Kinetic modeling to describe the potentials of single super phosphate and lime to remove Pb from contaminated waters

Phosphorus (P) deficiency is an important nutritional constraint for crop productivity in alkaline-calcareous saline-sodic soils. Generally, farmers apply different P fertilizers to overcome P deficiency; however, different P fertilizers may have different efficiency in saline-sodic and normal soils. An experiment was conducted to investigate the comparative effect of phosphatic fertilizers, viz. single super phosphate (SSP), di-ammonium phosphate (DAP) and triple superphosphate (TSP), on the growth of rapeseed. These fertilizers were applied to three different types of soils, viz. normal, saline-sodic soil-I {EC, 7 dS m−1; SAR, 25 (mmol L−1)1/2} and saline-sodic soil-II {EC, 14 dS m−1; SAR, 50 (mmol L−1)1/2). In normal soil, DAP was effective to enhance growth compared to other fertilizers. In saline-sodic soil-I, SSP enhanced shoot dry weight (SDW) to the maximum (51%) compared to control and by 12% and 21% compared to TSP and DAP, respectively. In saline-sodic-II, SSP increased SDW by 51% compared to control and by 14% and 20% compared to TSP and DAP, respectively. In saline-sodic soil-I, SSP-fertilized plants had 22% and 7% higher membrane stability index compared to plants grown with DAP and TSP. In saline-sodic soil-I and II, plants grown in pots fertilized with SSP accumulated the maximum chlorophyll contents, while control plants contained the minimum. In saline-sodic soils, SSP increased P concentration in shoot and Olsen P compared to other fertilizers. It is concluded that SSP is relatively more effective and improves plant growth in saline-sodic soils, while DAP is suitable for normal soils.

The effectiveness of some locally sourced phosphorus rocks (Sokoto Rock Phosphate (SRP), Crystallizer Super (CRY)) as P2O5 fertilizers for manuring oil palm applied on a long term basis (2000-2008) were evaluated along with conventional imported single superphosphate fertilizer at Okomu Oil Palm Plc., Ovia North East Local Government Area of Edo State, Nigeria. The rocks were tested at the rates of 1.5, 2.5 and 3.5 kg/palm/year respectively (214.5, 357.5 and 500.5 kg/ha), and the single superphosphate at 1.0, 2.0 and 3.0 kg/palm/year (143, 286 and 426 kg/ha). Urea (N), murate of potash (K), and kieserite (Mg) were applied as basal application at the rates of 0.5 kg N, 2.0 kg K and 0.2 kg mg/palm/year (71.5, 286 and 28.6 kg/ha) to all treatment plots except the control (treatment without fertilizer application). Treatments were laid out as Randomized Complete Block Design, replicated three times. The phosphorus sources enhanced soil pH and soil nutrient availability and thereby enhanced palm development and yield. Applied phosphorus fertilizers had significant (P≤0.05) effect on mean bunch number per palm, mean single bunch weight and fresh fruit bunch (FFB) production. Palms treated with these fertilizersperformed better than the control where no fertilizer was applied. Yield increases as rates of application increases and the optimum rates appeared to be 2.0 kg SSP, 2.5 kg SRP and 2.5 kg CRY beyond which there was no corresponding yield increase. Locally sourcedP2O5 competed favourably with the conventional inorganic single superphosphate as fertilizer for manuring oil palm. However, these fertilizers are better used in combined formwith single superphosphate due to their slow nutrients release and singly when Single superphosphate is not readily available. This along with basal application of N, K and Mg at the rates of 0.5, 2.0 and 0.2 kg /palm/year (71.5, 286 and 28.6 kg/ha) is very necessary for optimum yield. Key words: Fresh fruit bunch (FFB), oil palm, phosphorus treatment, rock phosphate, yield.

