scholarly journals Efficacy of a Phosphate-Charged Soil Material in Supplying Phosphate for Plant Growth in Soilless Root Media

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Young-Mi Oh ◽  
Paul V. Nelson ◽  
Dean L. Hesterberg ◽  
Carl E. Niedziela

A soil material high in crystalline Fe hydrous oxides and noncrystalline Al hydrous oxides collected from the Bw horizon of a Hemcross soil containing allophane from the state of Oregon was charged with phosphate-P at rates of 0, 2.2, and 6.5 mg·g−1, added to a soilless root medium at 5% and 10% by volume, and evaluated for its potential to supply phosphate at a low, stable concentration during 14 weeks of tomato (Solanum esculentumL.) seedling growth. Incorporation of the soil material improved pH stability, whether it was charged with phosphate or not. Bulk solution phosphate-P concentrations in the range of 0.13 to 0.34 mg·dm−3were associated with P deficiency. The only treatment that sustained an adequate bulk solution concentration of phosphate-P above 0.34 mg·dm−3for the 14 weeks of testing contained 10% soil material charged with 6.5 mg·g−1P, but initial dissolved P concentrations were too high (>5 mg·g−1phosphate-P) from the standpoint of phosphate leaching. The treatment amended with 10% soil material charged with 2.2 mg·g−1P maintained phosphate-P within an acceptable range of 0.4 to 2.3 mg·dm−3for 48 d in a medium receiving no postplant phosphate fertilization.

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 486C-486
Author(s):  
Young-Mi Oh ◽  
Paul V. Nelson ◽  
Dean L. Hesterberg

Soilless root media retain very little phosphate. This characteristic necessitates continual application of phosphate, which leads to excessive application and leaching. The phosphate desorption characteristics of synthetic hematite (a-Fe2O3), goethite (a-FeOOH), allophane (Si3Al4O12*nH2O), and a commercial alumina (Al2O3), previously determined for their maximum adsorption capacities, were evaluated to determine their potential for providing a low, constant soil solution phosphate supply with low phosphate leaching from soilless root media. The desorption isotherms of the clay minerals were obtained by introducing 10 mM KCl solution at 0.2 ml/min flow rate into a stirred flow reaction chamber loaded with clay adsorbed with phosphate at maximum adsorption capacity. The suspension in the reaction chamber was held at pH 6.4 during desorption. Effluent solutions were collected for phosphorus analysis until the equilibrium concentration of phosphorus in solution reached 0.05 mg•L-1. Adsorbed phosphorus at 0.05 mg•L-1 equilibrium concentration in solution was in the order allophane (19 mg•g-1) > alumina™ goethite (8 mg•g-1) > hematite (1.3 mg•g-1). The equilibrium concentration of phosphorus in solution over time showed that allophane releases phosphate for a longer time than the other clay minerals at a desirable soil solution concentration for plants, less than 5 mg•L-1. Among the clay minerals tested, allophane showed the most favorable potential to supply phosphate to plants in soilless root media.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 472A-472
Author(s):  
Young-Mi Oh ◽  
Paul V. Nelson ◽  
Dean L. Hesterberg

A soil material high in metal oxides collected from the Bw horizon of a Hemcross soil in the state of Oregon was charged with phosphate, added to a soilless root medium, and evaluated for its potential to supply phosphate at a low, stable concentration during 14 weeks of tomato cropping (three successive crops). Three rates of phosphate were charged on the soil material, 0, 2.2, and 6.5 m P/g soil material and the soil material was incorporated into a 3 peatmoss: 1 perlite (v:v) medium at 5 % (40 g) and 10 % (80 g) of the volume of a 13.6-cm pot (1.0 L of medium). Uncharged soil material incorporated into soilless root medium at 5% and 10% reduced soil solution phosphate to deficient levels for 2 and 7 weeks, respectively. Phosphate was adequately supplied for 7, 10, 12, and more than 14 weeks in the 2.2P-5%, 2.2P-10%, 6.5P-5%, and 6.5P-10% treatment, respectively, as determined by symptoms of P deficiency. Phosphate and K levels in soil solution were highest at the beginning of crop 1 and tended to decline thereafter. Incorporation of soil material into soilless root medium improved pH stability whether it was charged with phosphate or not. The loss of the phosphate-charged soil material was negligible, 0.3% for the 6.5P-5% treatment and 1.2% for the 6.5P-10% treatment. The minimum critical concentration of soil solution phosphate for tomato in a 3 peatmoss: 1 perlite (v:v) medium as determined by the pour-through extraction procedure was found to be 0.3 mg·L–1 or slightly less.


