Triple Superphosphate Application Research Articles

Integrating field surveys and remote sensing to optimize phosphorus resource management for rainfed rice production in the Central plateau of Burkina Faso.

Rice production in sub-Saharan Africa (SSA) is restricted by low water availability, soil fertility, and fertilizer input, and phosphate rock (PR) application is expected to increase production. Soil water conditions and soil types affect the efficacy of phosphorus fertilization in improving productivity. However, these factors are rarely discussed together. In this study, we aimed to investigate the soil types and soil water conditions in the fields, as well as their effects on rice productivity after phosphorus fertilization, and optimize the findings using remote sensing techniques. A soil profiling survey, followed by a field experiment in seven farmer fields, was performed in the Central plateau of Burkina Faso. The following treatments were applied: nitrogen and potassium fertilization without phosphorus (NK), PR application with NK (NK+PR), and triple super phosphate (TSP) application with NK (NK+TSP). Submergence duration and cumulative water depth were recorded manually. The inundation score, estimated using a digital elevation model, explained the distribution of soil types and soil water conditions and correlated negatively with sand content and positively with silt and clay content, indicating an illuvial accumulation of fine soil particles with nutrient transportation. The field experiment showed that although grain yield was significantly restricted by phosphorus deficiency, the increase in yield after phosphorus fertilization was higher in Lixisols and Luvisols than in Cambisols because of the low Bray-2-phosphorus content of Lixisols and Luvisols. The inundation score correlated positively with grain yields after NK+PR and NK+TSP treatments. In conclusion, soils with low inundation scores (mainly Lixisols and Luvisols) showed a drastic increase in grain yield after TSP application, whereas those with high inundation scores showed comparable yields after PR and TSP application despite the low phosphorus fertilization effect. Our findings would help optimize fertilization practices to increase rice productivity in SSA.

Assessing the influence of diverse phosphorus sources on bacterial communities and the abundance of phosphorus cycle genes in acidic paddy soils.

The impact of chemical fertilizers on soil microbial communities is well acknowledged. This study assesses the influence of various phosphorus sources on soil bacterial composition, abundance, and Phosphorus Cycle Gene Abundance. Three phosphorus sources (natural phosphate rock, triple super phosphate (TSP), and chemical fertilizer NPK) were field tested following two rice cultivation cycles. Soil samples were subsequently collected and analyzed for bacterial groups and phosphorus cycle genes. Results indicated that the bacterial community composition remained consistent, comprising five main phyla: Firmicutes, Actinobacteria, Proteobacteria, Halobacterota, and Chloroflexia, regardless of fertilizer type. NPK fertilizer significantly reduced the relative abundance of Chloroflexia by 19% and Firmicutes by 16.4%, while increasing Actinobacteria and Proteobacteria by 27.5 and 58.8%, respectively. TSP fertilizer increased Actinobacteria by 27.1% and Halobacterota by 24.8%, but reduced Chloroflexia by 8.6%, Firmicutes by 12.6%, and Proteobacteria by 0.6%. Phosphate rock application resulted in reductions of Chloroflexia by 27.1%, Halobacterota by 22.9%, and Firmicutes by 6.2%, alongside increases in Actinobacteria by 46.6% and Proteobacteria by 23.8%. Combined application of TSP, NPK, and phosphate rock led to increases in Proteobacteria (24-40%) and Actinobacteria (13-39%), and decreases in Chloroflexia (5.2-22%) and Firmicutes (6-12.3%) compared to the control (T0). While the different phosphorus sources did not alter the composition of phosphorus cycle genes, they did modulate their abundance. NPK fertilizer did not significantly affect ppK genes (57-59%) but reduced gcd (100 to 69%), 3-phytase (74 to 34%), appA (91 to 63%), and phoD (83 to 67%). Phosphate rock reduced appA and gcd by 27 and 15%, respectively, while increasing 3-phytase by 19%. TSP decreased ppK and phoD by 42 and 40%, respectively, and gcd and appA by 34 and 56%, respectively. Combined fertilizers reduced appA (49 to 34%), 3-phytase (10 to 0%), and gcd (27 to 6%), while increasing ppK (72 to 100%). Among tested phosphorus sources, natural phosphate rock was best, causing moderate changes in bacterial composition and phosphorus genes, supporting balanced soil microbial activity. These findings highlight the complex interactions between fertilizers and soil microbial communities, underscoring the need for tailored fertilization strategies to maintain soil health and optimize agricultural productivity.

