High Levels Of Phosphorus Research Articles

Organic Farming Enhances Diversity and Recruits Beneficial Soil Fungal Groups in Traditional Banana Plantations.

This study investigates the impact of organic (OF) and conventional farming (CF) on soil fungal communities in banana monoculture plantations on Madeira Island. We hypothesized that OF promotes beneficial fungal groups over harmful ones, sustaining soil health. Soil samples were collected from six plantations (three OF and three CF) for ITS amplicon sequencing to assess fungal diversity. Results showed that OF significantly enhanced fungal alpha-diversity (Shannon-Wiener index) and Evenness. The phylum Ascomycota dominated OF systems, while Basidiomycota prevailed in CF. Mortierella, a beneficial genus, was abundant in OF and is observed in CF but was less evident, being the genus Trechispora the most well represented in CF agrosystems. Additionally, OF was associated with higher soil pH and Mg levels, which correlated positively with beneficial fungal groups. Functional analysis revealed that OF promoted saprotrophic fungi, crucial for the decomposition of organic matter and nutrient cycling. However, both systems exhibited low levels of arbuscular mycorrhizal fungi, likely due to high phosphorus levels. These findings suggest that organic practices can enhance soil fungal diversity and health, although attention to nutrient management is critical to further improving soil-plant-fungi interactions.

Soil nutrient stocks in areas where oiticica (Licania rigida Benth) occurs in the paraiba hinterland

The experiment was conducted in the municipalities of Catolé do Rocha and Pombal, both located in the state of Paraíba in northeastern Brazil. The areas are composed of Eutrophic Fluvic Neosols, with low-activity clay and high natural fertility in flat relief. The factorial arrangement was 2x2, with a completely randomized design, with two municipalities: Catolé do Rocha and Pombal and two soil sampling depths: 0–20 cm and 20–40 cm, selecting 10 matrices of oiticica, L. rigida Benth, representing 10 replicates. In the municipality of Catolé, soil analysis revealed higher SB and CTC with lower pH and MOS compared to the municipality of Pombal. The chemical characterization of the soil in the surface layers presents higher concentrations of nutrients than in the subsurface layers, mainly regarding the levels of MO, reflecting in higher levels of phosphorus, sum of bases and cation exchange capacity.

Histone deacetylase 9 promotes osteogenic trans-differentiation of vascular smooth muscle cells via ferroptosis in chronic kidney disease vascular calcification.

Vascular calcification, a common complication of chronic kidney disease (CKD), remains an unmet therapeutic challenge. The trans-differentiation of vascular smooth muscle cells (VSMCs) into osteoblast-like cells is crucial in the pathogenesis of vascular calcification in CKD. Despite ferroptosis promotes vascular calcification in CKD, the upstream or downstream regulatory mechanisms involved remains unclear. In this study, we aimed to investigate the regulatory mechanism involved in ferroptosis in CKD vascular calcification. Transcriptome sequencing revealed a potential relationship between HDAC9 and ferroptosis in CKD vascular calcification. Subsequently, we observed increased expression of HDAC9 in calcified arteries of patients undergoing hemodialysis and in a rat model of CKD. We further demonstrated that knockout of HDAC9 attenuates osteogenic trans-differentiation and ferroptosis in VSMCs stimulated by high calcium and phosphorus. In addition, RSL3 exacerbated ferroptosis and osteogenic trans-differentiation of VSMCs exposed to high levels of calcium and phosphorus, and these effects were suppressed to some extent by HDAC9 knockout. In summary, our findings suggest that HDAC9 promotes VSMCs osteogenic trans-differentiation involving ferroptosis, providing new insights for the therapy of CKD vascular calcification.

