Phosphorus Content Research Articles

Phosphate fertilization to improve yield and chemical composition of banana ‘BRS SCS Belluna’ fruit

Phosphate fertilization improves banana yields, but due to the physiological effects of phosphorus on plants, it can also be used to improve the physical and chemical characteristics of the fruits, which can contribute to increasing the processing of green bananas and reducing losses in the production chain. Herein, the productivity of bunches and fruit, the biometric analysis of the fruit, dry matter content, and the chemical composition of immature fruit were evaluated when the cultivar BRS SCS Belluna (AAA) was grown under different levels of phosphate fertilization for two harvest cycles. The results showed that phosphate fertilizer levels interfered with bunch yield and fruit mass in both cycles, leading to yield gains of 44.3% (1st cycle) and 84.0% (2nd cycle) in bunches and 51.8% (1st cycle) and 81.9% (2nd cycle) in fruits. Fertilization promoted gains of up to 33.5% in fruit mass and enhanced the resistant starch content in the pulp, leading to an increase of 15.1%. The phosphorus, potassium, and calcium contents in green fruits increased with fertilizer levels in the first cycle, improving nutritional quality. These results have useful applications because they indicate that adequate management of phosphate fertilization can increase the potential of the cultivar for industrial processing of green fruits and the nutritional quality of the derived products.

Evaluating the Effects of Cigarette Smoking and Heated Tobacco Products on Hard Dental Tissues: A Comparative Histological and Colorimetric Analysis.

This study aimed to evaluate and compare the impact of cigarette smoking (CS) and heated tobacco (HT) on the alteration of color and ultrastructural characteristics of human enamel and cementum. According to tobacco companies, a less harmful substitute for CS is HT products. Nevertheless, comprehensive research on the effects of HT on tooth structures has been lacking. This study aimed to evaluate and compare the impact of CS and HT on the alteration of color and ultrastructural characteristics of human enamel and cementum. Thirty intact and noncarious human maxillary premolars extracted for orthodontic treatment purposes, previously disinfected, were used in the study. The specimens were randomly separated into six groups (n = 10), as follows: Group 1: enamel without smoking exposure; Group 2: enamel exposed to CS; Group 3: enamel exposed to HT; Group 4: cementum without smoking exposure; Group 5: cementum exposed to CS; and Group 6: cementum exposed to HT. The measurement of color change was conducted using a spectrophotometer. The surface alterations and mineral composition of enamel and cementum were evaluated using scanning electron microscopy and energy-dispersive X-ray spectroscopy. ANOVA test followed by Tukey's post hoc test was used to determine significant differences between groups. Results showed that CS had a more pronounced effect on enamel and cementum color changes than HT. The impact of CS and HT on color changes was more evident in cementum than in enamel. Surface morphology of enamel and cementum showed alterations in histology following exposure to both smoking types. Moreover, the mineral content experienced a significant reduction after using CS and HT. The reduction in calcium content after CS and HT exposure was similar. However, HT led to a significant decrease in the phosphorus content of enamel when compared with CS. At the same time, CS exposure in cementum resulted in a more significant reduction in Ca/P ratio than HT. Although HT may appear to present a lower danger to hard dental tissues than CS, it is not entirely harmless. CS results in more color changes on the enamel and cementum of teeth. Both smoking methods affected the mineral content of teeth, with CS having a significant effect on the roots, while HT significantly affected the crowns' mineral composition.

Nutritious and Nutritional Values of « milks » from Blighia sapida (K.D. Koenig) Arils and Soya Beans (Glycine Max)

African nations are not self-sufficient in milk and related solutions. So, some fruit, which get nutritious and nutritional value, can be valorized. The aim of this work was to evaluate the effect of Blighia sapida arils "milk" consumption on growth of rats and on the induction of diarrheoa compared to that of soya been "milk". For that, arils "milk" were produced using 0.5 kilogram of arils/ liter of distilled water and soya bean "milk" was brought. The two "milks" were freeze-dried and the powders were used to prepare concentrations (0, 200, 400 and 800 mg / kg of body weight) to be administered every three days to seven groups of rats during 15 days. Every three days, body weight was taken, faeces were collected and their moisture content was determined. Analysis showed that both powders are nutritiously rich. Soya bean "milk" powder protein and lipids content are higher than that of arils "milk" powder but it carbohydrates, calcium and phosphorus content are lower. Both "milks" are in favor of gain weight and they do not induce diarrhoea. So, we can envisage much production of it for human consumption.