Investigation of Impact of Phosphate Fertilizer Applied to Paddy Fields on Water Quality of Nearby Reservoirs

Phosphorous (P) is an essential element to plant growth and development necessitating P fertilizer applications for agricultural crops for better yields. Paddy, the main food crop of Sri Lankans is a fertilizer intensive crop where phosphorus nutrition is achieved via triple super phosphate applications. Since water circulating system of paddy fields are connected to other water bodies this soluble P can contaminate the nearby waterbodies. To detect the extent of P fertilizer leaching from paddy fields, a lysimeter experiment was carried out in the Low Country Intermediate zone, Sri Lanka for four consecutive growing seasons from 2015 to 2016. Paddy fields under two management practices; control run-off and continual run-off conditions were selected for the study. The farmers practice the Department of Agriculture recommended fertilizer application schedules. Lysimeters were placed in a Randomized Complete Block Design with triplicates at upper and lower ends of the gradient of the each site. Water samples were collected below the root zone, at a depth of 30 cm, irrigated, run-off, nearby water reservoirs and analyzed for water soluble of phosphate. The highest concentration of total phosphate in leached water (0.88 mg/L) did not exceed the drinking water standard threshold level of 2 mg/L of Phosphate. The quantified leached total Phosphate amount for controlled run-off condition and continual run-off condition were 0.49 ± 0.10 kg/ha and 0.46 ± 0.04 kg/ha, respectively without statistically significant differences. It represented 2% of the applied P fertilizer content of both sites. This indicates that paddy cultivation under both the conditions does not pose a threat to water quality of the nearby water bodies if the farmers adhere closely to the Department of Agriculture recommended fertilizer schedules.

Effect of Various Rates of P from Alternative and Traditional Sources on Butterhead Lettuce (Lactuca sativa L.) Grown on Peat Substrate

Previous research indicated the potential use of struvite (STR) as an alternative source of phosphorus (P) in crop production. A greenhouse experiment was conducted to evaluate the effect of STR and triple superphosphate (TSP) on the growth and chemical composition of butterhead lettuce grown on peat substrate over a three-month period (May–July). Both alternative (STR) and conventional (TSP) fertilizers were applied at three rates: (1) recommended rate based on the elemental content of substrate and crop nutritional need; (2) reduced rate (50% lower than recommended); and (3) increased rate (50% higher than recommended). Unfertilized (control) plants were also grown in the pot experiment. As expected, fertilizer application tended to increase the content of heavy metals in the substrate. Thus, an increase in Zn, Pb, and Cu content in peat substrate was found following STR amendments. However, compared with unfertilized plants, the applied rates of the STR and TSP fertilizers did not increase the content of Cd and Cu in the plant leaf, while Hg content was below the detection limit. In addition, Zn content in the plant leaf significantly decreased following STR and TSP applications. In comparison to unfertilized plants, both alternative and conventional fertilizers increased the content of P and nitrate nitrogen (N-NO3−) in the plant leaf while their effect on Mg content was negligible. The increased rate of STR was the best fertilizer treatment because it produced the largest number of leaves, which were also characterized by the highest P content. Our findings showed that STR was an effective source of P in butterhead lettuce cultivation without adverse effects on heavy metal accumulation.