Pelatihan Pembuatan Pupuk Hayati di Desa Gondel, Kecamatan Kedungtuban, Kabupaten Blora, Jawa Tengah

The rice productivity in Gondel Village, Kedungtuban District, Blora Regency, Central Java, has declined. Factors such as attacks by plant pests and diseases (OPT), climate change (DPI) impact, and decreasing soil quality are the leading causes of crop failure. This training aims to enhance the understanding and skills of Gondel Village farmers in making biofertilizers and introducing environmentally friendly pest and disease control methods. The activity involved 40 farmers from 8 farmer groups (Gemah Ripah, Margo Mulyo, Ngudi Makmur, Sido Dadi, Sido Makmur, Tambah Makmur, Tambah Rizki, and Sri Mulyo), with each group represented by five farmers. The training methods included analysis of soil chemicals, socialization, practical propagation of Trichoderma sp. on rice media, and biofertilizer production. Pre-test and post-tests were conducted to assess the improvement in farmers' knowledge. Trichoderma biofertilizer was formulated using carriers such as a) Manure and b) Compost, zeolite, and humic acid. The results of the soil chemical properties analysis showed that farmers' use of chemical fertilizers was very intensive, resulting in very high levels of phosphorus (P) and calcium (Ca) and high levels of potassium (K), magnesium (Mg), and cation exchange capacity (KTK). Evaluation results indicated that the training significantly improved the farmers' knowledge of biofertilizer production in theory and practice. However, some farmers still need further guidance on the propagation of the biological agent Trichoderma sp.

Assessment and Delineation of GPS-GIS Based Soil Fertility Maps of Instructional Farm, Malegaon Tehsil Baramati

The present investigation was conducted in the year 2023-24 at division of Soil Science, Dr. Sharadchandra Pawar College of Agriculture, Baramati with an objectives to assess the soil available nutrient status and delineation of GIS based maps of soil available nutrients. Using Arc-GIS 10, Version 10.8, fertility maps of the available macro nutrients were created. The area under the Instructional Farm had soil pH ranged from 7.11 to 8.32, categorized into the slightly alkaline to moderately alkaline categories while the EC varied from 0.21 to 1.99 dSm-1, indicating that most of the soils were non-saline. The soil's organic carbon and calcium carbonate contents ranged from 0.21 to 0.97 per cent and 1.50 to 19.75 per cent and they were classified into low to high and low to very high categories respectively. In the Instructional Farm, the ranges of available nitrogen, phosphorus and potassium content were 85.50 to 360.75, 23.29 to 80.08 and 202.5 to 968.68 kg ha-1 respectively. The Instructional Farm soils had very low to moderate levels of available nitrogen, moderately high to very high levels of available phosphorus and moderately high to very high levels of available potassium. The implementation of GPS-GIS-based techniques for soil sampling represents a significant advancement that will allow researchers and institute officials to track changes in soil fertility over the years. The soil fertility maps created for the Instructional Farm will be invaluable for establishing a scientifically sound fertilization schedule.

Infant Food Flours Made from Local Products to Combat Acute Malnutrition in Children Under 5 Years Old in Côte D’ivoire

In Côte d'Ivoire, recurring stock shortages and difficulties in accessing specialized food products compromise nutritional treatment. This study proposes food formulas of flours composed of locally available products capable of meeting the protein-energy needs of children aged 6 to 59 months diagnosed with moderate acute malnutrition. The methodological approach consists of formulating and determining the physicochemical, nutrient, and functional characteristics of four new formulations (1F, 2F, 3F, 4F, and 5F). The results indicate that the formulated foods have high levels of calcium (215.60-252,29 mg/100g MS), potassium (555,70-789,29 mg/100 g MS), magnesium (261,26-200,63 mg/100g MS), iron (4,86-7,03 mg/100g MS) and phosphorus (392,36 -469,36 mg/100g MS). The fat content varies from 9.66% to 23.86%. The energy value determined for all flours corresponds well to the Codex. The food formulas developed would also be able to meet more than 100% of the daily requirement of vitamins E and B1. The phytate (180.26 - 227.05 mg/100 g) and oxalate (66.00 - 88.00 mg/100 g) contents are low. The presence of phenolic compounds, including flavonoids (7.78-15.44 mg/100 g) and antioxidant activity (31.09-32.84%) would be a significant asset. The levels of deoxynivalenol (62 μg/kg) recorded in flours are below 200 μg/kg recommended for infants and young children. The proposed formulations have high-water absorption capacity (136.15 -252.94%) and high solubility index (56.84 -59.2%). The wettability time ranges from 3.66 ± 0.16 s to 33.71 ± 0.23 s. Flours (1F, 2F, 3F, 5F) have a better absorption capacity for refined palm oil (132 %, 139 %, 121 %; 115 %). The proposed new formulations have nutritional characteristics close to standard data and could therefore be recommended for children aged 6 to 59 months for complementary feeding in the context of the fight against moderate acute malnutrition.