An increase in the concentrations of water‐insoluble iron phosphate (Fe‐P) compounds in acidulated P fertilizers has raised the concern that the agronomic effectiveness of these P fertilizers will decrease. This study was conducted to evaluate the agronomic effectiveness of three sources of single superphosphate (SSP) varying in Fe‐P impurities for upland and flooded rice (Oryza sativa L.) grown for 55 d. A modal chemical analysis and X‐ray diffraction were used to characterize the SSP samples and their water‐leached forms. A greenhouse study was conducted where rates of 0, 5, 15, 30, 50, and 100 mg P kg−1 as total available P (water plus citrate‐soluble P) were applied from each SSP source and monocalcium phosphate (MCP) to a Hiwassee clay loam (thermic Rhodic Kanhapludult). The water‐soluble P contents of the SSP sources were 46, 80, and 86% of the total available P (water + citrate) corresponding to an increase of Fe content (2, 4, and 7%) in the phosphate rock sources used for SSP production. The main Fe‐P impurities in the SSP samples were identified as Fe3NaH8(PO4)6·6H2O and Fe3H9(PO4)6·6H2O. Single superphosphate with only 46% of water solubility was 91% as effective as MCP in increasing dry matter yield and 76% as effective for P uptake by upland rice. The other two SSP sources were as good as MCP in effectiveness for upland rice. All of the SSP sources were equally as effective as MCP in producing dry matter yield and P uptake by flooded rice.

Between 2004 and 2011 the German Government funded 17 different projects to develop techniques of phosphorus recycling from wastewater, sewage sludges, and sewage sludge ashes. Several procedures had been tested, such as precipitation, adsorption, crystallization, nano-filtration, electro-dialysis, wet oxidation, pyrolysis, ion exchange, or bioleaching. From these techniques, 32 recycling products were tested by five different institutes for their agronomic efficiency, that is, their plant availability, mainly in pot experiments. This manuscript summarizes and compares these results to evaluate the suitability of different technical approaches to recycle P from wastes into applicable fertilizers. In total, 17 products of recycled sewage sludge ashes (SSA), one meat and bone meal ash, one sinter product of meat and bone meal, one cupola furnace slag, nine Ca phosphates from crystallization or from precipitation, Seaborne-Ca-phosphates, Seaborne-Mg-phosphate, and 3 different struvites were tested in comparison to controls with water soluble P, that is, either single super phosphate (SSP) or triple super phosphate (TSP). Sandy and loamy soils (pH: 4.7–6.8; CAL-P: 33–49 ppm) were used. The dominant test plant was maize. Phosphorus uptake from fertilizer was calculated by the P content of fertilized plants minus P content of unfertilized plants. Calculated uptake from all products was set in relation to uptake from water soluble P fertilizers (SSP or TSP) as a reference value (=100%). The following results were found: (1) plants took up less than 25% P in 65% of all SSA (15 products); (2) 6 products (26%) resulted in P uptake of 25 and 50% relatively to water soluble P. Only one Mg-P product resulted in an uptake of 67%. With cupola furnace slag, 24% P uptake was reached on sandy soil and nearly the same value as TSP on loamy soil. The uptake results of Ca phosphates were between 0 and 50%. Mg-P products from precipitation processes consistently showed a better P supply in relation to comparable Ca-P compounds. With struvite the same P uptake as for water soluble P was reached. The fertilizer effect of the tested P recycling products can clearly be differentiated: TSP = struvite > Mg-P = sinter-P > Ca-P, cupola-slag > thermally treated sewage sludge ashes > meat-and-bone meal ash = Fe-P.

Inefficient phosphorus (P) fertilizer application often accumulates soil P, wasting valuable phosphate resources and contributing to environmental pollution. Given the suboptimal P fertilizer use efficiency (PUE), understanding soil P dynamics and selecting appropriate fertilizers is crucial. Fluvo-aquic soil and yellow-cinnamon soils were used in a rice pot trial to compare five P fertilizer types: single superphosphate (SSP), diammonium phosphate (DAP), calcium magnesium phosphate (CMP), triple superphosphate (TSP), and ammonium polyphosphate (APP), alongside a no P, control (CK). In fluvo-aquic soil, TSP and APP significantly increased rhizosphere P availability at anthesis, while SSP increased yield and shoot P accumulation at maturity. In yellow-cinnamon soil, DAP had the highest rhizosphere P availability at anthesis, while APP significantly increased shoot P accumulation at anthesis and shoot P accumulation and grain yield at maturity. Moreover, PUE was highest with SSP and CMP in fluvo-aquic soil and APP and TSP in yellow-cinnamon soil. Throughout the experiment, increased soil alkaline phosphatase activity promoted NaOH-Po conversion to NaHCO3-Pi, increasing rice shoot P uptake, yield, and PUE in both soils. Based on the above findings, it is recommended to apply SSP and TSP to fluvo-aquic soil and APP and TSP to yellow-cinnamon soil to achieve higher yield and PUE, which can be further confirmed by subsequent field-scale studies.