Soil Phosphorus and Corn Development Under Application of Phosphate Sources

Knowledge of the solubility of phosphate fertilizers is fundamental for phosphorus (P) recommendation management and for choosing the laboratory evaluation method of nutrient availability in the soil according to the history of fertilization. The aim was to evaluate the initial development of corn plants as a function of the application of triple superphosphate (TSP) and natural phosphate of Arraias (NPA) with and without liming and incubation time, as well as to evaluate the available P in the soil with the use the extractors Mehlich-1 and Mehlich-3. An experiment was installed in an 8 × 3 × 2 factorial scheme, being 8 fertilizer incubation times (180, 140, 100, 80, 60, 40, 20, 0 day(s) before planting), 3 P sources (control—without P, TSP and NPA) and 2 refers to the application of limestone (with and without limestone). Were evaluated the shoot and root dry matter, analysis of P, Ca, Mg, and Zn in shoot and P in roots. In the soil, P levels were determined by Mehlich-1 and Mehlich-3 extractors. There was a greater accumulation of P with the application of TSP with limestone in all incubation times. The application of the NPA allowed a greater accumulation of P in the plants without the application of lime. The previous incubation of the NPA did not favor the efficiency of this source, neither in the soil with corrected acidity nor in the soil with its original acidity. Mehlich-3 proved to be adequate to determine the phosphorus content in soil fertilized by NPA.

EFFECTS OF PHOSPHORUS AVAILABILITY ON NODULATION AND NITROGEN UPTAKE BY THREE LEGUME CROPS IN TWO GHANAIAN SOILS

Purpose: A greenhouse study of Soybean, Cowpea and Pigeon Pea was made at University of Ghana, to determine the effects of phosphorus availability on nodulation and nitrogen uptake by the afore mentioned legumes in two Ghanaian soils, Adenta and Nzema series.
 Methodology: Three P rates of 0mg, 50mg and 100mg P of TSP and TPR were applied to a kilogram of soil per pot in two soil series. The pots were arranged using Randomized Complete Block Design. GenstatR was used to do the statistical analysis.
 Findings: The results from this study showed that with or without Triple Super Phosphate (TSP) or Togo Phosphate Rock (TPR), soybean did not form nodules in the Nzema soil but nodulated with TSP application in the Adenta soil. The absence of nodulation even with high P from TSP by soybean in Nzema soil is surprising but the observation in the Nzema soil may be attributed to the absence of soybean Rhizobium cells or insignificant numbers of these rhizobia. The results of the present data indicated that treatments with higher P application gave higher N uptake and showed the link among P application, high nodule dry weight, and N uptake. The improvement in the dry matter yield of pigeon pea and cowpea on Adenta soil and soybean on the Nzema soil at TPR50 and TPR100 show the importance of P application to dry matter yield of legumes. Significant difference that was shown by cowpea on Nzema soil could be attributed to the ability of the crop to desorp P from sparingly available P sources through exudation of high amounts of organic acid anions, mainly citrate.
 Unique contributions to theory, practice and policy: In the soil, Rhizobium species must recognize their specific host before nodulation may take place and the absence of the appropriate Rhizobium species with the introduction of a legume into a given soil may result in no or poor nodulation. Low P availability is a challenge for crop species to nodulate since the rhizobia responsible for nitrogen fixation have a high P requirement. The toxicity of Aluminum to rhizobia may be due to inhibition of DNA replication because of binding of Aluminum to DNA. One factor that could have accounted for the better nodulation in soil is the higher acidity. The optimum pH for effective rhizobia growth in soils is between pH 6 and 7.

EFFECTS OF PHOSPHORUS AVAILABILITY ON NODULATION AND NITROGEN UPTAKE BY THREE LEGUME CROPS IN TWO GHANAIAN SOILS

Purpose: A greenhouse study of Soybean, Cowpea and Pigeon Pea was made at University of Ghana, to determine the effects of phosphorus availability on nodulation and nitrogen uptake by the afore mentioned legumes in two Ghanaian soils, Adenta and Nzema series.
 Methodology: Three P rates of 0mg, 50mg and 100mg P of TSP and TPR were applied to a kilogram of soil per pot in two soil series. The pots were arranged using Randomized Complete Block Design. GenstatR was used to do the statistical analysis.
 Findings: The results from this study showed that with or without Triple Super Phosphate (TSP) or Togo Phosphate Rock (TPR), soybean did not form nodules in the Nzema soil but nodulated with TSP application in the Adenta soil. The absence of nodulation even with high P from TSP by soybean in Nzema soil is surprising but the observation in the Nzema soil may be attributed to the absence of soybean Rhizobium cells or insignificant numbers of these rhizobia. The improvement in the dry matter yield of pigeon pea and cowpea on Adenta soil and soybean on the Nzema soil at TPR50 and TPR100 show the importance of P application to dry matter yield of legumes. Significant difference that was shown by cowpea on Nzema soil could be attributed to the ability of the crop to desorp P from sparingly available P sources through exudation of high amounts of organic acid anions, mainly citrate.
 Unique contributions to theory, practice and policy: In the soil, Rhizobium species must recognize their specific host before nodulation may take place and the absence of the appropriate Rhizobium species with the introduction of a legume into a given soil may result in no or poor nodulation. Low P availability is a challenge for crop species to nodulate since the rhizobia responsible for nitrogen fixation have a high P requirement. The toxicity of Aluminum to rhizobia may be due to inhibition of DNA replication because of binding of Aluminum to DNA. One factor that could have accounted for the better nodulation in soil is the higher acidity. The optimum pH for effective rhizobia growth in soils is between pH 6 and 7.

