Runoff losses from irrigated dairy pastures treated with phosphorus fertilisers of differing solubility in south-eastern Australia

Soil Research ◽  
2011 ◽  
Vol 49 (7) ◽  
pp. 633 ◽  
Author(s):  
A. J. Weatherley ◽  
B. F. Quin ◽  
K. B. Dassanayake ◽  
J. S. Rowarth
Keyword(s):  
Water Soluble ◽  
Current Recommendation ◽  
Single Superphosphate ◽  
North Central ◽  
Quality Guidelines ◽  
Eastern Australia ◽  
Quality Water ◽  
Runoff Losses ◽  
Fertiliser Application ◽  
Irrigation Runoff

In response to increasing concern about environmental quality, water authorities in many countries are imposing legislation limiting phosphorus (P) concentrations in water, which is having an impact on farming practice. This experiment investigated the agronomic effects and runoff losses associated with different forms of P fertiliser applied to an irrigated dairy pasture (soils were Vertic Calcic Red Chromosols; average Olsen P, 50 mg P/kg) in north-central Victoria, Australia. Single superphosphate (SSP), a sulfurised diammonium phosphate, or partially acidulated phosphate rock was surface-applied at 50 kg P/ha in March 2005 to a border-check, flood-irrigated dairy pasture (ryegrass–white clover) ten days before a scheduled irrigation. Dissolved reactive P (DRP) and total P (TP) were measured in runoff from whole bays on one replicate and from microplots on all three replicates for a period of 9 weeks. In all runoff events and all treatments, concentrations of DRP and TP in runoff greatly exceeded water quality guidelines for acceptable limits (0.045 mg P/L). The SSP resulted in significantly higher concentrations of P in runoff than the less water-soluble fertilisers. Even after the fifth irrigation, runoff from all fertilisers still exceeded the control. These results suggest that: (i) P fertilisers should not be applied in high-risk situations as insurance against yield loss; (ii) the current recommendation of withholding irrigation for 3 days after fertiliser application is insufficient to prevent potentially significant losses occurring; and (iii) runoff losses were dependent on the type of fertiliser applied, with a smaller proportion of P applied as sulfurised DAP lost in runoff.

A field study of phosphorus mobilisation from commercial fertilisers

Soil Research ◽  
2004 ◽  
Vol 42 (3) ◽  
pp. 313 ◽  
Author(s):  
D. Nash ◽  
M. Hannah ◽  
L. Clemow ◽  
D. Halliwell ◽  
B. Webb ◽  
...  
Keyword(s):  
Overland Flow ◽  
Soil Surface ◽  
Wetting Front ◽  
Single Superphosphate ◽  
Agricultural Catchments ◽  
Sampling Position ◽  
Eastern Australia ◽  
Before And After ◽  
Fertiliser Application ◽  
Flow Study

Fertilisers contribute to phosphorus (P) exported from agricultural catchments in south-eastern Australia. Phosphorus concentrations were initially measured in overland flow caused by rainfall after broadcasting either single superphosphate [SSP, Ca(H2PO4)2] or diammonium phosphate [DAP, (NH4)2HPO4] blends to pastures. In addition, P concentrations in overland flow were measured at intervals down border irrigation bay before and after fertiliser application. The period between fertiliser application and irrigation varied from 1 to 10 days.For the rainfall-induced overland flow, total dissolved P (TDP) concentrations were higher where DAP rather than SSP had been applied. For the irrigation study, sampling position behind the wetting front, irrigation pre and post fertiliser application, and irrigation number post fertiliser application explained 49.7, 20.5, and 15.2% of the total sum of squares, respectively. TDP concentrations were highest in the wetting front and diminished with distance behind the wetting front. For the irrigation before, and 2 irrigations following, fertiliser application, concentrations in the wetting front were 2.3, 17.6, and 6.5 mg TDP/L, respectively. In general, wetting front concentrations were c. 4 times the mean concentrations for the bays. As most P is exported when the wetting front enters the drainage network, sampling behind the wetting front would appear to underestimate P exports. The TDP concentration decreased as the time between fertiliser application and irrigation increased but the effects were variable between farms and fertilisers. Contrary to the rainfall induced overland flow study, in the irrigation study higher TDP concentrations were measured where SSP rather than DAP had been applied. This finding is explained in terms of differing rates of P mobilisation from the 2 fertiliser blends and an interaction with soil hydrology. The rapidly infiltrating water at the wetting front of irrigation-induced overland flow is likely to carry with it P mobilised at, or near, the soil surface and P infiltration will be proportional to mobilisation rates. It is suggested that higher rates of P mobilisation from DAP than SSP would reduce P exports in border irrigation systems where DAP is applied to the soil.