Fertilizers based on phosphate-metal-humate complexes are a new family of compounds that represents a more sustainable and bioavailable phosphorus source. The characterization of this type of complex by using solid (31)P NMR in several fertilizers, based on single superphosphate (SSP) and triple superphosphate (TSP) matrices, yielded surprising and unexpected trends in the intensity and fine structure of the (31)P NMR peaks. Computational chemistry methods allowed the characterization of phosphate-calcium-humate complexes in both SSP and TSP matrices, but also predicted the formation of a stable sulfate-calcium-humate complex in the SSP fertilizers, which has not been described previously. The stability of this complex has been confirmed by using ultrafiltration techniques. Preference towards the humic substance for the sulfate-metal phase in SSP allowed the explanation of the opposing trends that were observed in the experimental (31)P NMR spectra of SSP and TSP samples. Additionally, computational chemistry has provided an assignment of the (31)P NMR signals to different phosphate ligands as well as valuable information about the relative strength of the phosphate-calcium interactions within the crystals.

Longlife' phosphatic fertiliser is manufactured in New Zealand by mixing reactive phosphate rock (RPR) with single superphosphate (SSP) when the SSP is at an ex-den stage. Commercially produced Longlife (70:30 SSP:RPR) was evaluated in 6 field mowing trials in the North Island over 3 or4 years. Also, a 5050 (SSP:RPR) Longlife-type product was examined in 5 field trials throughout New Zealand over 5 or 6 years. Longlife was compared against SSP and/or triple superphosphate (TSP) in all trials, and RPR treatments were included in 7 trials. In all trials with commercially produced Longlife, the pasture response to Longlife tended to be less than that to SSP or TSP in the first 2 years and was significantly different (P 6.0 and/or rainfall ~800 mm/year). Keywords field trials, Longlife, phosphate, reactive phosphate rock, superphosphate

Recent field experiments have shown that high chloride (Cl) in irrigation waters can increase soil cadmium (Cd) uptake by crops because of the formation of soluble ion-pair complexes of Cd with Cl in soil solution. The present study was aimed at testing a hypothesis that KCl in granulated PK fertilizers may enhance Cd uptake by crops from Cd-containing P fertilizers because of close contact between Cd and Cl in the same granules. Less effect would be expected if the same granular PK fertilizers were bulk-blended because of separation of Cd and Cl in different granules. A single superphosphate (SSP) containing 32 mg Cd kg(-1) was granulated by the compaction process with KCl at a P to K ratio = 1:1. Granular KCl was also bulk-blended with granular SSP or Cd-free monocalcium phosphate (MCP) at the same P to K ratio. An acid Ultisol (pH 5.2) was treated with PK fertilizers at 400 mg kg(-1) each for P and K. Upland rice (Oryza sativa L.) and soybean [Glycine max (L.) Merr.] were grown to maturity, and signalgrass (Brachiaria decumbens Stapf.) was cut four times during the study. The results showed that the agronomic effectiveness in increasing crop yield was the same with SSP and MCP whether granulated or bulk-blended with KCl. Concentrations of Cd in plant tissue samples of all crops were much lower for MCP than for SSP. In all the plant tissue samples, except grain samples of upland rice, Cd concentrations obtained with granulated (SSP + KCl) were significantly higher than that with bulk-blended (SSP) + (KCl).