Essential oil phytochemistry and antifungal activity of lemongrass inoculated with arbuscular mycorrhizal fungi under different phosphorous levels

This study aimed to investigate the effect of inoculating Cymbopogon citratus (lemongrass) with arbuscular mycorrhizal fungi (AMF) Rhizophagus clarus and Claroideoglomus etunicatum under low and high phosphorus (P) levels on essential oil (EO) content, composition, and minimum inhibitory concentration (MIC) for four isolates of phytopathogenic fungi of the genus Fusarium. The EO content was obtained by the hydrodistillation process, followed by the evaluation of chemical constituents using gas chromatography coupled to mass spectrometry and MIC by microdilution in broth. The EO content increased 2.5-fold due to high P and inoculation with C. etunicatum compared with uninoculated under low P. Twenty-two compounds were identified in EO. The major components were citronellol, geraniol, citral, neral and geranial. The EO of lemongrass showed a MIC in the four phytopathogenic fungal isolates. Therefore, the secondary metabolites were influenced by P levels and AMF inoculation, increasing EO's content (until 2.5-fold), chemical composition (citral, neral and geranial) and MIC.

Metals geochemistry and ecological risk assessment in lateritic soils and their transfer to tea plants

ABSTRACT Tea plant cultivation has been demonstrated to change the physicochemical properties of soils and metal bioavailability. The present study reported the geochemistry of four selected metals (Fe, Mn, Cr, and Ni) in lateritic soil cores regarding various depths cultivated with tea plants of different ages (3, 6, and 10 years old). The ecological risk and bioaccumulation of these metals in tea plants were also evaluated. The results indicate the acidic property of tea plant cultivation soils (pH < 4.5) and highlight further soil acidification due to long-term cultivation. The soils were strongly affected by farming methods and showed high levels (average from all soil cores) of total organic carbon contents (4.0% w/w), total nitrogen (2806 mg kg−1), and total phosphorus (1730 mg kg−1). We suggest that the selected metals originated naturally, supported by a high percentage in residual fractions from the results of soil sequential extraction (over 95% for Mn, Fe, and Ni and ∼ 90% for Cr). These metals exhibited no ecological risk to the adjacent environment. Mn showed the highest bioavailability, possibly due to the acidic soils and nitrogen fertiliser applications, increasing the release of Mn from soils. Mn also exhibited the highest bioconcentration factor (BCF) among four metals and 2.4 ÷ 6.5-folds higher BCFs in tea leaves than in roots. Despite the dominant content of Fe in soils (average of 20% w/w), Fe indicated lower amounts in tea leaves than Mn (average of 513 mg kg−1 vs 1354 mg kg−1). This could be attributed to the formation of Fe-rich root coatings on the tea plant root surface as a barrier to prevent Fe from translocating to other higher tea plant parts. Ni and Cr, as potentially toxic metals, were found at the lowest contents in tea leaves with low BCFs, indicating consumer safety in terms of exposure by these metals.

A circular economy approach for utilization of tannery fleshing hydrolysate and kitchen wastes into organic fertilizer through enzymatic decomposition