The role of land use on phosphorus release and longitudinal changes of pollution in an agricultural watershed, Bostankar river, Iran

Phosphorus in surface waters accelerate algal growth and eutrophication, considerably influencing water quality. Spatiotemporal changes in phosphorus concentration are crucial for environmental issues. We aimed to study the temporal and spatial changes in water quality in a river and in a drainage water system considering different land uses. To this aim, 15 water samples were collected from the origin of the river to the estuary, in the Bostankar River watershed (N-Iran), during spring and winter. Further samples were collected from agricultural drainage water in rice fields, tea, flower, orange as well as kiwi gardens, and forests during spring and winter. EC, pH, TDS, and three forms of phosphorus (total, particulate, and soluble) were measured in the water samples. The results showed that water quality changes in agricultural drainage water were time-dependent; the average total phosphorus was 0.4 mg l-1 lower in the spring than in the winter. The highest phosphorus concentration (1.29 mg l-1) occurred in the winter in the drainage water of the orange gardens. Temporal and spatial changes of the river showed that water quality reduced from the river upstream (jungles and grasslands) towards the downstream (different agricultural land uses), and the amount of phosphorus increased from 0.25 to 0.5 mg l− 1. The TDS increased from 60 to 220 mg l− 1 in the river in the winter. Finally, the results showed that human activities were the main factor in river water quality reduction due to agricultural activities.

Smart watering of ornamental plants: exploring the potential of decision trees in precision agriculture based on IoT

Ornamental plant farmers face various challenges due to climate change and environmental stress that significantly affect plant health and growth. This research overcomes these challenges by developing an intelligent watering system that uses internet of things (IoT) technology and decision trees (DTs) algorithms to optimize the use of planting land by ensuring plants grow in the most optimal conditions, both in terms of water and nutrients and increase land productivity. The system is built by integrating various sensors to monitor soil moisture, air humidity, temperature, and light intensity in real-time. The collected data is used to automate watering schedules and provide recommendations on suitable plant species based on the soil nutrient content of nitrogen (N), phosphorus (P), and potassium (K). The use of the DTs algorithm helps in analyzing the data from the sensors and providing recommendations on the most suitable plants for the land. The smart watering system was tested in three zones, each simulating a different watering scenario, and successfully maintained optimal conditions for plant growth in each zone. The machine learning (ML) model with the DTs algorithm can predict the right type of ornamental plants based on the existing land conditions in three watering zones, with an accuracy of 89 %, 90 %, and 91 %, respectively. Furthermore, farmers can follow these recommendations to minimize damage and death of plants so that the level of productivity on the land becomes optimal.

Impact of Zinc and Silica Solubilizing Bacterial Consortia on Soil Nutrient Availability and Direct Sown Paddy

Effect of zinc and silica solubilizing bacteria and their consortia on paddy was studied under field conditions at Agricultural Research Station, Janagamaheswarapuram, Andhra Pradesh. Thirteen treatments were assessed for availability of nutrients viz., Nitrogen, Phosphorus, Potassium, Zinc and Silica in soil and concentration of Nitrogen, Phosphorus and Potassium in plant at 45, 90 and 120 days after sowing (DAS).Significantly highest nitrogen (198.9, 262.3 and 240.2 kg ha-1), available phosphorus (36.7, 64.7 and 40.6 kg ha-1), potassium (221.4, 349.6 and 263.5 kg ha-1), zinc (0.86, 1.14 and 0.98 ppm) and silica (66.8, 98.9 and 84.8 ppm) were recorded in T13 (RDF + ZnKJJ-4 & ZnPGG-1 + SiKPP-1 & SiPYY-3) at 45, 90 and 120DAS, respectively. In the plant, nitrogen (0.89, 1.10 and 0.98 %), phosphorus (0.46, 0.67 and 0.58 %) and potassium (1.87, 2.29 and 1.98 %) were significantly highest at 45, 90 and 120DAS, respectively, in T13. There was increase in the available nutrient content upto90 DAS which then decreased at 120DAS. It is inferred that consortia of two zinc solubilizing and two silica solubilizing microorganisms (T13) is useful for increased availability of Nitrogen, Phosphorus, Potassium, Zinc and Silica in soil and increased uptake of NPK by rice plant, which in turn reduce exogenous chemical fertilizers.

