PHOSPHORUS UPTAKE BY ALFALFA AS INFLUENCED BY PHOSPHATE SOURCE AND MOISTURE

1962 ◽  
Vol 42 (2) ◽  
pp. 254-265 ◽  
Author(s):  
J. D. Beaton ◽  
D. W. L. Read ◽  
W. C. Hinman

The effect of phosphate source and soil moisture during the initial soil-fertilizer reaction period on subsequent phosphorus uptake by alfalfa was investigated in a growth chamber. Phosphate-treated soils with moisture adjusted to four different tensions were stored at approximately 18 °C. for 10 weeks. Following this storage interval phosphorus uptake by alfalfa was measured using a short-term technique.Phosphorus content and phosphorus uptake by both tops and roots increased significantly when water-soluble materials such as ammonium polyphosphate, monoammonium and monocalcium phosphate were applied. Less soluble sources, i.e., hydroxyapatite and anhydrous dicalcium phosphate, were much less effective. Calcium metaphosphate produced intermediate results.Moisture content of the soil during the reaction period did not greatly alter subsequent P uptake. The water-soluble sources of phosphorus were affected to the greatest degree.Uptake of P was significantly correlated with the amount of P extracted by NaHCO3 from the treated soils. The highest degree of correlation occurred with ammonium polyphosphate treated soil. A significant negative correlation occurred with calcium metaphosphate. With the exception of the 0.8 bar treatment, moisture tension had little influence on the correlation of P uptake with NaHCO3 extractable-P.

Soil Research ◽  
1998 ◽  
Vol 36 (3) ◽  
pp. 389 ◽  
Author(s):  
M.E. Probert ◽  
P. W. Moody

The short-term (25 days) phosphorus (P) uptake by maize has been reported to be most strongly correlated with measurements of P intensity in soil. Correlations of P uptake with bicarbonate-extractable P (a measure of the quantity factor) were improved when indices of P buffer capacity were included, but not to the extent obtained with the direct measure of P intensity. Thus, one might infer that measurements of the quantity factor and P buffer capacity were less satisfactory for describing P availability. It is now shown that this conclusion results entirely from the model fitted to the data. By using a multiplicative rather than additive model, it is shown that bicarbonate-extractable P in combination with measures of P buffer capacity can describe the P uptake data equally as well as a direct measurement of P intensity.


1976 ◽  
Vol 56 (1) ◽  
pp. 9-20 ◽  
Author(s):  
R. W. SHEARD ◽  
A. J. LEYSHON

A laboratory procedure and apparatus design are described for the sampling of the soil solution and dissolved gases below the surface of a flooded soil without disturbance of the soil or the normal diffusion process. Ethylene and CO2 concentration increased in the dissolved gases of a flooded Maryhill loam (Ortho Humic Gleysol) as the duration of flooding increased from zero to 17 days and the redox potential (Eh) decreased. Soluble Fe and Mn slowly increased as the Eh decreased. The addition of NO3-N depressed ethylene formation and the release of soluble Fe and Mn. The addition of sucrose rapidly eliminated NO3-N from the soil solution, reduced the Eh to −330 mV, stimulated ethylene and CO2 formation, and further solubilized Fe and Mn. The accumulation of dry weight, total P and fertilizer P concentrations in corn were reduced by flooding soil for periods up to 12 days. The measurement of Eh, gases and Fe and Mn in the soil solution suggest that ethylene accumulation and O2 depletion were involved in the reduction of fertilizer P uptake.


Author(s):  
Sanja Annabell Schwalb ◽  
Michael Hemkemeyer ◽  
Conor Watson ◽  
Florian Wichern

AbstractTo reduce dependency on inorganic phosphorus (P) fertiliser, secondary P fertilisers such as struvite are becoming more important. However, the P uptake of these new fertilisers by plants is often not known and may be enhanced by plant associated microorganisms. We therefore investigated the effect of arbuscular mycorrhizae (AM) on P uptake in rye (Secale cereale L.), grown in the middle compartment of a box with chambers separated by a 30 µm mesh allowing fungal hyphae but not roots to penetrate. Plants with (AM) or without (control) mycorrhizae (Rhizophagus irregularis) were grown in a P limited sand medium for 72 days. After harvest, plants were analysed for mycorrhizal colonization, shoot and root development and nutrient (P, Ca, Mg) uptake. Further, pH was measured in each compartment. Shoot biomass of both treatments was not different, but root biomass was significantly lower in AM plants. Despite plants of the AM treatment being colonised by mycorrhizae, their P uptake was substantially lower compared to the control treatment, but root nutrient concentration was higher. Even though the pH in the mycorrhizal compartment of the AM treatment was significantly lower compared to the control, water- and CAL-extractable P were similar, indicating little P uptake from this compartment. Extractable P was reduced only in the root compartment of the control, which was associated with a lower pH compared to the AM treatment. In conclusion, mycorrhizae did not increase P uptake from struvite in rye plants. Non-mycorrhizal plants which invested more biomass into roots took up more P. Graphical abstract