2021 ◽  
Vol 22 (10) ◽  
pp. 5162
Author(s):  
Leangsrun Chea ◽  
Birgit Pfeiffer ◽  
Dominik Schneider ◽  
Rolf Daniel ◽  
Elke Pawelzik ◽  
...  

Low phosphorus (P) availability is a major limiting factor for potatoes. P fertilizer is applied to enhance P availability; however, it may become toxic when plants accumulate at high concentrations. Therefore, it is necessary to gain more knowledge of the morphological and biochemical processes associated with P deficiency and toxicity for potatoes, as well as to explore an alternative approach to ameliorate the P deficiency condition. A comprehensive study was conducted (I) to assess plant morphology, mineral allocation, and metabolites of potatoes in response to P deficiency and toxicity; and (II) to evaluate the potency of plant growth-promoting rhizobacteria (PGPR) in improving plant biomass, P uptake, and metabolites at low P levels. The results revealed a reduction in plant height and biomass 60–80% under P deficiency compared to P optimum. P deficiency and toxicity conditions also altered the mineral concentration and allocation in plants due to nutrient imbalance. The stress induced by both P deficiency and toxicity was evident from an accumulation of proline and total free amino acids in young leaves and roots. Furthermore, root metabolite profiling revealed that P deficiency reduced sugars by 50–80% and organic acids by 20–90%, but increased amino acids by 1.5–14.8 times. However, the effect of P toxicity on metabolic changes in roots was less pronounced. Under P deficiency, PGPR significantly improved the root and shoot biomass, total root length, and root surface area by 32–45%. This finding suggests the potency of PGPR inoculation to increase potato plant tolerance under P deficiency.


Weed Science ◽  
1986 ◽  
Vol 34 (1) ◽  
pp. 34-39 ◽  
Author(s):  
David L. Sutton

Hydrilla [Hydrilla verticillata(L.f.) Royle # HYLLI] was grown for 4 to 16 weeks in pans filled with either an organic muck-sand soil, sand, or sand mixed with Osmocote, Esmigran, and dolomite under outdoor conditions in plastic-lined pools with flowing pond water. Dry weight for plants cultured in sand plus the fertilizers was dependent on the concentration of fertilizer and was from 6 to 14 times that of plants cultured in sand alone. Dry weight was also higher for three treatments of sand amended with fertilizer than for plants cultured in the organic muck-sand soil. Water temperature for different growth periods influenced dry weight of hydrilla cultured with all three root media. Tuber production was independent of three levels of fertilizer for 16 weeks of plant growth, but plant weight was dependent on the concentration of nutrients in the root zone. Of nine plant tissue nutrients measured, only phosphorus in both the shoots and roots was dependent on the level of fertilizer in the root zone. This suggests that growth of hydrilla is controlled by nutrients in the root zone. The use of sand amended with various levels of fertilizers may be a way to simulate fertility levels of sediments as a method to study aquatic sites for their potential to support growth of hydrilla.


1980 ◽  
Vol 58 (20) ◽  
pp. 2200-2205 ◽  
Author(s):  
S. Asimi ◽  
V. Gianinazzi-Pearson ◽  
S. Gianinazzi

Growth and yield increases, obtained in nodulated soybeans growing in unamended sterile soil by inoculation with the vesicular–arbuscular (VA) mycorrhizal fungus Glomus mosseae, were accompanied by improved P uptake, lower root to shoot ratios, better nodulation with higher nitrogenase activity, and modifications in the pattern of the latter during plant growth. Stimulation of nitrogenase activity occurred early in plant development and preceded plant growth responses by about 2 weeks. Phosphate fertilization increased yield, percent P but not percent N of both mycorrhizal and nonmycorrhizal soybeans, and also modified the pattern and amount of nitrogenase activity during plant growth. Additions of 0.25 g KH2PO4/kg to the soil eliminated the mycorrhizal effect on plant growth, but nodule formation and nitrogenase activity were still significantly stimulated by the mycorrhizal infection. Mycorrhizal effects on nodulation were eliminated with 0.5 g KH2PO4 and on nitrogenase activity with the addition of 1.0 g KH2PO4. These higher levels of phosphate fertilization considerably diminished infection and, in particular, fungal spread within the roots.