Deciphering integrated soil potential ecological and human health risks attributable to industrial effluents irrigation and wheat consumption.

Iron-steel (IS) and textile (T) are among the major polluting industries worldwide which generate large quantities of effluents containing potentially toxic metals (PTMs). Irrigation application of these effluents due to freshwater shortage is a common practice in developing countries. The current research endeavors to investigate potentially toxic metals in IS and T effluents, contamination status and ecological risk assessment of irrigated soils, PTMs accumulation in grains of diverse wheat germplasm and human health risk appraisal. Soil irrigation with effluents significantly enhanced soil nitrate-nitrogen (T, 285.86mg/kg; IS, 539.70mg/kg), phosphorus (T, 8.35mg/kg; IS, 11.44mg/kg), organic matter (T, 6.05%; IS, 4.48%) and PTMs contents compared to control (C). Enrichment factor and geo-accumulation index revealed substantial contamination trend of PTMs in IS (Ni > Cr > Co > Cd > Pb > Zn > Mn) and T (Co > Cd > Ni > Cu > Cr) treated soils. Potential ecological risk index and modified potential ecological risk index placed T (very high risk) and IS (considerable risk) irrigated soils in respective categories, with highest risk contributions from Cd, Co and Ni. The interactive effects for PTMs accumulation in grains of 30 wheat genotypes were recorded significant. Average PTMs accumulation in grains for the three irrigation treatments was IS > T > C for Zn, Cr, Mn, Pb, Fe, Ni and T > IS > C for Co, Cd, Cu. Multivariate statistical analysis ( principal component analyses) was used to identify the wheat genotypes with higher or lower grain PTMs accumulative potential on effluent irrigation. The genotypes with a lower grain PTMs accumulation and human health risks are recommended for cultivation in agro-systems receiving IS and T effluents, in order to safeguard wheat crop and human health.

Species-Dependent Response of Brassica chinensis L. to Elevated CO2 Gradients Influences Uptake and Utilization of Soil Nitrogen, Phosphorus and Potassium

Employing elevated CO2 (eCO2), similar to increasing atmospheric CO2 in a greenhouse, is a common practice used to increase vegetable crop yields. However, the responses of nutrient availability, nutrient uptake and use efficiency in leafy vegetables to eCO2 remain largely unknown. The plant biomass production, nitrogen (N), phosphorus (P) and potassium (K) contents, nutrient uptake, and soil enzymatic activities of three Brassica chinensis varieties of ‘Longpangqing’, ‘Heimeiren’ and ‘Qingjiangbai’ were thus assessed under ambient CO2 (C0, 420/470 ppm, day/night) and eCO2 (C1, C0 + 33.3%C0; C2, C0 + 66.7%C0; and C3, C0 + 100%C0) for 4 months. Biomass production was significantly enhanced in these three tested B. chinensis varieties along with eCO2 gradients, with the highest biomass production under C3. Moreover, the eCO2 significantly increased plant N and K uptake, P and K use efficiency, soil saccharase, urease, and phosphatase activities, but decreased plant P content, soil available N and K, and catalase activity. Under eCO2, ‘Qingjiangbai’ exhibited higher biomass production and P and K uptake, without a decrease in soil available N and P. Consequently, more external fertilizer supplementation (especially N, followed by K) is required to maintain or promote Brassica chinensis yield under eCO2, while these management strategies must be carefully considered for different crop varieties.

Polyphosphate-kinase-1 dependent polyphosphate hyperaccumulation for acclimation to nutrient loss in the cyanobacterium, Synechocystis sp. PCC 6803

Polyphosphate is prevalent in living organisms. To obtain insights into polyphosphate synthesis and its physiological significance in cyanobacteria, we characterize sll0290, a homolog of the polyphosphate-kinase-1 gene, in the freshwater cyanobacterium Synechocystis sp. PCC 6803. The Sll0290 protein structure reveals characteristics of Ppk1. A Synechocystis sll0290 disruptant and sll0290-overexpressing Escherichia coli transformant demonstrated loss and gain of polyphosphate synthesis ability, respectively. Accordingly, sll0290 is identified as ppk1. The disruptant (Δppk1) grows normally with aeration of ordinary air (0.04% CO2), consistent with its photosynthesis comparable to the wild type level, which contrasts with a previously reported high-CO2 (5%) requirement for Δppk1 in an alkaline hot spring cyanobacterium, Synechococcus OS-B’. Synechocystis Δppk1 is defective in polyphosphate hyperaccumulation and survival competence at the stationary phase, and also under sulfur-starvation conditions, implying that sulfur limitation is one of the triggers to induce polyphosphate hyperaccumulation in stationary cells. Furthermore, Δppk1 is defective in the enhancement of total phosphorus contents under sulfur-starvation conditions, a phenomenon that is only partially explained by polyphosphate hyperaccumulation. This study therefore demonstrates that in Synechocystis, ppk1 is not essential for low-CO2 acclimation but plays a crucial role in dynamic P-metabolic regulation, including polyP hyperaccumulation, to maintain physiological fitness under sulfur-starvation conditions.

