Phosphorus Content Research Articles

ANALYSIS OF THE EXISTING SOILS IN THE ROOTSTOCK PLANTATION AND IN THE VINE PLANTATIONS SUPPLYING THE SHOOTS OR CANES IN THE DRĂGĂŞANI VINEYARD

The study was carried out in the years 2023-2024 at SCDVV Drăgăşani, in the plantation of „SO4-4” rootstocks and in the vine plantations supplying the shoots or canes of the „Victoria”, „Alutus”, „Vilarom” and „Crâmpoşie Aromată” grape cultivars. These grape cultivars are considered varieties of certain value, they were created at the Drăgăşani Viticulture and Winemaking Research-Development Station. The object of study of this paper is the soil cover, researched in its maintenance with the other geographical factors in order to establish the agro-productive capacity of the plantations, to highlight the main negative attributes and the ameliorative measures. The study followed the contents of phosphorus, potassium and nitric nitrogen, in three repetitions, the soil samples being taken from the depths of 0-20 cm, 20-40 cm, 40-60 cm from the lower, middle and upper slopes of the plantations, in order to the fertilization corresponding to the fertilizing of the soil from the plantation of SO4-4 rootstocks and from the vine plantations providing of the shoots or canes necessary for the improvement of the production technologies of the viticultural propagation material in the current context of climate change. The samples taken from these plantations were analyzed at OJSPA Râmnicul Vâlcea, Romania.

Coupled Electrolysis–Microfiltration System for Efficient Phosphorus Removal and Recovery in the Form of Iron Phosphate Compounds from Wastewater

Electrochemical technology presents a promising approach for phosphorus recovery from wastewater. Nevertheless, its application in industry is hindered by relatively low phosphorus recovery efficiency, high energy consumption and complex reactor configurations. In this study, a coupled electrolysis and microfiltration system was designed for phosphorus recovery in the shape of iron phosphate compounds with the use of steel pickling wastewater as the iron source. In the electrolysis unit, the anode diffusion layer was extracted from the porous anode surface with the production of an acid effluent and an alkaline effluent. The alkaline effluent was mixed with the stainless steel acid washing wastewater generated from the steel pickling process and then introduced into the microfiltration unit to intercept the iron phosphate crystals. The filtered effluent was finally introduced into the air aeration unit to further reduce the phosphorus content in the water. And the extracted acid solution could be reused in the pickling step of the iron and steel manufacturing process. The experimental results show that the coupled system achieved phosphorus recovery of 42~80% at a current density of 5~20 mA cm−2, accompanying energy consumption of 5.78~9.15 kWh (kg P)−1 and current efficiency of 79~43%, when the phosphorus concentration was 3 mM and the iron–phosphorus molar ratio was 1.5. After the microfiltration treatment, the residual phosphorus could be further reduced to 0.5 mg L−1 within 30 min at an aeration rate of 80 mL min−1, which met the discharge standard. The presence of interfering ions (HCO3− and SiO42−) posed inhibited effects on phosphorus recovery. Generally, this study provides a green and environmentally friendly way to efficiently recover phosphorus resources from wastewater.

