Diammonium Phosphate Research Articles

In vitro Assessment Indicates that Fertilizers Commonly Used in Legume Production Differentially Inhibit Commercial Rhizobial Strains

ABSTRACT In-vitro rhizobial inhibition by fertilizers commonly used in legume production was assessed with commercial inoculant strains, Bradyrhizobium lupini WU425, Mesorhizobium ciceri CC1192 and Rhizobium leguminosarum bv. viciae WSM1455, and a commercial granular inoculant (WSM1455). Standard bacterial inhibition assays were used with four fertilizers: single superphosphate (SSP), granulated DAP (based on diammonium phosphate) and MAP (monoammonium phosphate), and a compound fertilizer (MAP with ZnSO4). WSM1455 was strongly inhibited by DAP and MAP fertilizers, and moderately by SSP, with DAP being non-lethal. However, CC1192 and WU425 were not inhibited by DAP and were less sensitive to MAP fertilizers, with the effects being bacteriostatic rather than bactericidal. Apart from pH effects (particularly SSP), comparisons with analytical grade products indicated that fertilizer impurities might contribute to this inhibition. Granular inoculant mixed with MAP or DAP rapidly lost moisture and viability (75% within 1 h). The fertilizers were found to inhibit rhizobia with strain by fertilizer interactions, with differences in degree and lethality. Consequently, it is suggested that close placement of inoculated seeds near fertilizer at planting or mixing granular inoculants with fertilizers risks poor nodulation outcomes. These in-vitro findings need field validation but may be considered valuable in providing advice to legume growers.

Carboxymethyl Chitosan as a Reversible Template of Calcium Phosphate for Multifunctional Conservation of Carbonate Stone.

The accelerated deterioration of carbonate stone artifacts under climate change has long been an urgent issue. Inspired by biomineralization, we developed carboxymethyl chitosan-diammonium hydrogen phosphate (CD) composite and investigated the conservation effectiveness of the CD composite compared to diammonium hydrogen phosphate (DAP) on limestone. The morphologies and microstructures were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR). The consolidating effectiveness was investigated through a compressive strength test. The protective ability was assessed by disintegration resistance test, acid attack resistance test, salt attack resistance test, and freeze-thaw aging cycle test. SEM observations revealed that carboxymethyl chitosan (CMCS) served as an effective template, inducing the in situ formation of a uniform and continuous calcium phosphate coating on both the surface and interior of the stone. The tests indicated that the CD composite further enhanced the consolidating effectiveness and improved resistance to disintegration and freeze-thaw cycles. Notably, as an amphiphilic polyelectrolyte, CMCS functioned as a pH buffer and a protective barrier against sodium sulfate salts, which improved the resistance to acid and salt attacks. Additionally, the CD composite did not cause significant variations in the esthetic appearance or water vapor permeability. We then applied the CD composite at an actual carbonate stone cultural heritage site, successfully demonstrating the feasibility of CD application and the reversibility of CMCS in a real-world setting. Based on the study's results, our approach provides a new perspective for developing multifunctional and sustainable conservation materials for carbonate stone artifacts.

Chitozan-zeolite Composite Fertilizer Formulations for Enhancing Nutrient Use Efficiency

The experiment was carried out in the Department of Soil Science and Agricultural Chemistry at the College of Agriculture, Vellayani, Kerala, from January to May 2024. Slow release fertilizer formulations (SRF) containing all the major (N, P,K), secondary (Ca, Mg, S) and micronutrients (Zn, B) were prepared using compatible fertilizer materials(urea, diammonium phosphate, muriate of potash, phosphogypsum, magnesium sulphate, zinc sulphate and borax), carrier materials (zeolite and chitosan) which are mixed in five ratios (1:1,1:2,1:3,2:1,3:1) and prepared by two methods namely solid impregnation and solute impregnation. Ten formulations were prepared with different combinations of fertilizer mix, carrier materials and impregnation methods. These formulations were prepared to meet the specific nutrient needs of solanaceous crops (75:40:25 N:P:K kgha-1) and the soil nutrient status. The formulations were characterized for their physical (hygroscopicity, moisture content and stability) and electro-chemical properties (pH, EC) and observed that they are non hygroscopic, non caking and are highly stable. The moisture content of formulations ranged from 2.57 % to 3.92 %, pH 6.30 to 6.81 and EC 10.06 to 16.29 dS m-1. The nutrient content in these formulations were 10.21 to 12.02 % nitrogen, 3.82 to 4.63 % phosphorus, 2.65 to 5.28 % potassium, 5.58 to 6.58 % calcium, 2.46 to 3.08% magnesium, 2.58 to 3.46% sulphur, 1.06 to 1.23% zinc and 0.15 to 0.24% boron. The highest nutrient content was obtained in formulation containing fertilizer mix + C-Z (1:1) prepared by solid impregnation method.

