil to a greater extent than woolly clover and medic, whereas biserrula acidified soil least. Irrespective of pasture species and growth stage, specific acid production correlated well with concentrations of excess cations and calcium in shoots. Furthermore, total excess cation, ash alkalinity, and calcium in shoots were all good indicators of total acid production across all of the species.

Copper nutrition of subterranean clover (Trifolium subterraneum L. cv. Seaton Park). I. Effects of copper supply on growth and development

1981 ◽  
Vol 32 (2) ◽  
pp. 257 ◽  
Author(s):  
DJ Reuter ◽  
AD Robson ◽  
JF Loneragan ◽  
DJ Tranthim-Fryer
Keyword(s):  
Root Growth ◽  
Growth And Development ◽  
Copper Deficiency ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Growing Season ◽  
Internode Elongation ◽  
Plant Parts ◽  
Lateral Branches

Effects of severe and moderate copper deficiency on the development of leaves and lateral branches, on the distribution of dry weight within the plant, and on seed yield of Seaton Park subterranean clover were assessed as part of three glasshouse experiments. Copper deficiency markedly depressed top and root growth without producing any distinctive symptoms. It retarded phasic development by delaying development of leaves and lateral branches, senescence of plant parts, and flowering: it also depressed the proportion of stem plus petiole in plant tops and decreased internode elongation, pollen fertility and the number of burrs and seeds formed. As a result of its effect in delaying flowering, copper deficiency would depress seed production particularly strongly when low soil water supply shortens the growing season. The need for suitable procedures for diagnosing copper deficiency is emphasized by the lack of specific plant symptoms in this species.

Seed yield and nutritive value of dry, mature subterranean clover (Trifolium subterraneum L.)

2001 ◽  
Vol 41 (2) ◽  
pp. 169 ◽  
Author(s):  
Y. J. Ru ◽  
J. A. Fortune
Keyword(s):  
Seed Yield ◽  
Dry Matter ◽  
Mineral Content ◽  
Nutritive Value ◽  
Subterranean Clover ◽  
Zinc Content ◽  
Trifolium Subterraneum ◽  
Crude Fibre ◽  
Dry Matter Digestibility ◽  
Wide Range

The nutritive value of 26 cultivars of dry, mature subterranean clover was evaluated at Shenton Park, Perth, Western Australia. The cultivars were divided into 3 maturity groups according to flowering time and each cultivar was sown in blocks comprising 4 replicates. The plots were grazed by sheep at 2-week intervals during the growing season. Dry mature plant material and soil were sampled in summer to examine the effect of grazing and cultivar on seed yield and nutritive value of feed residues. Cultivars heavily grazed in spring had a low herbage mass. There was no difference in seed yield and seed weight between heavily and lightly grazed cultivars. Dry matter digestibility and mineral content of dry residues was inconsistent for the 2 grazing treatments. The dry matter digestibility of dry, mature subterranean clover ranged from 40 to 56%, with a wide range of crude fibre, nitrogen and mineral content for the 26 cultivars. While most minerals in the dry residues were above the requirement for sheep, 7 cultivars had a zinc content less than the maintenance requirement for sheep. There was an imbalance for all cultivars in calcium: phosphorus with a range of 4–10: 1. Concurrent estimates on the yield and composition of seed indicated that seed can be resource of minerals for grazing animals in summer. Most cultivars had a seed yield over 100 g/m2 with that of 9 cultivars being over 130 g/m2. Seed was rich in nitrogen, sodium, phosphorus, potassium, magnesium, zinc and copper, and poor in sodium, calcium and manganese. However, there were no cultivars with an appropriate ratio of calcium and phosphorus. The imbalance in nitrogen and sulfur was a result of high nitrogen content with the ratio ranging from 19: 1 to 29: 1.

Sign in / Sign up

Export Citation Format

Share Document