Rates Of Triple Superphosphate Research Articles

Evaluate the phosphorus application response in potatoes under high phosphorus soil test in Florida

Phosphorus (P) is an indispensable nutrient for agricultural crops, existing in both organic and inorganic forms within the soil matrix. However, its runoff and leaching could potentially pollute the natural water bodies worldwide through eutrophication. Despite the elevated soil P levels indicated by soil tests, the potato crop necessitates substantial P fertilization due to its relatively superficial root structure and short growth period, particularly when compared to longer-cycle agronomic crops such as corn or cotton. This investigation was designed to assess the response of potato tuber yield and quality to incremental P fertilizer applications during the 2021 and 2022 growing seasons. The research was performed in the 2021 growing season across two different agricultural sites at the Hastings Agricultural Extension Center (HAEC), incorporating eight varying rates of Triple Super Phosphate (TSP) (formulation 0-46-0% N–P2O5–K), specifically 0, 28, 56, 84, 112, 140, 168, and 224 ​kg P2O5 ha−1. In the subsequent 2022 season, the study expanded to include three additional sites at HAEC, testing six different TSP levels at 0, 22, 45, 67, 90, and 112 ​kg P2O5 ha−1. A randomized complete block design (RCBD) with four replications was employed throughout the 2021 and 2022 seasons. The cumulative data from 2021 to 2022 indicated that total and marketable yields across all sites increased in response to increasing P rates (p ​< ​0.05), exhibiting a linear trend in most locations. When aggregating data from all sites, a quadratic yield response pattern emerged. In 2021, P uptake was statistically significant, with mean values fluctuating between 18.69 and 45.09 ​kg ​P ha−1. The P application was correlated with enhanced total P removal from the soil, though the specific gravity of the tubers remained unaffected by any level of P application. The study results suggest applying P improves potato yield even if the soil test P falls in the high range.

Phosphorus Mobilizing Capacity of Selected Grain Legumes Grown Under Phosphorus-Deficient Conditions

Compared with other crops, legumes have superior ability to mobilize part of non-labile phosphorus (P) into labile/available forms. We explored the P-mobilization potential of selected grain legumes and its influence on growth, P uptake, and yield under P-deficient conditions. A pot experiment was carried out in a greenhouse with soybean (<em>Glycine max </em>L.), cowpea (<em>Vigna</em> <em>unguiculata </em>L.), green gram (<em>Vigna radiata </em>L.), and black gram (<em>Vigna mungo </em>L.) with two P fertilizer applications; without (Pdeficient) and with (P-sufficient) Department of Agriculture recommended rates of triple super phosphate. Each crop was harvested at maturity and the bulk and rhizosphere soils were collected to quantify different P fractions using Hedley’s sequential fractionation. Dry weight and P accumulation in different plant organs, <em>i.e. </em>roots, stems, leaves, and pods, were measured. Most plant organs maintained similar dry weight and tissue-P concentration irrespective of the P levels applied. All crops reduced their total plant-P uptake under P-deficient conditions. However, this did not make any change in either pod dry weight or P concentration of pods. Soybean and mung bean had a greater P accumulation compared to cowpea and black gram under both P levels. In contrast, cowpea and black gram showed improved P use efficiency (PUE) than other two legumes. Available P concentration (NaHCO3-P) in rhizosphere soil is greater than that in bulk soil in soybean and cowpea whereas the rhizosphere NaHCO3-P content in mung bean was greatly decreased compared to that of bulk soil when the crop was cultivated in P-deficient soil. The concentration of non-labile P fraction in rhizosphere of all grain legumes were significantly low compared to that of the bulk soil. Results suggest that selected grain legumes could be cultivated in P-deficient soil as they can adapt either through enhancing P uptake or increasing PUE.

Enhancing Wheat and Soybean Yields in a Subtropical Oxisol Through Effective P Fertilization Strategies

Phosphorus (P) deficiency limits agricultural production in tropical and subtropical soils, where soil mineralogy is dominated by kaolinite, iron, and aluminum oxides. The aim of this work was to compare two application methods of P, to the soil surface and to the sowing line, to determine the most effective strategy to increase wheat and soybean yields on an oxidic subtropical soil in Brazil under field conditions. Additionally, four inorganic P fertilizers (monoammonium phosphate (MAP); single superphosphate (SS); triple superphosphate (TP); and natural rock phosphate (NP)) in a wheat crop and four different P rates (zero, 0; low, 45; medium, 90; and high, 180 kg ha−1 of P2O5) of TP in a soybean crop were tested after being applied to the soil surface and to the sowing line. A significant increase in yield (54%) was only found when TP was applied to the sowing line in comparison with the soil surface in wheat plants, probably due to its high solubility. However, the application method did not produce a significant effect in soybean yields, probably because this crop has a different P requirement and root distribution pattern than wheat. In the case of P fertilizers applied to the soil surface, higher wheat yields were observed with NP and MAP in comparison with TP. Finally, a linear increase was observed in soybean yields while increasing the P rate, finding significant differences between the plants fertilized with the highest P rate and the non-P-fertilized plants (24% yield increase in the first case). Our results highlight the need for specific P fertilization strategies for the different crops grown on subtropical regions where soil mineralogy curbs P availability.

