Source Of Phosphate Fertilizer Research Articles

Utilizing rice husk biochar and selected phosphate fertilizer to increase phosphate status of ultisol and shallots (Allium ascalonicum L.) production

Low soil phosphorus (P) availability is an important impediment to successful shallot cultivation in ultisols, a type of soil distinguished by its low fertility. A field experiment was conducted to investigate the effects of rice husk biochar in combination with various types of phosphate fertilizers on ultisol P status, growth performance and production of shallot. The experiment followed a completely randomized design with three replications and involved the two fixed factors: the application of three different levels of rice husk biochar (0, 5, and 10 t ha-1) and addition of three distinct phosphate fertilizer sources (90 kg ha-1) that included triple superphosphate (TRP), rock phosphate (RP) and guano. Our experiment revealed that using rice husk biochar in conjunction with various sources of P fertilizer had a propensity to raise the pH, enhance the availability and total P content in the observed soil. Furthermore, the application of 5 t ha-1 of rice husk biochar, along with the use of TSP resulted in the highest P availability in the soil. The use of biochar and P fertilizers has the potential to be an effective strategy for improving soil phosphorus status and increasing shallot production, as evidenced by the weight of storable bulbs.

The Effect of Phosphorus Fertilizer Sources and Lime on Acidic Soil Properties of Mollic Rhodic Nitisol in Welmera District, Central Ethiopia

The soil acidity problem is intensified by improper utilization of synthetic fertilizers in addition to other naturally existing causes; thus, it is important to consider effects on soil health beyond seasonal crop productivity. Most widely used sources of soluble phosphate fertilizers cannot perform effectively on acidic soil due to its fixation. Field experiments were conducted on the acidic nitisols of Welmera District in two locations to determine the effects of using lime and different phosphorus fertilizer sources on the soil acidity attributes and nutrient use efficiency of barley crops. Treatments include a factorial combination of 4 different phosphate fertilizer sources (PARP, MOHP, NPSB, and NAFAKA) with 2 application rates (34.5 kg P2O5 ha−1 and 69 kg P2O5 ha−1) and 2 lime application rates computed from soil exchangeable acidity result 404.25 kg·ha−1 and 563.9 kg·ha−1 for on-station and on-farm sites, respectively, with no lime application (1/4th of LR and 0 lime). Partially acidulated rock phosphate as a phosphorus fertilizer significantly improves soil acidity attributes such as exchangeable acidity, present acid saturation, and plant available phosphorus, and also another soil nutrient status is significantly affected by using different phosphorus sources with the lime application. Application of PARP phosphate sources significantly improves soil exchangeable acidity and present acid saturation by 42% and 41%, respectively, over the commonly used NPSB standard sources of phosphorus fertilizer. Using lime with alternative phosphate sources also contributes to more effective nutrient use efficiency and barely yields improvements with a productive acid soil amendment option. Maintaining soil health by using those integrated approaches improves the efficient utilization of scarce unrenewable resources on sustainable bases.

The Effect of Planting Arrangement of Nitrogen and Phosphorus on Yield and Physiological Traits of Guar (Cyamopsis tetragonoloba L.) in Iran