This study presents a sustainable method for converting tannery fleshing waste (FH) into organic fertilizer using enzymatic decomposition with crude protease. After extracting fat from the enzymatic hydrolysis, the enzyme-rich residue was mixed with dried kitchen waste (KW) and allowed to decompose for 45 days, producing nutrient-rich fertilizer. FT-IR spectroscopy confirmed the presence of important functional groups, including hydroxyl, aliphatic hydrocarbons, esters, and amide-I linkages. The organic fertilizers had higher nutrient content, with nitrogen (1.08-1.67%), phosphorus (0.78–0.98 %), potassium (0.1–0.76 %), and magnesium (239–259.5 ppm) which is higher than commercial fertilizers. FESEM-EDX analysis revealed a dense, porous structure with a high surface concentration of calcium, which enhances nutrient release in the soil. Dissolution tests showed that nutrients from the organic fertilizer were released gradually over 36 hours, whereas commercial NPK fertilizers released nutrients within 150 minutes in simulated soil-water conditions. Field trials with a Randomized Complete Block Design (RCBD) demonstrated improved growth in Malabar spinach, particularly with fertilizer sample S-5, which had an optimal flesh to kitchen waste (FH to KW) ratio of 1:10. Although S-5 had a lower nitrogen content (1.08 %), it contained higher levels of phosphorus (0.98 %), potassium (0.765 %), and magnesium (259.5 ppm), contributing to enhanced plant growth. The organic fertilizer resulted in a shoot length of 38.8 ± 2.0 cm, root length of 16.33 cm, 31 ± 3 leaves, and 95.12 % dry matter of the plant. Heavy metal analysis of the plant confirmed that levels of chromium (Cr), iron (Fe), nickel (Ni), cadmium (Cd), copper (Cu), and lead (Pb) were within WHO safety limits. Phytotoxicity tests of the fertilizer also showed no negative impact on Malabar spinach seed germination.

Impact of phosphorus fertilization on the yield and quality of various Alfalfa (Medicago sativa L.) varieties in light chestnut soils

This study investigates the impact of phosphorus fertilization on the yield and quality of various alfalfa (Medicago sativa L.) varieties grown in light chestnut soils. Conducted over a three-year period from 2013 to 2015, the research was carried out in the Karasay district of the Almaty region under irrigated conditions. The experiment included six alfalfa varieties: NS Alfa, VS Banat, Mediana, Nera, Niagara, and Kokoray. Four phosphorus treatments were applied: control (no phosphorus), 60 kg/ha (P60), 90 kg/ha (P90), and 120 kg/ha (P120), using double superphosphate as the phosphorus source. The results demonstrated that phosphorus fertilization significantly enhanced both the yield and quality of alfalfa. Across all varieties, the highest yield was observed with the application of 120 kg/ha phosphorus. For instance, NS Alfa's yield increased from 283.3 c/ha in the control to 349.7 c/ha with P120, reflecting a 23% increase. Similarly, VS Banat and Mediana exhibited yield increases of 23% and 25%, respectively, at the highest phosphorus level. The study also revealed improvements in the nutritional quality of alfalfa hay. Crude protein content increased from 20.3% to 22.0% in NS Alfa, while digestible protein content rose from 11.20% to 12.40%. Other quality parameters, including fat and carotene content, also improved significantly with higher phosphorus levels. Moreover, the availability of nitrate nitrogen and mobile phosphorus in the soil increased progressively with higher phosphorus application rates, contributing to better nutrient uptake and overall plant health. This research underscores the importance of phosphorus fertilization in maximizing alfalfa yield and quality. The findings suggest that the optimal phosphorus application rate for enhancing alfalfa production in light chestnut soils is 120 kg/ha, providing valuable insights for sustainable agricultural practices in similar agro-ecological zones.

Assessing the impact of organic resources and phosphorus on nutrient uptake, soil traits and seed potato productivity

AbstractImproving tuber yield size to boost seed potato (Solanum tuberosum) production efficiency is a paramount goal, particularly in Punjab, India, a major contributor to the nation's seed supply. To optimize nutrient absorption, soil quality, and yield of seed‐sized tubers, research was conducted in Ludhiana and Jalandhar over two years. Employing a split‐plot design, three organic treatments (farmyard manure [FYM], biofertilizer, control) were tested in main plots, while five phosphorus fertilizer levels (46.9, 62.5, 93.8, 125, 0 kg ha−1 P2O5) were examined in subplots. Results revealed that FYM notably enhanced nitrogen, phosphorus, and potassium uptake in both haulm and tubers compared to other organics. Moreover, higher phosphorus levels, particularly 125 kg ha−1 P2O5, maximized nutrient uptake. Soil attributes like available nitrogen remained unaffected, whereas phosphorus availability increased with FYM and higher phosphorus levels. Available potassium remained consistent across treatments. Soil pH, electrical conductivity, and organic carbon were unchanged with 125 kg ha−1 P2O5 treatments. FYM and biofertilizer significantly increased total tuber yields, with FYM showing a remarkable 30% boost compared to the control, and 125 kg ha−1 P2O5 phosphorus levels resulting in a notable 24% increase, indicating enhanced seed potato production strategies. Principal component analysis underscored the positive correlation between tuber yield and soil attributes, particularly favoring FYM and 125 kg ha−1 P2O5 treatments. Overall, FYM application and optimal phosphorus fertilizer levels are pivotal for augmenting nutrient uptake, soil health, and yield in seed potato cultivation.