ЭФФЕКТИВНОСТЬ СИДЕРАТОВ В ЗЕМЛЕДЕЛИИ НЕЧЕРНОЗЕМЬЯ

The results of research on the effectiveness of mineral fertilizers are presented. It was found that the highest content of nitrogen, phosphorus and potassium was in winter rye plants grown using slanted and full siderates. The minimum content of nutrients was in winter rye plants grown using an occupied pair. The maximum grain yield was obtained by cultivating winter rye using pure steam with the use of mowing siderate and sideral steam. On a non-fertilized background, it amounted to 3.27 t/ha and 3.25 t/ha, respectively, and on a fertilized background, 4.12 t/ha and 4.08 t/ha. The grain from these variants had the maximum crude protein content. In terms of the effectiveness of the effect on the yield and grain quality of winter rye, the mown siderate was not inferior to the full sideral fertilizer. The study of the use of siderates in the sowing form showed that during the autumn period, peas and mustard accumulated the largest biomass, and rapeseed accumulated the least. The largest amount of nitrogen 33 kg/ha was accumulated in the biomass of peas, and phosphorus 6 kg/ha and potassium 36 kg/ha by the biomass of white mustard. The least amount of nutrients accumulated in the biomass of rapeseed. Sowing of sideral crops had a positive effect on the formation of yields and improving the quality of winter rye grain. The yield of winter rye grown without sowing siderates and without fertilizing was 2.32 t/ha. The increase in the variant with seeded vetch was 0.47 t/ha, with seeded mustard - 0.37 t/ha and with seeded peas - 0.40 t/ha. The sowing of spring rapeseed did not lead to a significant increase in the yield of winter rye. Nitrogen fertilization of winter rye during the spring tillering phase provided an increase in grain yield by 0.62 t/ha. Against the background of top dressing, the sowing of vetch provided an increase in grain yield of 0.48 t/ha, white mustard – 0.39 t /ha, seeded peas – 0.32 t/ha. There was no reliable increase from the sowing of spring rapeseed.

Nutritional profiles of some preferred food grasses of the greater one-horned rhinoceros before and after grassland burning in Manas National Park, India

The nutritional variations of food plants play a significant role in the health and population dynamics of wildlife. The body conditions of vulnerable greater one-horned (GOH) rhinoceros (Rhinoceros unicornis) in Manas National Park, Assam, India deteriorate noticeably during the late monsoon to winter, and improve after routine grassland burning, when rhinos feed on the newly emerged leaves and young shoots of grasses. To investigate this, we analysed the nutritional parameters of the leaves of five grass species preferred by rhinos, including three tall (Saccharum spontaneum, S.narenga and Imperata cylindrica) and two short grasses (Cynodon dactylon and Axonopus compressus), before and after grassland burning. Leaf samples were collected in triplicate from five different sites in MNP before (September) and after (March) grassland burning. Biochemical analyses showed the highest crude protein content in S. narenga before and after grassland burning. S. spontaneum and S. narenga had the highest and second highest fat contents, respectively, after grassland burning. Crude fibre content in S. narenga increased significantly (p < 0.05) after grassland burning, but not in the other two tall grasses. The total ash content and the acid-insoluble ash content increased significantly (p < 0.05) in post-burning samples of all five grasses. The short grasses A. compressus and C. dactylon showed the highest calcium and phosphorus contents, respectively, after grassland burning, highlighting their significance in the diets of GOH rhinos along with tall grasses with higher proximate nutrient contents, and their contribution to the improved health status of rhinos after grassland burning. This study will be helpful for improved management of rhino health and their habitats, essential to maintaining the progress made in MNP since the 2008 to 2012 GOH rhino reintroductions under the Rhino Vision 2020 initiative.

Plant Diversity, Productivity, and Soil Nutrient Responses to Different Grassland Degradation Levels in Hulunbuir, China

Grassland degradation could affect the composition, structure, and ecological function of plant communities and threaten the stability of their ecosystems. It is essential to accurately evaluate grassland degradation and elucidate its impacts on the vegetation–soil relationship. In this study, remote sensing data based on vegetation coverage were used to assess the degradation status of Hulunbuir grassland, and five different grassland degradation degrees were classified. Vegetation community composition, diversity, biomass, soil nutrient status, and their relationships in different degraded grasslands were investigated using field survey data. The results showed that grassland degradation significantly affected the species composition of the vegetation community. As degradation intensified, species richness declined, with the proportion of Gramineae and Legume species decreasing and Asteraceae species increasing. Additionally, the proportion of annual species initially increased and then decreased. Degradation also markedly reduced aboveground, belowground, and litter biomass within the communities. Soil moisture, electrical conductivity, organic carbon, total carbon, total potassium, and hydrolyzable nitrogen contents in non-degraded areas were higher than those in severely degraded areas. Conversely, soil total phosphorus content and bulk density gradually increased with degradation. Nitrate nitrogen and ammonium nitrogen levels in severely degraded soils were significantly higher than those in non-degraded soils. Plant diversity in the study area was significantly positively correlated with aboveground biomass and belowground biomass, and it positively correlated with soil nutrient total carbon and available carbon but negatively correlated with soil bulk density. Results of the partial least squares path model showed that grassland degradation had significant negative effects on plant diversity, soil nutrients, and biomass. Soil nutrients were the main factors affecting ecosystem productivity. The direct effect of plant diversity on biomass was not significant, suggesting that soil nutrients may play a more important role than plant diversity in determining biomass during grassland degradation. The results illustrated the relationships among soil nutrients, plant diversity, and biomass in degraded grasslands and emphasized the importance of an integrated approach in the effective management and restoration of degraded grasslands.