To study the effect of planting arrangement of nitrogen and phosphorus on yield and physiological traits of guar, a factorial experiment in a randomized complete block design with three replications in two cropping years 2019-20 and 2020-21 in the research center and agricultural and natural resources education of southern Kerman was implemented. Nitrogen at three levels (20, 60, and 100 kg pure nitrogen per hectare) from urea and phosphorus fertilizer source at two levels (zero and 75 kg P2O5 source per hectare) from monopotassium phosphate fertilizer source and planting row spacing at three levels (30, 45 and 60 cm) equivalent to 47, 31 and 24 plants per square meter, plant density were considered. The results showed that nitrogen, phosphorus, and planting density significantly affected all traits. Planting row spacing affected all characteristics except seed gum and phosphorus levels were effective on all traits except glycine betaine and leaf sodium. The highest yield components and seed gum were obtained from N3P2D3 treatment (application of 60kg/ha nitrogen, 75 kg/ha phosphorus, and 60 cm row spacing) which was no different from N2P1D3 treatment and the highest leaf proline content was related to N2P2D3 treatment and the highest glycine content was betaine and leaves. Sodium was related to N2P1D3 treatment. The highest grain yield and yield components in the first and second year of N2P2D2 treatment (application of 60 and 75 kg of nitrogen and phosphorus, respectively, with a row spacing of 45 cm) were obtained at 4300 and 4200 kg/ha, respectively, with N3P1D2 and N3P2D2 was not significantly different. The highest levels of carotenoids and chlorophyll a and b were related to N3P2D3 treatment. Based on the results of this study, it seems that this plant does not need high levels of nitrogen and phosphorus in terms of legume, but is affected by nitrogen and phosphorus for high yield and product quality. Regarding row spacing, if the goal is to achieve a high yield, row spacing of 45 cm and high quality 60 cm spacing is recommended and can be considered as a low-expectation plant in the cultivation pattern program in the climatic conditions of southern Kerman

SUSTENTABILIDADE NO USO DE FÓSFORO: UMA REVISÃO BIBLIOGRÁFICA COM FOCO NA SITUAÇÃO ATUAL DO ESTADO DE SÃO PAULO, BRASIL

SUSTAINABILITY IN PHOSPHORUS USE: A BIBLIOGRAPHIC REVIEW FOCUSING ON THE CURRENT SITUATION IN THE STATE OF SÃO PAULO, BRAZIL. Phosphorus is a non-renewable element essential for the existence of life and also for food security. This resource has the property of limiting plant growth, becoming a fundamental part of agricultural production. On the other hand, when this element is present in high concentrations in aquatic environments, it can start a phenomenon called eutrophication, which causes a series of changes in biological succession processes and strongly negative impacts on species’ biodiversity and wealth. In this context, this work aimed, from an extensive bibliographical review, to gather strategic and essential information related to phosphorus sustainability, provoking a reflection regarding scenarios that involve this indispensable nutrient, focusing on the current situation of the State of São Paulo, Brazil, an important case study, both for the Brazilian and international scenario, by a gathering of data on the current situation of two of the main watersheds in the corresponding region. Relevant technologies used for phosphorus removal in eutrophicated environments are also addressed. Finally, the possibility of reusing the nutrients present in eutrophicated water bodies as an alternative source of phosphate fertilizer for agriculture is demonstrated.

Froth flotation separation of phosphate ore using a novel hammer-like amidoxime surfactant

Phosphate fertilizer, as a necessary nutrient for crops in agriculture, plays a vital role in addressing global food security concerns. The source of phosphate fertilizer is mainly obtained through the production of phosphate ore, which has caused widespread concern. However, in the traditional process, the low production efficiency and high dosage of common surfactants have severely restricted the development and utilization of phosphate rock resources. In this work, a new designed hammer-like amidoxime surfactant (DPA) was characterized and introduced as an outstanding collector to recover high quality phosphate ore. The micro-flotation tests indicated that DPA had more excellent collecting ability and selectivity(The phosphorite recovery was always lower than 15%) than common monomolecular collector 1-dodecylamine (DA). Bench-scale flotation tests showed that a high quality phosphorite concentrate with higher grade and recovery (33.65% and 79.46%, respectively) could be enriched using lower dosage DPA. Economic estimate for a 5000 t/d phosphorite ore concentrator would result in an annual profit increase of approximately $8675330.65 by DPA collector. Density functional theory(DFT) calculations revealed that DPA reacted with Nucleophilic reagent (Phosphorite) by the reactive site of –CH2NH(CH2)2C(NOH)N+H3 group and more easily absorbed on the surface of Phosphorite than DA. Therefore, the above results prove that amidoxime surfactant DPA is an efficient and economic collector to recover high quality phosphate ore, which provides an important guarantee for the production of phosphate fertilizer.