Synergistic Effect of Influence Factors on Ammonia Volatilization in Fertilizer Solution: A Laboratory Experiment

Ammonia volatilization, which is one of the main ways that nitrogen gas is released from farmland, restricts promotion of the utilization of nitrogen fertilizer and contains some potential environmental risks. To investigate the general pattern of ammonia volatilization under actual paddy field conditions, we designed an indoor simulated system to measure the amount of ammonia volatilized within a single time period by controlling the pH and concentration of NH4+ (c(NH4+)) in the solution, the gas–liquid interfacial gas velocity, and the ambient temperature. In this paper, the influence of these factors, the synergistic effect on ammonia volatilization, and their quantitative relationship are discussed. We used solutions of ammonium bicarbonate (SAB) and diammonium phosphate (SDP) for the simulation experiments, and the results showed that there is a significant linear relationship between the amount of ammonia volatilization and c(NH4+). The correlation coefficients were between 0.9214 to 0.9897 and 0.8932 to 0.9904 for SAB and SDP, respectively. The quantitative relationship between temperature and pH and the influence factor (CIF) and the initial ammonia volatilization fluxes (IAVFs) was analyzed by the least-squares method, and the degrees of polynomial were one and two, respectively. The regression equations of the SAB and SDP among the amount of ammonia volatilization with the concentration of ammonium nitrogen, the temperature, and the pH were calculated by using MATLAB. Considering the effects of temperature and pH on the CIF and IAVFs under individual conditions, we used a binary cubic model to fit the relationship between temperature and pH to the CIF and IAVFs. The simulation results showed that the correlation coefficients between the CIF and IAVFs for SAB were 0.9980 and 0.9680, respectively, and the correlation coefficients were 0.9946 and 0.9708 for SDP, respectively. The quantitative equation took into account the coefficient of determination and degrees of polynomial, and the ammonia volatilization fluxes can be calculated by using these equations.

A statistical approach to predict flexural strength and flame retardation properties for natural fibre/ epoxy composites

This research investigates the development of a mathematical model to predict the influence of flame retardants (FR) on the mechanical and flame retardancy performance of natural fibre reinforced thermosetting composites. The study focuses on two types of FRs: Diammonium Phosphate (DAP) and silica fumes that were added to Jute reinforced epoxy composites (JRECs). Two mathematical models were established based on three variables and two measured responses. The variables include FRs type, FR content, and FR method of preparation, while the measured responses are Limiting oxygen index (LOI) and Flexural strength (FS). The models were developed using a statistical approach based on multiple linear regression fitting and validated using analysis of variance (ANOVA) technique. The developed models were verified using experimental result data from literature and the analysis of these models showed that the maximum discrepancy between the observed and predicted values for relative LOI and relative FS was within the range of [Formula: see text] 6% and [Formula: see text] 5%, respectively. This research contributes to the understanding of the impact of FRs on the mechanical and flame retardancy performance of natural fibre reinforced thermosetting composites, which can aid in the design and development of safer and more efficient composite materials.

Sonochemical synthesis characterization and biocompatibility studies of polymeric composites for biomedical applications

In this work the in situ synthesis of mixtures of Polymethylmethacrylate (PMMA), High Density Polyethylene (HDPE) and Polypropylene (PP) with biocompatible ceramics was carried out, using high frequency ultrasound as an energy source. Starting from calcium hydroxide and ammonium hydrogen phosphate, two different crystalline phases were obtained: hydroxyapatite (HA) and calcite (CaCO3). FTIR and XRD studies showed that for the materials prepared with HDPE, only CaCO3 was formed during the synthesis process. When Polypropylene used, mixtures of HA with CaCO3 were obtained, while for the materials synthesized with Polymethylmethacrylate, only pure HA was obtained. DSC analyses did not reveal any significant changes in the melting temperatures of HDPE and PP, nor in the glass transition temperature of PMMA with the incorporation of HA and CaCO3, in the polymeric matrices. TGA, showed that the decomposition temperatures of these materials increased with respect to those of the polymers alone, indicating a significant thermal stability. Biocompatibility tests with osteoblastic cells and Scanning Electron Microscopy (SEM) studies showed that the composites of PMMA with HA, PP with HA/CaCO3 and HDPE with CaCO3, are capable of promoting cell adhesion and proliferation mechanisms, revealing potential applications as biomaterials for bone replacement.