Management implications following the reconstruction of the small and shallow Lake Mustijärv (Estonia)

Lake Mustijärv was reconstructed by sediment removal following an almost complete siltation. Here we evaluate challenges and opportunities for the management of the lake. We focused on the stream discharging to the lake (i.e., external loading), sediment retention in accumulation basins (i.e., internal processes) as well as the ecosystem-level response to stressors based on biological variables (phyto- and zooplankton, macrophytes, fishes and zoobenthos). Urban and agricultural inputs elevated ammonium and total phosphorus concentrations in the lake, challenging lake reconstruction efforts. Sediment transport highly increased the risk of faster filling of the lake, associated with upstream streambed excavation. Sediments trapped at the accumulation basins release nutrients that enhance eutrophication. We, however, observed a rapid recovery in fish, macrophytes, and zoobenthos, despite the significant disturbances. Lake Mustijärv is in eutrophic condition, reflected by phytoplankton (Pseudanabaena, Closteriopsis dominance) and zooplankton (Keratella, Polyarthra dominance) composition. To improve lake water quality will require controlling external nutrient inputs, underlining the importance of better coordinated activities between the local (lake restoration) and regional (catchment use) scales.

Complex landscape, instream and anthropogenic environmental features drive genetic and morphological structuring amongst brown trout (Salmo trutta) populations in a dendritic river system

Abstract Untangling the patterns and proximate drivers of intraspecific genetic and phenotypic structuring informs our understanding of the evolutionary processes shaping diversity. This study investigated morphological and genetic structuring of brown trout (Salmo trutta L.) populations across varying spatial scales in a single, complex, dendritic river catchment and examined the potential natural and anthropogenic environmental features driving this structuring. Morphometric and hierarchical genetic structuring analyses of fish from 22 sampling sites in the River Foyle catchment, Ireland (~ 4500km2) identified 19 morphologically distinct groups and 15 genetically distinct populations, separated by river distances ranging from 0.4 km to 188 km. Isolation by Distance was the main factor shaping both genetic and morphological divergence, indicating that strong philopatry is one of the major drivers of the observed population structuring in this system. However, both natural and anthropogenic environmental variables also explained pairwise genetic and morphological differences between sampling sites. Thus, the pairwise differences in the area of woodland in the upstream catchment, water phosphorus concentration, biological oxygen demand, catchment slope, urban area in upstream catchment, altitude, site specific percentage of canopy cover and dissolved oxygen concentration in the river channel were correlated with genetic divergence. The pairwise differences in the concentration of suspended solids, the extent of bankside overhang, the composition of bedrock, boulder and cobble substrates, watercourse width, catchment slope and site altitude were correlated with between-site morphological differences. We hypothesise that local differential selection pressures comprising both natural environmental variation and variation resulting from anthropogenic effects, in combination with strong philopatry and random genetic processes drive the clearly defined genetic and phenotypic patterns described here.