Soybean Yield, Yield Components, and Phosphorus Concentration Under Different Phosphate Sources

ABSTRACT The productive potential of soils in tropical regions is limited by the low availability of nutrients, especially phosphorus (P). Owing to soil physicochemical characteristics, a substantial part of the amount provided through fertilization is unavailable for plants. Despite numerous studies, disagreements remain regarding the best way to use the various phosphate sources available in Brazil. The objective of this study was to evaluate soybean yield, yield components, and P concentration under different phosphate fertilizer sources and rates in two soil types. Triple superphosphate (TSP) provided the highest grain yield and shoot dry weight, while Supraphos and Algerian natural phosphate (NPAr) showed intermediate values. Mehlich-1 and resin extractants were highly correlated with each other and were efficient in the evaluation of available P. The agronomic efficiency index (AEI) and triple superphosphate equivalent (EqTSP) were better in sandy soil. At the highest P rate (200 mg kg−1), the NPAr and Supraphos sources tended to match the activity of TSP.

Management of phosphorus nutrient amid climate change for sustainable agriculture.

Nutrients are essential for plant growth and development and influence overall agricultural production. Phosphorus (P) is a major nutrient required for many physiological and biochemical functions of a plant. Phosphate rock is the major source of phosphate fertilizer but is becoming increasingly limited in both developing and developed countries. The resources of phosphate rock need to be conserved, and import dependency on phosphate fertilizer needs to be minimized; this will help increase the availability of phosphate fertilizer over the next 300 yr. Climate change creates new challenges in the management of nutrients including P, affecting the overall production of crops. The availability, acquisition, and translocation of P are influenced by the fluctuation of temperatures, pH, drought, and elevated CO2 . Both lower and higher soil temperatures reduce uptake and translocation of P. High soil pH affects P concentration and decreases the rate of plant P uptake. Low soil pH decreases the activity of soil microorganisms, the rate of transpiration, and P uptake and utilization. Elevated CO2 decreases P uptake from soil by the plants. Future research is needed on chemical, molecular, microbiological, and physiological aspects to improve the understanding on how temperature, pH, drought, and elevated CO2 affect the availability, acquisition, and transport of P by plants. Better P management strategies are required to secure the P supply to ensure long-term protection of soil fertility and to avoid environmental impacts such as eutrophication and water pollution, ensuring sustainable food production.

Agronomic Efficiency of Phosphorus Fertilizers With Associate Technology in Soy Crop in Cerrado Soil

For commercial soybean production, the presence of phosphorus in the soil is essential, not only to increase productivity but also because it affects basic functions in plant metabolism. Phosphate fertilizers have low efficiency in Cerrado soils. For this reason, the use of technologies associated with phosphate fertilizers is important to increase their efficiency in the soil. The experiment was conducted at Fazenda Rio Brilhante in Coromandel, MG. The experiment was laid out in a randomized block design in a 4 × 4 + 1 factorial arrangement. Treatments consisted of four phosphate fertilizer sources (MAPCONVENCIONAL, MAPpol 1, MAPpol 2, and FOM), four P2O5 doses (40, 80, 120, and 160 kg ha-1), and the control treatment (no phosphorus application). The soybean cultivar RK8115 IPRO with a plant population of 340 thousand plants per hectare was used. The experimental plots consisted of five planting lines with a spacing of 0.5 meters and a length of 7 meters. In the experiment, phosphorus leaf, morphological evaluation of plant height, stem diameter, number of stems, and pods were measured. For plant biomass, the dry matter of leaves, stems, and pods were determined. For yield evaluation, the calculation of productivity and RAE was compared with MAPCONVENCIONAL. For sources, data were subjected to analysis of variance, and means were separated by Tukey’s rate test (p < 0.05). For P2O5 doses, regression model fitting was performed using the ExpDes.pt package of R Studio software. Morphological assessments responded linearly to P doses, except for DPM. Leaves and pods P content and yield were affected by P dosage and P sources, with a quadratic response to P dosage. Maximum yield efficiency was achieved at P2O5 doses of 122.73; 145.07; 112.03; and 94.71 kg ha-1, with yields of 3818.30; 4064.67; 4089.03; and 3952.63 kg ha-1 for MAPCONVENCIONAL, MAPpol 2, MAPpol 1, and FOM, respectively. However, MAPpol 1 and FOM provided a dose reduction of 26 and 15 compared to the maximum yield of MAPCONVENCIONAL, respectively.