Unlocking the potential of Spirulina microalgae: Cultivating in wastewater treatment for sustainable biofuel production

Municipal wastewater, known for its high nitrogen and phosphorus levels, disrupts natural biogeochemical cycles. However, these nutrients are vital for cultivating green algae, which show potential as a sustainable energy source. In this study, Spirulina microalgae biomass was cultivated from diluted municipal wastewater and converted into biofuel to assess its compatibility with conventional diesel applications. Algae growth rate, nutrient removal from wastewater, and proximate and ultimate analyses of the biomass were conducted. Elemental, functional group, and chemical analyses of the biodiesel were also performed using an elemental analyzer, Fourier-transform infrared (FTIR) spectroscopy, and Gas Chromatography-Mass Spectrometry (GC-MS), respectively. Results showed effective removal of calcium, magnesium, potassium, and nitrogen nutrients by 44.7%, 71.7%, 50%, and 55.6%, respectively, through algae cultivation. Proximate and ultimate analyses confirmed the biomass's energy content and efficiency for energy production. Elemental analysis of biodiesel revealed significant contributions of carbon, hydrogen, and oxygen, while FTIR and GC-MS analyses identified carbon-based components and methyl esters as major constituents, respectively. Physicochemical properties of algae biodiesel met ASTM D6751 limits. This comprehensive assessment suggests that Spirulina algae from wastewater treatment holds promise as a viable energy source for diesel applications.

Land use/cover drive functional patterns of bacterial communities in sediments of a subtropical river, China

The bacterial community in sediment serves as an important indicator for assessing the environmental health of river ecosystems. However, the response of bacterial community structure and function in river basin sediment to different land use/cover changes has not been widely studied. To characterize changes in the structure, composition, and function of bacterial communities under different types of land use/cover, we studied the bacterial communities and physicochemical properties of the surface sediments of rivers. Surface sediment in cropland and built-up areas was moderately polluted with cadmium and had high nitrogen and phosphorus levels, which disrupted the stability of bacterial communities. Significant differences in the α-diversity of bacterial communities were observed among different types of land use/cover. Bacterial α-diversity and energy sources were greater in woodlands than in cropland and built-up areas. The functional patterns of bacterial communities were shown that phosphorus levels and abundances of pathogenic bacteria and parasites were higher in cropland than in the other land use/cover types; Urban activities have resulted in the loss of the denitrification function and the accumulation of nitrogen in built-up areas, and bacteria in forested and agricultural areas play an important role in nitrogen degradation. Differences in heavy metal and nutrient inputs driven by land use/cover result in variation in the composition, structure, and function of bacterial communities.

Assessing the impact of rainfall on water quality in a coastal urban river utilizing the environmental fluid dynamics code

The Haihe River, flowing through Tianjin City, grapples with pollution challenges, notably high levels of nitrogen (N) and phosphorus (P) leading to eutrophication and unpleasant odors, particularly aggravated by rainfall. This study used Environmental Fluid Dynamics Code to comprehensively analyze the water environment under three scenarios: low flow year, normal flow year, and high flow year. The investigation delves into N and P concentrations, computes atmospheric deposition fluxes, and evaluates the loads and retention ratios of N and P in the urban river network of Tianjin City. Scenario analysis reveals distinct trends, with high flow years associated with elevated N and hydrodynamics levels, while low flow years exhibit contrasting patterns. Key findings include 1) wet deposition fluxes contributing 21% of NH4+-N and 9% of TP river loads, 2) continuous rainfall and runoff resulting in immediate or delayed increases in NH4+-N, TN, and TP concentrations in surface water, 3) an increase in average N:P mole ratios downstream along the Haihe River, and 4) N and P mean retention ratios were 48% and 63%, respectively. The study suggests that implementing sponge city construction and sustainable drainage systems may improve water quality by mitigating the direct discharge of rainfall runoff into the river.