Valorisation of Deinking Paper Sludge for Fertiliser Purposes: New Perspective in Sustainable Agriculture

The growth of the global population, coupled with concomitant economic development, has resulted in the generation of a substantial quantity of waste. The transition of the European Union’s economy towards a closed-loop model is prompting a comprehensive search for waste management concepts across a range of industrial sectors. The objective of this study is to valorise deinking paper sludge, which has a high potential for soil formation due to its high organic matter content. To produce organic–mineral fertiliser, the deinking sludge was subjected to acid hydrolysis, then neutralised with KOH solution and enriched with poultry litter ash. The final products were characterised in terms of their nutrient and heavy metal content. The bioavailability of phosphorus, along with the forms in which it occurs in fertilisers, was determined through the implementation of a five-step fractionation procedure. Furthermore, an eight-week incubation period was conducted to assess the fertilisers’ performance in soil. Soil samples were tested on a weekly basis for pH, water-soluble and bioavailable phosphorus content using the spectroscopic method after previous extraction in water and Bray’s solution, and catalase activity using the titrimetric method. The resulting fertilisers were found to meet the requirements for organo-mineral fertilisers and were categorised as PK-type fertilisers with a total nutrient content of 24.6–39.3%. Fractionation studies demonstrated that the fertilisers contained 20–30% of the total potentially bioavailable phosphorus. Furthermore, the long-term release of phosphorus from the fertilisers was confirmed through incubation studies. Additionally, the fertilisers were observed to contribute to an increase in catalase activity in the soil.

Comparative Study on the Nutritional Quality of Peanut in Saline and Non-Saline Land

Saline soils, as a special class of soil types, have unique physicochemical properties that have far-reaching effects on crop growth and quality characteristics. In order to better develop saline soils as a reserve resource, it is particularly important to exploit the potential of saline crops. Peanut, as one of the important crops in saline soils, can have different quality characteristics depending on the differences in soil salinity and alkalinity, as well as growing conditions. In this study, we compared the nutritional quality and functional composition of five peanut varieties grown in coastal saline soils, with the same varieties grown in non-saline soils in similar areas. The results showed significant differences (p<0.05) between saline and non-saline peanuts in the contents of ash, zinc, phosphorus, β-VE, Cis-11-eicosatetraenoic acid, palmitoleic acid, linolenic acid, and total antioxidant removal capacity, whereby the former was higher than the latter by 0.12 g/100 g, 4.1 mg/kg, 321 mg/kg, 8.98 μg/g, 0.36%, 0.01%, and 0.01%, respectively, and the total antioxidant capacity was lower than that of the latter by 9.18 μg Trolxo/g of fresh weight. Sodium element and superoxide dismutase (SOD) activity contents were extremely significantly (p<0.01) different in peanuts grown in both land types, where the former was higher than the latter by 261.9 mg/kg and 285 U/g, respectively. Water, fat, protein, calcium, copper, iron, potassium, magnesium, manganese, Vc, α-VE, total VE, VB3, 5-methyl-tetrahydrofolate, 5-formyl-tetrahydrofolate, total phenols, total flavonoids, ABTS free radical scavenging capacity, DPPH free radical scavenging capacity, fatty acids (except for Cis-11-eicosapentaenoic acid, palmitoleic acid, and linolenic acid), phytosterols, and guanines showed no significant differences (p<0.01). To sum up, the origin and soil environment have an effect on the quality of peanuts. These results also provide a scientific basis for the quality assessment of peanuts in saline soil.

Study of temperature dynamics and influencing factors during composting process

Abstract This study investigated the most influential composting parameters (temperature, pH, humidity, C/N ratio, and CO2 emissions) on final compost quality. Composting bags (turned daily) containing prunings, lignocellulose material, cattle manure, and household organic waste were monitored for eight weeks across three batches. All the temperature data registered daily were statistically analyzed with one-way ANOVA to verify the consistency between batches. This study employs a first-order kinetic model to quantify the decomposition of organic matter in composting, revealing the influence of temperature on the decomposition rate. Principal component analysis was conducted for these factors and their interactions with respect to the final compost quality. Finished compost showed a significantly high nitrogen, phosphorus, and potassium content compared with that in the feedstock of the initial compost mixture, while there was constant organic carbon content. In addition to the control of key parameters, a linear regression analysis allowed us to identify the factors that most influenced temperature. We identified two key models: one including pH, humidity, C/N ratio, and CO2 emissions, and another focusing only on CO2. This study emphasized the importance of monitoring and controlling the crucial parameters of the composting process in order to obtain quality compost suitable for application in soil use. Moreover, high temperatures possibly attained in the process of aerobic decomposition destroy the pathogens, making the end products safer for uses in agriculture.

