Diammonium Phosphate Research Articles

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.

Plant growth promoting Rhizobacteria for sustainable tomato production

Numerous phosphate solubilizing bacteria (PSB) are found in the rhizosphere, benefiting the host plant in different mechanisms and promoting sustainable agriculture. They improve soil fertility with minimum cost requirements using an eco-friendly approach, which is an essential attribute for small-scale farm production. Thus, isolation, characterization, and evaluation of symbiotic effectiveness are hierarchical procedures to develop bioinoculants. Using a dual (plate and liquid medium) screening technique and a greenhouse trial, four potential PSB strains (Mk-1–25, Mk-13–16, Mk-20–7, and Mk-20–20) were selected from tomato rhizosphere soil. All isolates exhibited the following traits: produced colony clear-zone, lowered liquid medium pH, gram-positive, produced urease and IAA, dissolved substantial P from various substrates, symbiotically effective, and improved tomato growth and yield. Taxonomically, they belong to Bacillus and Priestia species (i.e., Mk-1–25 Bacillus halotolerance, Mk-13–16 Bacillus amyloliquefaciens, Mk-20–7 Bacillus megaterium, and Mk-20–20 Priestia megaterium). Among the current strains, Bacillus halotolerance recorded higher SI (3.11), was able to grow in extreme conditions (10% salt, up to 45 °C), produced HCN and siderophore, and improved tomatoes’ shoot length and weight, in contrast, Mk-20–20 produced HCN, siderophore, was able to fix nitrogen, improved tomato germination, shoot dry weight, and fruit weight. Various P-supplements (Ca3(PO4)2, bonemeal, FePO4, AlPO4, compost, and DAP fertilizer) were added to induce tomato-strain symbiotic interaction; hence, compost substantially promoted the interaction and resulted in higher symbiotic effectiveness. Ca3(PO4)2 was a good media composite preferred by most PSB strains; consequently, a higher concentration (219 µg/ml) of dissolved P was recorded from the liquid medium after 10 days of incubation than other substrates. Based on the data obtained from laboratory and greenhouse trials, the current strains were found to be potential candidate. Future work should confirm their efficacy at the field level using model host crops at different sites to recommend them as farm inputs and biofertilizer.

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.

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.

Foliar Fertilization on BRRI dhan28 To Reduce Soil Application of Nitrogenous Fertilizer

The experiment was conducted at the research farm of Crop Physiology and Ecology Department, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur during November 2019 to June 2020 to find out the effect of foliar fertilization on the performance of rice var. BRRI dhan28 and to estimate how much nitrogenous fertilizer can be saved by foliar fertilization without yield reduction. The experiment was laid out following split plot design with three replications. Four levels of foliar fertilization (F0 – No foliar fertilization, F1 – Foliar fertilization with 2% KNO3, F2 - Foliar fertilization with 2% DAP and F3 - Foliar fertilization with 1% American NPKS) were placed in the main plot treatments whereas three nitrogen fertilizer levels (N50 -50% of the recommended nitrogen fertilizer, N75 – 75% of the recommended nitrogen fertilizer and N100 – 100% of the recommended nitrogen fertilizer) were placed randomly in the sub-plots. Foliar fertilization with KNO3, DAP (Di-ammonium phosphate) and American NPKS significantly increased the grain yield (t ha−1) compare to control (F0) but KNO3 and American NPKS performed better than DAP. Foliar fertilization with KNO3 and American NPKS could save 25% of recommended nitrogen fertilizer but foliar fertilization with DAP could not save nitrogen fertilizer applied in soil for getting comparable grain yield found in F0N100. Foliar fertilization of KNO3 and American NPKS with recommended nitrogen fertilizer applied in soil could increase 11.8 and 12.5% grain yield, respectively compare to F0N100. Bangladesh Agron. J. 2024, 26(2): 77-85

Phosphorus fertilization promotes carbon cycling and negatively affects microbial carbon use efficiency in agricultural soils: Laboratory incubation experiments

Soil organic carbon (SOC) loss from intensive agriculture represents a major global concern. Consequently, strategies to improve soil management to mitigate or abate SOC losses and enhance carbon (C) sequestration are urgently needed. Nutrient availability, especially nitrogen (N) and phosphorus (P), regulates soil C cycling and storage. While N effects are well studied, less is known about how soil P status and different fertilizer types affects SOC dynamics. This laboratory incubation assessed how two common P fertilizers, diammonium phosphate (DAP) and single superphosphate (SSP), affected microbial activity and C immobilization in the zone of soil directly around the fertilizer granule (prillosphere) across three contrasting agricultural soils (Inceptisol, Vertisol, Alfisol). Soils were amended with DAP or SSP granules and C turnover assessed with 14C-labeled glycine, malic acid or glucose, alongside unfertilized controls. After three weeks, soil pH, electrical conductivity (EC), Olsen-P and microbial C use efficiency (CUE) were measured. DAP increased pH in the Inceptisol (acidic soil), while SSP decreased pH in all soils. Both fertilizers increased EC and Olsen-P, but SSP enhanced Olsen-P more than DAP. Cumulative 14CO2 emissions were 19–20 % higher with P fertilizers compared to the control, with DAP stimulating faster initial C mineralization rates than SSP, except in the Alfisol. P addition reduced microbial CUE by 23–34 % across all soils and substrates versus the unfertilized control. We ascribe this reduction in CUE to an alleviation of nutrient limitation or a fertilizer-induced osmotic stress. The co-addition of N either in DAP or glycine did not alter the P-induced CUE response suggesting that P was more important than N in regulating microbial CUE in these soils. We conclude that P fertilization increased short-term C turnover and may lead to reduced C storage in soil, however, further long-term (>1 year) research is needed to identify optimum P management strategies to minimize C losses in agricultural soils.

