Potential water quality impact and agronomic effectiveness of different phosphorus fertilisers under grazed dairying in Southland

2012 ◽  
pp. 225-229
Author(s):  
R.W. Mcdowell ◽  
L.C. Smith
Keyword(s):  
Water Quality ◽  
Surface Runoff ◽  
Surface Water Quality ◽  
Water Soluble ◽  
Agronomic Effectiveness ◽  
Pasture Production ◽  
Water Soluble P ◽  
P Loss ◽  
Relative Agronomic Effectiveness ◽  
Soluble P

Phosphorus (P) loss from land is a central factor in poor surface water quality in Southland. Much loss of P can occur if surface runoff occurs soon after the application of highly water soluble P fertilisers (e.g. superphosphate). Three P fertilisers (superphosphate, serpentine super, and a Ca-phosphate) of different water solubilities were applied (30 kg P/ha in spring) to a grazed dairy pasture, and the relative agronomic effectiveness and P losses determined. Across all 3 years, there were no differences in annual pasture production among the different types of P fertilisers. For 2 years out of 3, significantly more P was lost via surface runoff from the superphosphate-treated plots than from plots treated with either serpentine super or the Ca-phosphate. On average, the use of low water soluble Ca-P fertiliser decreased P losses by an average of 47% over the 3 years. It is currently recommended that to decrease P losses associated with fertiliser, applications should be timed when runoff events are unlikely for at least 3 weeks following application. If this runoff cannot be avoided, or to ensure P losses are as low as possible, the use of a low water soluble P product may be of benefit. Key words: Surface runoff, phosphate fertilisers, phosphorus loss, superphosphate.

scholarly journals Effect of water and citrate solubility on agronomic effectiveness of acidulated phosphates in three consecutive corn crops

2002 ◽  
Vol 26 (3) ◽  
pp. 729-736 ◽  
Author(s):  
L. I. Prochnow ◽  
B. van Raij ◽  
J. C. Kiehl
Keyword(s):  
Fertilizer Application ◽  
Water Soluble ◽  
Ammonium Citrate ◽  
Original Form ◽  
Agronomic Effectiveness ◽  
Water Soluble P ◽  
Long Run ◽  
Randomized Design ◽  
Soluble P ◽  
Corn Plants

In the process of phosphate rock acidulation, several impure P compounds may be formed along with the desirable Ca and NH4 phosphates. Such compounds normally reduce the content of water-soluble P and thus the agronomic effectiveness of commercial fertilizers. In order to study this problem, a greenhouse experiment consisting of three consecutive corn crops was conducted in samples of a Red-Yellow Latosol (Typical Hapludox) in a completely randomized design (6 x 2 x 2), with four replicates. Six commercial fertilizers were added to 2 kg of soil at a rate of 70 mg kg-1 P, based on the content of soluble P in neutral ammonium citrate plus water (NAC + H2O) of the fertilizers. Fertilizer application occurred either in the original form or leached to remove the water-soluble fraction, either by mixing the fertilizer with the whole soil in the pots or with only 1 % of its volume. The corn plants were harvested 40 days after emergence to determine the shoot dry matter and accumulated P. For the first crop and localized application, the elimination of water-soluble P from the original fertilizers resulted in less bioavailable P for the plants. For the second and third crops, the effects of P source, leaching and application methods were not as evident as for the first, suggesting that the tested P sources may have similar efficiencies when considering successive cropping. The conclusion was drawn that the water-insoluble but NAC-soluble fractions of commercial P fertilizers are not necessarily inert because they can provide P in the long run.