Diverse Farming Systems and their Impact on Macro and Microelement Content of Vegetables & Crops.

The present study investigates the effect of conventional and organic farming systems on the nutritional profile of crops. Different crops, namely -millet, sorghum, sesame, mustard, fenugreek, berseem, pea, potato, and onion were cultivated through conventional agriculture in which chemical fertilizers like urea, DAP (Diammonium Phosphate) and pesticides were used and organic farming in which organic fertilizers like seaweed and vermicompost were used. The experimental study was done on a field in north India from 2019 to 2021 in six different seasons, and the nutrient profile of the crops with respect to macroelements (S, K, Na, P, Ca, Mg) and microelements (B, Cu, Fe, Mn, Zn, Al) was compared. Macro and microelements were analyzed by Element analyzer and ICP-OES in both types of farming systems. The content of macro, as well as microelements, was found to be significantly higher in all the organically produced crops as compared to the conventionally grown crops. Significant differences were observed in the macroelement content of organic onion (P- 900 mg/kg, K-2000mg/kg) and organic pea (K 2250 mg/kg) as compared to the content of conventionally grown onion (P-756 mg/kg, K- 1550 mg/kg) and pea (K-2000 mg/kg). Similarly, microelement content in the organic sesame (Fe - 3.12 mg/kg), organic millet (Fe- 2.19 mg/kg), and organic potato (Zn-200 mg/kg) was higher as compared to conventionally grown sesame (Fe 2.05 mg/kg), millet (Fe- 1.56 mg/kg) and potato (Zn 167 mg/kg). This investigation concludes that crops with optimum nutritional content can be produced through organic farming with minimum input and maximum production.

Nutrient and energy conservation through nano-fertilizers in maize

In the current scenario, achieving food security while conserving resources and energy is a significant challenge. Maize is a widely cultivated but nutrient-exhaustive crop. The adoption of nanotechnology-based nano-fertilizers offers a pathway to achieving sustainable yields while reducing fertilizer requirements and conserving energy. A field experiment was conducted during the Kharif season of 2021 to explore nutrient and energy conservation through nano-fertilizers in maize at the University of Agricultural Sciences, GKVK, Bengaluru. The experiment involved nine treatments comprising various combinations of the recommended dose of fertilizers (RDF) with nano-urea and nano Di-Ammonium Phosphate (DAP) under a Randomized Complete Block Design (RCBD). The results indicated that Treatment T5 - 75% of the Recommended Dose of Nitrogen (RDN) + Nano-N—achieved a higher yield (10.20% higher than the conventional practice, T1-RDF + Farmyard Manure (FYM)) and improved nutrient uptake at harvest [299.22, 55.56, and 208.26 kg of nitrogen (N), phosphorus (P), and potassium (K) per hectare, respectively]. This treatment also demonstrated greater physiological efficiency (36.11, 200.66, and 52.70 kg of maize per kg of N, P, and K, respectively), higher energy output (260,851 MJ ha?¹), improved energy use efficiency (16.93), enhanced energy productivity (0.627 kg MJ?¹), and better energy profitability (15.93). Using 75% of RDN + Nano-N increases yield while reducing fertilizer use and conserving energy.

Phosphorus-Nitrogen Interaction in Fire Retardants and Its Impact on the Chemistry of Treated Wood.

This work focuses on the changes in the chemical composition of wood caused by impregnation with fire retardants such as guanidine carbonate (GC), urea (U), diammonium phosphate (DAP) and their mixtures. The treated wood was tested using the oxygen index (LOI), Py-GC/MS analysis and FTIR Spectroscopy. The wood was vacuum treated at a pressure of 0.8 MPa for 20 min and then subjected to thermal degradation using the LOI. This way, degraded and nondegraded layers were obtained and ground (0.2 mm). All treatment variants achieved the class of non-flammable materials based on LOI tests; the exception was the 5% urea solution, defined as a flame-retardant material. Using the analytical methods, it was found that cellulose and hemicelluloses undergo the fastest thermal degradation. This study found that the variant protected with a 5% mixture of GC and DAP before and after the degradation process had the best fire-retardant properties regarding cellulose content in the wood. The highest content of anhydrosugars characterised the same variants, the amount of which indicates a slowdown in the degradation process and, consequently, a reduction in the release of levoglucosan during combustion, suggesting potential applications in fire safety.