Phosphorus Dynamics in Sugarcane Fertilized With Filter Cake and Mineral Phosphate Sources

Organic residual material such as filter cake, combined with mineral phosphate fertilizers, may alter the soil phosphorus (P) bioavailability for sugarcane as a consequence of the competing effect in adsorption sites. This study aimed to quantify the changes in both the inorganic and organic soil P fractions as amended by phosphate fertilizer sources and filter cake and to link the P fractions to sugarcane response. An experiment was conducted in an Oxisol, in a randomized block design with factorial arrangement of 4 × 2, and three replications. Three P fertilizer sources (triple superphosphate, Araxá rock phosphate, and Bayóvar® reactive phosphate) plus a control (no P) were evaluated under both the presence and absence of filter cake. At the end of the second crop cycle, the following were measured: the cane yield, the tissue P content, and soil P fractions. All fertilizer sources were efficient in supplying P to sugarcane. Araxá rock phosphate generated a higher accumulation in moderately labile P, whereas the soluble triple superphosphate resulted in higher labile P. The filter cake, as a source of nutrients and organic matter, has an important contribution to maintain more available P for sugarcane absorption, especially when associated with triple superphosphate. The amount of P absorbed by sugarcane was correlated with the soil labile P (r = 0.58) and also with the inorganic P moderately labile (r = 0.42). Both fractions must be taken into account for a short- to medium-term availability of P for sugarcane in Oxisols.

Effect Of The Type Of Organic Matter And a Source Of Phosphorous On The Growth, Yield Of Corn (Zea maysL.) Under Different Levels From Phosphorous In Gypsum Soil

   A biological experiment was carried out for the purpose of knowing the effect of the type of organic matter, source and level of phosphorous on the growth and yield of corn (Zea mays L.) in gypsum soil.  The experiment was carried out in one of the agricultural fields in Salah al-Din Governorate / Al-Alam district in the year 2019. The study included three factors (type of organic fertilizer, phosphorous source and phosphorous level).  The factor included the type of organic fertilizer (not adding Z, compost K and sheep waste S), while the second factor included the source of phosphate fertilizer (Triple super phosphate T, diammonium phosphate D), and the third factor included phosphorous levels (0, 90, 180 and 270) kg P ha-1.  The experiment was carried out in three replications according to a randomized complete block design (RCBD).  Sheep manure outperformed compost in all growth and yield traits, and diammonium phosphate fertilizer outperformed Triple le super phosphate, and the level (270) kg P ha-1 was superior to the rest of the addition levels in all growth and yield traits. The interaction between sheep manure and diammonium phosphate fertilizer at the level of addition (270) kg P ha-1 gave the highest average in the dry weight of the vegetative mass after 45 and 75 days of planting, it reached (55.50 and 130.81) gm plant-1, respectively, Chlorophyll content in leaves (52.80) SPAD and grain yield reached (8119) kg ha-1.

These spots of excavation tell: using early visitor accounts to map the missing graves of waterloo

ABSTRACT This paper uses the writings of early visitors to the field of Waterloo to examine the treatment of the dead following the battle fought on 18 June 1815. It is proposed that these memoirs and journals, along with various artworks, contain information that can assist not only in the explanation of the complexities of body disposal, but also guide us to the location of grave sites on the battlefield. It is further suggested, on the basis of the picture building from recent archaeological investigations, that at least some of the larger graves were exploited for human and animal bone, which in the first half of the nineteenth century served as an important source of phosphate fertilizer.