The fate of phosphorus under contrasting border-check irrigation regimes

Soil Research ◽  
2008 ◽  
Vol 46 (4) ◽  
pp. 309 ◽  
Author(s):  
R. W. McDowell ◽  
D. Rowley
Keyword(s):  
Water Quality ◽  
Soil Moisture ◽  
Surface Water ◽  
Surface Water Quality ◽  
Rainfall Simulation ◽  
Pasture Production ◽  
Olsen P ◽  
Grazed Pastures ◽  
P Loss ◽  
P Concentration

Flood-irrigation, to the extent that outwash (runoff from border-check bays) occurs, is a major cause of P loss from grazed pastures and has potential to harm surface water quality. We used a combination of rainfall simulation to produce runoff and field sampling of outwash to investigate processes of P loss from treatments receiving no irrigation and irrigation at 10%, 15%, and 20% soil moisture and every 21 days (3w). Intact soil blocks were removed from each treatment, dung removed, soils wetted to about 32% soil moisture, and runoff produced via rainfall simulation. This indicated that P losses were proportional to soil Olsen P concentrations (29.8–51.4 mg Olsen P/kg; 0.096–0.541 mg dissolved reactive P/L). Olsen P concentration was less in those treatments receiving a greater number of irrigations due to increased pasture production and, presumably, loss via outwash. When soil blocks were allowed to dry, concentrations in runoff more than doubled and were paralleled by a decrease in soil microbial biomass P. However, when outwash was sampled in the field, P loss was greater in more frequently irrigated treatments. This was attributed to increased stocking rates and P-release from dung masking any soil effect. However, differences in P loss in outwash from 2 treatments (without recent grazing) were attributed to different soil moisture before irrigation. Assuming 25% of irrigation is lost as outwash, annual loads were estimated to range from 0.7 kg P/ha in the 10% treatment, irrigated 2.6 times a year, to 12.6 kg P/ha in the 3w treatment, irrigated 6.5 times per year. This suggests that the frequency of irrigation and stocking rate dictate the majority of P lost in this system (not soil P concentration). Hence, mitigation practices should be promoted to minimise outwash in intensively sheep-grazed pastures and potential surface water quality impacts.

scholarly journals How Effective Are Existing Phosphorus Management Strategies in Mitigating Surface Water Quality Problems in the U.S.?

2021 ◽  
Vol 13 (12) ◽  
pp. 6565
Author(s):  
Shama E. Haque
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Management Strategies ◽  
Surface Water Quality ◽  
Land Application ◽  
Water Soluble ◽  
Phosphorus Recovery ◽  
Water Bodies ◽  
The Past ◽  
The U.S

Phosphorus is an essential component of modern agriculture. Long-term land application of phosphorous-enriched fertilizers and animal manure leads to phosphorus accumulation in soil that may become susceptible to mobilization via erosion, surface runoff and subsurface leaching. Globally, highly water-soluble phosphorus fertilizers used in agriculture have contributed to eutrophication and hypoxia in surface waters. This paper provides an overview of the literature relevant to the advances in phosphorous management strategies and surface water quality problems in the U.S. Over the past several decades, significant advances have been made to control phosphorus discharge into surface water bodies of the U.S. However, the current use of phosphorus remains inefficient at various stages of its life cycle, and phosphorus continues to remain a widespread problem in many water bodies, including the Gulf of Mexico and Lake Erie. In particular, the Midwestern Corn Belt region of the U.S. is a hotspot of phosphorous fertilization that has resulted in a net positive soil phosphorous balance. The runoff of phosphorous has resulted in dense blooms of toxic, odor-causing phytoplankton that deteriorate water quality. In the past, considerable attention was focused on improving the water quality of freshwater bodies and estuaries by reducing inputs of phosphorus alone. However, new research suggests that strategies controlling the two main nutrients, phosphorus and nitrogen, are more effective in the management of eutrophication. There is no specific solution to solving phosphorus pollution of water resources; however, sustainable management of phosphorus requires an integrated approach combining at least a reduction in consumption levels, source management, more specific regime-based nutrient criteria, routine soil fertility evaluation and recommendations, transport management, as well as the development of extensive phosphorus recovery and recycling programs.

scholarly journals The influence of long-term sewage sludge application on the activity of phosphatases in the rhizosphere of plants