Effects of humic acid on the root growth and its interaction with coated diammonium phosphate on yield of wheat

Coated diammonium phosphate (CDAP) and humic acid (HA) have improved crop phosphorus fertilizer use efficiency. However, the effects of different phosphorus concentrations and HA incorporation on wheat and their potential mechanisms are unknown. This study aimed to elucidate the impact of varying phosphorus concentrations and HA applied in combination with coated phosphate fertilizers on wheat growth and its yield. An incubation experiment was performed using different phosphorus (P) concentrations (P0%, P1%, P10%, and P100% in Hoagland nutrient solution) combined with two HA content (0 and 0.1 g L−1). Finally, the wheat pot experiments were presented with two HA application rates (0 and 45 kg ha−1) and two P levels (60 and 75 kg P2O5 ha−1) under the condition that two forms of P fertilizer (CDAP and diammonium phosphate (DAP)) were comprised. At the same P rate, the auxin (IAA) and cytokinin (CTK) content in wheat seedlings of HA-added treatments was increased by 11.30%- 40.33% and 12.03%-29.21%, respectively, compared with the HA-free treatment. The CDAP combined with HA that improved the wheat growth and increased the yield and P use efficiency (PUE) by 2.7%-4.3% and 6.7-7.1 percentage points. Furthermore, the interactions between the types of P fertilizer (DAP, CDAP) and the application rate of HA were recorded as being significant (p < 0.01) for the wheat yield. In conclusion, as an environmentally friendly fertilizer, the combination of CDAP and HA increased enhanced root growth, and then maximized yields and PUE, which is important for P resource conservation and environmental protection.

Establishing fire protection patterns in wood using impregnation compositions from inorganic salts

An issue related to using inorganic salts for fire protection of wood is to ensure their flame-inhibiting ability and compatibility with wood and application technology. That is why the object of research was to establish the effectiveness of inhibitory properties of mixtures of inorganic salts during interaction with the flame and enabling interplay with wood. A synergistic increase in the inhibitory capacity of mixtures of aqueous solutions of salts of diammonium phosphate and ammonium sulfate at a ratio of 2:1, and for a mixture based on orthophosphoric acid, urea, and oxyethylidenediphosphonic acid in the concentration range of 20–25 % by mass, has been proven. During the interaction of the specified mixtures with the wood surface, it was found that after application to the wood surface, the dispersed component of the free energy of the wood surface decreased to zero; instead, the polar component increased 13 times, which indicates a change in the wood surface. During the tests of wood samples on the effect of the burner flame, it was found that the untreated sample ignited on second 53, and the flame spread throughout the sample for 102 s. On the other hand, the samples treated with a mixture of an aqueous solution of phosphate and ammonium sulfate, as well as a mixture of aqueous solutions based on orthophosphoric acid and urea and oxyethylidenediphosphonic acid, did not catch fire, the flame did not spread over the surface, and the flammability index was 0. The practical significance is that the results were taken into account when designing flame retardant compositions for wood. Thus, there are reasons to assert the possibility of targeted regulation of wood protection processes through the use of mixtures of inorganic salts capable of forming a protective layer on the surface of the material that inhibits the burning of wood

Rice Response to Struvite and Other Phosphorus Fertilizers in a Phosphorus-Deficient Soil Under Simulated Furrow-irrigation