High plasma magnesium and phosphorus levels and their correlation with struvite urolithiasis in buffaloes

BackgroundUrolithiasis is a common urinary tract disease in buffaloes, almost exclusively affects young males, and has significant economic and production impacts. We have investigated hemato-biochemical and urinary changes in an attempt to deduce their correlation with struvite urolithiasis in buffaloes. MethodsTen male buffalo calves with obstructive urolithiasis were used. Blood samples were used for hematology and elemental analysis. Urine samples were used for physico-chemical examination, microscopy, and elemental analysis. Uroliths were subjected to chemical functional group determination using the FTIR spectroscopy. ResultsThe mean neutrophil, leukocyte, and neutrophil-to-lymphocyte ratio was significantly (p < 0.05) higher in urolithic buffaloes than in healthy controls. The mean blood calcium and magnesium concentrations were significantly (p < 0.05) lower and higher in urolithic buffaloes than in healthy controls, respectively. Mean blood phosphorus concentration and calcium-phosphorus ratio were found to be non-significantly (p > 0.05) higher and lower in urolithic buffaloes than in healthy controls, respectively. The urine pH was highly alkaline. Multiple prismatic lid-shaped crystals, along with erythrocytes, leukocytes, and epithelial cells, were found in urine. The mean urinary magnesium and phosphorus concentrations were non-significantly (p < 0.05) higher in urolithic buffaloes than in healthy controls. A positive correlation of magnesium (r = 0.864, p = 0.001) and phosphorus (r = 0.849, p = 0.002) concentrations between the blood and urine was observed in urolithic buffaloes. The FTIR spectra of uroliths were similar to those of magnesium ammonium phosphate hexahydrate, MgNH4PO4·6H2O or struvite. ConclusionThe findings suggest that high plasma magnesium and phosphorus concentrations have a positive correlation with struvite urolithiasis in buffaloes.

Anti-osteoporosis effect of Prunus humilis fruit on ovariectomized rats via modulating the function of bone metabolism

Prunus humilis Bge. (PH), also known as calcium fruits, is rich in minerals and polyphenols. Given its high content of calcium and other mineral elements, it is believed to be an ideal health fruit to prevent osteoporosis (OP). Hence, the present research aimed to estimate the anti-osteoporotic activity of the fruit of PH in ovariectomized (OVX) rats and to explore the corresponding mechanisms. By utilizing LC-QTOF-MS/MS, 18 primary components, including 14 flavonoids and 4 phospholipids were elucidated in PH. The results of inductively coupled plasma optical emission spectrometry demonstrated that PH exhibited high levels of calcium (1573–1829 mg/kg), phosphorus (1328–1731 mg/kg), and magnesium (897–1027 mg/kg). The pharmacodynamic experiments conducted on OVX rats revealed that continuous oral intervention with PH (10–62.5 mg/kg/day) for three months resulted in significant improvements in both bone mineral density and bone microarchitecture. Meanwhile, the intervention with PH also effectively reversed the bone resorption and formation factors, including type I collagen carboxy-terminal peptide, acid phosphatase 5 tartrate-resistant, deoxypyridinoline, alkaline phosphatase, and procollagen amino-terminal peptide. Additionally, the utilization of LC-QTOF-MS/MS metabolomics revealed the identification of 16 differential metabolites linked to 9 metabolic pathways, all of which were recovered following PH treatment. Furthermore, the protein levels of β-catenin, Wnt1, Sirt1, and FOXO3a were significantly up-regulated after PH intervention, indicating a potential association between the anti-osteoporosis properties of PH and the Wnt/β-catenin and Sirt1/FOXO3a signaling pathways. Our findings provide a new idea for the prevention and treatment of OP through the daily consumption of PH, a sweet and flavorful fruit.

