Levels Of Available Phosphorus Research Articles

Ecological Assessment of Non-Target Impact on the Intensity of Human-Induced Changes in Gray Forest Soils

This article presents studies on determining the rate of anthropogenic influences on the gray forest soils sustainability. At present, various pollutants from the atmosphere affect soils. This leads to a decrease in soil fertility, water and air pollution, a decrease in crop yields, and deterioration of product quality. A study of the gray forest soils sustainability to anthropogenic influences incompatible with natural processes is of particular interest to select groups by the degree of anthropogenic transformation. Therefore, the objective of this study was to determine the rate of anthropogenic influences on the grey forest soils sustainability and the degree of their anthropogenic transformation. This requires determining the change in the agrochemical indicators of the fertility of gray forest soils disturbed by overburdened quarrying. Identifying the nature of changes in the texture and micro-aggregate composition of the disturbed soils. Assess the nature of changes in the heavy metals content in gray forest soils of the areas chemically polluted by unauthorized disposal of industrial wastes. Reveal the nature of technogenic load and ecological hazard of industrial waste on the fertile layer of gray forest soils in the chemically polluted area. The research was conducted on an agricultural land site, where soil samples of gray forest soils were extracted. As a result, the gray forest soils’ sustainability to anthropogenic impact, incompatible with natural processes, was assessed. The rates of organic content reduction due to violation of the humus layer were proved. The decrease level of available phosphorus was proved, significant fluctuations for potassium in the soils were revealed. A significant decrease in soil acidity has been confirmed. The influence of chemical pollution of the soil cover by heavy metals has been found out. The intensity of anthropogenic load of industrial waste on the soil depending on the soil contamination levels of heavy metals was revealed.

Phosphorus equivalency of phytase with various evaluation indicators of duck in starter.

This study was conducted to evaluate phosphorus (P) equivalency of phytase with various evaluation indicators of ducks in starter (0-14days). Three hundred and twenty 1-day-old Cherry Valley ducks were randomly assigned to eight groups. The dietary treatments were four levels of available phosphorus (aP) with 0.25%, 0.32%, 0.39%, and 0.46% (treatments I-IV) and four levels of phytase added to low-aP basal diet (treatment I) with 300, 600, 900, and 1200 units (U) per kg (treatments V-VIII). The results were that compared to treatment I, increasing aP and supplementary phytase significantly (p<0.05) improved body weight (BW), BW gain (BWG), feed intake (FI), live BW, carcass weight, semieviscerated weight, eviscerated weight, leg muscle weight, and decreased feed conversion ratio (FCR). Treatments V and VI did not significantly increase tibia ash, tibia calcium, and tibia P of 14-day-old ducks (p>0.05). Following the increase of aP level (treatments I-IV), apparent utilization of Ca and P of ducks increased with varying degrees. With the increase of dietary phytase level (treatments V-VIII), the apparent utilization of Ca and P showed no significant difference (p>0.05) but an increasing trend. Serum P reached the highest level when adding 600U/kg phytase (treatment VI). Serum Ca and serum alkaline phosphatase activity showed no significant difference among treatments V-VIII (p>0.05). Based on corn-soybean-rapeseed meal diet, with the evaluation indexes of FI, BWG, tibia ash, tibia Ca, tibia P, and apparent utilization of Ca and P, the addition of 500U/kg phytase could release aP of 0.03%, 0.04%, 0.02%, 0.01%, 0.02%, 0.08%, and 0.07%, respectively. On the same way, the addition of 1000U/kg phytase could release aP of 0.07%, 0.09%, 0.06%, 0.02%, 0.07%, 0.09%, and 0.09%, respectively.

Prediction of Regional Forest Soil Nutrients Based on Gaofen-1 Remote Sensing Data