Effects of mixed land use on urban stormwater quality under different rainfall event types

The joint effect of mixed land uses and rainfall event types was studied using a two-year field monitoring program in four urban catchments in Calgary, Alberta, Canada. Event mean concentration (EMC) and event pollutant load (EPL) were employed to evaluate the total suspended sediment (TSS), nitrogen and phosphorus. The correlation analysis showed that most nitrogen and phosphorus components (except for NO2−/NO3− and TDP) predominantly exist in particulate form in the study areas. The correlation for EPL was notably stronger than EMC, which can be attributed to varying rainfall characteristics. The differences in EMCs and EPLs of TSS, nitrogen and phosphorus across catchments indicated that the complexity and spatial distribution of mixed land use can influence the generation and transportation of pollutants in urban runoff. The impacts of rainfall characteristics on stormwater quality are integrated rather than driven by a single rainfall characteristic. Brief but intense events tended to elevate TSS, nitrogen and phosphorus concentrations, especially in complex land-use catchments. Events with long antecedent dry days and short duration also resulted in increased pollutant concentrations, while events with long duration and low intensity could result in higher EPLs. The effect of mixed land use on water quality can vary depending on rainfall event types. Seasonal variations were found in EMC and EPL of TSS, nitrogen and phosphorus, with higher values in the spring and summer than the fall. Seasonal variations are mainly influenced by rainfall conditions, temperature and anthropogenic activities (e.g. lawn fertilization and de-icing with sands). MLR considering rainfall characteristics is an effective method for predicting stormwater quality within a single catchment. Considering complexity and spatial distribution of mixed land use can improve the accuracy of the harmonized MLR model. This research provided insights into understanding the complexities introduced by mixed land use and rainfall event types in urban stormwater quality.

Calcium fertilization on the Phalaenopsis ssp. cultivation (Orchidaceae)

The cultivation efficiency and quality improvement of Phalaenopsis sp. production through mineral nutrition has been widely studied. The objective of this study was to evaluate the effects of different concentrations of calcium (Ca) in the nutrient solution on the growth, nutrient uptake, and overall health of Phalaenopsis sp. Seedlings obtained from in vitro propagation at 6 months of age were fed biweekly with a nutrient solution suggested by Hoagland and Arnon with modified Ca concentrations of 0 mM, 1.25 mM, 2.5 mM, 5 mM, 7.5 mM, and 10 mM. After 24 months, characteristics such as number of leaves, width and length of the largest leaf, total leaf area, dry mass of leaves and roots, leaf texture, and number and dry mass of flowers were evaluated. Macronutrient content was determined from leaf dry mass. Substrate pH and electrical conductivity were also measured. Increasing Ca concentrations up to 6.25 mM improved leaf length, total leaf area, number of flowers and flower dry mass. Leaf texture and electrical conductivity of the substrate increased up to a Ca concentration of about 2.5 mM. Leaf nitrogen and phosphorus contents increased with higher Ca concentrations. Optimal Ca fertilization at 6.25 mM had positive effects on both vegetative and reproductive growth, with no visual symptoms of Ca deficiency observed during vegetative development. These results emphasize the importance of precise and tailored nutrient management, not only to avoid hidden deficiencies, but also to maximize the quality and commercial value of Phalaenopsis sp. plants.