Acoustic analysis of an intergrade zone between two call races of the Limnodynastes tasmaniensis complex (Anura : Leptodactylidae) in south-eastern Australia

1975 ◽  
Vol 23 (1) ◽  
pp. 113 ◽  
Author(s):  
MJ Littlejohn ◽  
JD Roberts
Keyword(s):  
Acoustic Analysis ◽  
Secondary Contact ◽  
Ecological Gradient ◽  
North Central ◽  
Call Structure ◽  
Central Victoria ◽  
South Eastern ◽  
Eastern Australia ◽  
Mating Calls ◽  
South Eastern Australia

Mating calls of the northern and southern call races of the L. tasmaniensis complex are described. Analysis of call structure along a transect across the main contact between these allopatric forms in north central Victoria indicates that there is a zone of intergradation between 90 and 135 km wide, about 215 km long and with a north-westerly orientation. The interaction is interpreted as a secondary contact in which there is hybrid or recombinant superiority along a subtle ecological gradient.

scholarly journals Field evaluation of water or citrate soluble phosphorus in modified phosphate rocks for soybean

2001 ◽  
Vol 58 (1) ◽  
pp. 165-170 ◽  
Author(s):  
Luís Ignácio Prochnow ◽  
José Francisco da Cunha ◽  
Ariel Francisco Candiotti Ventimiglia
Keyword(s):  
Field Evaluation ◽  
Water Soluble ◽  
Ammonium Citrate ◽  
Low Grade ◽  
Triple Superphosphate ◽  
Single Superphosphate ◽  
Standard Source ◽  
Extractable P ◽  
P Fertilizers ◽  
P Sources

Ten P fertilizers were collected (commercial fertilizers) or synthesized (experimental sources) in order to obtain single superphosphates varying in water and citrate solubility. A standard source of P was also produced by crystallization of the water-soluble fraction of a triple superphosphate. Eleven P sources were band applied to a medium textured Xanthic Hapludox, in Bahia, Brazil (low content of resin-extractable P) at a rate of 80 kg ha-1 of NAC + H2O (neutral ammonium citrate plus water) soluble P2O5, with soybean as the crop which was grown to maturity. A check plot (control) was included in the study. Three of the P sources [single superphosphate produced from Araxa phosphate rock (PR), low-grade single superphosphate produced from Lagamar PR and the standard source of P] were also applied at rates to provide 40 and 120 kg ha-1 of NAC + H2O soluble P2O5. Yield of soybean was evaluated by analysis of variance with mean comparison performed utilizing LSD lines, considering the P sources applied at a rate of 80 kg ha-1 of P2O5 + control. Regression procedures were used to study the relation between yield of soybean and rates of P2O5. The fertilizers tested performed equally well as a source of P for soybean. The level of water-soluble P did not influence fertilizer performance.

Modelling phosphorus exports from rain-fed and irrigated pastures in southern Australia

Soil Research ◽  
2005 ◽  
Vol 43 (6) ◽  
pp. 745 ◽  
Author(s):  
D. Nash ◽  
L. Clemow ◽  
M. Hannah ◽  
K. Barlow ◽  
P. Gangaiya
Keyword(s):  
Component Model ◽  
Year Effect ◽  
Storm Flow ◽  
Additive Component ◽  
Eastern Australia ◽  
Grazing Systems ◽  
Fertiliser Application ◽  
Excessive Nutrients ◽  
Major Factors ◽  
Land Manager

Pasture-based grazing systems contribute to the excessive nutrients found in some streams in south-eastern Australia. This study investigated phosphorus (P) exported in runoff from a rain-fed dairy pasture (Darnum) and 4 bays of irrigated dairy pasture (MRF). Runoff was monitored for 7 years at Darnum and 2 years at the MRF to identify factors associated with the variation in total P (TP) concentrations between events. The flow-weighted mean annual P concentrations in runoff varied between 3.3 and 28.2 mg TP/L for Darnum and 6.2 and 31.5 mg TP/L for the MRF. The relationships between TP concentrations in runoff and days between fertiliser application and runoff, days between grazing and runoff, and total storm flow were examined using an additive component model that explained 61% and 70% of the variation in log-transformed TP for Darnum and the MRF, respectively. The interval between application of fertiliser and runoff and the effect of year were highly significant and explained most of the variation in TP. Grazing and fertiliser application were identified as the major factors that may affect TP concentrations that the land manager can control (preventable). The estimates of year effect (i.e. the component of TP not explained by the other variables and over which the land manager had no apparent means of control) ranged from 1.60 mg (s.e. 1.99) to 7.14 mg (s.e. 1.90) TP/L in non-drought years (>45 kL/ha runoff annually). The year effect averaged 5.7 and 6.9 mg TP/L for Darnum and the MRF, respectively. It is shown that an additive component model provides a useful structure for investigating similar, field-scale data.