EFFECTS OF PHOSPHORUS AVAILABILITY ON NODULATION AND NITROGEN UPTAKE BY THREE LEGUME CROPS IN TWO GHANAIAN SOILS

Purpose: A greenhouse study of Soybean, Cowpea and Pigeon Pea was made at University of Ghana, to determine the effects of phosphorus availability on nodulation and nitrogen uptake by the afore mentioned legumes in two Ghanaian soils, Adenta and Nzema series.
 Methodology: Three P rates of 0mg, 50mg and 100mg P of TSP and TPR were applied to a kilogram of soil per pot in two soil series. The pots were arranged using Randomized Complete Block Design. GenstatR was used to do the statistical analysis.
 Findings: The results from this study showed that with or without Triple Super Phosphate (TSP) or Togo Phosphate Rock (TPR), soybean did not form nodules in the Nzema soil but nodulated with TSP application in the Adenta soil. The absence of nodulation even with high P from TSP by soybean in Nzema soil is surprising but the observation in the Nzema soil may be attributed to the absence of soybean Rhizobium cells or insignificant numbers of these rhizobia. The improvement in the dry matter yield of pigeon pea and cowpea on Adenta soil and soybean on the Nzema soil at TPR50 and TPR100 show the importance of P application to dry matter yield of legumes. Significant difference that was shown by cowpea on Nzema soil could be attributed to the ability of the crop to desorp P from sparingly available P sources through exudation of high amounts of organic acid anions, mainly citrate.
 Unique contributions to theory, practice and policy: In the soil, Rhizobium species must recognize their specific host before nodulation may take place and the absence of the appropriate Rhizobium species with the introduction of a legume into a given soil may result in no or poor nodulation. Low P availability is a challenge for crop species to nodulate since the rhizobia responsible for nitrogen fixation have a high P requirement. The toxicity of Aluminum to rhizobia may be due to inhibition of DNA replication because of binding of Aluminum to DNA. One factor that could have accounted for the better nodulation in soil is the higher acidity. The optimum pH for effective rhizobia growth in soils is between pH 6 and 7.

EFFECTS OF PHOSPHORUS AVAILABILITY ON NODULATION AND NITROGEN UPTAKE BY THREE LEGUME CROPS IN TWO GHANAIAN SOILS

Purpose: A greenhouse study of Soybean, Cowpea and Pigeon Pea was made at University of Ghana, to determine the effects of phosphorus availability on nodulation and nitrogen uptake by the afore mentioned legumes in two Ghanaian soils, Adenta and Nzema series.
 Methodology: Three P rates of 0mg, 50mg and 100mg P of TSP and TPR were applied to a kilogram of soil per pot in two soil series. The pots were arranged using Randomized Complete Block Design. GenstatR was used to do the statistical analysis.
 Findings: The results from this study showed that with or without Triple Super Phosphate (TSP) or Togo Phosphate Rock (TPR), soybean did not form nodules in the Nzema soil but nodulated with TSP application in the Adenta soil. The absence of nodulation even with high P from TSP by soybean in Nzema soil is surprising but the observation in the Nzema soil may be attributed to the absence of soybean Rhizobium cells or insignificant numbers of these rhizobia. The improvement in the dry matter yield of pigeon pea and cowpea on Adenta soil and soybean on the Nzema soil at TPR50 and TPR100 show the importance of P application to dry matter yield of legumes. Significant difference that was shown by cowpea on Nzema soil could be attributed to the ability of the crop to desorp P from sparingly available P sources through exudation of high amounts of organic acid anions, mainly citrate.
 Unique contributions to theory, practice and policy: In the soil, Rhizobium species must recognize their specific host before nodulation may take place and the absence of the appropriate Rhizobium species with the introduction of a legume into a given soil may result in no or poor nodulation. Low P availability is a challenge for crop species to nodulate since the rhizobia responsible for nitrogen fixation have a high P requirement. The toxicity of Aluminum to rhizobia may be due to inhibition of DNA replication because of binding of Aluminum to DNA. One factor that could have accounted for the better nodulation in soil is the higher acidity. The optimum pH for effective rhizobia growth in soils is between pH 6 and 7