Identification of differences in digestive organ weight, bone mineral concentration, and ileal transcriptomic profiles of low and high weight broiler chicks

Abstract A growth monitoring study (0–7 day of age) was conducted involving 87, one-day old Ross 308 male broilers to evaluate organ weights, bone parameters and ileal transcriptomic profile of broiler chicks as influenced by day 7 bodyweight (BW) grouping. The chicks were raised in a deep-litter house under common controlled environmental conditions and commercial starter diet. Chicks were grouped on day 7 into two distinct BW, super performer (SP) and under performer (UP) with bodyweights >260, and <200 g respectively. Results revealed that the SP chicks had significantly higher bone ash, sodium (Na), phosphorus (P) and rubidium (Rb) concentrations compared to the UP chicks on D7. In contrast, the UP chicks had significantly higher tibial cadmium (Cd), caesium (Cs) and lead (Pb) compared to the SP group; the UP chicks also had proportionally heavier relative gizzard weight than the SP chicks. The ileal transcriptomic data revealed differentially expressed genes (DEG) between the two groups of chicks, with 150 upregulated and 83 down-regulated genes with a fold change of ≥1.25 or ≤ 1.25 in the SP chicks relative to the UP chicks. Furthermore, functional annotation and pathway analysis revealed that some of these DEG were involved in various pathways including calcium signalling, Wnt signalling, cytokine-cytokine receptor interaction and mucin type O-glycan biosynthesis. This study revealed that chicks of the same breed and of uniform environmental and diet management exhibited differences in digestive organ weights, tibial bone characteristics and ileal gene expression that may be related to BW.

Root morphology, nitrogen metabolism and amino acid metabolism in soybean under low phosphorus stress.

Phosphorus deficiency is a major influence on growth and development of soybean. Therefore, improving phosphorus utilization efficiency in soybean is a research priority for the soybean community. In this experiment, Liaodou 13 (high phosphorus utilization: HPE) and Tiefeng 3 (low phosphorus utilization: LPE) were used as test varieties. We investigated changes in root morphology, amino acid content, and content of key substances of the nitrogen metabolic pathway with normal phosphorus (0.5 mM) and low phosphorus (0.005 mM) treatments. The results showed that the root length, root surface area and number of lateral roots of HPE roots were higher than those of LPE roots under normal and low phosphorus conditions. The contents of different types of amino acids showed different trends in two varieties. The HPE showed small change in the content of total hydrolyzed amino acids under the low phosphorus condition when compared to the normal phosphorus treatment by a 6.67% decrease, on the contrary LPE showed a drastic decrease by 20.36%. However, HPE exhibited similar decreasing trends in the contents of hydrolyzed and free aspartic acid with the low phosphorus treatment. Moreover, the contents of free histidine and valine in LPE were significantly increased by 657.84% and 149.29% respectively, in contrast to significant decreases in HPE. In aspects of major nutrient elements, the contents of phosphorus, total nitrogen and ammonia nitrogen in both HPE and LPE varieties decreased to dramatic levels. However, the nitrate nitrogen content significantly increased 78.51% for HPE and 65.12% for LPE. Compare to the normal condition, the GOGAT activity in HPE decreased by 5.18% but increased by 33.10% in LPE. Compare to the normal condition, the GS activity in HPE increased by 7.26% but decreased by 21.72% in LPE under phosphorus deficiency. In summary, the phosphorus-efficient soybean variety HPE exhibited superior tolerance to low phosphorus deficiency through advantageous root morphology, phosphorus uptake and transfer capability, and balanced amino acid metabolism and nitrogen metabolism pathways.