The study on the spatial distribution of forest soil nutrients is important not only as a reference for understanding the factors affecting soil variability, but also for the rational use of soil resources and the establishment of a virtuous cycle of forest ecosystems. The rapid development of remote sensing satellites provides an excellent opportunity to improve the accuracy of forest soil prediction models. This study aimed to explore the utility of the Gaofen-1 (GF-1) satellite in the forest soil mapping model in Luoding City, Yunfu City, Guangdong Province, Southeast China. We used 1000 m resolution coarse-resolution soil map to represent the overall regional soil nutrient status, 12.5 m resolution terrain-hydrology variables to reflect the detailed spatial distribution of soil nutrients, and 8 m resolution remote sensing variables to reflect the surface vegetation status to build terrain-hydrology artificial neural network (ANN) models and full variable ANNs, respectively. The prediction objects were alkali-hydro-nitrogen (AN), available phosphorus (AP), available potassium (AK), and organic matter (OM) at five soil depths (0–20, 20–40, 40–60, 60–80, and 80–100 cm). The results showed that the full-variable ANN accuracy at five soil depths was better than the terrain-hydrology ANNs, indicating that remote sensing variables reflecting vegetation status can improve the prediction of forest soil nutrients. The remote sensing variables had different effectiveness for different soil nutrients and different depths. In upper soil layers (0–20 and 20–40 cm), remote sensing variables were more useful for AN, AP, and OM, and were between 10%–14% (R2), and less effective for AK at only 8% and 6% (R2). In deep soil layers (40–60, 60–80, and 80–100 cm), the improvement of all soil nutrient models was not significant, between 3 and 6% (R2). RMSE and ROA ± 5% also decreased with the depth of soil. Remote sensing ANNs (coarse resolution soil maps + remote sensing variables) further demonstrated that the predictive power of remote sensing data decreases with soil depth. Compared to terrain-hydrological variables, remote sensing variables perform better at 0–20 cm, but the predictive power decreased rapidly with depth. In conclusion, the results of the study showed that the integration of remote sensing with coarse-resolution soil maps and terrain-hydrology variables could strongly improve upper forest soil (0–40 cm) nutrients prediction and NDVI, green band, and forest types were the best remote sensing predictors. In addition, the study area is rich in AN and OM, while AP and AK are scarce. Therefore, to improve forest health, attention should be paid to monitoring and managing AN, AP, AK, and OM levels.

Soil mapping and characterization of the Mapou basin, Haiti

Soil mapping and characterization are extremely important, acting as a link between the preservation of the environment, sustainable agricultural practices as well as food-security, especially in one of the poorest and most food-insecure nations in the world. Soil mapping was carried out in the Mapou basin in the South-East Department of the Haiti, in order to contribute with the land use, agriculture planning, as well as soil conservation and food-security. Relationships with the different land uses and landscape attributes of the study area were determined. For this purpose, 24 soil profiles and three mini-trenches were dug, which were classified according to the World Reference Base for Soil Resources – WRB. In this region, the most representative soils were classified as following: Regosols, Leptosols, Cambisols, Luvisols, Lixisols, Calcisols, Fluvisols, Chernozems and Acrisols. Haplic Lixisoils are the deepest soil class in the region. All soils are strongly influenced by the properties of the parent material. Overall, soils are eutrophic with low levels of available phosphorus. Also, soils are weakly developed, shallow and strongly susceptible to erosive processes due to the steep slope and removal of the soil coverage. Data presented in this work will guide sustainable agricultural practices and soil management in the long-term scenario.

A new approach for quantifying phosphorus requirement in Colossoma macropomum using CT scanning

Available phosphorus (AP) requirement for tambaqui (Colossoma macropomum) was evaluated using different response parameters, and CT scanning was used to determine the adequacy of dietary P along with bone mineralization data. A total of 192 tambaqui juveniles (17 ± 0.85 g) were stocked into 24 70 L-tanks using randomized block design (different floors) with six treatments (1.3, 2.4, 4.8, 6.3, 7.8 and 8.8 g kg−1 AP) and four replicates. Fish were fed ad libitum with six semi-purified diets containing graded levels of AP for 90 days. The dietary AP requirement was estimated using non-linear regression models. No mortality or apparent signs of P deficiency were observed. Increasing dietary AP levels improved all performance variables. Dietary P levels significantly affected bone density. The estimated P requirement for tambaqui was 6.3, 3.68, 5.0 and 6.91 g kg−1 diet for improved weight gain, bone density, vertebrae mineralization and carcass mineral deposition, respectively. CT scanning allowed the visualization of bone structures affected by P deficiency and could predict the P requirement based on vertebrae mineralization. Additionally, blood chemistry parameters were significantly affected by the dietary P level, except for serum calcium. Thus, the use of 6.3 g kg−1 AP in tambaqui diets can maintain normal growth and bone mineralization of juveniles from 17–150 g.

