A study of phosphorus nutrition and water supply on the early growth and survival of buffel grass grown on a sandy red earth from south-west Queensland

1975 ◽  
Vol 15 (73) ◽  
pp. 239 ◽  
Author(s):  
EK Christie
Keyword(s):  
Seedling Growth ◽  
Growth Rates ◽  
Phosphorus Concentration ◽  
Root Penetration ◽  
Buffel Grass ◽  
Phosphorus Absorption ◽  
South West ◽  
Red Earth ◽  
Drought Survival ◽  
Phosphorus Application

The influence of phosphorus application on the growth and drought survival of buffel grass on a sandy red earth in south west Queensland was studied in a series of pot experiments. An omission nutrient trial showed phosphorus was the principal nutrient limiting seedling growth, the severity of the deficiency increasing with time. A further pot experiment showed that at rates greater than 24 kg P ha-1 luxury consumption occurred. The critical phosphorus concentration for the plant was estimated to be 0.26 per cent. The available (0.01 NH2SO4 extractable) soil phosphorus concentration corresponding to this critical tissue concentration was 25 p.p.m. Beyond the 2-leaf seedling stage, the seedling depended increasingly on external phosphorus for growth. Under conditions of phosphorus deficiency, phosphorus absorption rates were insufficient to maintain tissue phosphorus at the concentrations necessary for healthy growth, and relative growth rates were low. In the presence of phosphorus, absorption and growth rates increased. Maturity of phosphorus deficient plants was characteristically delayed but with little yield loss. The addition of phosphorus increased seedling growth rate, root development and drought survival. The depth of root penetration is considered to be the major factor responsible for survival.

Physiological responses of semiarid grasses. I. The influence of phosphorus supply on growth and phosphorus absorption

1975 ◽  
Vol 26 (3) ◽  
pp. 423 ◽  
Author(s):  
EK Christie ◽  
J Moorby
Keyword(s):  
Optimal Growth ◽  
Yield Response ◽  
Phosphorus Concentration ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Buffel Grass ◽  
Phosphorus Absorption ◽  
Low Concentrations ◽  
Nutritional Characteristics ◽  
Phosphorus Requirements

Experiments were carried out under controlled conditions to investigate the physiological bases for species differences in yield and nutrient responses to variations in phosphorus supply. Buffel grass (Cenchrus ciliaris), and to a less extent Mitchell grass (Astrebla elymoides), showed a much larger yield response to increasing phosphorus supply than mulga grass (Thyridolepis mitchelliana). Mitchell and mulga grasses had much lower relative growth rates than buffel grass. Mulga grass required a lower external phosphorus concentration for optimal growth than Mitchell and buffel grasses; this was attributed to its superior system for absorbing and transporting phosphate from low concentrations, but was not associated with any yield advantage, yield being related more to the photosynthetic than to the nutritional characteristics of the plants. Differences between species in their external phosphorus requirements for growth and their distribution in semiarid Queensland are discussed.

Residual effects of phosphorus fertiliser in a stylo-native grass pasture on a duplex red earth soil in the semi-arid tropics of North Queensland

1994 ◽  
Vol 34 (2) ◽  
pp. 173
Author(s):  
KA Shaw ◽  
MA Gilbert ◽  
JD Armour ◽  
MJ Dwyer
Keyword(s):  
Soil Analysis ◽  
Residual Effects ◽  
Native Grass ◽  
Soil P ◽  
Initial Application ◽  
Red Earth ◽  
P Application ◽  
Stylosanthes Scabra ◽  
Phosphorus Application ◽  
Establishment Phase