Development of homemade oral nutrition supplements for individuals with kidney failure on hemodialysis: physicochemical properties, nutrient composition, and sensory evaluation

Purpose Protein-energy wasting is a common complication among patients with kidney failure undergoing dialysis. This study aims to develop a homemade oral nutrition supplement (ONS) to fulfill the energy and protein requirements of these patients. Design/methodology/approach Three formulations of homemade ONS were developed using soybean milk, whey protein isolates and canola oil. Two of these formulations were flavored with pineapple and honeydew juices, respectively. The energy and macronutrient contents were determined using proximate analyses, and mineral contents were determined using inductively coupled plasma optical emission spectroscopy. The acceptance of homemade ONS for five attributes, namely color, taste, odor, consistency and overall acceptability, was assessed using the nine-point hedonic scale. Findings The homemade ONS provided 198–212 kcal and 8.4–9.6 g protein per 100 mL, which were comparable to commercial products. Similarly, the sodium (45–65 mg/100 mL) and phosphorus (56–66 mg/100 mL) contents were on par with commercial products. However, the potassium content of homemade ONS was higher, ranging from 141 to 155 mg per 100 mL. The sensory evaluation indicated that the formulation added with honeydew juice had a similar degree of acceptance as the commercial ONS, while formulations containing pineapple juice and without added fruit juice were less favored. Originality/value A few studies have investigated the development of food products for individuals with kidney failure on dialysis. However, to the best of the authors’ knowledge, this is the first study to focus on developing a homemade ONS specifically tailored to meet the unique nutritional needs of hemodialysis patients. In addition, this research included a comprehensive assessment of the beverage’s nutritional content and sensory attributes.

Linking leaf dark respiration to leaf traits and reflectance spectroscopy across diverse forest types.

Leaf dark respiration (Rdark), an important yet rarely quantified component of carbon cycling in forest ecosystems, is often simulated from leaf traits such as the maximum carboxylation capacity (Vcmax), leaf mass per area (LMA), nitrogen (N) and phosphorus (P) concentrations, in terrestrial biosphere models. However, the validity of these relationships across forest types remains to be thoroughly assessed. Here, we analyzed Rdark variability and its associations with Vcmax and other leaf traits across three temperate, subtropical and tropical forests in China, evaluating the effectiveness of leaf spectroscopy as a superior monitoring alternative. We found that leaf magnesium and calcium concentrations were more significant in explaining cross-site Rdark than commonly used traits like LMA, N and P concentrations, but univariate trait-Rdark relationships were always weak (r2 ≤ 0.15) and forest-specific. Although multivariate relationships of leaf traits improved the model performance, leaf spectroscopy outperformed trait-Rdark relationships, accurately predicted cross-site Rdark (r2 = 0.65) and pinpointed the factors contributing to Rdark variability. Our findings reveal a few novel traits with greater cross-site scalability regarding Rdark, challenging the use of empirical trait-Rdark relationships in process models and emphasize the potential of leaf spectroscopy as a promising alternative for estimating Rdark, which could ultimately improve process modeling of terrestrial plant respiration.

Influence of nitrogen treatments on some nutrient concentration and bioactive compounds of broccoli.

Nitrogen fertilization in broccoli is very important for plant growth and productivity. However, it is known that the nitrogen source of the nitrogen fertilizer is also effective on quality parameters. In this study we investigated the effects of different nitrogen sources (ammonium sulphate and calcium nitrate) on bioactive compounds and leaf nutrients of broccoli cultivars (Monet, Italian and Karadede). The highest total phenolic content was 0.24 mg g- 1 fw in cultivar Monet. Nitrate-based fertilizer treatments provided higher total phenolic (0.28 mg g- 1 fw) and flavonoid (0.56 mg g1 fw) contents and FRAP (0.24 mmol g- 1 fw) values compared to ammonium-based fertilizer treatments. On the other hand, DPPH (0.77 mmol g- 1 fw) values were higher in the ammonium nitrogen treatments. Among the cultivars, Monet had the highest total phenolics, flavonoids and FRAP values. When leaf nutrient concentrations were analyzed, ammonium sulfate application resulted in higher sulfur (0.86%), zinc (20.72mg kg- 1) and manganese (28.80mg kg- 1) concentrations compared to calcium nitrate. Calcium nitrate treatment provided the highest calcium (2.09%) and iron (37.50mg kg- 1) concentration in Monet cultivar. Phosphorus (0.31-0.35%) and magnesium (0.073-0.084%) concentrations differed among cultivars. In conclusion, the choice of nitrogen source and cultivar in broccoli cultivation plays an important role in the bioactive compound profile and nutrient composition of the broccoli crop. The results provide useful information for the improvement of broccoli quality.