The effectiveness of a Pi (iron oxide-impregnated paper) method was compared with that of Bray-1 method in extracting phosphorus (P) from an acid Hartsells silt loam (Typic Hapludult, pH 4.8) treated with low-release P fertilizers derived from Dorowa (Zimbabwe) phosphate rock (DPR) with maize (Zea mays L) as indicator crop in a randomized block design greenhouse experiment with three replicates. The fertilizers used were finely ground DPR, partially acidulated DPR (PADPR), a compacted mixture of DPR + triple superphosphate (TSP) + urea + potassium chloride (DTUK) with half of P from DPR and half from TSP, and a commercial grade single superphosphate (SSP) as a standard. The results indicated that the correlation between Bray-1 and Pi-extractable P was high (r = 97***). The regression coefficients for dry matter yield (DMY) and P uptake (PUPT) as a function of Bray-1 P level of SSP (DMY = 1.16 + 0.24Bray-1 P; PUPT = 0.93 + 0.45Bray-1 P) were significantly lower (p < 0.001) than those for DTUK (DMY = 1.16 + 0.43Bray-1 P; PUPT = 0.93 + 0.74Bray-1 P) and PADPR (DMY = 1.16 + 0.47Bray-1 P; PUPT = 0.93 + 0.82Bray-1 P). That is, a given soil-extractable P level with SSP resulted in a lower dry matter yield or P uptake than that from DTUK and PADPR. Thus, Bray-1 underestimated the agronomic effectiveness of DTUK and PADPR with respect to SSP. Based on this greenhouse research, soil testing for fertilizer recommendations using the Bray-1 test may result in two different response functions, one for water-soluble P sources and another for water-insoluble P sources.

In the present work, we have measured the radon gas concentration; effective dose and exhalation rate for some fertilizers samples, raw materials, triple super phosphate and single super phosphate by using alpha-emitters registrations that are emitted from radon gas in CR-39 nuclear track detector after irradiated with gamma rays. The results indicated that the highest average radon gas concentration in fertilizer samples was found in raw material, triple super phosphate (T.S.P) samples (269.620Bq/m3and 186.8 Bq/m3,respectively) while the lowest average radon gas concentration was found in single super phosphate ( S.S.P.) for powder and granules samples, 79.6 Bq/m3 and 52.90 Bq/ m3, respectively . These results show that the radon concentration; effective dose and exhalation rate in all fertilizers samples and waste product are below the allowed limit according to the International Commission of Radiation Protection agency.

Pasture production, phosphorus (P) concentration, and P uptake by mixed pasture following addition in the autumn of 50 and 100 kgP ha−1 as single superphosphate (SSP), triple superphosphate (TSP) and Sechura phosphate rock (SPR), and of 50 kgP ha−1 of Chatham Rise phosphorite (CRP) were measured for one year on a Wainui silt loam (Typic Dystrochrept) and Tokomaru silt loam (Typic Fragiaqualf). A sharp increase was measured in the P concentration of mixed pasture immediately following the application of 50 and 100 kg P ha−1 as either SSP or TSP at both sites. However, this increase was not accompanied by an increase in pasture production. In contrast, the application of 50 kgP ha−1 as either SPR or CRP resulted in only small initial increases in the P concentration of mixed pasture, as did the addition of 100 kgP ha−1 as SPR at both sites. The potential P losses by animal transfer in dung, which could result from the use of these four P fertilisers, were calculated using a P cycle constructed for intensively grazed, steep hill country pasture. Potential losses of fertilizer P, calculated as a percentage of fertilizer P added, were 7–14% for SSP and TSP, and 4–5% for SPR and CRP in the first year at the two sites. The implications of these results to the efficiency of P fertilizer use are discussed.