1992 ◽  
Vol 26 (9-11) ◽  
pp. 2341-2344 ◽  
Author(s):  
D. A. Edwards ◽  
Z. Liu ◽  
R. G. Luthy

Aggregated amphiphiles in an aqueous or solid/aqueous system can substantially enhance the uptake of polynuclear aromatic (PNA)compound into a bulk solution. The extent of PNA compound incorporated in an amphiphilic aggregate solution in the absence of solids is linearly dependent on the bulk solution concentration of the aggregated form of the amphiphile. In a system in which solids are in contact with a solution, however, the relationship is nonlinear as a result of the adherence of both amphiphile and PNA compound to the solids. The formation of amphiphile aggregates in the bulk solution of a system containing solids occurs only after a much greater amount of amphiphile has been added to the system than would be required for a similar system containing only solution. The partitioning of PNA compound between the solid, the colloidal amphiphilic aggregates in bulk solution, and the rest of the bulk solution can be characterized with two different partition coefficients and a number of other parameters, all of which are obtainable from independent experiments. The total fraction of PNA compound incorporated into bulk solution can be estimated with a mathematical model. Model results for the uptake of pyrene into a C8PE9.5 aggregate solution are shown plotted with experimental data. The effect of amphiphile aggregates on PNA compound transport in porous media may in some cases be substantial.


Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1534
Author(s):  
Jing-Wei Fan ◽  
Xiao-Wei Yang ◽  
Tao Wang ◽  
Yuan Li ◽  
Hong Zhao ◽  
...  

Genotypic variations of alfalfa (Medicago sativa L.) to both phosphorus (P) deficiency and water deficiency are evident on the Loess Plateau of China. Here, we compare the adaptive mechanisms between an introduced cultivar (Arkaxiya) and a landrace (Longzhong) subjected to P- and water-limited conditions. The two genotypes were grown in a soil medium with 0, 4.2, 8.4 and 16.8 μg applied P per gram dry soil. Three water treatments were imposed (maintained at 75–90%, 45–55% and 30–35% of pot capacity (PC)) 28 days after sowing (DAS). At high soil P and high soil water content (SWC), high rates of net photosynthesis (Pn) contributed to greater plant growth and P-use efficiency (PUE) in the introduced Arkaxiya compared to the landrace Longzhong. However, at low SWC, Longzhong had enhanced antioxidative defense (mainly SOD and CAT) compared to Arkaxiya. In addition, shorter shoot length and greater branching in Longzhong than Arkaxiya may also facilitate adaptation to low SWC. The contrasting adaptive mechanisms of the two genotypes provide a number of early-screening parameters associated with plant growth for the selection and introduction of alfalfa targeted at different rainfall and available P environments.


1992 ◽  
Vol 26 (9-11) ◽  
pp. 2389-2392 ◽  
Author(s):  
D. P. Smith

A previously developed spherical diffusion model of interspecies molecular hydrogen transfer was applied to a mathematical model of ethanol and propionate methanogenesis in a dispersed-growth, continuously stirred tank reactor (CSTR). Steady-state methanogenesis at a 0.10 day−1 space velocity required a hydrogen concentration difference of 1.12 × 10−5 aim (8.4 × 10−12 moles/cm3) between the surface of the propionate organisms and the bulk solution. The total difference in hydrogen concentration between source organism and sink organism Ihydrogenotrophic methanogenstwas 2.1 × 10−5 atm (1.6 × 10−11 moles/cm3). Steep gradients in hydrogen concentration existed only at close proximity to the bacterial spheres, with hydrogen concentration approaching bulk solution concentration at distances greater than 10 microns. Small hydrogen gradients and the bulk solution concentration prevailed through the majority of the reactor aqueous volume. Overall, the incorporation of hydrogen mass transfer resistance into the mathematical model had only a slight effect on hydrogen partial pressure, organic substrate levels, and bacterial mass concentrations predicted by the steady-state solution.


HortScience ◽  
2017 ◽  
Vol 52 (10) ◽  
pp. 1362-1367 ◽  
Author(s):  
Josh B. Henry ◽  
Ingram McCall ◽  
Brian Jackson ◽  
Brian E. Whipker

A series of experiments investigated the effects of increasing phosphate–phosphorus (P) concentrations on the growth and development of four horticultural species. In experiment 1, petunia [Petunia atkinsiana (Sweet) D. Don ex W.H. Baxter] plants were grown using eight P concentrations, and we found that the upper bound for plant growth was at 8.72–9.08 mg·L−1 P, whereas concentrations ≤2.5 mg·L−1 P caused P deficiency symptoms. Experiment 2 investigated P growth response in two cultivars each of New Guinea impatiens (Impatiens hawkeri W. Bull) and vinca [Catharanthus roseus (L.) G. Don]. Growth for these plants was maximized with 6.43–12.42 mg·L−1 P. In experiment 3, ornamental peppers (Capsicum annuum L. ‘Tango Red’) were given an initial concentration of P for 6 weeks and then switched to 0 mg·L−1 P to observe whether plants could be supplied with sufficient levels of P, and finished without P to keep them compact. Plants switched to restricted P began developing P deficiency symptoms within 3 weeks; however, restricting P successfully limited plant growth. These experiments indicated that current P fertilization regimens exceed the P requirements of these bedding plants, and depending on species, concentrations of 5–15 mg·L−1 P maximize growth.


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