Changes in soil respiration after application of in situ soil amendment and phosphate fertilizer under soybean cultivation at Ultisol South Lampung, Indonesia

Several inputs are needed to increase the production of soybean in Ultisol. The Application of organic soil amendment will increase carbon, nutrients, and water stored in the soil. Besides, the soil structure becomes stable so that plants will be more tolerant of climate change. The higher organic C in the soil, the more fertile soils, the plants grow healthier and fertile, and then the emission of CO2 gas into the air can be suppressed. Therefore, this study aims to determine soil respiration (CO2) due to the application of in situ soil amendment and phosphate fertilizer. This research was conducted at the research station of BPTP Natar, South Lampung, from July to November 2019, arranged with random complete block design in two factorials. The first factor is the source of phosphate fertilizer is without P fertilizer, TSP fertilizer 200 kg ha-1, and rock phosphate 5 tons ha-1, and the second factor is the application of soil in situ amendments. i.e.: without the soil amendment, rice husk biochar 5 tons ha-1 (B1), organonitrofos compost 10 tons ha-1, and cow dung manure 10 tons ha-1. All experimental units were fertilized with urea at a dose of 50 kg ha-1 and KCl at a dose of 200 kg ha-1. The result showed that the highest soil respiration was obtained in the plot treated with rock phosphate and cow dung manure at the single factor. The combination of rock phosphate and cow dung manure resulted in the highest of soil respiration.

Sustentabilidade do cultivo de mandioca em comunidades indígenas do Pantanal Brasileiro

We aimed with this study to help maximizing cassava production for subsistence in indigenous communities at the Brazilian Pantanal, by introducing minimal changes to the usual indigenous way of cultivation aiming to reduce human labor in weed management in this crop. For that, we tested distinct intercrops and phosphate sources, taking the Babassu Indigenous Village, located in Miranda‑MS, Brazil, as a reference. The experiment involved the intercrop of cassava with pigeon pea (Cajanus cajan), jack‑bean (Canavalia ensiformis) and millet (Pennisetum americanum) and the source of phosphate fertilizer (mycorrhizal inoculants, P2O5 and without fertilization / mycorrhizal inoculum). Soil samples were collected to study the soil seed bank of spontaneous species. We adopted the phytosociological method to assess the absolute level of infestation, its composition density, frequency, dominance and importance value, and diversity coefficients of Simpson and Shannon-Weiner, as well as the Shannon Evenness Proportion (a sustainability coefficient) for all treatments. Areas were also grouped by similarity of plant species. Cultivation of cassava for subsistence in indigenous areas also selects certain spontaneous species, and management should focus in removing mostly by hand those established in the crop row; the damage to the crop may be higher in years of high abiotic stresses. There is no effect of phosphate supply source (P) in the level or composition of spontaneous species. There is clear evidence that the continued cultivation of cassava for subsistence in indigenous areas of the Brazilian Pantanal is sustainable over time, mainly when intercropped with other food species.

Sulfur, Na2-EDTA and their mixture effects on phosphorus release from cow bone char in P-poor sandy soil

Abstract The high cost and environmental problems related to the production of phosphate fertilizers as well as their excessive and continuous applications represent great challenges in modern agriculture. Therefore, we conducted an incubation experiment using sandy soil to evaluate the effects of elemental sulfur, disodium ethylene diamine tetra-acetic acid (Na2-EDTA) and their mixture with cow bone char as well as incubation periods on changes of phosphorus (P) availability, water soluble P, soil pH, electrical conductivity (EC), soluble calcium (Ca) and soluble sulfate (SO4). Applying sulfur (S), Na2EDTA and their mixture with cow bone char improved significantly phosphorus availability in soil, Olsen-P value increased from 7.65 mg kg−1 (control) to 12.20 mg kg−1 (cow bone char + sulfur), 12.80 mg kg−1 (cow bone char + Na2-EDTA) and 13.07 mg kg−1 (cow bone char + sulfur + Na2-EDTA) at the end of incubation periods While, cow bone char + sulfur + Na2-EDTA treatment lead Olsen-P to decline significantly with increasing incubation periods. Amending soil by sulfur with cow bone char treatment caused significant increase in the Olsen-P with increasing incubation periods. Cow bone char + sulfur and cow bone char + Na2-EDTA showed non-significant differences in Olsen-P. Because of the increase in phosphate fertilizer prices, the results of this study demonstrated the great potential of cow bone char usage which is a promising way to improve phosphorus availability in P-poor soil as well as being a clean alternative and renewable source of phosphate fertilizer. Consequently, we recommend utilizing cow bone char with sulfur as slow release fertilizer with time due to their low cost and it is a safe source of phosphorus in sustainable agriculture, rather than using Na2-EDTA due to its high price.