A field experiment was established to define the phosphorus (P) requirement for establishment and maintenance of a mixed legume pasture (Stylosanthes scabra cv. Seca, S. hamata cv. Verano, S. guianensis cv. Graham, Macroptilium atropurpureum cv. Siratro) introduced into a native grass pasture on an infertile duplex red earth. Rates of 0, 5, 10, 20, and 40 kg P/ha were applied to separate plots in year 1 (1982), 2, and 3. In year 5 (1986 growing season), half of each plot that had received 20 and 40 kg P/ha in year 3 was refertilised at the original rate to ensure that maximum yields were defined. Bicarbonate- or acid-extractable soil P concentrations of 8 mg/kg were sufficient for 80% maximum legume yield. The residual value of applied P in the surface soil, as measured by soil analysis, decreased exponentially, but an initial application of 40 kg P/ha was still sufficient to produce near-maximum legume yield after 5 years. Phosphorus application increased the dry matter yield of legume. During the establishment phase (years 1 and 2 after planting) yields reached maximum at 10 and 20 kg P/ha, respectively, but increased linearly in subsequent years. When the original rates were reapplied in year 5, peak yield occurred at 20 + 20 kg P/ha, and there was no difference between this yield and that from plots receiving 40 kg P/ha in year 1. Native grass yields increased with P application only in years 4 and 5 of the experiment. Stylos demonstrated good tolerance to low P supply. In year 1, 80% of the total legume yield consisted of Graham stylo and Siratro, whereas in subsequent years, Seca and Verano made up 70 and 20%, respectively, of the total, irrespective of treatment. Yield of legume at nil P, relative to maximum, increased from 5% in year 1 to 42% in year 5.

Biology of littoral blenniid fishes on the coast of south-west England

1983 ◽  
Vol 63 (1) ◽  
pp. 223-237 ◽  
Author(s):  
P. Milton
Keyword(s):  
Growth Rates ◽  
Age Groups ◽  
Food Chains ◽  
Similar Treatment ◽  
Food Items ◽  
South West ◽  
Abundant Food ◽  
Competition For Food ◽  
Littoral Species ◽  
South West England

Observations in the field, and in the laboratory, of littoral fishes of south-west England during the period 1978–80 have shown that the three blenniid species found with any frequency on the shore constitute an important link in food chains. The occurrence, age, habitat and diet of Blennius (Lipophrys) pholis L., Coryphoblennius galerita L., and Parablennius gattorugine Brunnich have been considered; B. pholis was by far the most common of the three, with very few P. gattorugine being found intertidally. Of the latter, only age groups 0, 1 and 2 were represented in the littoral populations, whereas in the truly littoral species age groups 0–10 were found for B. pholis and 0–6 for C. galerita. Measurements of growth rates for the three species have been compared with growth rates of B. pholis and C. galerita at other sites, and a similar treatment has been afforded to dietary constituents. A discussion of the possible competition for food and refuge between the three species, and with other littoral teleosts, concludes that highly efficient partitioning of resources reduces competition to a minimum, with the exception of abundant food items which are (in any case) probably underexploited.

Dormancy, germination and seedling growth of two Kalaharian perennials of the genus Harpagophytum (Pedaliaceae)

1988 ◽  
Vol 4 (2) ◽  
pp. 185-198 ◽  
Author(s):  
W. H. O. Ernst ◽  
T. Tietema ◽  
E. M. Veenendaal ◽  
R. Masene
Keyword(s):  
Gibberellic Acid ◽  
High Temperatures ◽  
Seedling Growth ◽  
Seed Coat ◽  
Growth Rates ◽  
Natural Conditions ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Respiration Rates ◽  
Drought Avoidance

ABSTRACTDormancy and germination ecology of two Harpagophytum species (Pedaliaceae) from an open Acacia savanna in Botswana were investigated. The maintenance of dormancy is governed partly by the seed coat but mainly by the endosperm and the embryo itself, as demonstrated by removal of the endosperm. Dissemination of the seed from the fruit can be delayed for several years without affecting the viability of the embryo, due to very low respiration rates.Germination can be enhanced slightly by high temperatures under natural conditions, and by gibberellic acid or removal of the endosperm under laboratory conditions. Relative growth rates for both Harpagophytum species are lower than for subtropical grasses and legumes, due to a strong investment in root and tuber biomass. Germination and seedling growth is discussed in relation to the drought avoidance syndrome and the animal disperser syndrome.