Synthesis of a new flame retardant and performance study of flame retardant epoxy resin

This paper aims to study a new halogen-free flame-retardant curing agent, 6,6'-(1,5-bis((4-(4-aminobenzyl)phenyl)amino)pentane-1,5-diyl)bis(dibenzo-oxaphosphinine 6-oxide) (DOPO-DMG). The DOPO-DMG was synthesized using 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), 4,4-Diaminodiphenyl methane (DDM), and glutaric dialdehyde as raw materials in this paper. The chemical structures of DMG and DOPO-DMG were characterized by 1H NMR and FTIR. The results showed that the DOPO -DMG was successfully prepared. The thermal stability, mechanical and flame properties, as well as the morphology of the char layer in composite materials were investigated separately using TG (Thermogravimetric analysis), tensile and Charpy impact tests, LOI (Limiting Oxygen Index) and UL-94 (UL-94 HB flammability standard), and SEM (scanning electron microscope). When IFR (Intumescent Flame Retardants) was added to the EP, the LOI of the composite material improved. DOPO-DMG exhibited excellent flame-retardant properties and produced no toxic fumes when burned in case of fire. Under optimal conditions, it was found that adding DOPO-DMG with a phosphorus content of 2.01% to the epoxy resin resulted in an LOI of 28.8, UL 94 rating of V-0, tensile strength of 39.1 MPa, impact strength of 5.2 KJ/m2 respectively, and a char yield at 800°C of 25.63%.

Effects of Biochar and Organic Acid Addition on Phosphorus State and Yield of Cotton Field Under Different Phosphate Fertilizer Application Rates

The purpose of this study is to investigate the effect of biochar and organic acid on soil phosphorus effectiveness, plant accumulation phosphorus absorption, yield composition, and phosphorus equilibrium under different phosphorus fertilizer dosage conditions. Using the field test method, different phosphate fertilizer dosage treatments (0, 50, 100, 150 kg P2O5/ha) were set, and a control group, biochar (BC), and organic acid (OA) addition treatment were set up on this basis. During the experiment, the soil fast-acting phosphorus, accumulated phosphorus absorption, and cottonseed yield of cotton were measured, and the utilization of phosphorus fertilizer and phosphorus surplus were calculated. The results showed that the addition of biochar and organic acid significantly improved the soil phosphorus content, plant accumulation phosphorus absorption, cottonseed yield, and phosphate fertilizer utilization. In particular, in terms of plant accumulation of phosphorus absorption, cottonseed production and phosphate fertilizer utilization, biochar was better than organic acids, increasing by 10.2%, 0.29%, and 0.21%, respectively. Under the conditions of phosphorus fertilizer loss, the addition of biochar can effectively improve the effectiveness of phosphorus in soil and regulate the absorption and distribution of phosphorus in cotton, thus promoting the yield of cottonseed. In summary, the addition of biochar has important application potential in phosphorus management in cotton fields, which can provide a scientific basis for the sustainable development of cotton fields in Xinjiang. The results provide a reference for the rational use and management of phosphate fertilizer in cotton fields and promote the sustainable development of agriculture.