#1648 Chronic kidney disease-mineral bone disorder and fractures in predialysis patients

Abstract Background and Aims Chronic Kidney Disease (CKD) patients have a complex physiopathology of bone fragility given the development of mineral bone disorder (CKD-MBD) and are at increased fracture risk [1]. Bone turnover, mineralization, and volume (TMV) classification, as proposed by Kidney Disease Improving Global Outcomes (KDIGO), defines different subtypes of renal osteodystrophy (ROD), and is evaluated through bone biopsies and respective histomorphometric analysis. The impact of these parameters and of different ROD subtypes in fracture occurrence has not been evaluated. We aim to evaluate the incidence of fractures in patients with predialysis CKD and the relationship of ROD subtypes and the impact of bone volume with the occurrence of fractures. Method We conducted a retrospective study that enrolled 54 patients (40-89 years old) followed in a predialysis clinic between 2014-2023. Blood tests, bone biopsies and histomorphometric analysis were performed at the beginning of follow-up. Data from dual x-ray absorptiometry (DXA) scan were collected if available. Information regarding clinical evident fractures was recorded from analysis of clinical registries. Radiographies of the thoracic and/or lumbar spine were evaluated to detect asymptomatic vertebral fractures. Results Median follow-up time was 7.5 ± 3 years. Mean age at the time of bone biopsy was 65.4 ± 9.8 years old and most patients were male (n = 43, 79.6%). The majority had CKD stage 4 (53.7%). During follow-up, 20 (37%) patients progressed to kidney replacement therapy and 5 (9.3%) died. DXA scan was performed in 19 patients (35.2%). Of these, 5 had osteoporosis (T-score ≤-2,5). The histomorphometric analysis showed that 40.7% (n = 22) patients had normal bone histology, 37% (n = 20) low bone turnover with normal mineralization (adynamic bone disease) and 22.3% (n = 12) high bone turnover with normal mineralization (hyperparathyroid bone disease). Two patients sustained clinical evident fractures. Radiographies of 51 patients were reviewed and asymptomatic vertebral fractures were identified in 3 (5.9%). The group that suffered fractures had higher phosphorus levels and these differences were statistically significant (4.1 mg/dL vs 3.5 mg/dL, p = 0.047). None of the patients with osteoporosis diagnosed by DXA scan fractured and bone mineral density (BMD) by DXA was similar between the groups (−1.05 vs −1.04, p = 0.530). The different histomorphometric subtypes and circulating biomarkers did not correlate with the incidence of fractures. Patients with fractures had more frequently low bone volume (40%) than patients who do not sustained fractures (25.5%) but this difference was not significant (p = 0.579). BV/TV was lower in the group that sustained fractures during follow-up (16.1 (11.9-17.2) vs 19.0 (16.2-23.6)) and this achieved borderline significance (p = 0.052). Femoral neck BMD measures in the patients who had an available DXA scan did not show any correlation with BV/TV (r = 0.039, p = 0.874). Conclusion No relationship was found between different ROD subtypes and the incidence of fractures. However, when considering bone volume isolated (but not BMD assessed by DXA), a marginally significant association was found between a low BV/TV value and the occurrence of fractures. High phosphorus levels also associated with fractures and have been previously described as a possible risk factor for fractures not only in CKD patients but also general population [2, 3]. Further studies with a larger population are needed to validate these conclusions with statistical power.

#3065 Factors associated with recurrence or persistently high parathormone levels after parathyroidectomy in patients with CKD

Abstract Factors associated with recurrence or persistently high parathormone levels after parathyroidectomy in patients with secondary hyperparathyroidism receiving renal replacement therapy Background and Aims Resistant hyperparathyroidism that indicates surgery usually occurs in patients with CKD who receive renal replacement therapy (RRT). This study aims to evaluate the factors associated with persistent or recurrent high levels of PTH after parathyroidectomy due to SHPT in patients receiving RRT. Method In this retrospective study, we included 66 adult patients (mean age: 46.86 ± 13.79) with parathyroidectomy for SHPT receiving renal replacement therapy. Clinicopathological features, laboratory parameters (preoperatively, at the first hour of surgery, at least every three months for at least two years after surgery), type of surgery and pathologic diagnosis were recorded from the medical records. Persistence was defined as failure to achieve a decrease in PTH level of more than fifty percent of preoperative PTH level. Recurrence was defined as elevated PTH levels after six months post-operation (&amp;gt;600 pg/mL). Results The demographics and clinical characteristics of the study population are described in Table 1. High PTH levels were observed in nineteen patients, while recurrence was observed in nine. Persistence was associated with lower preoperative ALP levels (455.27 ± 296.23, 619.72 ± 593.18, p = 0.017). Recurrence was associated with higher preoperative CRP levels (22.89 ± 6.82, 6.82 ± 5.35, p:0,046) and postoperative high phosphorus levels (4.93 ± 0.99, 4.16 ± 1.09, p = .049). Conclusion In our study persistence of high parathormone levels were more common in patients with lower preoperative ALP levels and recurrence was associated with higher preoperative CRP levels and postoperative inadequate phosphorus control. In conclusion, patients with lower ALP and higher CRP levels can be suitable for total parathyroidectomy, which is associated with a lower recurrence rate in SHPT. Also, postoperative phosphorus control can be a key point for preventing the patients' recurrence of high PTH level.