Green and facile synthesis of high-quality water-soluble Ag-In-S/ZnS core/shell quantum dots with obvious bandgap and sub-bandgap excitations

2018 ◽  
Vol 753 ◽  
pp. 364-370 ◽  
Author(s):  
Yanyan Chen ◽  
Qiang Wang ◽  
Tianyong Zha ◽  
Jigang Min ◽  
Jingying Gao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Water Soluble ◽  
Core Shell ◽  
Facile Synthesis ◽  
High Quality ◽  
Quality Water

Synthesis and Upconversion Luminescence of High-Quality Water-Soluble NaYF4:Yb3+, Er3+ Nanoclusters

2016 ◽  
Vol 16 (4) ◽  
pp. 3802-3805 ◽  
Author(s):  
Jing Tang ◽  
Lianbo Wang ◽  
Qiuping Li ◽  
Yan Cui ◽  
Enyan Wang ◽  
...  
Keyword(s):  
Water Solubility ◽  
Hexagonal Phase ◽  
Upconversion Luminescence ◽  
Biological Imaging ◽  
Water Soluble ◽  
X Ray ◽  
Transmission Electron ◽  
Quality Water ◽  
Bright Green ◽  
Facile Solvothermal Method

Hexagonal phase NaYF4:Yb3+, Er3+ nanoclusters were prepared using a facile solvothermal method. The structures and morphologies of the products were investigated using an X-ray powder diffractometer and a transmission electron microscope. Modified by the capping agent of poly(acrylic acid), the as-prepared NaYF4 NCs show excellent water solubility. Under 980-nm excitation, the aqueous solution of the sample displayed a bright green upconversion (UC) fluorescence. The luminescence dynamics were further studied based on the UC excitation pathways and the emission processes. Such water soluble UC samples may find application in the field of biological imaging.

A laboratory study of phosphorus mobilisation from commercial fertilisers

Soil Research ◽  
2003 ◽  
Vol 41 (6) ◽  
pp. 1201 ◽  
Author(s):  
D. Nash ◽  
M. Hannah ◽  
L. Clemow ◽  
D. Halliwell ◽  
B. Webb ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Total Variation ◽  
Laboratory Study ◽  
High Moisture ◽  
Single Superphosphate ◽  
South Eastern ◽  
Extractable P ◽  
Eastern Australia ◽  
Water Extractable ◽  
South Eastern Australia

Phosphorus (P) exported from pastures following fertiliser application contributes to the nutrients and associated problems in the streams and rivers of south-eastern Australia. This laboratory study examined whether attributes of P fertilisers may affect P exports soon after their application to field soils; 3 commercial fertilisers [diammonium phosphate (DAP), single superphosphate (SSP), and sulfur-coated single superphosphate (CSSP)] were applied to 2 repacked soils (Arawata and Ellinbank) at 5 moisture contents.Soil type was the most important factor affecting water-extractable P (expressed as a percentage of the P added as fertiliser), accounting for 30% of the total variation. The majority of this variation is explained by the water-extractable P concentrations in the Arawata low moisture treatments. These treatments [7, 6, and 6% soil moisture when equilibrated at 99, 95, and 86.5% relative humidity (RH), respectively] contained water-extractable P concentrations c. 3 times higher than the high moisture (c. 20 and 25% soil moisture) or the Ellinbank treatments. This result probably reflects differences in soil properties including the extent of water repellency and P adsorption.Fertiliser type explained only 6.9% (P < 0.001) of the total variation in water-extractable P, partially as a result of the 86.5% RH (a low moisture) Arawata treatment. In this Arawata low moisture treatment, the mean extractable P was similar for both DAP and SSP, 13.1% [least significant interval (l.s.i.) 16.7–10.3] and 11.3% (l.s.i. 14.3–8.9), respectively, but for SSP, water-extractable P increased over time unlike any other treatment. Water-extractable P from DAP was approximately double that from SSP for the Ellinbank and high moisture treatments. The higher water-extractable P following DAP application is explained in terms of its chemical properties and reaction products. Sulfur coating the SSP granules (CSSP) increased water-extractable P, as did higher soil moisture.This study suggests that under conditions present in most pastures in south-eastern Australia and depending on soil hydrology, water-extractable P and P export from fertilisers may increase in the order DAP > CSSP > SSP if overland flow occurs soon after their application.

