Effect of banded fertilizers on soil solution composition and short-term root-growth .3. Monocalcium phosphate with and without gypsum

Soil Research ◽  
1995 ◽  
Vol 33 (6) ◽  
pp. 899 ◽  
Author(s):  
PW Moody ◽  
SA Yo ◽  
DG Edwards ◽  
LC Bell
Keyword(s):  
Soil Solution ◽  
Regression Line ◽  
Accurate Estimate ◽  
Al Toxicity ◽  
Solution Composition ◽  
Mn Toxicity ◽  
Soil Solution P ◽  
Highly Correlated ◽  
Set Up ◽  
P Movement

A layer of Ca(H2PO4)2.H2O (MCP) or MCP plus CaSO4.2H2O was spread over duplicate columns of six soils to simulate the effects of banded MCP or superphosphate (MCP plus CaSO4.2H2O) on soil solution composition. A separate column was set up without fertilizer addition for each soil to act as a control (background) treatment. The soils used were 0-10 cm samples from two Kurosols, a Ferrosol, a Vertosol, a Kandosol, and a 50-60 cm sample from the Kandosol. Prior to fertilizer addition, the columns were wet up to the water content at a matric suction of 10 kPa. Following 5 days of fertilizer-soil contact, soil sections were recovered at 5 mm increments from the fertilizer layer to a distance of 50 mm. Soybean (Glycine max: (L.) Merr.) seedlings were grown for 48 h in each section and relative root elongation (RRE) was determined. Soil solution was then extracted from each section and analysed. The distance of phosphorus (P) movement from both MCP and MCP plus CaSO4.2H2O was better correlated with P buffer capacity determined at a solution P concentration of 3.2 �M than at 320 �M. This suggests that the precipitation reactions which occur at the fertilizer site when MCP dissolves are independent, of the soil, and it is only in soil sections further removed from the fertilizer source (i.e. with lower soil solution P concentrations) that the P sorption properties of the soil become important in determining the extent of P movement. The amount of inorganic P (Pi) in the soil solution was summed over all soil sections for each fertilizer source, and was correlated with citrate-dithionite extractable Fe and Al using step-up regression techniques. Citrate-dithionite extractable Fe was highly correlated with P-i (r = -0.937, P < 0.001), and the addition of citrate-dithionite extractable Al did not significantly (P = 0.05) increase the variation accounted for. RRE decreased in proximity to the fertilizer. When RRE was plotted against the electrical conductivity of the soil solution, all data points fell below the regression line previously obtained for various salts (Moody et al. Aust. J. Soil Res. 1995, 33, 673-87), indicating that the reduction in RRE was not due solely to osmotic effects. Multiple regression analysis indicated that a combination of the activities of Al3+ (aAl) and Mn2+ (aMn) explained 83% of the variation in RRE when both fertilizer sources were considered in all soils except the Kurosols. There was evidence of organic complexing of soil solution Al in the two Kurosols and so an accurate estimate of Al3+ activity could not be made. For the soils other than the Kurosols, separate regressions of RRE against ant and a(Mn) indicated a 10% reduction in RRE set activities of 1.9 and 70 �M, respectively. Based on these activities, banding of MCP and MCP plus CaSO4.2H2O caused Al toxicity in all soils, and Mn toxicity in all soils except one of the Kurosols. Manganese toxicity occurred further from the fertilizer band than Al toxicity in the Ferrosol and the Kandosol. The dual occurrence of Al and Mn toxicities indicates that both factors need to be considered simultaneously when determining the effects of banded fertilizer on RRE.

MOVEMENT OF PHOSPHORUS TO BARLEY ROOTS GROWING IN SOIL

1970 ◽  
Vol 50 (1) ◽  
pp. 57-64 ◽  
Author(s):  
P. K. OMANWAR ◽  
J. A. ROBERTSON
Keyword(s):  
Soil Solution ◽  
Mass Flow ◽  
P Concentration ◽  
Growth Room ◽  
Major Process ◽  
Apparent Diffusion ◽  
Soil Solution P ◽  
P Movement ◽  
Diffusion Mass

A plant growth room experiment was conducted using seven soils of Alberta with a treatment of 300 ppm of P on four of the soils. The contributions to the movement of P to the roots were calculated according to the method of Barber and co-workers, with some modifications. Results of the experiment showed clearly that movement by mass flow was the most important process of P transport to roots in soils treated with 300 ppm of P. Apparent diffusion was found to be the major process of P movement to roots in untreated soils, which included two soils with naturally high levels of available P. Root interception was found to be of least importance in P movement to roots. Since the concentration of P in soil solution affected the amounts of P reaching the roots by diffusion, mass flow or root interception, the importance of the determination of soil solution P is emphasized. A correlation of 0.86 was obtained between the yield and soil solution P concentration of the untreated soils.