Response of Soybean (Glycine max (L.) Merr) to PS-Foundation 1-0-1 Biostimulant, Triple Super Phosphate, and Rhizobium Inoculant

ABSTRACTSoybean yields in Ghana are low and stagnant in spite of the trio of recommendations: (1) improved seed, (2) rhizobium inoculant and (3) phosphorous fertilizer application being promoted by government to boost productivity. This study evaluates the response of soybean to Pro-soil biostimulant, triple super phosphate (TSP), and rhizobium inoculant in the interior savanna of Ghana. A treatment structure comprising two mainplot factors (biostimulant and conventional), and four subplots factors; TSP, inoculant, TSP+Inoculant and unamended control arranged in a split-plot design was used for this study. Apart from dry matter which increased by 42%, Pro-soil biostimulant as a stand-alone management practice did not significantly increase agronomic parameters measured in this study. Biostimulant did not have a significant effect on grain yield, nodule weight, nodule number, canopy diameter, and plant height. Application of TSP alone, and in combination with inoculant, significantly increased yield, plant dry matter, nodule weight, nodule number, and dry pod weight. Highest soybean yield was obtained from TSP + Inoculant treatment, averaging 3.6 t ha−1 compared to 1.8 t ha−1 for control. Biostimulant, TSP+Inoculant combination resulted in yields as high as 4 t ha−1. Overall, the results indicate that neither PS-Foundation biostimulant nor rhizobia inoculation can be used as stand-alone management practices to increase soybean yield. However, an integrated application of PS-Foundation biostimulant, TSP, and inoculant could double current soybean yields in Ghana.

ASSESSMENT OF PHOSPHORUS AVAILABILITY FROM UNREACTIVE TOGO PHOSPHATE ROCK BY LEGUME AND CEREAL CROPS IN TWO GHANAIAN SOILS

Purpose: In recent years, phosphate rock (PR) for direct application has been tested in tropical acid soils as a potential alternative to conventional water-soluble P fertilizers like Single Superphosphate (SSP) and Triple Superphosphate (TSP). However, direct application of PR with low reactivity does not always give satisfactory results. Legume and cereal crops represent a strategy that can be used to solubilize P from some of these unreactive PRs. The objective of this study was to assess the availability of P from unreactive Togo Phosphate Rock (TPR) relative to TSP by six (6) crop species in two Ghanaian soils.
 Methodology: The study was conducted in the greenhouse of the Crop Science Department, University of Ghana. Three P rates, 0mg, 50mg and 100mg P of TPR and TSP were applied to a kilogram of soil per pot in the two soil series. Randomized Complete Block Design was used to do the analyses.
 Results/Findings: Application of TSP resulted in higher dry matter and P uptake irrespective of the soil type. Among the legumes, cowpea gave the highest dry matter yield. Fairly, a similar trend was obtained with the application of TPR. Among the cereals, the average P uptake by sorghum from TPR was the highest, followed by maize and millet in the Nzema soil. In the Adenta series, P uptake by maize was the highest, followed by sorghum and millet. Phosphorus (P) uptake by the cereals from TPR was generally better in the Adenta than the Nzema soil.
 Unique contribution to theories, practice and policy: Results show increasing the rate of TPR to 100mg P/pot resulted in an increase in dry matter yield and P uptake in both soils, but was inferior to 100mg P/pot TSP application. Consequently, the rate of application of TPR should always be high if farmers want the best from their investments. Again, the low relative agronomic effectiveness of TPR for all the crops, proved the low reactivity of the material and its subsequent low performance compared with the water-soluble P. The low reactivity and the high molar mass of PO43-/CO32- of the TPR will always make it difficult for P to be made available from the TPR despite the acidity of the soil, the high density of the crops and the ability of the tested crops to exude organic acids, which facilitate phosphorus availability from TPR, therefore making TPR unsuitable for direct application.