Increased Carrier Volume Improves Preemergence Control of Rigid Ryegrass (Lolium rigidum) in Zero-Tillage Seeding Systems

2013 ◽  
Vol 27 (4) ◽  
pp. 649-655 ◽  
Author(s):  
Catherine P. D. Borger ◽  
Glen P. Riethmuller ◽  
Michael Ashworth ◽  
David Minkey ◽  
Abul Hashem ◽  
...  
Keyword(s):  
Weed Control ◽  
Droplet Size ◽  
Water Soluble ◽  
Zero Tillage ◽  
Tillage System ◽  
Quality Water ◽  
High Carrier ◽  
Rigid Ryegrass ◽  
Carrier Volume ◽  
The Impact

PRE herbicides are less effective in the zero-tillage system because of increased residual crop stubble and reduced soil incorporation. However, since weeds are not physically controlled in the zero-tillage system, reliance on efficacy of PRE herbicides is increased. This research investigated the impact of carrier volume and droplet size on the performance of PRE herbicides (in wheat crops at four sites in 2010) to improve herbicide efficacy in conditions of high stubble biomass in zero-tillage systems. Increasing carrier volume from 30 to 150 L ha−1increased spray coverage on water-sensitive paper from an average of 5 to 32%. Average control of rigid ryegrass by trifluralin (at Cunderdin and Merredin sites) and trifluralin or pyroxasulfone (at Wickepin and Esperance sites) improved from 53 to 78% with increasing carrier volume. Use of ASABE Medium droplet size improved spray coverage compared with ASABE Extremely Coarse droplet size, but did not affect herbicide performance. It is clear that increased carrier volume improves rigid ryegrass weed control for nonwater-soluble (trifluralin) and water-soluble (pyroxasulfone) PRE herbicides. Western Australian growers often use low carrier volumes to reduce time of spray application or because sufficient high-quality water is not available, but the advantages of improved weed control justifies the use of a high carrier volume in areas of high weed density.

Germination behaviour in beach spinifex (Spinifex hirsutus Labill.)

1972 ◽  
Vol 20 (3) ◽  
pp. 241 ◽  
Author(s):  
RL Harty ◽  
TJ McDonald
Keyword(s):  
Sea Water ◽  
Field Capacity ◽  
Water Soluble ◽  
Lettuce Seed ◽  
Tetrazolium Chloride ◽  
Chemical Inhibitors ◽  
Eastern Australia ◽  
Pot Trials ◽  
Germination Behaviour ◽  
Germination Experiments

This paper deals with threshing and seed germination studies on hand-harvested beach spinifex (Spinifex hirsutus Labill.). This work was carried out as part of a detailed study of the autecology of beach spinifex, an important pioneer sand stabilizer on beaches and dunes along the coast of eastern Australia. Hammer-milling was suitable for threshing out caryopses from beach spinifex inflorescences, but in the process the caryopses were excessively damaged. A barley de-awning machine produced spikelets (caryopses enclosed in lemma, palea, and glumes plus the base of the associated spine) which were free flowing and therefore suitable for mechanical planting. Laboratory germination experiments disclosed that the caryopses were negatively photoblastic when germinated alone, or enclosed within the spikelet. Alternating thermoperiods (10-25, 15-25, 20-25 ; 10-35, 15-35, 20-35�C) were generally superior to constant thermoperiods (25, 30, 35") in the induction of germination. The germination of caryopses from inflorescences harvested 2 months previously agreed with an estimate of viability made by using tetrazolium chloride. This indicated that beach spinifex seed has no pronounced after-ripening requirements. The rate of germination of caryopses and their germinative capacity were markedly increased when the caryopses were removed from the spikelets. It is likely that germination in the spikelet is inhibited by a slow rate of gaseous exchange between the embryo and the atmosphere. A sensitivity to anaerobic conditions was demonstrated by soaking spikelets for varying periods up to 48 hr in distilled and sea water. Such treatments led to a decrease in germination. Pot trials showed that in waterlogged sand, no appreciable germination occurred below 3.75 cm. In sand held at field capacity, some germination occurred down to the maximum depth tried (8.75 cm), but the best germination was from 2.5 to 3 .75 cm. Soaking spikelets in distilled water for 48 hr and testing the leachate on germinating lettuce seed failed to disclose the presence of water-soluble chemical inhibitors in the spikelets.

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