Soil phosphorus tests I: What soil phosphorus pools and processes do they measure?

2013 ◽  
Vol 64 (5) ◽  
pp. 461 ◽  
Author(s):  
Philip W. Moody ◽  
Simon D. Speirs ◽  
Brendan J. Scott ◽  
Sean D. Mason
Keyword(s):  
Soil Solution ◽  
Buffer Capacity ◽  
Activity Ratio ◽  
Clay Content ◽  
Soil P ◽  
Olsen P ◽  
Soil Solution P ◽  
Highly Correlated ◽  
Soil P Tests ◽  
P Supply

The phosphorus (P) status of 535 surface soils from all states of Australia was assessed using the following soil P tests: Colwell-P (0.5 m NaHCO3), Olsen-P (0.5 m NaHCO3), BSES-P (0.005 m H2SO4), and Mehlich 3-P (0.2 m CH3COOH + 0.25 m NH4NO3 + 0.015 m NH4F + 0.013 m HNO3 + 0.001 m EDTA). Results were correlated with soil P assays selected to estimate the following: soil solution P concentration (i.e. 0.01 m CaCl2 extractable P; Colwell-P/P buffer index); rate of P supply to the soil solution (i.e. P released to FeO-impregnated filter paper); sorbed P (i.e. Colwell-P); mineral P (i.e. fertiliser reaction products and/or soil P minerals estimated as BSES-P minus Colwell-P); the diffusive supply of P (i.e. P diffusing through a thin gel film, DGT-P); and P buffer capacity (i.e. single-point P buffer index corrected for Colwell-P, PBICol). Across all soils, Colwell-P and BSES-P were highly correlated with FeO-P (r = 0.76 and 0.58, respectively). Colwell-P was moderately correlated with mineral P (r = 0.24), but not solution P. Olsen-P and Mehlich-P were both highly correlated with FeO-P (r = 0.80 and 0.78, respectively) but, in contrast to Colwell-P and BSES-P, also showed moderate correlations with soil solution P (r = 0.29 and 0.34, respectively) and diffusive P supply (r = 0.31 and 0.49, respectively). Correlation coefficients with mineral P were r = 0.29 for Olsen-P and r = 0.17 for Mehlich-P. Soils were categorised according to their pH, clay activity ratio, content of mineral P and CaCO3 content, and the relationships between the empirical soil P tests examined for each soil category. Olsen-P and Colwell-P were correlated across all soil categories (r range 0.66–0.90), and a widely applicable linear equation was obtained for converting one soil test to the other. However, the correlations between other soil tests varied markedly between soil categories and it was not possible to develop such widely applicable conversion equations. Multiple step-up linear regressions were used to identify the key soil properties affecting soil solution P, P buffer capacity, and diffusive P supply, respectively. For all soil categories, solution P concentration (measured by CaCl2-P) increased as rate of P supply (measured as FeO-P) increased and P buffer capacity decreased. As an assay of sorbed P, Colwell-P alone did not significantly (P > 0.05) explain any of the variability in soil solution P, but when used in the index (Colwell-P/P buffer index), it was highly correlated (r = 0.74) with CaCl2-P. Soil P buffer capacity was dependent on different properties in different soil categories, with 45–65% of the variation in PBI accounted for by various combinations of Mehlich-Al, Mehlich-Fe, total organic C, clay content, clay activity ratio, and CaCO3 content, depending on soil category. The diffusive supply of P was primarily determined by rate of P supply (measured as FeO-P; r range 0.34–0.49), with significant (P < 0.05) small improvements due to the inclusion of PBICol and/or clay content, depending on soil category. For these surface soil samples, key properties of pH, clay activity ratio, clay content, and P buffer capacity varied so widely within individual Australian Soil Orders that soil classification was not useful for inferring intrinsic surface soil P properties such as P buffer capacity or the relationships between soil P tests.