The effect of Tetranychus urticae Koch (Acari: Tetranychidae) infestation on some plant nutrients and growth parameters of common bean under laboratory conditions

We investigated the effect of two-spotted spider mite Tetranychus urticae Koch infestation on some nutrient elements and growth parameters of common bean plants under laboratory conditions (28±2 °C, 65±10% RH, photoperiod of 16/8 (L/D) h). Three different plant growth stages (young: 2nd trifoliate- leaf formation, middle: pre-flowering, old; fruit formation) were infested with four mite densities (0, 20, 40, 80 (adult mites/plant)) and four replications per treatment in completely randomized design were used. The infested plants were left for 14 days, and then macro- (P, K, Ca, Mg) and micronutrients (Fe, Cu, Mn, Zn, B) in leaf samples were determined, number and length of leaves and height and dry weight of plant were recorded. The lowest phosphorus content (0.19%) was recorded in the old stage of the plant in the treatment with a density of 40-mites, while it was 0.29 and 0.25% in the young and middle stage, respectively. However, the lowest potassium content (6.59%) was observed at the density of 40 mites and in the young stage. As the density of mites increased, the calcium content in the plant decreased, but no change in the magnesium content. Micronutrients did not significantly vary with mite density, except for copper, which showed a difference. The increase in mite density resulted in an increase in the plant dry weight and a decrease in plant height and leaf length. This study may further suggest fertilization programs might help to overcome nutrient deficiencies in crops due to mite infestation.

Evaluation of the Chemical Composition and Feeding Value of Sweet Orange Pulp and Pineapple Peel Meals as Fibre Sources in Pigs’ Rations

The piggery industry in Nigeria is on the verge of collapsing due to the high cost of conventional feed resources including wheat offal and palm kernel cake that usually form bulk in the diets of pigs. This study was, therefore, designed to compare the chemical composition of orange pulp meal, pineapple peel meal, and wheat offal and evaluate their feeding value in pig rations. The orange pulp and pineapple peels were dried on a concrete floor and analyzed for chemical composition. Three experimental diets were formulated with orange pulp and pineapple peel meals replacing wheat offal as a fibre source. Thirty crossbred (Chester white x Landrace) growing pigs with an average initial weight of 8.20 -- 8.75kg were distributed into three groups, with ten animals per group, and assigned to the three experimental diets. The average daily feed intake and weight gain were monitored throughout the 56-day duration of the experiment. Seven days to the end of the experiment, three pigs randomly selected for the digestibility trial were individually housed in metabolism crates and allowed 5 days of adaptation to the crates and feed before faecal collection commenced. Animals were fed the experimental diets at approximately 4% of their body weight, and the faeces of the animals were collected for 5 days. The determination of the nutrient composition of feed and faecal samples was performed. Data collected were subjected to analysis of variance using a completely randomized design. The result indicated that samples were significantly (P<0.05) different in crude protein composition, with the wheat offal having the highest value corresponding to 9.21 ± 0.12%. Orange pulp had the highest content of ash (6.72 ± 0.12%). The gross energy values were 15.23MJ/kg, 15.31MJ/kg and 16.15MJ/kg for pineapple peel, orange pulp and wheat offal, respectively. The highest manganese concentration was observed in wheat offal (5.19± 0.11mg/l), while orange pulp and wheat offal were higher in sodium and phosphorus concentrations. The pigs fed an orange pulp meal diet recorded the highest average daily weight gain (0.31 kg) and a superior feed conversion ratio (4.19) relative to others. Digestibility values were similar across the three treatment groups. It was, therefore, concluded that orange pulp and pineapple peal meal could serve as alternative fibre sources in growing pigs' rations. Key words: Wheat offal, pineapple peel, orange pulp, growing pigs, digestibility

Control system and process optimization for electroless nickel plating

A novel method based on mid-frequency vibration is proposed to eliminate coating defects such as bubbles during electroless nickel plating. An automated control system for the plating, enabling precise and stable measurements and adjustments of critical parameters such as plating solution temperature, pH, and nickel ion concentration, is also established, which significantly improves process efficiency and coating quality. Experimental results indicate that the system is capable of realizing stable operation over extended periods. A nonporous nickel–phosphorus coating with a thickness greater than 200 μm is successfully obtained, with high phosphorus content, robust adhesion, and superior machinability.