The urgent need to reduce phosphorus discharges for sustainable mangrove wetland management

Phosphorus affects microbial metabolic activity, nitrogen and carbon cycling in mangrove sediment, but its influence on carbon stability and greenhouse gases emission remains unclear. This study compared greenhouse gases (CO2, N2O, and CH4) emissions from mangrove sediment receiving wastewater containing various phosphorus concentrations, and evaluated its long term effect on sediment carbon flux when phosphorus pollution is eliminated. Significant increases in greenhouse gases flux and decrease of total organic carbon and readily oxidizable organic carbon in the sediment were observed after phosphorus discharge. Specifically, the N2O flux was reduced significantly at high phosphorus levels while the CO2 flux and the microbial biomass organic carbon was increased. The copy numbers of ammonia oxidation (AOA-amoA, AOB-amoA) gene, denitrification (narG, nirK) gene and methanogenesis (mcrA) gene increased with the increasing phosphorus concentration. During the wastewater discharge period for 70 days, the global warming potential of sediment flux at high phosphorus discharge condition was more than 4 times that of the control group, and the loss of total organic carbon and readily oxidizable organic carbon was 4.66 % and 7.1 %, respectively. During the remediation period (71–101 days), the greenhouse gases flux decreased rapidly, ends up with a similar level of the control group. Our results indicate that using mangrove wetland for pollution minimization in the coastal aquaculture industry could increase greenhouse gases emisison significantly, it is therefore essential to reduce phosphorus discharges from various anthropogenic activities, and local authorities must set up more stringent discharge standards in the future.

Organic fertilizer prepared by thermophilic aerobic fermentation technology enhanced soil humus and related soil enzyme activities

AbstractOrganic fertilizer (OF) prepared from chicken manure in a high‐temperature aerobic fermenter contains high levels of nitrogen, phosphorus and potassium. The effect of high‐nutrient OF substitution for chemical fertilizer (CF) on soil organic carbon stability is worth exploring. We used OF to replace CFs for supplying crops, and we set five OF replacement rates as 0, 25%, 50%, 75% and 100% in the black soil zone of Northeast China. We explored the variations in soil humus carbon contents, enzyme activities and nutrient contents (0–10 cm and 10–20 cm). Two‐way ANOVA results showed that interaction between soil depth and OF substitution significantly affected soil pH, total nitrogen, organic carbon, available potassium, water‐soluble carbon substance (WSSC) and activities of soil β‐galactosidase (β‐gal), N‐acetyl‐β‐D‐glucosaminidase (NAG) and cellobiohydrolase. The treatments of OF75 and OF100 increased soil pH, and the content of soil organic carbon, humic acid carbon (HAC), fulvic acid carbon (FAC), WSSC, total phosphorus, available phosphorus (AP), total potassium and available potassium was increased in OF75 and OF100 treatment. Treatments of OF75 and OF100 increased the tested soil enzyme activities except for oxidase activities of 0–10 cm soil layer. There was a positive correlation between HAC and AP contents, and a positive correlation between FAC and soil pH, total nitrogen and available potassium contents. The key influencing factors of soil FAC were the activities of NAG, α‐galactosidase and β‐gal. It can be concluded that OF substitution promoted soil humus carbon accumulation by affecting hydrolase activity related to carbon conversion.