AbstractWastewater-recovered phosphorus (P), in the form of the mineral struvite (MgNH4PO4⋅6H2O), may provide a sustainable alternative to decreasing rock-phosphate reserves. Struvite can be generated via precipitation methods, potentially reducing the amount of P runoff to aquatic ecosystems. The objective of this greenhouse tub study was to evaluate the effects of chemically- and electrochemically precipitated struvite (CPST and ECST, respectively) on above- and belowground plant response in a hybrid rice (Oryza sativa) cultivar grown using furrow-irrigation compared to other common fertilizer-P sources [i.e., triple super phosphate (TSP) and diammonium phosphate (DAP)]. Rice was grown in tubs in controlled environmental conditions in a greenhouse for a full growing season in a P-deficient, silt-loam soil (Typic Glossaqualfs). Plant nutrients (i.e., N. P. K. Mg, Zn) were determined at the end of the growing season through Mehlich-3 extraction. Below- and aboveground rice dry matter (DM), root-P concentration and uptake, aboveground tissue-P uptake, total aboveground and total plant DM, grain yield, and grain P uptake from CPST and ECST did not differ from DAP or TSP. However, aboveground tissue-P concentration was greater (P &lt; 0.05) from TSP (0.05%) than from ECST, CPST, and the unamended control (UC). Total aboveground (i.e., vegetative plus grain) tissue-P uptake was largest (P &lt; 0.05) from TSP (4.8 g m− 2), which did not differ from DAP or CPST, and was at least 1.1 times greater than from ECST and the UC. Despite only a few differences from the UC, the many similar rice responses among struvite and other common fertilizer-P sources suggest that struvite, especially ECST, is a potential alternative fertilizer-P source that warrants further research into struvite’s role in food production.

Strategies to reduce the culture medium costs for a high‐yield and high‐selectivity bio‐based 2,3‐butanediol production

AbstractBio‐based 2,3‐butanediol (2,3‐BDO) production on a large scale depends on critical factors, such as culture medium, oxygen supply, pH and biosafety. In this study, three strategies for reducing culture medium costs were investigated: carbon/nitrogen (C/N) ratio; low‐cost nitrogen sources (crude yeast extract, brewer's yeast extract, corn steep liquor, urea, sodium nitrate, ammonium chloride, ammonium sulfate and dibasic ammonium phosphate); and microbial pH autoregulation. Batch fermentations were performed in a microaerobic environment using wild‐type and safe Paenibacillus peoriae NRRL BD 62. The yield and selectivity of 2,3‐BDO were used as control variables. A ratio between 2,3‐BDO production and glucose consumption (YP/S) of almost 80% and an optical purity of 87% levo‐2,3‐BDO, with no acetoin accumulation, were achieved in an NH4Cl‐based medium at C/N = 8.5 g/g and without external pH control, considering an initial glucose of 10 g/L. Based on Free on Board prices, a 63% savings in culture medium costs was achieved by replacing commercial yeast extract at pH 5. Validation assays with higher initial glucose concentrations showed a YP/S of 0.40 g/g and an optical levo‐/meso‐2,3‐BDO ratio of 1:0.8, with negligible acetoin accumulation. Therefore, the NH4Cl‐based medium at C/N = 8.5 g/g and without pH control was considered economically promising for high‐yield and high‐selectivity bio‐based 2,3‐BDO production.

Probing into Volumetric and Acoustic Properties of Aqueous l-Ascorbic Acid in the Presence of Diammonium Hydrogen Phosphate and Potassium Chloride

Probing into Volumetric and Acoustic Properties of Aqueous <scp>l</scp>-Ascorbic Acid in the Presence of Diammonium Hydrogen Phosphate and Potassium Chloride

The Synergistic Effects of Different Phosphorus Sources: Ferralsols Promoted Soil Phosphorus Transformation and Accumulation

Phosphorus (P) application can enhance soil P availability and alter P fractions. However, the P accumulation and transformation of different P sources in low-phosphorus red soil remain unclear. Two-year (2018–2019) field experiments were conducted to investigate the effects of five P source treatments (CK—no phosphorus; SSP—superphosphate; MAP—calcium–magnesium phosphate; DAP—monoammonium phosphate; and CMP—diammonium phosphate) on the P accumulation of maize and soil P fractions in low-P red soil using the Hedley Sequential Method. The results showed that P application significantly increased P uptake, Olsen-P, total phosphorus, and most of the soil P fractions. Compared to the CMP, MAP, and DAP treatments, SSP had a relatively higher P accumulation and labile P pool, with a slightly lower moderately labile P pool. The SSP treatment mainly increased soil-available P content and crop P uptake by increasing the labile P pool (resin-P and NaHCO3-Pi) and reducing the moderately labile P pool and non-labile P pool. The P activation coefficient (PAC%) and Olsen-P were positively correlated with labile P (resin-P, NaHCO3-Pi, and NaHCO3-Po) and moderately labile P (NaOH-Pi and 1 M HCl-Pi) and negatively correlated with Fe2O3 and Al2O3. The results suggest that SSP has a priority effect on the crop P uptake and soil P availability in low-P red soil.

