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.

Quantifying pasture dry matter responses to applications of potassium fertiliser for an intensively grazed, rain-fed dairy pasture in south-western Australia with or without adequate nitrogen fertiliser

2009 ◽  
Vol 49 (2) ◽  
pp. 121 ◽  
Author(s):  
M. D. A. Bolland ◽  
I. F. Guthridge
Keyword(s):  
Dairy Cows ◽  
Western Australia ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Soil Samples ◽  
Italian Ryegrass ◽  
Soil Test ◽  
Soil Test K

Rain-fed dairy pastures on sandy soils common in the high rainfall (>800 mm annual average) Mediterranean-type climate of south-western Australia comprise the annual species subterranean clover (Trifolium subterraneum L.) and annual and Italian ryegrass (Lolium rigidum Gaud. and L. multiflorum Lam.). In wet years, clover becomes potassium (K) deficient and shows large dry matter (DM) responses to applied fertiliser K due to leaching of K in soil by rainfall. In contrast, ryegrass rarely shows DM responses to applied K. Many dairy pastures in the region are now intensively grazed to maximise pasture use for milk production, and nitrogen (N) fertiliser is applied after each grazing. It is not known if frequent applications of fertiliser N to these pastures changes pasture DM responses to applied K. Therefore, a long-term (2002–07) field experiment was undertaken on an intensively grazed dairy pasture in the region to quantify pasture DM responses to applied fertiliser K with or without applications of adequate fertiliser N (141–200 kg N/ha per year). Soil samples (top 10 cm of soil) were collected from each plot of the experiment each February to measure soil test K by the standard Colwell sodium bicarbonate procedure used for both K and phosphorus soil testing in the region. When no N was applied, pasture comprised ~70% (dry weight basis) clover and 25% ryegrass, compared with ~70% ryegrass and 25% clover when adequate N was applied. Significant linear responses of pasture DM to applied K occurred in 3 of the 6 years of the experiment only when no N was applied and clover dominated the pasture. The largest response varied from ~1.7 to 2.0 t/ha DM consumed by dairy cows at all grazings in each year, giving a K response efficiency of between 8 and 10 kg DM/ha per kg K/ha applied. Significant pasture DM responses to applied N occurred at all grazings in each year, with ~2–3 t/ha extra DM consumed by dairy cows at all grazings in each year being produced when a total of 141–200 kg N/ha was applied per year, giving an N response efficiency of ~7–19 kg DM/ha per kg N/ha applied. Soil test K values were very variable, attributed to varying proportions of soil samples per plot collected between and within cow urine patches, containing much K, arbitrarily deposited on experimental plots during grazing. Soil test K values were not significantly affected by the rates of K applied per year. A re-evaluation of results from the major soil K test study conducted for pastures in the region confirm that ryegrass rarely showed DM responses to applied K, and that for clover, soil K testing poorly predicted the likelihood of K deficiency in the next growing season.

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.

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.

Responses of subterranean clover and Italian ryegrass to application of lime

2001 ◽  
Vol 41 (2) ◽  
pp. 177 ◽  
Author(s):  
M. D. A. Bolland ◽  
Z. Rengel ◽  
L. Paszkudzka-Baizert ◽  
L. D. Osborne
Keyword(s):  
Lolium Multiflorum ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Water Soluble ◽  
Italian Ryegrass ◽  
Energy Concentration ◽  
Soluble Carbohydrates ◽  
Dry Matter Digestibility ◽  
Loam Soil ◽  
Yield Responses

A glasshouse experiment evaluated dried herbage yield responses of dense swards of subterranean clover (Trifolium subterraneum cv. Trikkala) or Italian ryegrass (Lolium multiflorum cv. Aristocrat) to applications of different amounts of lime (0, 2.5, 5.0, 7.5, 10 and 12.5 t lime/ha) to either a loam or a sand. Yields were measured at 4 harvests [29, 51, 86 and 108 days after sowing (DAS)] when ryegrass plants had 3 leaves per tiller. Increasing amounts of lime raised the pH (1: 5, soil: 0.01 mol CaCl2/L) of the loam by 2.7 units and that of the sand by 2.0 units. Applications of lime significantly (P<0.05) increased dry herbage yields, by between 16 and 53%, for: (i) clover on the loam soil at 86 and 108 DAS, and for the sand at 108 DAS; (ii) ryegrass on the loam at 51, 86 and 108 DAS, and on the sand at 108 DAS. Increasing amounts of lime had no effect on the concentration of nutrient elements in dried herbage of either clover or ryegrass, except that the concentration of calcium increased, and the concentration of sodium, manganese and zinc (and boron for ryegrass only) all decreased. Additions of lime had no effect on dry matter digestibility, metabolisable energy, concentration of crude protein or water-soluble carbohydrates in dried herbage at any of the 4 harvests.