Addition of Milkfish (Chanos chanos) Bone Meal into the Churros Product

Milkfish production in Karawang in 2016 was 19,166 tonnes which resulted in high bone waste. Therefore, there is a need for innovation in the utilisation of milkfish bone meal as a nutritional enhancer for churros products. The purpose of this study was to determine the process flow of making churros with the addition of milkfish bone meal, determine the quality of hedonic test, determine the chemical quality of microbiological levels, determine the appropriate packaging and business analysis of churros. Churros were made in four treatments with formulations F0 without the addition of milkfish bone meal, F1 2.5%, F2 5%, and F3 7.5%. The results showed that hedonic testing of churros with F3 was the best formulation with a moisture content of 5.73%, the highest moisture content was 37.9% in F0. Ash content in F0 0.56%, F1 2.26%, F2 2.83%, F3 4.13. The calcium content in sample F0 was 10.8.99 mg/100g, F3 1470.71 mg/100g. The results of phosphorus testing on churros, sample F0 as much as 982.2 mg / kg, while in F3 has a phosphorus content of 6,516.75 mg / kg. The ALT test results on F0 and F3 churros have met the SNI 8372: 2018 standard with a value of 2.5 x 103 colonies/gram in all samples. The results of the business analysis of milkfish bone meal churros are said to be feasible with a selling price of 45,000 per package.

Combined measures in lake restoration – A powerful approach as exemplified from Lake Groote Melanen (the Netherlands)

Controlling lake eutrophication is a challenge. A case-specific diagnostics driven approach is recommended that will guide to a suite of measures most promising in restoration of eutrophic lakes as exemplified by the case of the shallow lake Groote Melanen, The Netherlands. A lake system analysis identified external and internal nutrient load as main reasons for poor water quality and reoccurring cyanobacterial blooms in the lake. Based on this analysis, a package of restoration measures was implemented between January 2015 and May 2016. These measures included fish removal, dredging, capping of peat rich sediment with sand and an active barrier (lanthanum-modified bentonite), diversion of two inlet streams, reconstruction of banks, and planting macrophytes. Dredging and sand capping caused temporarily elevated turbidity and suspended solids concentrations, while addition of the lanthanum-modified clay caused a temporary exceedance of the Dutch La standard for freshwaters. Diversion of inflow streams caused 35 % less water inflow and larger water level fluctuations, but the lake remained water transporting with strongly improved water quality as was revealed by comparing five years pre-intervention water quality data with five years’ post-intervention data. Total phosphorus concentration in the water column was reduced by 93 % from 0.47 mg P l-1 before the intervention to 0.03 mg P l-1 after the intervention, total nitrogen by 66 % from 1.27 to 0.21 mg N l-1, total chlorophyll-a by 75 % from 68 to 16 µg l-1, cyanobacteria chlorophyll-a by 88 % from 32 to 4 µg l-1. Turbidity had declined by 58 % from 23.5 FTU to on average 9.9 FTU. No cyanobacteria blooms were recorded over the entire post-intervention monitoring period (2016–2021). Submerged macrophytes increased from complete absence before intervention to around 10 %–15 % coverage after intervention. Repeated fish removal lowered the fish stock to below 100 kg ha-1 with 12 % of bream and carp remaining. Hence, the package of cohesive measures that was based on a thorough diagnosis resulted in rapidly, strongly and enduringly improved water quality. This case provides evidence for the power of combining measures in restoring eutrophic lakes.

Vermicompost Effects on Soil Chemistry and Biology: Correlations with Basil's (Ocimum basilicum L.) Total Phenolic Content and Phenological Traits

This study explores the effects of vermicompost on the chemical and biological properties of soils, their nutrient content, and the impact on the growth and phenolic content of basil (Ocimum basilicum L.). Using a controlled experimental setup, we tested five dosages of vermicompost (0%, 4%, 12%, 20%, and 24%) to evaluate their influence on soil biological activity by measuring basal respiration (CO2-C), microbial biomass C (MBC-C), and dehydrogenase enzyme activity (DHA) as well as on basil's growth parameters and total phenolic content (TPC). The results show that vermicompost addition to soil enhanced soil microbial activity in direct proportion to the dose of vermicompost. The application of lower dosages of vermicompost (4% and 12%) significantly enhanced both fresh and dry weights, suggesting an improvement in nutrient uptake and soil structure, which likely facilitated better root growth and nutrient absorption. However, higher dosages (20% and 24%) were associated with reduced growth metrics, likely due to nutrient overload or salt stress. Notably, the highest vermicompost concentration (24%) led to a substantial increase in total phenolic content (TPC) in basil leaves, correlating with decreased growth metrics. This response indicates the plant's defensive mechanism against oxidative stress caused by excess nutrients or salinity from the vermicompost. A multiple regression analysis following a correlation analysis also revealed an inversely proportional relationship between phosphorus content in the soil and total phenolic content in basil leaves. Our findings illustrate that while moderate vermicompost dosages optimize plant growth and health, higher concentrations can strategically enhance phenolic content due to nutrient overload or salt-induced stress. These results offer critical insights for tailoring organic amendment applications to balance plant growth and biochemical properties in agricultural practices.