Assessing Heavy Metal Contamination in Commonly Used Fertilizers for Polyculture Fish Ponds and Its Implications for Human Health: A Comprehensive Investigation.

Over-fertilizing fish ponds can cause pollution, introducing heavy metals into the food chain and posing health risks. The present study investigated the incidence of heavy metals (Pb, Cu, Cd, and Cr) in commonly applied fertilizers, including nitrogen, phosphorus and potassium (NPK), triple superphosphate (TSP), and di-ammonium phosphate (DAP), and their association with heavy metals in water, sediment, and cultured fish species (Catla catla, Labeo rohita, and Cyprinus carpio) in polyculture fish ponds. The study was conducted over 4months, with four groups in triplicates: control (no fertilizer), group 1 (NPK), group 2 (TSP), and group 3 (DAP). Heavy metal analysis was carried out using atomic absorption spectrophotometry before and after fertilizer application. Significantly (p < 0.05) higher levels of heavy metals were observed in water and sediment after applying fertilizers, with the most pronounced results in group 3 (DAP) followed by group 2 (TSP). The concentration of heavy metals was significantly (p < 0.05) higher in group 3 (DAP) fertilizers compared to other groups. Compared to the control, the concentration and bioaccumulation of heavy metals were significantly (p < 0.05) higher in the fertilizer-applied groups, with notably higher levels in group 3 (DAP). Cluster analysis and the correlation matrix did not show any significant association between the heavy metals and the fertilizers, indicating a complex interplay between the biotic and abiotic factors of the system. The health index (HI) value was < 1 in fish muscles of all studied groups, indicating the fish are safe for consumption. The study recommends monitoring and regulating fertilizer use, especially DAP, to prevent heavy metal contamination, and exploring sustainable alternatives to minimize environmental and health risks.

Enhancing the fermentation rate and aroma compounds of kiwi wine via the addition of nitrogen during the stationary phase

Nitrogen addition is a viable strategy for preventing sluggish or stuck fermentation and enhancing aroma profiles in the winemaking industry. Herein, nitrogen, in the form of amino acids mixture or diammonium hydrogen phosphate (DAP), was added at different fermentation periods to investigate its effects on the fermentation characteristics, non-volatile compounds and aroma profiles of kiwi wines. Both the amino acids mixture and DAP shortened fermentation time by 1–2 days and balanced organic acid proportion by reducing malic acid content and increasing citric acid content. Adding DAP significantly decreased higher alcohols content, whereas higher alcohols content was remarkably increased with amino acids mixture supplementation. Furthermore, nitrogen addition during the stationary phase was most conducive to synthesizing other beneficial aromas, especially acetate esters and medium-chain fatty acid ethyl esters (MCFAEEs), and improving the perception of tropical fruity and cream aromas in kiwi wines. Partial least-squares regression (PLSR) results showed there was a tight correlation between amino acids and volatile compounds. This study provides an insight into the development of high-quality kiwi wine and should serve as the theoretical foundation to support the application of nitrogen addition in the wine industry.

Application of different phosphatic fertilizers influences the different phosphorus fractions and morphophysiological traits of wheat in saline sodic soil

Nutrient constraints in salt-affected soils are one of the limiting factors for crop production. We investigated phosphorus (P) availability to wheat crop and its correlations with different fractions of P in salt-affected soils in response to various phosphatic fertilizer’s application. Three different types of soils having electrical conductivity of soil extract (ECe) < 4 dS m−1 and sodium adsorption ratio (SAR) < 13.2 (mmol L−1)1/2, ECe 8 dS m−1 SAR 20 (mmol L−1)1/2 and ECe 12 dS m−1 and SAR 30 (mmol L−1)1/2 were used for this experiment. Different P fertilizers viz. control, diammonium phosphate (DAP), single super phosphate (SSP) and nitrophos (NP) were applied on these soils. The doses of nitrogen, phosphorus and potassium were remained same for all the treatments. The P fractions, agronomic parameters and P-availability to plants were determined. Results indicated increase in shoot dry weight (61%) and photosynthetic rate (9%) in SSP treated soil at EC 8 dS m−1 and SAR 20 (mmol L)1/2. The total P (7.6%) in soil and respiration rate (1.9%) in plant was recorded maximum in DAP treated soil at EC 8 dS m−1 and SAR 20 (mmol L)1/2, and membrane stability index (44%) in plant shoot, extractable P (23%) in soil and P concentration (22%) in shoot were recorded maximum in SSP treated soil at EC 12 dS m−1 and SAR 30 (mmol L)1/2. It was concluded that SSP fertilizer perform better in salt-affected soil for growth and yield of wheat compared to other phosphatic fertilizers.