Meat qualities in the sheep with special reference to Scottish breeds and crosses. I

1939 ◽  
Vol 29 (4) ◽  
pp. 544-626 ◽  
Author(s):  
H. Pálsson
Keyword(s):  
Scientific Basis ◽  
Accurate Estimate ◽  
Quantitative Composition ◽  
Carcass Quality ◽  
Strongly Correlated ◽  
Precise Measure ◽  
Total Fat ◽  
Highly Correlated ◽  
High Degree ◽  
The Relationship

1. By establishing the relationship between linear carcass measurements and the quantitative composition of the carcass in terms of bone, muscle and fat, we have provided a scientific basis for the use of many measurements hitherto only presumed to provide an index to carcass quality.2. External carcass measurements are correlated with weight of the skeleton. The most useful for this purpose are length of tibia + tarsus and length of the fore-cannon.3. As indices of muscle, external measures are only of indirect value. Thus, both F – T and G/F × 100 are strongly correlated with weight of muscle as a percentage of skeletal weight.4. Similarly, F provides an index of fat, being negatively correlated with fat as a percentage of bone.5. For muscle and fat internal measures permit a more precise estimate to be made. A + B is the best index of the former while C + J + Y provide the most accurate estimate of the weight of fat.6. Still better indices for muscle and fat are provided by suitable combinations of external and internal measurements. Thus L/10 + A + B is very highly correlated with the weight of muscle, and L/10 × (C + J + Y) is the best index of fat in the hoggets. For bone, a most efficient single index is shown to be the weight of the fore-cannon bone.7. The weight of the skeleton can be estimated with a high degree of accuracy from the weight of the bones in either one leg or loin. Both these joints combined, however, provide a still better estimate.8. The muscle in one leg or loin + leg provides an excellent index of the weight of muscle in the whole carcass.9. The fat in one leg, loin, or both these joints combined provides a good index of the weight of the total fat in the carcass. Both joints combined give the most precise measure.10. The value of certain measurements which are not necessarily associated with the quantity of the major tissues of the carcass, but which nevertheless have important qualitative significance, is emphasized.

Amelioration of subsurface acidity in sandy soils in low rainfall regions .2. Changes to soil solution composition following the surface application of gypsum and lime

Soil Research ◽  
1994 ◽  
Vol 32 (4) ◽  
pp. 847 ◽  
Author(s):  
CDA Mclay ◽  
GSP Ritchie ◽  
WM Porter ◽  
A Cruse
Keyword(s):  
Ionic Strength ◽  
Soil Solution ◽  
Ion Pairs ◽  
Chemical Properties ◽  
Sandy Soils ◽  
Soil Surface ◽  
Field Trials ◽  
Annual Rainfall ◽  
First Year ◽  
Solution Composition

Two field trials were sampled to investigate the changes to soil solution chemical properties of a yellow sandplain soil with an acidic subsoil following the application of gypsum and lime to the soil surface in 1989. The soils were sandy textured and located in a region of low annual rainfall (300-350 mm). Soil was sampled annually to a depth of 1 m and changes in soil solution composition were estimated by extraction of the soil with 0.005 M KCl. Gypsum leaching caused calcium (Ca), sulfate (SO4) and the ionic strength to increase substantially in both topsoil and subsoil by the end of the first year. Continued leaching in the second year caused these properties to decrease by approximately one-half in the topsoil. Gypsum appeared to have minimal effect on pH or total Al (Al-T), although the amount of Al present as toxic monomeric Al decreased and the amount present as non-toxic AlSO+4 ion pairs increased. Magnesium (Mg) was displaced from the topsoil by gypsum and leached to a lower depth in the subsoil. In contrast, lime caused pH to increase and Al to decrease substantially in the topsoil, but relatively little change to any soil solution properties was observed in the subsoil. There was an indication that more lime may have leached in the presence of gypsum in the first year after application at one site. Wheat yields were best related to the soil acidity index Al-T/EC (where EC is electrical conductivity of a 1:5 soil:water extract), although the depth at which the relationship was strongest in the subsoil varied between sites. The ratio Al-T/EC was strongly correlated with the activity of monomeric Al species (i.e. the sum of the activities of Al3+, AlOH2+ and Al(OH)+2 in the soil solution. An increase in the concentration of sulfate in the subsoil solution (which increased the ionic strength, thereby decreasing the activity of Al3+, and also increased the amount of Al present as the AlSO+4 ion pair) was probably the most important factor decreasing Al toxicity to wheat. The results indicated that gypsum could be used to increase wheat growth in aluminium toxic subsoils in sandy soils of low rainfall regions and that a simple soil test could be used to predict responses.