1987 ◽  
Vol 38 (6) ◽  
pp. 1033 ◽  
Author(s):  
JS Yeates ◽  
DG Allen

The effectiveness of three finely ground rock phosphates (PRs) was compared with ordinary superphosphate (OSP) for subterranean clover growth and for increasing soil bicarbonate-extractable P levels over two successive 8-week periods on a very acid clay-loam (pH (0.01 M CaCl2) 4.3) in a glasshouse experiment. All PR sources were poorly effective compared to OSP. Maximum dry matter and P uptake of each PR source was less than that of OSP at each harvest. Relative to surface application, mixing throughout the soil reduced the effectiveness of OSP for dry matter and P uptake, but had little effect on the PR sources. Relative to OSP, the effectiveness of PR sources did not increase at the second harvest. Bicarbonate-extractable P levels for soil-incorporated Island PR plateaued below the highest rate applied. Phosphorus uptake by the herbage at harvests 1 and 2 was not well related to soil bicarbonateextractable P levels at harvest 1, and source dependency was indicated. Soil pH was markedly increased by each of PR sources at application rates within the rates required to reach maximum dry matter and P yield. Increased soil pH at high PR applications is likely to have reduced PR dissolution, and contributed to low agronomic effectiveness. Dry matter yield at both harvests was dependent on P concentration in the tops, regardless of the P source or method of P application. A higher soil buffering capacity for pH, P or Ca than was present in this soil seems necessary for sufficient PR dissolution to achieve the same agronomic effectiveness as OSP.


1986 ◽  
Vol 107 (2) ◽  
pp. 335-341 ◽  
Author(s):  
G. S. Bahl ◽  
N. T. Singh

SummaryLaboratory studies were conducted on four soils to ascertain the effect of P content and texture on the capacity factor (P buffering capacity) of soils and in turn the effect of these factors combined with moisture content of soil on the diffusion coefficient of P (Dp). A glasshouse experiment was conducted to study the relationship of Dp with P uptake by maize and wheat. The buffer capacity decreased by the application of P in all four soils. There was a significant negative correlation between buffer capacity and Olsen's extractable P but positive correlation with other soil factors. The relative influence of different soil variables on the buffer capacity was in the order: free iron > percentage clay > exchangeable aluminium. The Dp value increased significantly with applied P, the maximum (3·2-fold over control) being in Tolewal loamy sand. The increase in clay and moisture content of soil also increased the Dp value. The drymatter yield and P uptake was significantly correlated with Dp, the r value being higher at later stages of growth of maize and wheat.


1984 ◽  
Vol 56 (4) ◽  
pp. 291-298
Author(s):  
Helinä Hartikainen

The effect of peat ash and basic slag on the P supply to turnip rape was compared with that of calcitic and dolomitic limestone in a pot experiment performed with two acid mineral soils of pH 4.8 (CaCl2). Changes in soil properties induced by various liming agents were investigated in an analogous incubation test, and the results served to interpret the observations made in the pot experiment. When the liming materials were added in equal quantities, their ability to reduce soil acidity decreased in the sequence: calcite > dolomite > basic slag > peat ash. However, their growth-promoting effect appeared only in the second year and was not related to the neutralizing ability. In the muddy fine sand soil (3.0 % of org. C) poor in water-soluble P, the peat ash and basic slag were equally effective as calcite in increasing the dry matter yields. In the fine sand soil (6.4 % of org. C), the basic slag and dolomite significantly increased the second yield. The efficiency of peat ash and basic slag seemed to be attributable to their positive impact on P resources. In fact, peat ash served as a slowly acting P-fertilizer rather than as a liming agent. In the basic slag treatment, an increased silicate concentration obviously resulted in desorption of P. In the P-deficient muddy fine sand, the peat ash was equivalent to calcite in intensifying the P uptake. On the other hand, in the fine sand soil where the polymerization of Al due to an increased pH obviously resulted in enhanced P retention, the P uptake was higher in the soils treated with peat ash and basic slag than in those amended with conventional liming agents.