Distribution and determinants of organic carbon and available nutrients in tropical paddy soils revealed by high–resolution sampling

Rice is one of the most important crops in China; however, the loss of paddy area and imbalanced soil nutrient composition threaten food security in China owing to the increasing food demand. Soil nutrients significantly influence soil fertility, quality, and productivity, thereby controlling rice production and agroecosystem sustainability. However, a systematic assessment of the nutrient distribution and its driving factors is lacking in the low–yield paddy soils of southern China. In this study, 3239 surface paddy soil samples covering an area of 1278 km2 were collected and analyzed for soil organic carbon (SOC), alkaline hydrolyzable nitrogen (AN), available phosphorus (AP), and available potassium (AK). The dominant factors influencing SOC, AN, AP, and AK were identified using a Random Forest (RF) method. We identified deficient levels of SOC (8.94 g kg−1), SOC density (SOCD, 21.1 t ha−1), AN (55.3 mg kg−1), and AK (37.2 mg kg−1) in tropical paddy soils, but high levels of AP (34.7 mg kg−1). According to the RF, SOCD was significantly correlated with soil AN and AK, implying their coupled cycling in tropical paddy soils; however, the negative correlation between SOC and AP signified decoupling. Compared with waterloggogenic paddy soils, gleyed paddy soils had significantly higher SOC concentrations and densities but significantly lower AP and AK concentrations and pH. Analyses of cropping system effects indicated that double– and triple–cropping systems had significantly higher SOC, bulk density (BD), SOCD, AP, AK, and pH than those of single–cropping systems. These results suggested that tropical paddy soils can potentially sequester OC and available nutrients via efficient soil management. Considering the deficient AN and AK levels of single–cropping system and their high importance on SOCD and soil productivity, double– and triple–cropping systems (generally with high N and K fertilization and residue return) are recommended as an efficient approach to improve the poor soil nutrient status and enhance the OC pool and rice production in tropical paddy soils.

Preliminary Results of Effect of Rotational Grazing of Farmed Red Deer (Cervus elaphus) on the Biochemical Status of Soil

The aim of the study was to identify the trends and dynamics of changes in the chemical and biochemical properties of soil induced by rotational grazing of farmed deer. Soils pH and the content of mineral nitrogen forms, total nitrogen, and organic carbon were determined in the study and the activity of three soil enzymes. The monitored soils were slightly acidic and neutral, with pH in 1 mol KCldm−3 ranging from 6.37 to 7.03. The contents of content of organic carbon, total nitrogen in the monitored soils were in the range of 9.42–19.37 gkg−1 and 1.13–2.24 gkg−1, respectively, while the contents of N-NH4+ and N-NO3− of 1.34–7.08 mgkg−1 and 102.8–619.5 mgkg−1, respectively. The mean levels of nitrate nitrogen in the pasture soils were lower than that in the mown soil. The soils from the pastures were characterized by a higher level of available phosphorus, potassium, and magnesium forms than the mown soil. In the deer grazing areas, the activity of all enzymes was clearly higher than in the soil from the control plot. The results of the present pilot study have demonstrated a positive effect of cervid grazing on the biochemical parameters of the soil environment.

English

In this study rhizosphere soil of cornat a milk stage was collected to investigate characteristic metabolites and their potential functions. Total nitrogen, organic matters, ammonium nitrogen, pH values, available phosphorus and potassium were determined by semimicro-Kjeldahl method, potassium dichromate (external heating) method, indophenol blue colorimetric method, potentiometry, NaHCO3leaching-molybdenum-antimony colorimetric method and NH4OAc leaching-flame spectrometry, respectively. In addition, UPLC-Q/TOF-MS was adopted for non-targeted metabolomicanalysis. As revealed by results, the total nitrogen contents in soils collected from Dongchuang (i.e., DCMRS for short)0.67±0.14mg/kg lower than from Fumin (i.e., FMMRS for short); moreover, both DCMRS and FMMRS were acid soils. DCMRS contains higher levels of AN (Ammonium nitrogen), SOC (Soil organic carbon), and AP (Available phosphorus) than FMMRS. The amount of TN (Total nitrogen) contained in FMMRS soil was2.410±0.422mg/kg, which is higher than DCMRS. All data derived from UPLC-Q/TOF-MS met the corresponding requirements for further analysis. Metabolites such as 2-methyl-1-propylamine, gamma-butyrolactone and 3-methyl-1-butylamine were detected in DCMRS and FMMRS samples. Several pathways were included, such as lipid metabolism, xenobioticsbiodegradation and metabolism, terpenoids and polyketides, and amino acid metabolism. Through comparison of FMMRS and DCMRS, metabolic pathways associated with nitrogen, carbon, and antibiotic metabolism including iron transport were significantly different between them. Taken together, FMMRS is more fertile, less acidic, and higher in nitrogen than DCMRS.© 2021 Friends Science Publishers