Optimum source, rate, timing, and placement of phosphorus fertilizer for Illinois soybean

AbstractConsistent increases in soybean (Glycine max L.) grain yields over the past decades in Illinois have co‐increased P demand, but—as for many US Midwest states—P fertilizer recommendations are outdated. We evaluated soybean grain yield, P uptake and removal with grain harvest, and P use efficiency in 4 site‐years of field trials on Argiudolls‐Endoaquolls and Fragiudalfs‐Hapludalfs under annual P application treatments of source (monoammonium phosphate [MAP], diammonium phosphate [DAP], triple superphosphate [TSP]), rate (partial vs. full maintenance rate), and timing–placement combination (fall and spring broadcast, spring banding). Substituting ammonium phosphate fertilizers, the most commonly used P fertilizers in the US Midwest, with N‐free TSP supported similar yields and resulted in similar P removal as hypothesized, while avoiding co‐applied N that can be subject to losses primarily via leaching. Soybean yield and grain P removal were unresponsive to rate, timing, and placement even at the partial rate, although banding and spring application may have reduced N loss risk for MAP and DAP. Given the challenges in accurately estimating P removal rate by grain harvest due to the variability in yield and grain P concentrations across years, assessment of P use efficiency should focus on long‐term balance between fertilization (input) and crop removal (output).

Direct writing of calcium phosphate/graphite nanocomposite film using laser-induced graphitization of polyimides

We report the direct writing of calcium phosphate/graphite nanocomposite using laser-induced graphitization of suspension-covered polyimide (PI) films. Calcium phosphate/graphite nanocomposites are desirable for the osteoconductive, osteoconductive, and resorptive properties of calcium phosphate and the electrical conductivity of graphitic carbon. Two forms of calcium phosphate, namely, EggCaP and CaOP, were synthesized by chemomechanical alloying of diammonium hydrogen phosphate (DHP) with eggshells – a waste material – and reagent-grade calcium oxide (CaO) powders, respectively. Fourier transform infrared (FTIR) spectroscopy of the synthesized powders revealed the phase change of starting materials to calcium phosphates (CaP), and powders were suspended in methanol to form printing suspension. Laser irradiation of synthesized CaP powder suspension-covered polyimide (PI) surfaces resulted in the formation of electrically conductive films due to laser-induced graphitization of PI. Laser-induced graphited films based on EggCaP suspension (ELIG) and CaOP (CLIG) had a sheet resistance of 25 Ω/∎ and 30 Ω/∎, respectively, and had lower resistance than the LIG films formed from bare PI (60 Ω/∎). Raman spectroscopy revealed that repeated laser irradiation of ELIG and CLIG film led to decreased defects and higher graphitization. ELIG had an ID/IG ratio of 0.65 after the first irradiation, but repeated irradiation reduced the ratio to 0.38. Similarly, CLIG had a higher ID/IG ratio of 0.55 during the first irradiation, and repeated irradiation reduced it to 0.42. Furthermore, CO, CO stretch modes, and various PO4 groups were also found in the Raman spectrum, indicating the formation of CaP/graphite nanocomposites in the graphitized films. SEM results showed that both graphitized films had closed foam-like microstructure with CaP particles deposited on the pore walls. Films formed after single irradiation had discrete CaP particle deposits on the surface, but repeated laser irradiation led to the integration of CaP particles into the pore walls. The ELIG films showed higher incorporation of the CaP particles and the highest electrical conductivity. The laser-induced graphitic transformation leads to incorporating the CaP particles into a conductive substrate, resulting in a CaP/graphite nanocomposite. The high electrical conductivity, closed-foam-like microstructure, porosity, biocompatibility, and hierarchical surface roughness of the ELIG and CLIG films make them attractive for biosensors, bioelectronics, and implant applications.