Regional deposition of 3.6-micron particles and lung function in asthmatic subjects

1991 ◽  
Vol 71 (6) ◽  
pp. 2238-2243 ◽  
Author(s):  
M. Svartengren ◽  
M. Anderson ◽  
G. Bylin ◽  
K. Philipson ◽  
P. Camner
Keyword(s):  
Airway Resistance ◽  
Regression Line ◽  
Test Phase ◽  
Phase Iii ◽  
Poor Correlation ◽  
Small Airways ◽  
Single Breath ◽  
Regional Deposition ◽  
Severe Asthmatic ◽  
Highly Correlated

In a group of moderately severe asthmatic subjects, regional deposition of 3.6-microns (aerodynamic diameter) monodispersed Teflon particles labeled with 111In was studied twice. The particles were inhaled with maximally deep inhalation at 0.5 l/s. Lung retention was measured at 0, 6, 24, and 48 h by use of a profile scanner equipped with two 13 x 5-cm NaI crystals. The retentions at 24 (Ret24) and 48 h were highly correlated (r = 0.96 with a slope of the regression line close to 1). There was a poor correlation between retention at 6 h and Ret24 (r = 0.54). The Ret24 values at the two exposures were well correlated (r = 0.86). There were significant correlations between airway resistance as well as single-breath nitrogen test phase III and Ret24 (r = 0.70 and 0.67, respectively). The correlation between single-breath nitrogen test phase III and Ret24 persisted also when only subjects within a narrow interval of airway resistance were included. The study indicates that regional deposition can be studied by measurements of Ret24 in subjects with moderately severe asthma and that it is dependent on changes in both large and small airways.

scholarly journals Effects of Liming on Grass Growth, Soil Solution Composition, and Microbial Activities

1987 ◽  
Vol 33 (2) ◽  
pp. 177-185 ◽  
Author(s):  
Masayuki Hojito ◽  
Shuji Higashida ◽  
Akira Nishimune ◽  
Kinya Takao
Keyword(s):  
Soil Solution ◽  
Microbial Activities ◽  
Solution Composition ◽  
Grass Growth

scholarly journals Phosphorus leaching in sandy soils .I. Short-term effects of fertilizer applications and environmental conditions

Soil Research ◽  
1988 ◽  
Vol 26 (1) ◽  
pp. 177 ◽  
Author(s):  
DM Weaver ◽  
GSP Ritchie ◽  
GC Anderson ◽  
DM Deeley
Keyword(s):  
Soil Solution ◽  
Environmental Conditions ◽  
Management Practices ◽  
Sandy Soils ◽  
Summer Rainfall ◽  
Application Rate ◽  
Short Term ◽  
Coastal Superphosphate ◽  
Soil Solutions ◽  
Soil Solution P

The consequences of previous as well as current environmental conditions and management practices on the potential for phosphorus (P) to be lost by drainage from sandy soils in the short term (< 1 year) were studied in the laboratory and the field. The potential for P losses by drainage was estimated by measuring soil solution P levels and rapidly released P. Rapidly released P was measured by determining the concentration of dissolved inorganic P contained in filtered (<0.45 pm) soil solutions after incubating soil at saturation for 15 min at ambient temperature. In the laboratory, sandy soils were incubated with ordinary superphosphate, coastal superphosphate (a granulated mixture of equal parts of superphospate, rock phosphate and elemental sulfur) or lime-superphosphate (a lime-reverted superphosphate with 18% kiln dust) and sequentially desorbed with deionized water. The effects of the extent of leaching, fertilizer type, application rate and the time of contact with the soil on soil solution P levels were investigated. The influence of annual pasture death and summer rainfall on rapidly released P in soils that had been pre-treated by leaching were also investigated. Phosphorus concentrations decreased logarithmically in the successive supernatants of the sequentially desorbed soils. More P was desorbed from soils incubated with superphosphate and lime-superphosphate than soil incubated with coastal superphosphate. At each level of pre-leaching, the P concentrations in the soil solution increased with increasing time. The level, to which the P concentration in the soil solution increased at each time, decreased with increased extent of pre-leaching. The addition of P fertilizers increased the concentration of P in the soil solution. The concentrations increased with increasing application rate and were much higher for superphosphate than for coastal superphosphate; however, there was little effect of contact time on soil solution P levels. Rapidly released P levels after leaching increased during a period of no further leaching. Additional moisture or plant material during this period of no further leaching increased the rate and extent to which rapidly released P increased. Monitoring of rapidly released P in the 0-2, 2-5, 5-10 and 10-20 cm layers of field plots, with and without applications of superphosphate, showed that sampling depth, water flow path, fertilizer management, rainfall pattern and background P levels would affect the estimate of short-term P losses. Rapidly released P in the 0-2 cm layer varied markedly with time and was higher (P < 0.05) than that in lower soil layers. Rapidly released P increased after the winter and spring rains diminished and then decreased after the rains commenced again at the end of the summer. A possible annual cycle of P in sandy soils in a mediterranean climate is postulated by considering the laboratory and field data in combination.

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