1989 ◽  
Vol 61 (1) ◽  
pp. 1-6
Author(s):  
Helinä Hartikainen

The water and acid acetate extractions as predictors of the P uptake by plants were compared in a two-year pot experiment and a simultaneous incubation test. The accuracy of these methods was dissimilarly affected by individual cultivation measures, such as the addition of nutrient salts and liming. In contrast to acetate-extractable P, the water-soluble P proved to be sensitive to the salt addition reducing the water extraction test values markedly. On the other hand, in limed soils the water-soluble P seemed to be more closely related to the P uptake by plants than the acetate-extractable P which tended to overestimate available reserves.


2021 ◽  
Author(s):  
Katherine Williams ◽  
Daniel McKay Fletcher ◽  
Chiara Petroselli ◽  
Siul Ruiz ◽  
Nancy Walker ◽  
...  

<p>Phosphorus (P) is critical for plant growth and can limit crop yields, but rock phosphate (the primary source of agricultural P) is a finite resource which is predicted to run out within 50-250 years. However, since P is important for short-term yield gains, it is often over-applied, causing run-off and water pollution. It is crucial to apply the right fertilisers at the most efficient rate, time, and place to protect our food security and environment for the future.</p> <p>Optimal application requires an understanding of the processes affecting P availability to plants. Fertilisers range from soluble in water (e.g TSP) to only slightly soluble (e.g. struvite). However, experiments testing the efficacy of fertilisers with different solubilities have reached variable results. Standard soil testing methods sample at fixed time points, while the dissolution, diffusion, sorption and uptake of P are dynamic processes, so to make predictions we must understand those dynamics.</p> <p>We used image-based modelling to investigate the predicted effects of dissolution rate and soil buffer power on P uptake by spring wheat root systems taken from X-ray CT images. We added a P source to represent a fertiliser granule and modelled the predicted P uptake based on 1 day, 1 week, and 14 week dissolution of the same amount of P for two realistic soil buffer powers.</p> <p>We demonstrated that rapid dissolution increased short-term root uptake, but dissolution over 1 week did not differ from dissolution over 1 day. We also found that root system architecture has a large effect on the efficiency of a P fertiliser pellet, highlighting the importance of application location. These results provide a starting point for predictive modelling of the efficacy of different P fertilisers in different soils, and our image-based approach gives the ability to add different root architectures for different species or varieties.</p>


2001 ◽  
Vol 58 (1) ◽  
pp. 165-170 ◽  
Author(s):  
Luís Ignácio Prochnow ◽  
José Francisco da Cunha ◽  
Ariel Francisco Candiotti Ventimiglia

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.


2017 ◽  
Vol 14 (22) ◽  
pp. 5239-5252 ◽  
Author(s):  
Daniel Puppe ◽  
Axel Höhn ◽  
Danuta Kaczorek ◽  
Manfred Wanner ◽  
Marc Wehrhan ◽  
...  

Abstract. The significance of biogenic silicon (BSi) pools as a key factor for the control of Si fluxes from terrestrial to aquatic ecosystems has been recognized for decades. However, while most research has been focused on phytogenic Si pools, knowledge of other BSi pools is still limited. We hypothesized that different BSi pools influence short-term changes in the water-soluble Si fraction in soils to different extents. To test our hypothesis we took plant (Calamagrostis epigejos, Phragmites australis) and soil samples in an artificial catchment in a post-mining landscape in the state of Brandenburg, Germany. We quantified phytogenic (phytoliths), protistic (diatom frustules and testate amoeba shells) and zoogenic (sponge spicules) Si pools as well as Tiron-extractable and water-soluble Si fractions in soils at the beginning (t0) and after 10 years (t10) of ecosystem development. As expected the results of Tiron extraction showed that there are no consistent changes in the amorphous Si pool at Chicken Creek (Hühnerwasser) as early as after 10 years. In contrast to t0 we found increased water-soluble Si and BSi pools at t10; thus we concluded that BSi pools are the main driver of short-term changes in water-soluble Si. However, because total BSi represents only small proportions of water-soluble Si at t0 (< 2 %) and t10 (2.8–4.3 %) we further concluded that smaller (< 5 µm) and/or fragile phytogenic Si structures have the biggest impact on short-term changes in water-soluble Si. In this context, extracted phytoliths (> 5 µm) only amounted to about 16 % of total Si contents of plant materials of C. epigejos and P. australis at t10; thus about 84 % of small-scale and/or fragile phytogenic Si is not quantified by the used phytolith extraction method. Analyses of small-scale and fragile phytogenic Si structures are urgently needed in future work as they seem to represent the biggest and most reactive Si pool in soils. Thus they are the most important drivers of Si cycling in terrestrial biogeosystems.


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