Soil nutrients and enzyme activities based on millet continuous cropping obstacles

In order to evaluate the effects of continuous cropping of millet on soil nutrients and soil enzyme activities, the present study was based on four treatments of 2 years of continuous cropping (T1), 3 years of continuous cropping (T2), 4 years of continuous cropping (T3) and rotational cropping (CK), based on 4 years of no fertilizer positioning experiments, and the soil nutrients, soil enzyme activities and millets yields were determined, respectively. The results showed that with the increase of continuous cropping years, the millet yield decreased and was significantly lower than that of rotating with legume crops, and compared with CK, the yields of T1, T2 and T3 treatments were reduced by 8.92%, 13.73% and 37.60%, respectively; the soil nitrogen and phosphorus contents were reduced, the quick-acting potassium content did not change obviously, and the soil pH was increased; Soil urease, alkaline phosphatase, sucrase and catalase activities generally showed a decreasing trend and the decrease was more significant with the increase in the number of years of continuous cropping. Therefore, in order to maintain the soil fertility and increase the millet yield, it is necessary to practice crop rotation and stubble reversal between millets and leguminous crops such as kidney beans, and to apply certain fertilizers.

Soil pH and organic matter: Key edaphic factors in sustaining optimum yield and quality of pomelo fruit

Identifying the soil properties associated with crop yield and quality variation is crucial for developing sustainable agronomic strategies. However, such information on pomelo production is scarce. Hence, forty independent sites in the primary pomelo production areas of Pinghe County were selected to investigate the influence of soil properties on pomelo yield and quality, and to provide reference for future soil management strategies. The results showed positive correlations between pomelo yield and soil pH, along with exchangeable calcium and magnesium, but this comes at the expense of fruit flavor quality. Meanwhile, soil organic matter positively influenced fruit flavor quality. Furthermore, a significant positive effect on fruit nutritional quality was noted across various soil properties, except for organic matter and available phosphorus concentration. A random forest model was used to predict pomelo yield, flavor quality, and nutritional quality based on soil properties and yielded R2 values of 0.50, 0.60, and 0.50, respectively. Partial least squares regression and structural equation modeling identified soil pH and organic matter as pivotal pomelo yield and quality determinants. The categorization of samples into four groups based on differences in pH and organic matter highlighted that integrating soil acidification remediation with organic matter increased is essential for sustainable pomelo production. Overall, this study offers comprehensive insights into the effects of holistic soil management on achieving both high yield and quality in pomelo cultivation. Furthermore, these findings serve as valuable reference for advancing sustainable production practices across large fruit types beyond the pomelo.

Enterobacter cloacae Rs-2 inoculum replaces fertiliser application by half in the field and modifies microbial community structure

Using microbial inoculant partial substitution synthetic fertilizer is a new type of environmentally friendly way to significantly improve the corps production and ecological environment. The effects of supplementing Enterobacter cloacae Rs-2 with synthetic fertilizer on the maize growth and soil microbial community diversity in field were investigated in this paper. The optimal fermentation conditions were determined as 5 g·L−1 industrial glucose, 30 g·L−1 industrial peptone, 1 g·L−1 MgSO4 and 0.5 g·L−1 KCl firstly. Field experiment showed that the fresh weight of shoots and roots was increased by 39.69% and 32.46% when half synthetic fertilizer was replaced by microbial inoculant. The soil physical and chemical properties were also greatly improved, especially the contents of available phosphorus, water-soluble calcium and alkali-hydrolyzed nitrogen were significantly increased in T4 (Rs-2 and half chemical fertilizer) and full chemical fertilizer treatment. This result was accompanied by increased the relative abundance of genes related to phospholipid metabolism, phosphotransferase system (PTS) and oxidative phosphorylation metabolism, indicating that Rs-2 may play an important role in the transformation and utilization of phosphorus in soil. The richness, dominance of Proteobacteria, Enterobacteriaceae in the microbial communities were further improved when the microbial inoculant applied. Function prediction PICRUSt analysis indicated that amines and amino acids were the most representative of the total carbon source utilization by the soil microbial communities. It was concluded that the application of 50% of the synthetic fertilizer supplemented with 30 mL microbial inoculant enhanced both the functional diversity of soil microbial communities and maize yield.