Strategic management of nano-fertilizers for sustainable rice yield, grain quality, and soil health

Conventional fertilizers, although widely available, are relatively low in nutrient use efficiency and cause serious environmental concerns like eutrophication, greenhouse gas (GHG) emissions, nitrate poisoning, and soil pollution. With this in mind, a randomized block design (RBD) experiment was conducted in an experimental field taking 10 treatments and 3 replications to investigate the effects of integrated approaches of nano-formulated DAP fertilizer applications on rice growth, yield, and nutrient use efficiency over conventional approaches. The result revealed that plant height, panicle length, number of tillers hill−1, total number of grain panicle−1, and root length were maximum in T10 treatment (50% of the soil test recommended doses (STD) for N and P + seedling root dipping (SRD) with nano DAP at 5 mL L−1 + twice foliar sprays (FS) with nano DAP at 4 mL L−1 at 25 and 45 DAT (date after transplanting). The highest mean grain yields (4.12 and 4.05 Mg ha−1) and nutrient uptake were recorded in the T2 treatment (100% STD), but this was at par with T10 treatment. The highest benefit–cost ratio (2.26) was recorded in T10, which was 3.5% higher than T2. N and P agronomic use efficiency (AUE) ranged from 7.5% to 31.5% and 15% to 63%, and recovery efficiency (RE) ranged from 30% to 94.2% and 11.2% to 90.4%. The highest nutrient use efficiency was recorded with T10, followed by T9, and lowest in T4. Post-harvest soil pH and available N and P were significantly highest in T10. Soil MBC, MBN, MBP, urease, and phosphatase activity were found significantly higher in T2, followed by T10. The integrated application of 50% STD for N and P + SRD with nano DAP at 5 mL L-1 + twice FS with nano DAP at 4 mL L−1 at 25 and 45 DAT application can be a suitable substitute for conventional DAP and urea for rice in climate-smart agriculture as it possibly reduces environmental pollution while undisturbing crop yield over the 100% STD.

Cyclodextrin grafted chitosan thermosensitive hydrogel using dual gelling agents: Drug delivery and antibacterial materials

In this paper, three kinds of cyclodextrin-grafted-chitosan (CD-g-CS) were synthesized from chitosan (CS) and β-cyclodextrin (β-CD) with different ratios. And a series of hydrogel with good temperature sensitivity and injectability were prepared by using sodium glycerophosphate (GP) and ammonium hydrogen phosphate (AHP) as dual gelling agents. The gelation formation time of hydrogel was short, and the shortest time was 0.75 min. The FTIR spectrum and 1H-NMR spectrum showed the structure of the compounds and intermolecular interactions. The molecular docking technique probed the encapsulation mechanism of the drug with β-CD. The SEM results showed that the hydrogel had a highly interconnected three-dimensional spatial structure. The swelling ratio of hydrogel was not less than 150 % within 1 h and the degradation rate of hydrogel was not less than 75 % within 14 days. The in vitro drug release results showed that the hydrogel had optimal sustained release effect, and the cumulative release ratio was 58.3 % in 34 h. The release kinetics analysis exhibited that the hydrogel conformed to the Riter-Peppas model. The hemocompatibility test and cytotoxicity test proved that the hydrogel had good biocompatibility and biosafety. The antibacterial experiments showed that the hydrogel could inhibit the biological activity of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Therefore, the CD-g-CS/GP-AHP hydrogel has a broad application prospect in the biological fields of drug delivery and antibacterial materials.

Nanobiochar-Coating Regulates N and P Release from DAP Fertilizer in Soil and Improves Maize Crop Productivity

Nanobiochar-Coating Regulates N and P Release from DAP Fertilizer in Soil and Improves Maize Crop Productivity

Developing inorganic coatings with nano-TiO2 for heritage concrete and assessing their self-cleaning performance by a new laboratory test

Heritage concrete and cement mortars urgently need preventive treatments which slow down their deterioration, allow to avoid extensive demolition and reconstruction, and preserve the aesthetic significance of texturized surfaces. In this paper new inorganic treatments were developed, which combine the self-cleaning behaviour of nano-TiO2 and the beneficial effect of inorganic consolidants. In a preliminary phase, two consolidants were investigated for the incorporation of titania nanoparticles, namely diammonium phosphate and ethyl silicate (TEOS), and the latter one was selected as the most promising one. In the second phase, combined treatments with TEOS and titania nanoparticles were developed and applied by different techniques to cement mortars manufactured to mimic historic substrates, providing a novel and valuable solution for heritage concrete protection that is unprecedented in the literature. Besides evaluating the photoactivity of the treatments in terms of methylene blue discolouration, a novel test was developed in this study to assess in a more realistic way the actual ability of the treatments to boost the removal of soiling by rain. The combination of TEOS and nano-TiO2 into a single treatment has the potential to slow down carbonation and chloride diffusion, to help the removal of soiling and to provide the substrates with antimicrobial activity, hence it can be considered highly innovative. The results also showed that more realistic laboratory assessment procedures are necessary to predict the actual effectiveness of the treatments when applied to real substrates and exposed to real outdoor conditions. The novel test proposed and applied in this study may serve as a basis for the development of a new procedure of assessment of self-cleaning ability.