2008 ◽  
Vol 53 (No. 9) ◽  
pp. 375-381 ◽  
Author(s):  
J. Balík ◽  
D. Pavlíková ◽  
V. Vaněk ◽  
M. Kulhánek ◽  
B. Kotková
Keyword(s):  
Sewage Sludge ◽  
Fertilizer Application ◽  
Water Soluble ◽  
Organic Fertilizers ◽  
Lower Content ◽  
Alkaline Phosphatases ◽  
Soil P ◽  
Water Soluble P ◽  
Soluble P

Model experiments using rhizoboxes were carried out in order to evaluate the influence of different plants (wheat, rape) on the changes in water extractable contents of P, the pH/H2O value and the activity of acidic and alkaline phosphatase in soil of plant rhizosphere. For this experiment, a Cambisol with different long-term fertilizing systems was used: (i) control (with no fertilizer application), (ii) sewage sludge, and (iii) manure. A lower content of water-soluble P was observed in close vicinities of root surfaces (up to 2 mm) at all the studied variants. The control (non-treated) variant reflected a significantly lower content of water-soluble P in the rhizosphere compared to the fertilized ones. The activities of the acidic and alkaline phosphatases were significantly higher in the rhizosphere compared to the bulk soil (soil outside the rhizosphere). The long-term application of organic fertilizers significantly increased phosphatase activity; the activity of the acidic phosphatase was significantly higher in the rhizosphere of rape plants compared to wheat. The variant treated with manure exhibited an increased activity of both the acidic and alkaline phosphatases compared to the variant treated with sewage sludge. In the case of the variant treated long-term with sewage sludge, the portion of inorganic P to total soil P content proportionally increased compared to the manure-treated variant. Soil of the rape rhizosphere showed a trend of lower pH/H<sub>2</sub>O value of all variants, whereas the wheat rhizosphere showed an opposite pH tendency.

Water-soluble p-carboxybenzylated beechwood 4-O-methylglucuronoxylan: structural features and properties

2000 ◽  
Vol 42 (2) ◽  
pp. 123-131 ◽  
Author(s):  
A. Ebringerová ◽  
J. Alföldi ◽  
Z. Hromádková ◽  
G.M. Pavlov ◽  
S.E. Harding
Keyword(s):  
Structural Features ◽  
Water Soluble ◽  
Water Soluble P ◽  
Soluble P

A route to virtually unlimited functionalization of water-soluble p-sulfonatocalix[4]arenes

2020 ◽  
Vol 56 (29) ◽  
pp. 4122-4125
Author(s):  
Alexander Gorbunov ◽  
Anna Iskandarova ◽  
Kirill Puchnin ◽  
Valentine Nenajdenko ◽  
Vladimir Kovalev ◽  
...  
Keyword(s):  
Water Soluble ◽  
Reaction Sequence ◽  
Water Soluble P ◽  
Cuaac Reaction ◽  
Soluble P

Diverse narrow-rim derivatives can be easily prepared from p-sulfonatocalix[4]arenes using the propargylation/CuAAC reaction sequence.

Mechanochemical Activation and Characterization of Low-Medium Grade Phosphorite Ore

2013 ◽  
Vol 690-693 ◽  
pp. 3529-3532
Author(s):  
Yu Xing ◽  
Hong Gao ◽  
Yuan Fang Ying ◽  
De Zheng Qu
Keyword(s):  
Mechanochemical Activation ◽  
Planetary Mill ◽  
Water Soluble ◽  
Particle Sizes ◽  
Leaching Rate ◽  
Activation Time ◽  
Activation Effect ◽  
Water Soluble P ◽  
Soluble P

The activation effect of ball-to-powder ratio and activation time on phosphorite ore that takes place in mechanochemical activation has been investigated in present paper, which is carried out in a planetary mill AGO-II. The results show that, particle sizes decreased after activation; the leaching rate of water-soluble P2O5 increased 4.6 percentage as ball-to-powder ratio rose from 8:1 to 40:1; the activated particle of samples has been highly dispersed, while the leaching rate of water-soluble P2O5 reached 10.1% after milling 15 minutes during activation, which was 4 times as high as the un-activated samples. The results show a potential utilization of low-medium grade phosphorite ore with mechanochemical activation directly.

Sign in / Sign up

Export Citation Format

Share Document