Water Availabilities Associated with Natural Phosphate and Triple Superphosphate in Radish Cultivation

Aims: The objective of this study was to evaluate the development of giant Crimson radish cultivated in a oxisol under phosphate fertilizer sources (natural phosphate, triple superphosphate, natural phosphate + triple superphosphate and control) associated with water availabilities (40, 80 and 120% of the field capacity).
 Study Design: The experimental design was completely randomized, in a 4x3 factorial scheme, with 4 replications (48 units).
 Place and Duration of Study: The research was conducted in a greenhouse belonging to the Federal University of Mato Grosso, in the municipality of Rondonópolis (MT).
 Methodology: The dystrophic Oxisol was used to fill the 1.5 dm3 pots. The irrigation management was in accordance with the methodology of the maximum water retention capacity, by the gravimetric method. Phosphate fertilization was applied before sowing using 265 mg dm-3 phosphorus, varying the source used, triple superphosphate and Bayovar Natural phosphate. After the emergence of the plants, the other nutrients were applied to the soil. The parameters related to vegetative development and after the harvest of radish were evaluated at 20 and 35 days after sowing.
 Results: The parameters fresh mass of the aerial part, dry mass of the tubercle, dry mass of the aerial part, fresh mass of tubercle and length of tubercle had the highest values with the use of triple superphosphate, and for the field capacities of 80 and 120%. The highest harvest index (1.51) was found for the use of Natural phosphate in the field capacity of 120%. The water consumption by the plants was higher with the use of triple superphosphate and field capacity of 120% (6,425.25 L). The efficiency of water use was better with the application of triple Superphosphate and 40% of the field capacity (0.0547 g mL-1).
 Conclusion: There was influence of both water availabilities and phosphate fertilization on the studied parameters. Triple superphosphate associated with 80% of the field capacity allowed the best productivity averages for radish.

Phosphate Sources and Their Placement Affecting Soil Phosphorus Pools in Sugarcane

Phosphate fertilizer placement at sugarcane (Saccharum spp.) establishment can strongly influence the distribution of soil P pools over crop cycles, and has a great influence in the availability of this nutrient to plant uptake. Our main objective was to evaluate sugarcane yield as well as changes in the distribution of soil P pools, under phosphate fertilizer sources and their management, over two years of sugarcane cultivation. The experiment was established in August 2013 with two phosphate sources (TSP (triple superphosphate) and RP (Bayovar rock phosphate)) and three application methods: as broadcast, at planting furrow and combining half broadcast/half plant furrow, all at the rate of 180 kg ha−1 soluble P2O5 being applied at crop establishment. Sugarcane yield and P uptake was evaluated, and soil was sampled after harvest in August 2015 to analyze P fractions. Substantial amounts of P derived from fertilizers were accumulated as inorganic and/or organic moderately labile P. Broadcast application of TSP was not able to enhance total P in 0–40 cm layer compared to control treatment. In general, TSP was more effective to supply P for sugarcane and keep more of this nutrient in all labile fractions in the soil. However, the potential residual effect of RP (Ca-P) is expected in the following years, slowly solubilizing over the time.