In many parts of the world it has become more economical to use triple superphosphate (TSP) rather than single superphosphate (SSP) as a pasture fertilizer where only P deficiency exists. Coating TSP with elemental S is an attractive alternative to SSP for situations where P and S deficiency exists. A pot experiment was conducted on an S deficient Aquic Haplustalf soil to compare the ability of gypsum (G) and S coated TSP to supply S to a ryegrass/white clover pasture over 14 repeated harvests over a 96 week period. The adhesives used to coat S to TSP were UNE1, UNE3, UNE2 and a commercial product (HF). The reverse dilution 35S technique was used to calculate fertilizer S uptake. Total yields were highest with G and UNE1. Total fertilizer S recovery by the pasture was 64.4% for G and 52.3% and 52.9% for UNEl and UNE3 respectively. These amounts were significantly higher than from UNE2 or HF. The time course of fertilizer S release varied between products and shows that bonding method can affect S availability from S coated TSP products.

A alface (Lactuca sativa L.) é uma hortaliça bastante exigente em fósforo, sendo pouco tolerante à acidez do solo. O objetivo deste trabalho foi avaliar a resposta da cultura da alface a diferentes fontes de fertilizantes fosfatados solúveis e reativos de lenta solubilidade, na presença de calagem, visando aumento da produtividade. Utilizou-se o delineamento em blocos casualizados, com seis tratamentos (superfosfato simples, termofosfato magnesiano, superfosfato triplo, Fosmag, fosfato reativo de Arad e testemunha na ausência de fósforo), em quatro repetições, conduzido em um latossolo vermelho Distrófico. Na ausência de fósforo obtiveram-se menores produções e diâmetro de plantas, bem como todas as demais variáveis de crescimento, indicando elevada resposta de fósforo pela cultura da alface. Houve resposta significativa às diferentes fontes de fósforo, no que diz respeito à massa fresca e seca da parte aérea, massa fresca de raízes e teor de P no solo, em ordem decrescente com as fontes Fosmag, superfosfato triplo, superfosfato simples, termofosfato magnesiano e fosfato reativo de Arad. Com relação à massa seca de raízes e diâmetro das plantas, as fontes Fosmag e superfosfato triplo foram equivalentes. Os teores de P acumulados nas folhas foram superiores para as fontes Fosmag, superfosfato triplo e superfosfato simples, quando comparados com o termofosfato magnesiano e Arad, em condições em que a acidez foi corrigida.

Effect of different components of single superphosphate on organic matter degradation and maturity during pig manure composting

Organic and inorganic fertilizers improve soil fertility and give both macro and micronutrients to the soil for better growth of agricultural crops. Therefore, current study was designed to find out the efficacy of inorganic phosphorus (P) alone and in combination farmyard manure (FYM) applied in various doses on production and quality aspects of garlic. A field experiment was organized in a randomized complete block design, replicated thrice using different rates of P in the form of single super phosphate (SSP) and farmyard manure (FYM). Seven different treatments of various levels of P, either using inorganic phosphorus from SSP alone or in combination with organic phosphorus from FYM, i.e. T0 = control; T1 = 50 kg P.ha-1 (SSP); T2 = 70 kg P.ha-1 (SSP); T3 = 90 kg P.ha-1 (SSP); T4 = 25 kg P.ha-1 (SSP) + 25 kg P.ha-1 (FYM); T5 = 35 kg P.ha-1 (SSP) + 35 kg P.ha-1 (FYM); T6 = 45 kg P.ha-1 (SSP) + 45 kg P.ha-1 (FYM)] were applied to the soil. All the growth, yield and quality parameters recorded showed significant response when P was applied in combination of inorganic and organic sources as compared with control and inorganic P alone. A combined treatment of 45 kg P.ha-1 (SSP) + 45 kg P.ha-1 (FYM) gave comparatively better results in terms of plant height (66.87 cm), fresh leaf weight (2.70 g), leaf area plant-1 (83.83 cm2), relative leaf chlorophyll content (11.90), weight of bulb plant-1 (42.66 g), diameter of bulb (4.50 cm), number of cloves bulb-1 (8.50), bulb yield (4382.96 kg ha-1) and vitamin C content (6.43 mg 100 g-1). Thus, it was concluded from this study that a combined treatment of 45 kg P.ha-1 (SSP) + 45 kg P.ha-1 (FYM) should be applied for quality production of garlic under rainfed conditions of Rawalakot.