The spatial distribution of soil nutrients matter and variation characteristics of Datong Abandoned Coal Mine area in Huainan City

This paper describes the analysis of nutrients matter in soil sampled from Datong abandoned mining area in Huainan City. Spatial interpolation in GIS is applied to the revelation of spatial distribution of nutrients matter. Results show that: In abandoned land in Datong coal mining, the level of available phosphorus in soil was very short and the following grades, and the level of nitrogen was short grades, and the level of organic matter was medium and the following grades. Distribution of these heavy metals present a stronger spatial relevance because their spatial pattern are mainly influenced by natural factors such as complex micro-geomorphology, vegetation, topography, strongly human disturbance and other structural factors. All of spatial variability was middle and small scale. Characteristic of spatial variation was relation with the complex distribution object. Random factors, such as sampling interval, soil type and so on, play a relatively greater role in spatial variability of nutrients matter.

Effects of Dietary Available Phosphorus Levels and Phytase Supplementation on Performance, Egg Quality and Serum Biochemical Parameters of Hy-Line Brown Laying Hens from 40 to 60 Weeks of Age

This study was performed to evaluate the effects of available phosphorus (AP) levels with or without supplemental phytase on the performance, egg quality, and serum biochemical parameters of laying hens. A total of 540 laying hens (40-week-old) were housed in cages and assigned to 6 dietary treatments with 5 replicates each, for 20 weeks. The treatments consisted of 0.20%, 0.25%, and 0.30% AP diets with or without phytase supplementation. During the 20-week period, egg production was lowest in hens fed the 0.20% AP diet; however, phytase supplementation in the diet completely corrected the adverse effect (<i>P</i>&lt;0.05). No consistent difference was observed in egg production between hens fed the 0.25% and 0.30% AP diets and those fed the 0.20% and 0.30% AP diets with phytase supplementation. Similarly, egg mass was lowest in the 0.20% AP diet-fed group, and no difference in egg mass was observed in the 0.25% and 0.30% AP diet as well as the phytase-supplemented diet groups; however, egg mass was improved in the phytase-supplemented diet groups(<i>P</i>&lt;0.05). Egg quality traits did not differ with dietary treatments. Serum alkaline phosphatase level showed a linear decrease (<i>P</i>&lt;0.05) in the phytase-treated groups with increasing AP levels; moreover, a numerically linear increase (<i>P</i>&lt;0.05) in serum Ca and P levels was observed in the phytase-treated groups. The results of this study indicate that phytase supplementation in the diet of laying hens could increase egg production and may lead to greater mineral absorption.

Soil Properties Under Different Vegetation Types in Chittagong University Campus, Bangladesh

Soil physical and chemical properties at three layers such as top (0-10 cm), middle (10-20 cm) and bottom (20-30 cm) layers under three different vegetation types were studied. Soil samples were collected from Acacia forest, vegetable and fallow lands of Chittagong university campus, Chittagong, Bangladesh. Results showed that sand was the dominant soil particle followed by clay and silt fractions in all soil depths under different vegetation types. Soils of fallow land showed the highest values of bulk density while forest soils had the lowest values at three depths. Acacia forest soil having lowest values of dispersion ratio (DR) is less vulnerable while fallow soil with highest DR values is more vulnerable to soil erosion. The lower pH value at all soil layers in three ecosystems represented that soils under study are acidic in nature. Contents of organic matter, total nitrogen, exchangeable cations (Ca2+, Mg2+, K+ and Na+) and cation exchange capacity (CEC) were observed higher in Acacia forest soils compared to vegetable and fallow soils. Only soils of vegetable land had higher level of available phosphorus in three layers than that of other two land covers. The study also revealed that different soil properties were observed in three different vegetation types might be due to variation in vegetation and agronomic practices.