Seed production and persistence of Carnamah and other early strains of Trifolium subterraneum in the wheatbelt of Western Australia

1967 ◽  
Vol 7 (24) ◽  
pp. 25 ◽  
Author(s):  
GB Taylor ◽  
RC Rossiter
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Western Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growing Season ◽  
Early Flowering ◽  
The Other ◽  
Factors Affecting ◽  
Seed Yields

Seed production and persistence of the Carnamah, Northam A, Dwalganup, and Geraldton strains of subterranean clover (Trifolium subterraneum L.) were examined in undefoliated swards in the wheatbelt of Western Australia. The early flowering characteristic of Carnamah was not always associated with higher seed yields. Only when there was a well-defined, early finish to the growing season, or when flowering was very much earlier in Carnamah (viz., following an early 'break' to the season), did this strain clearly outyield both Northam A and Geraldton. The seed yield of Dwalganup was generally inferior to that of the other strains. Factors affecting regeneration are discussed. Under low rainfall conditions, poorer germination-regulation of Carnamah, compared with Geraldton and Northam A, would be expected to result in poorer persistence unless offset by higher seed yields in the Carnamah strain.

Digesta flow studies in sheep fed two mature annual legumes

1994 ◽  
Vol 45 (4) ◽  
pp. 889
Author(s):  
X Li ◽  
RC Kellaway ◽  
RL Ison ◽  
G Annison
Keyword(s):  
Amino Acids ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Apparent Digestibility ◽  
Total N ◽  
Flow Rates ◽  
Dietary Nitrogen ◽  
Nitrogen Intake ◽  
Trifolium Resupinatum

Mature subterranean clover (Trifolium subterraneum cv. Junee) and Persian clover (Trifolium resupinatum cv. Kyambro) were fed to cannulated sheep. Flow rates of dry matter and nitrogen in the abomasum and ileum were estimated using a double marker method. Contents of hemicellulosic polysaccharides (xylose and mannose monomers) were higher in Kyambro than in Junee. Although Junee contained higher levels of total N and amino acids, the relative concentrations of cystine and methionine were markedly higher in Kyambro. Dry matter intakes and flow rates in the abomasum, ileum and faeces were similar on Kyambro and Junee. Dietary nitrogen intake was lower and endogenous re-cycled nitrogen higher on Kyambro than on Junee. Ileal flow of nitrogen was similar to nitrogen intake on Kyambro. Apparent nitrogen digestibility was lower in the whole tract and higher in the intestines on Kyambro. The higher apparent digestibility of nitrogen in the intestines of sheep eating Kyambro was associated with a greater proportion of nitrogen leaving the stomach coming from endogenous sources. The lower nitrogen digestibility of Kyambro in the whole tract indicated lower digestibility of dietary nitrogen, which was associated with higher contents of xylose and mannose.

Comparison of the phosphate requirements of burr medic and yellow serradella with subterranean clover in the low rainfall wheatbelt of Western Australia

1992 ◽  
Vol 32 (8) ◽  
pp. 1077 ◽  
Author(s):  
BH Paynter
Keyword(s):  
Seed Production ◽  
Western Australia ◽  
Maximum Yield ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Yield Response ◽  
Absolute Maximum ◽  
Absolute Yield ◽  
Burr Medic ◽  
Internal Efficiency

Burr medic (Medicago polymorpha) and yellow serradella (Ornithopus compressus) were compared with subterranean clover (Trifolium subterraneum) in their response to freshly topdressed phosphate in the low rainfall wheatbelt of Western Australia. Species were compared on the amount of applied phosphorus (P) required for 90% maximum yield and the ratio of their curvature coefficients from the Mitscherlich relationship between P applied and absolute yield. On marginally acidic, medium-textured soils, burr medic had a higher external shoot requirement for applied P than subterranean clover. Relative differences between the species were affected by season, initial concentration of bicarbonate-extractable P in the soil (0-10 cm), and timing of plant harvest during the growing season. Burr medic generally achieved a higher absolute maximum yield at each harvest, a larger absolute yield response, and a larger percentage response to applied P than subterranean clover. There was no difference between burr medic and subterranean clover with respect to the internal efficiency of P use for shoot production. For seed production, the external requirements of burr medic and subterranean clover for applied P were similar according to the criterion of P required at 90% maximum yield, but burr medic had a higher requirement if curvature coefficient was the criterion for comparison. Burr medic also had a higher internal efficiency of P use for seed production than subterranean clover. On an acidic, light-textured soil, yellow serradella had a lower requirement for applied P than subterranean clover, according to both criteria for all harvests in 2 separate years.

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.

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.

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.

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