A31P-NMR spectroscopic study of phosphorus forms in two phosphorus-fertilized grassland soils in eastern Canada

Phosphorus (P) fertilization can increase grassland production, but will also alter P forms, changing their cycling and potential for loss in runoff. We assessed the effects of mineral P fertilization on soil P forms in timothy swards at two sites in Quebec, Canada. Soil samples (10 cm depth) were collected in autumn 2013 from replicate plots at Lévis on a Kamouraska clay and at Normandin on a Labarre clay loam, each having received three rates of triple superphosphate (0, 20, and 40 kg P ha−1) for 4 yr. These were analyzed for pH, total carbon (TC), total nitrogen (TN), and total phosphorus (TP); Mehlich-3-extractable aluminium (AlM3), iron (FeM3), calcium (CaM3), and P (PM3); and31P nuclear magnetic resonance spectroscopy (31P-NMR) following sodium hydroxide–ethylenediaminetetraacetic acid (NaOH–EDTA) extraction. Phosphorus fertilization had no significant effects on soil TC, TN, AlM3, FeM3, CaM3, and pH, but significantly increased TP, NaOH–EDTA-extractable total P and total inorganic P, PM3, orthophosphate, and glucose 6-phosphate at both sites. In contrast, NaOH–EDTA-extractable total organic P, total orthophosphate diesters, and scyllo-inositol hexaphosphate decreased with P fertilization. Phosphorus fertilization over 4 yr increased soluble inorganic P and decreased organic P at both grassland sites.

Phosphorus Rates on Growth Parameters of Maize (Zea mays L.) in Reddish Brown Earth under Greenhouse Condition

Phosphorus is an essential element for plants. However, many soils lack sufficient in formthat is readily available to crops to ensure optimum growth especially in dry zone soils in SriLanka. Hence, this study was undertaken with the objective of evaluating the impact ofdifferent rates of Triple Super Phosphate (TSP) as a source of Phosphorus for maize (Var.Sampath) growth under greenhouse condition. Top soils at a depth of 0-25 cm were collectedfrom research farm, Puliyankulama and from a farmland in Kahatagasdigiliya, Anuradhapuradistrict. Greenhouse experiment conducted for both soils. Twenty pots were arranged in acompletely randomized design with four treatments (0, 20, 30 and 40 kg of Phosphorus ha-1)and five replicates for a single experiment. Soil samples were taken at 4, 8, 10, 12 and 16weeks after planting (WAP). The soil samples were analysed for soil pH, electricalconductivity (EC) and available Phosphorus (Olsen’s method). The leaf Phosphorus contentat 50% tasseling stage was measured using dry ash method. The growth parameters wereplant heights at 4, 8, 10 and 12 WAP, number of days to 50% tasseling and number of days to80% silking. Results indicate soil pH, EC, and leaf Phosphorus % are not significantlydifferent (p&lt;0.05) at different levels of Phosphorus in both locations. However, soil availablePhosphorus is significantly different (p&lt;0.05) to the control. Conversely it does not showsignificant different (p&lt;0.05) among fertilized treatments at both sites. Moreover, plant heightat 50% tasseling stage, number of days to 50% tasseling and number of days to 80% silkingare not significantly different (p&lt;0.05) among any treatments at both soil types. Hence, theresults further revealed that the different levels of P treatments have no significant effect onsoil pH, EC, available P, leaf P and growth parameters of maize variety Sampath undergreenhouse conditions.

Utilization of Poultry Manure Phosphorus for Corn Production

There is uncertainty about the need for supplemental P fertilization after applying poultry manure for corn (Zea mays L.). This study evaluated the effects of manure and fertilizer P on corn by establishing 17 on‐farm trials in Iowa. Manure from broilers, egg layers (Gallus gallus domesticus), or turkeys (Melleagris gollopavo) was used at each site. Replicated treatments were the combinations of three manure rates (0, 53, and 104 kg P ha−1 on average across sites) and four triple superphosphate rates (0–75 kg P ha−1). Initial Olsen P (15‐cm depth) was 5 to 23 mg P kg−1 across sites. Uniform rates of 168 kg N ha−1 and 56 to 112 kg K ha−1 were applied. Measurements were early plant dry weight (DW); P concentration and P uptake (V5–V6 stage); and grain yield, P concentration, and P removal. Increases in plant DW and P uptake were unrelated to soil‐test P, were more frequent for manure, and only one site that was responsive (P ≤ 0.10) to fertilizer was not responsive to manure. Phosphorus fertilization in addition to manure increased plant DW at four sites and P uptake at eight sites. Both P sources increased grain yield at eight sites with &lt;15 mg Olsen P kg−1, only manure increased it at another site, and supplemental fertilization did not increase yield at any site. The results provided no evidence for lower P availability of poultry manure P than fertilizer P for corn yield and showed no need for supplemental P fertilization at prevailing manure rates used by farmers.