Rhizosphere soil affects pear fruit quality under rain-shelter cultivation

The use of rain shelters in pear cultivation has been shown to improve yields and the appearance and quality of fruit, as well as reduce diseases and pests; however, how rain shelters affect soil chemical properties, soil enzyme activity, and soil microbial diversity remains unknown. Here, we studied pear trees under rain-shelter cultivation and open-field cultivation in the same orchard and compared fruit quality, soil chemical characteristics, soil enzyme activity, and soil microbial diversity. Results showed that rain shelters can significantly (p &lt; 0.05) increase the sugar content (sweetness) of pear fruits and decrease the content of acids. The levels of available phosphorus, available potassium, organic matter, and water in soils under rain shelters were significantly (p &lt; 0.05) lower than in soils in open fields. Rain-shelter treatment increased soil polyphenol oxidase activity and decreased phosphomonoesterase, urease, and sucrase activity. Analysis of microbial carbon-source utilization rates and microbial diversity showed that open-field cultivation is beneficial for microbial carbon-source utilization and microbial diversity in rhizosphere soil. Our study found that rain-shelter cultivation is not beneficial to soil fertility, microbial carbon-source metabolism and utilization, matter cycling, or microbial diversity and that the use of rain shelters may require appropriate nutrient and organic matter supplementation to maintain long-term cultivation of crops; whereas, the effects of environmental factors on open-field cultivation are greater, and more refined water and fertilizer management is required to improve fruit quality.

Yield and must composition of grapevines subjected to phosphate fertilization in Southern Brazil

Abstract: The objective of this work was to evaluate the yield and must composition of 'Cabernet Sauvignon' and 'Chardonnay' grapevines subjected to phosphorus applications to a soil from a high-altitude region of Southern Brazil, during three crop seasons. Experiments 1 and 2 were carried out in 'Cabernet Sauvignon' and 'Chardonnay' commercial vineyards, respectively, in the municipality of Água Doce, located in the Midwestern region of the state of Santa Catarina. The soil from the two vineyards was classified as a Typic Humicryept. The used source of P was triple superphosphate (45% P2O5). From 2011 to 2013, at flowering, a total of 0, 10, 20, 40, and 80 kg ha-1 P2O5 were applied in the crown projection area, to the soil surface, without incorporation, in both vineyards. Soil and leaf P concentration, yield parameters, and must quality were evaluated. The increase in P availability decreased total titratable acidity and tartaric acid in the must of the 'Cabernet Sauvignon' grapevine in the 2013/2014 crop season and increased pH and total soluble solids in the must of the 'Chardonnay' grapevine in the 2011/2012 crop season. Phosphorus application to the soil increases the levels of available phosphorus, but does not result in higher yields for 'Cabernet Sauvignon' and 'Chardonnay' grapevines.

Second-crop cowpea under residual phosphorus doses in the Brazilian Amazon

ABSTRACT The southeastern mesoregion of the Brazilian Pará state is an important soybean producer, and the second-crop system can increase the local agricultural production. However, Latosols with medium to very clayey texture predominate in the region and, despite being suitable for farming, they naturally have low levels of available phosphorus (P). This study aimed to evaluate the yield of second-crop cowpea [Vigna unguiculata (L.) Walp] under doses of residual P in a Yellow-Latosol. Two experiments were installed under field conditions. The experimental design was randomized blocks, with five treatments (residuals of 0, 50, 100, 150 and 200 kg ha-1 of P2O5) and four replications. The first experiment consisted of cultivating second-crop cowpea after the soybean harvest, with phosphate doses provided during the soybean planting, and the second of second-crop cowpea after the rice harvest, with phosphate doses provided during the rice planting. The 1,000-grain weight and production of pods, husks and grains were evaluated. The production of pods and husks were higher in the area with residual P. The highest yield was obtained in the residual dose of 200 kg ha-1 of P2O5, reaching a grain yield of 1,256 kg ha-1 after the soybean harvest and 885 kg ha-1 after the rice harvest.

Soil Chemical Property Variation under Different Conservation Agriculture Practices, in Bako Tibe District, West Shoa, Ethiopia