The influence of dietary calcium and phosphorus concentration on their absorption in the cow

1967 ◽  
Vol 68 (2) ◽  
pp. 263-268 ◽  
Author(s):  
R. Manston
Keyword(s):  
Dietary Intake ◽  
Dietary Calcium ◽  
Phosphorus Concentration ◽  
Isotope Techniques ◽  
Phosphorus Absorption ◽  
Calcium And Phosphorus

Experiments were carried out in dry, nonpregnant cows by varying dietary concentrations of calcium and phosphorus. Calcium and phosphorus absorption were measured by balance and isotope techniques. It was found that absorption of calcium or phosphorus increased when the dietary intake of the element increased, but only for a few days.

Biology of Fire Ephemerals of the Sandplains of the Kwongan of South-Western Australia

1985 ◽  
Vol 12 (6) ◽  
pp. 641 ◽  
Author(s):  
JS Pate ◽  
NE Casson ◽  
J Rullo ◽  
J Kuo
Keyword(s):  
Life Cycle ◽  
Reproductive Biology ◽  
Seedling Growth ◽  
Western Australia ◽  
Growth Rates ◽  
Dry Matter ◽  
Dry Weight ◽  
Growing Season ◽  
Adaptive Significance ◽  
Sexually Dimorphic

The growth, longevity, mineral relationships and reproductive biology of 18 species of fire ephemerals were examined in sclerophyllous shrubland, located mainly within the Jurien : Badgingarra region of the Northern Sandplains of the kwongan of SW. Australia. Ten of the species were monocarpic, completing their life cycle within the 6-8 month winter growing season after a summer or autumn fire. The remaining species were polycarpic, commencing reproduction in their second season and surviving and reproducing for a further two to eight seasons (depending on species). Detailed study was made of growth and dry matter allocation in the dioecious, sexually dimorphic, polycarpic species Tersonia brevipes (Gyrostemonaceae). Monocarpic species tended to produce smaller seeds, and exhibited greater seed output per unit biomass and higher harvest indices for dry matter and minerals than polycarpic species. Certain monocarpic species showed great plasticity in final dry weight, e.g. a 2700-fold difference between largest and smallest individuals in a sample of 250 plants of Stipa elegantissima (Poaceae), and a 180-fold range in a similarly sized sample of Macarthuria apetala (Aizoaceae). The fire ephemerals studied generally exhibited faster seedling growth rates, greater concentrations of P and N (but not of Ca, Mg and K) in seedling dry matter, but usually lesser concentrations of P and N (but not of Ca, Mg and K) in seed dry matter than in cohabiting obligate seeder or sprouter species with potential life spans exceeding 15 years. The above-mentioned features of fire ephemerals are suggested to be of special adaptive significance within the context of exploitation of transiently non-limiting habitat resources immediately following fire.

scholarly journals LOWBUSH BLUEBERRY RESPONSE TO PHOSPHORUS FERTILIZATION.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1148d-1148
Author(s):  
John M. Smagula ◽  
M. Susan Erich.
Keyword(s):  
Phosphoric Acid ◽  
Leaf Tissue ◽  
Leaf Nitrogen ◽  
Phosphorus Fertilization ◽  
Phosphorus Concentration ◽  
Nutrition Surveys ◽  
Lowbush Blueberry ◽  
Phosphorus Application ◽  
Phosphorus Levels

Nutrition Surveys of commercial blueberry fields in 1987 and 1988 indicated leaf phosphorus levels were below the standard (0.125%) in most fields. To determine if phosphorus was limiting, liquid phosphorus (23% phosphoric acid) was applied preemergence at 0, 22.4, 44.8 67.2, or 88.6 kg/ha to 3 commercial blueberry fields identified in 1987 as very low (<.111%), 3 low (.111-.125%), and 3 adequate (>.125%) in leaf phosphorus. Phosphorus concentration in leaf tissue sampled in July 1989 increased linearly with increasing rates of phosphorus. Phosphorus application raised leaf phosphorus levels more in fields which had levels below 0.125%. Fields with higher phosphorus levels were also higher in leaf nitrogen, potassium, and calcium.

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