COMPORTAMENTO MINERAL DOS TERMOFOSFATOS DE ALUMÍNIO COM ADIÇÃO DE ESCÓRIA EM 700 E 1100 °C

Thermophosphate consists of the thermal treatment of the rock, with or without addition of other materials, being an excellent source of phosphate fertilizer, presenting other nutrients and beneficial elements such as Mg and Si. In this work were used Al-phosphates from Sapucaia (Bonito, State of Para) and slag of the blast furnace (Maraba, State of Para), in the ratio 80/20, being subjected to calcination at 700 oC and 1100 oC with the objective of verifying the behavior of crystalline phases in these temperatures. The samples were calcined and then characterized by X-ray diffraction (XRD). These analyzes showed that the phosphate ore consists of phases of the crandallite group and quartz and the slag by amorphous material. After calcination at 700°C, the phases of the thermophosphate and slag-thermophosphate are restructured tending to amorphous, except quartz. At this temperature, the solubility of the phosphate material favors the increase in P2O5 content. At 1100° C the identified crystalline phases were: aluminum oxide, aluminum and iron phosphates, calcium and iron phosphates, and silicon oxide. Studies evaluating these materials in agriculture may determine their agronomic efficiency.

Assessment of heavy metals concentration in phosphate rock deposits, Hazara basin, Lesser Himalaya Pakistan

Naturally occurring phosphate rock is the only essential source for the production of fertilizers. Heavy metals and phosphate concentrations are quite higher in phosphate rock formed by sedimentary processes. This detail study was conducted to evaluate the heavy metal concentrations in part of the Hazara region, which is the only source of phosphate fertilizer in the country. Heavy metals are considered as one of the main pollutant responsible for environmental contamination of soil. This study included the concentration of phosphorite in the Hazara region in the three useful forms: total phosphorite, extractable phosphorite and water soluble forms. The phosphorous extracted from sedimentary deposits used to maintain the natural content in agricultural soil which was being depleted due to the regular practice of crop harvest. The data collected during this studies were statically analyzed which refers the significant variations in P, Zn, Cr, Mn, As, Cu, Fe, Ni, & Pb. Zn and Cr concentration in Hazara phosphates. Heavy metals for instance Pb, Cr, Zn and Cu present in higher amount than usable limits and may create environmental pollution (air, surface & groundwater and soil) and health issues of humans. Therefore it is recommended that managing remedial steps are necessary around the mining regions to avoid environmental and health issues.

Phosphate Fertilizer Sources and Use in Africa: Challenges and Opportunities

Phosphate Fertilizer Sources and Use in Africa: Challenges and Opportunities

Agronomic Efficiency of Two Types of Lime and Phosphate Fertilizer Sources in Brazilian Cerrado Soils Cultivated with Soybean

With the increase in phosphate fertilizer prices, there is a need to find lower-cost alternatives that are as efficient as soluble sources such as single (SSP) and triple superphosphate (TSP). In Brazil’s northern and northeastern regions, there are reserves of igneous rocks with low solubility containing high concentrations of total phosphorus (P) that can be used to produce fertilizers, such as thermalphosphates. To assess the efficiency of sources of P and two types of lime on soybean yield, a field experiment was carried out in an area with dystrophic Red Latosol (Oxisol) in a Cerrado region in the southern part of Maranhão State. The experimental design was randomized blocks in a 2 × 3 × 4 factorial scheme, with four replicates. The treatments were two types of lime [calcitic (CL) (<5 dag kg−1 of MgO) and dolomitic (DL) (>13 dag kg−1 of MgO)], three phosphate fertilizer sources [triple superphosphate (TSP), “Yoorin” thermalphosphate (YT), and experimental thermalphosphate (ET)], and four rates of phosphorus pentoxide (P2O5; 0, 100, 200, and 300 kg ha−1). After 2 years of cultivation, the application of DL resulted in greater soybean yields than the application of CL. The two lime types influenced the pH, carbon (C), calcium (Ca), and magnesium (Mg) concentrations as well as the Ca/Mg, Ca/K, and Mg/K ratios in the soil. With respect to sources of P, the YT applied in the soil with DL produced an agronomic efficiency index (AEI) similar to that of TSP, whereas in the soil with CL, the TSP, YT, and ET were similar, with maximum technical efficiency (MTE) under both conditions starting at 230 kg ha−1 of P2O5. The critical concentration of available phosphorus (P) in the soil (Mehlich-1 extractant) for cultivation of soybean under the climate and soil conditions studied was between 5.0 and 6.0 mg kg−1.