Changes in Soil pH and Extractable Phosphorus Following Application of Turkey Manure Incinerator Ash and Triple Superphosphate

During the incineration of turkey manure, a wide variety and concentration of nutrients are conserved in the turkey manure ash (TMA). In particular, the high concentration of citrate-soluble phosphorus (P) (43 g kg−1) may make it a suitable P source for crop production. The ash is alkaline with a pH of 12.2. We conducted a soil incubation study using a low-P soil with a pH of 6.2 to evaluate the effects of TMA on soil pH and extractable P. Two TMA rates, based on citrate-soluble P (10.9 and 21.9 mg kg−1), were compared with equivalent rates of triple superphosphate (TSP). In addition, a 0-P control was included. At the rates tested, TMA slightly increased soil pH, but this increase would be of minor agronomic importance. At equivalent P rates, changes in water-soluble P (WSP) concentrations with TMA and TSP were similar. Changes in iron-oxide-strip–extractable P (FeO P) and Bray 1 P concentrations were greater with TMA than with TSP. In contrast, changes in Olsen P concentrations were greater with TSP than with TMA for up to 32 days. For TMA, the ability of the tests to extract P was ranked, from highest to lowest, as Bray 1 P > FeO P > Olsen P > WSP, and for TSP they were ranked Bray 1 P ≥ Olsen P ≥ FeO P > WSP. However, the Bray 1 P and FeO P tests tended to overestimate plant-available P because they measured more citrate-soluble P than that added with TMA. We conclude that TMA can be used as a P source for crop production and that the Olsen test may provide a better estimate of plant-available P in TMA-amended soil.

Phosphorus fertilizer induced changes in the soil available P, the P nutrition and the growth of Pinus radiata seedlings grown in association with understory

A study was carried out to investigate changes in the soil plant-available P, the P nutrition and the growth of Pinus radiata seedlings grown in association with understory, broom (Cytisus scoparius L.) or ryegrass (Lolium multiflorum) on Orthic Allophanic Soil, following the application of three rates of triple superphosphate (TSP) (0, 50, and 100 mg·kg−1P) under a glasshouse condition. The application of P fertilizer enhanced P availability in the rhizospheric of radiata seedlings and the bulk soils in a P-deficient site. P availability in the rhizospheric soils of ryegrass and broom, grown in association with radiata, were also increased by the presence of radiata roots. P concentrations in new shoot needles, old shoot needles, stem and roots of radiata pine increased with increase rates of TSP application, but the effects of ryegrass and broom on P nutrition of radiata seedlings depended on the soil P status. In the absence of P fertilizer addition (control treatment), P concentrations in new shoot needles, old shoot needles, stem, and roots of radiata grown in association with broom were higher than those with ryegrass, whereas, when P fertilizer was added (50 and 100 mg·kg−1) the P concentration was lower. This is probably related to the growth of broom that may have removed much of the plant-available P in the soil as indicated by the consistently lower Bray-2 P concentration in the rhizosphere soil of radiata in association with broom than that in the rhizosphere soil of radiata in association with grass at the two high P rates. Furthermore, in the high P fertile soil (application rate of 100 mg·kg−1), the dry matter yield of radiata was lower when it was grown with broom than with ryegrass. This result suggests that in moderate to high P fertile soils, P. radiata seedlings grow better with ryegrass than with broom, because broom grows vigorously in high P fertile soil and competes with P. radiata for P and perhaps for other nutrients as well.

Assessment of the phosphorus status of oilseed rape by plant analysis

Phosphorus (P) concentrations in young plants of rapeseed (Brassica napus cv. Wesway) were related to seed and oil yields to develop a tissue test for the diagnosis of P deficiency. Critical P concentrations were defined as those concentrations required to sustain 90% of maximum yield. In 2 field experiments in successive seasons on a P-deficient soil, rates of triple superphosphate from 2.5 to 120 kg/ha were banded with the seed. The lowest P concentration in young shoots (17-19 weeks from sowing) associated with a P supply that was adequate for plant growth was approximately 0.31%. The youngest fully-expanded leaf was a reliable plant part to sample, its P concentration being about 0.05% lower than the concentration of the whole shoot. Critical P concentrations in young plants for sustaining 90% of maximum seed and oil yields were higher, namely 0.33 and 0.28% for whole shoots and youngest fully-expanded leaves respectively. The critical P concentration in seeds was about 0.35%.