Improving growth, phytochemical, and antioxidant characteristics of peppermint by phosphate-solubilizing bacteria along with reducing phosphorus fertilizer use

Phosphorus is a vital nutrient for plant growth and development. Its deficiency in farmlands is obviated by the phosphate fertilizer application. Excessive consumption of phosphate fertilizers harms to human health and the environment. Some soil bacteria are capable to increase phosphate fertilizers efficiency. Two-year field experiment was conducted to evaluate the effect of phosphate-solubilizing bacteria inoculation with phosphorus fertilizer on growth, antioxidant status, and phytochemical features of peppermint (Mentha piperita L.). The treatments were three amounts triple superphosphate (0, 50, and 100 kg ha−1) and PSB strains (Pseudomonas putida and Pantoea agglomerans) which were arranged as factorial based on randomized complete block design. The results showed that phosphorus supplying by chemical fertilizer or PSB improved peppermint growth features included stem number, leaf length, leaf number, and dry weights of leaf, stem, and plant. The contents of photosynthetic pigments increased by chemical or biological phosphorus fertilizer application. The application of PSB with triple superphosphate reduced soluble carbohydrates and increased protein. The antioxidant enzymes activities including catalase, peroxidase, ascorbate peroxidase, and polyphenol oxidase were increased by the PSB inoculation. In contrast, activities of these enzymes were reduced by the triple superphosphate application. The highest EO yield was obtained by Pseudomonas putida and Pantoea agglomerans inoculation as phosphate-solubilizing bacteria with 50 kg ha −1 triple superphosphate. The menthol content was increased in response to the triple superphosphate and the PSB inoculation. Therefore, PSB inoculation increased phosphate fertilizer efficiency which leads to reducing phosphate fertilizer consuming and increasing the plant biomass as well as EO yield.1

Influence of Phosphorus forms on Growth and Yield of Cowpea, Kales and Amaranth Vegetable Species

Maximum production potential of leafy vegetable is limited by phosphorous (P) deficiency in the soils. This is due to the high cost of the phosphate fertilizer and the fixed form of the available phosphorous in the soil. There is therefore, need for farmers to use alternative and cheaper sources of P that are economic friendly to supply the required mineral nutrition to their crops. Rock phosphate is widely available but has a challenge in solubilization to make P available to the crops. In the current study, the aim was to evaluate the effect phosphate forms and acidulate rock phosphate on growth and yield of selected leafy vegetables. The experiment was laid out in Randomized Complete Block Design in split-plot arrangement, with three leafy vegetables (cowpeas, kales and amaranth) being the main plots, and various sources of P (Triple super phosphate (TSP) Mijingu Phosphate Rock(MPR), Mijingu phosphate Rock + sulphur (MPR)PR+S and control) constituting the subplots with three replicates. The collected data included: root dry weight, leaf area, shoot fresh weight and leaf area and was subjected to SAS for ANOVA and where there were significant differences between means were further separated using the Fischer’s LSD at 5% level of significance. The results revealed that there were significant increase in the growth parameters of the vegetables as an effects of phosphorus application compared with the control. TSP elicited the best results in all the tested parameters in 5 WAP, 6 WAP and 7 WAP respectively in both seasons The highest value of root dry weight (11.2 g), leaf area (1905.0 cm2), number of branches (40.67) shoot fresh weight (236.8 g) as influenced by TSP application in the vegetable species. The MRP + sulphur also followed in superiority of increasing the growth parameters which is an indication that sulphur can be used in solubilizing rock phosphate and making it a suit alternative for farmers. Thus, farmers are advised to directly apply rock phosphate and sulphur to soil as a possible alternative to the more expensive soluble phosphate fertilizers in tropical cropping system.

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.