Dynamics of sediment phosphorus in the middle and lower stretch of River Ganga, India: insight into concentration, fractionation, and environmental risk assessment of phosphorus.

Despite continuous efforts, eutrophication is still occurring in freshwater and phosphorus (P) is the most important nutrients that drive the eutrophication in rivers and streams. However, little information is availableabout the distribution of P fractions in river sediment. Here, the sequential extraction approach was used to evaluate the sediment P fractionation and its content in the anthropogenically damaged river Ganga, India. Different sedimentary P fractionsviz. exchangeable (Ex-P), aluminum bound (Al-P), iron bound (Fe-P), calcium bound (Ca-P), and organically bound phosphorus (Org-P), were quantified. Significantly higher level of total P was recorded inpre-monsoonseason (438.5 ± 95.8mg/kg), than other [winter (345.7 ± 110.6mg/kg),post-monsoon(319.2 ± 136.3mg/kg), andmonsoon(288.6 ± 77.3mg/kg)] seasons. Different P fractionssuch as Ex-P, Al-P, Fe-P, Ca-P and Org-P varied from 2.88-12.8mg/kg, 7.64-98.8mg/kg, 32.2-179.2mg/kg, 51.97-286.1mg/kg and 9.3-143.7mg/kg, respectively, which correspondingly represented 0.5-10.54%, 3.41-20.18%, 17.27-37.82%, 37.35-60.2%, 4.15-25.88% of the Total P with a rank order of P-fractions was Ca-P > Fe-P > Org-P > Al-P > Ex-P. Bio-available P contributes a considerable portion (37.9-46.0%) of total P which may increase the eutrophication to overlying water. Results demonstrate that inorganic P species control the P bio-availability in both time and space. However, an estimated phosphorus pollution index based on sediment total P content showed no ecological risk of phosphorus to Ganga River sediment.

Eurasian watermilfoil (Myriophyllum spicatum) alters its root topology but conserves its root branching in response to freshwater cultural eutrophication

Cultural eutrophication is the main cause of the decline of submerged plants in freshwater ecosystems. While many studies have focused on the nutrient uptake by the roots of these plants, less attention has been given to the effects of eutrophication on root structure. We designed a mesocosm experiment with Eurasian watermilfoil (Myriophyllum spicatum), a submerged plant indigenous to the Eurasian continent. The responses of plant functional traits, including growth traits, morphological traits and root topological indices, to different nitrogen (N) and phosphorus (P) concentrations were elucidated. We found that high P concentrations suppressed all the morphological traits and reduced the root topological traits, whereas N concentrations had a comparatively minor effect. Although the root branching of M. spicatum did not change, its root topology became more dichotomous with fewer exterior root links being formed in nutrient-rich habitats, and the root form changed from deep and thin to shallow and dense with increasing P concentrations. The root nutrient absorption ability of M. spicatum may decrease with cultural eutrophication, and this change most likely reduces its anchoring ability and increases its sensitivity to dislodge from the sediment if disturbed by hydraulic forces.

Preparation of phosphorylated rice husk for cadmium adsorption: Crucial role of phosphonyl group

Rice husk is a locally available biomass for preparation of adsorbents to deal with cadmium (Cd) contamination in paddy system. In this study, phosphorylation of rice husk using H3PO4 and NH4H2PO4 was carried out in the presence of urea at 165℃ to obtain APB-C and NPB-C, respectively. According to the material characterizations, phosphonyl groups were successfully grafted on the rice husk. Both APB-C and NPB-C had high performance for Cd(II) adsorption with the capacities of 146 and 129 mg/g, respectively. The main mechanism of Cd(II) adsorption was ion exchange with NH4+. The adsorption capacity was linearly corelated with phosphorus content (R2 = 0.9997), while the Langmuir constant had high correlation efficient (R2 = 0.996) with phosphonyl group percentage. Further quantum chemical calculation showed higher interaction energy between Cd(II) and phosphonyl group than other groups. These results indicated that phosphonyl group governed Cd(II) adsorption on phosphorylated biomass.