INFLUENCE OF MINERAL PHOSPHATE FERTILIZATION ON ACCUMULATION OF CADMIUM IN SOIL

In this current work, the influence of mineral phosphate fertilization on accumulation of cadmium in soil was studied. Rock Phosphate (RP) and Triple super phosphate (TSP) were selected as a common source of P fertilizers and enriched by Cd contamination. An incubation experiment was undertaken for 60 days. Soil was incubated with RP or TSP with 0.0, 20.0, 40.0 and 80.0 kg P2O5 ha-1. Soil samples were then taken after 1, 3, 7, 15, 30 and 60 days from incubation course. The most important results gained from the current study were: Cd concentration in RP was enriched 87 times of crustal abundance where Cd concentration in TSP was enriched 73 times crustal abundance. Although the TSP produced higher available P comparing with RP, the differences were not significant. For both TSP and RP applications, Cd extracted by DTPA as a proxy of bioavailable pool of Cd in soil was increased by increasing the P fertilizer rates and by consequence of incubation period. A negative relationship between soil pH and DTPA-Cd has been obtained. The increase of Cd sorption in this study might be attributed to the increase of soil pH caused by the P additions. This might be obvious in the decreasing of DTPA-Cd under higher pH values. The Cd in TSP might be more readably available than that of RP. The concentration of DTPA-Cd in incubated soil increased slightly due to the application of phosphate fertilizers, but the concentration did not reach contamination levels under different treatments.

Effect of Triple Super Phosphate on the Growth and Yield of Boro Rice in Haor Areas of Sunamganj District in Bangladesh

A field experiment was conducted at Bilpar village of Sunamganj district in Bangladesh during November 2016 to May 2017 to find out the effects of Triple Super Phosphate (TSP) fertilizer on the growth and yield of boro rice in haor areas. Two factors viz. varieties (BRRI dhan29 and BRRI dhan58) and six TSP fertilizer levels [F1- 85 kg TSP ha-1 (Farmers’ practice), F2- 142 kg TSP ha-1, F3- 127 kg TSP ha-1, F4- 112 kg TSP ha-1 (BARC recommended dose), F5- 97 kg TSP ha-1, F6- 82 kg TSP ha-1] were included in the experiment. The experiment was conducted in the farmers’ field and laid out in a RCBD with three replications. Data were taken on plant height and tillers hill-1 at 15 days intervals. The yield and yield contributing parameters were also taken at harvest. Plant height, number of total tillers, effective tillers hill-1, panicle length, sterile spikelets, 1000 grain weight, grain and straw yield varied significantly due to variety. BRRI dhan58 produced higher number of effective tillers (10.60) and grains panicle-1 (136.9) over BRRI dhan29. BRRI dhan58 produced higher grain yield (8.92 t ha-1) compared to BRRI dhan29 (7.27 t ha-1). All the studied parameters differed significantly with the application of TSP fertilizer except non-effective tillers hill-1. Application of 112 kg TSP ha-1 produced the highest number of effective tillers hill-1 (12.00) and the lowest in farmers practice (7.20). Fertilizer Recommendation Guide based TSP fertilizer (112 kg ha-1) produced the highest grain yield (8.80 t ha-1) of boro rice and the lowest grain yield (7.40 t ha-1) in farmers’ practice. Results of the study elucidated that TSP application at 112 kg ha-1 was effective to improve the rice productivity.

Influence of P Sources and Rhizobium Inoculation on Growth and Yield of Soybean Genotypes on Ferric Lixisols of Northern Guinea Savanna Zone of Ghana

ABSTRACTSoybean is becoming an important cash crop in northern Ghana. Yet the yields are low due to use of low yielding varieties and limited use of inputs. Greenhouse and field experiments were carried out to evaluate the effects of two phosphorus (P) sources and Rhizobium inoculation on growth, nodulation, P uptake, and yield of three soybean genotypes on Ferric Lixisols of the Guinea savanna zone of Ghana. The P sources were triple superphosphate (TSP) and Morocco phosphate rock (MPR), while the genotypes were TGx 1448-2E, TGx 1904-6F, and TGx 1955-4F. The greenhouse experiment was conducted at the University of Ghana, Legon in a completely randomized design. The field experiment which was carried out in the Upper East region of Ghana was laid out in a split-split plot design with four replicates. In both the greenhouse and field experiments, application of TSP at 30 kg P ha−1 resulted in significantly higher growth and P uptake in shoot compared with MPR and control. Soybean genotypes showed significant differences in growth, nutrient uptake, and grain yield in both the greenhouse and the field experiments. Rhizobium inoculation increased nodule number and dry weight but did not increase grain yield. The genotype TGx 1955-4F appears to show greater potential for increasing productivity of soybean in low P soils in northern Ghana.

Potential of Eppawala rock phosphate as a phosphorus fertilizer for rice cultivation in acid sulphate soils in Matara District of Sri Lanka

Eppawala Rock Phosphate (ERP) is a phosphorus (P) resource in Sri Lanka containing about (28% to 42%) of P2O5 and an alternative for imported Triple Super Phosphate (TSP). Low water solubility of ERP has limited its use as a P fertilizer for rice. However, ERP could be used as a P source for rice grown in acidic soils due to its increased solubility under acidic conditions. This study was carried out during Yala 2015 and Maha 2015/16 seasons to investigate the potential of ERP as a source of P for paddy grown in acid sulphate soils in the Nilwala valley in Matara District. Six treatments including a control were arranged in a Randomized Complete Block Design with three replicates. Treatments were comprised of TSP as a basal application (recommendation of the Department of Agriculture) and by ERP as basal and split applications at rates of 25 and 50 kg P2O5 kg/ha respectively. Application of TSP resulted in a significantly higher plant height and dry matter production in comparison to the control. Application ERP at a rate of 25 P2O5 kg/ha as a split application and 50 P2O5 kg/ha (both split and single applications) showed a comparable plant height and an increase in dry matter production increment in comparison to the control. Significantly higher average panicle lengths and grain yields were observed in both TSP and ERP applied treatments in comparison to the control in Yala 2015. However, comparable increments were observed only in TSP applied treatment and ERP applications at a rate of 25 P2O5 kg/ha as a split application and 50 P2O5 kg/ha in Maha 2015/2016. Inconsistency of growth and yield performances of ERP treatments indicated the importance of long term experiments to determine suitable rates and methods of ERP application. This short-term study showed that ERP is a potential substitute for TSP for paddy grown in acid sulphate soils in Matara District.

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.

Effect of amendments on contaminated soil of multiple heavy metals and accumulation of heavy metals in plants.

The contamination of soil with heavy metals is a severe problem due to adverse impact of heavy metals on environmental safety and human health. It is essential to remediate soil contaminated with heavy metals. This study has evaluated the effects of pine biochar, kaolin, and triple super phosphate (TSP) on multiple heavy metals (Ni, Zn, Cu, and Cd) in contaminated soil and accumulation of heavy metals in plants. The amendments can reduce availability of heavy metals in soil by increasing pH, adsorption, complexation, or co-precipitation. Different amendments have variable effects on accumulation of heavy metals in plants and in soil due to its diverse mechanism of stability. The results showed that application of triple super phosphate (TSP) has significant reduced soil Cd exchangeable (EXC) fraction from 58.59 to 21.30%. Bound to carbonates (CAR) fraction decreased from 9.84 to 5.11%, and bound to Fe-Mn oxides (OX) fraction increased from 29.61 to 69.86%. The triple super phosphate (TSP) has the ability to stabilize Cu and especially Cd. However, triple super phosphate (TSP) has enhanced ecological risk of Zn and Ni. Application of pine biochar has significantly enhanced soil pH. The kaolin has significantly reduced EXC fraction of Cd and increased OX fraction of Cu. The amendments and heavy metals have not caused significant effect on SPAD value of Buxus microphylla Siebold & Zucc (B. microphylla). The triple super phosphate (TSP) has significant decreased biomass of B. microphylla and bamboo-williow (Salix sp.) by 24.91 and 57.43%, respectively. Pine biochar and kaolin have increased the accumulation of Zn and Cd in plants. It is concluded that triple super phosphate (TSP) was effective in remediation of Cd and kaolin was effective in remediation of Cd and Cu. Pine biochar was effective in remediation of Cd, Cu, and Zn.