Conservation agriculture is claimed to be one of the solutions for the problems of poor agricultural productivity in sub-Saharan countries. The impact of conservation agriculture depends on environmental factors such as slope, vegetation, soil type, rain fall pattern and intended crops. This study was conducted from 2013 to 2014 with the objective of assessing the impact of conservation agriculture practices on soil chemical properties. Five main treatments were selected for the study: Monocropping (maize) without crop residue, Monocropping (maize) with crop residue, Crop rotation (maize and haricot bean) with crop residue, Intercropping (Haricot bean with maize) with crop residue and a grazing land as a control. A Randomized complete block design with four replications was used. A total of 40 composite soil samples (4 replication * 5 treatments * 2 soil depth) were collected and analysed for selected soil chemical properties. Results showed that soils in the study area were moderately acidic, and contained medium level of available phosphorus (AP) (7.33±0.58 mg/kg), but low concentration of total N (0.176±0.02%). Soil pH, soil organic carbon (SOC), total nitrogen (TN), C/N, and AP did not significantly differ (p=0.958, p=0.998, p=0.219, p=0.140 and 0.568) respectively, among the treatments following the four year of conservation agricutural practices. Thus, conservation agriculture has little effect on soil properties in short term, but it may take longer time to influence on different soil chemical properties in the study area.

Microbial Community Structures and Important Associations Between Soil Nutrients and the Responses of Specific Taxa to Rice-Frog Cultivation.

Rice-frog cultivation is a traditional farming system in China and has been reintroduced as an agricultural practice in China in recent years. The microbial community in paddy rhizospheric soils has attracted much attention because many microorganisms participate in functional processes in soils. In this study, Illumina MiSeq sequencing-based techniques were used to investigate soil microbial communities and functional gene patterns across samples obtained by conventional rice cultivation (CR) and rice-frog cultivation (RF). The results showed that RF significantly affected the microbial community composition and richness, which indicated that the rhizospheric microorganisms responded to the introduction of tiger frogs into the paddy fields. Operational taxonomic units (OTUs) from Sandaracinaceae, Anaerolineaceae, Candidatus Nitrososphaera, Candidatus Nitrosotalea, Candidatus Nitrosoarchaeum and some unclassified OTUs from Euryarchaeota and Agaricomycetes were significantly enriched by RF. The abiotic parameters soil organic carbon (SOC), nitrate nitrogen (NO3−-N), and available phosphorus (AP) changed under RF treatment and played essential roles in establishing the soil bacterial, archaeal, and fungal compositions. Correlations between environmental factors and microbial communities were described using network analysis. SOC was strongly correlated with Anaerolineaceae, Methanosaeta, and Scutellinia. NO3−-N showed strong positive correlations with Opitutus, Geobacter, and Methanosaeta. NH4+-N was strongly positively associated with Sideroxydans, and TN was strongly positively correlated with Candidatus Nitrotoga. Compared to conventional CR, RF greatly enriched specific microbial taxa. These taxa may be involved in the decomposition of complex organic matter and the transformation of soil nutrients, thus promoting plant growth by improving nutrient cycling. The unique patterns of microbial taxonomic and functional composition in soil profiles suggested functional redundancy in these paddy soils. RF could significantly affect the bacterial, archaeal, and fungal communities though changing SOC and AP levels.

Decrease in diversity and shift in composition of the soil bacterial community were closely related to high available phosphorus in agricultural Fluvisols of North China

ABSTRACT Our objectives were to investigate whether AP affects the soil bacterial community composition and diversity in high-level available phosphorus (AP) soils. The bacterial community was analysed through high-throughput sequencing using the Illumina MiSeq platform. Fifteen soils, including barren land, cropland and greenhouse soils which were sandy loam Fluvisols, were selected from different fields in Beijing, China, with AP contents ranging from 5.03 to 391.45 mg kg−1. Statistical analyses revealed high AP (>100 mg kg−1) decreased alpha diversity (Shannon’s index, H’) but not beta diversity of the soil bacterial community. The sequencing of 16S rRNA genes showed that Proteobacteria, Bacteroidetes and Acidobacteria were the dominant phyla in sandy loam Fluvisols. AP, soil organic carbon (SOC) and total nitrogen (TN) had synergistic influence on the shift of the bacterial community composition. Moreover, AP was the main driving factor affecting the soil bacterial community composition compared with other environmental factors. The members of the Proteobacteria, Bacteroidetes and Actinobacteria belonging to copiotrophic taxa typically increased in relative abundance in high-P soils, while oligotrophic taxa (mainly Acidobacteria) decreased in relative abundance. Our results demonstrated that the bacterial community composition would shift from oligotrophic to copiotrophic with increasing levels of AP.

The response of microbial composition and enzyme activities to hydrological gradients in a riparian wetland

Hydrological condition is one of the important factors impacting microbial structure in riparian wetlands. However, how these microbial communities respond to different hydrological gradients through environmental factors remains uncertain. The main objective of this research was to identify soil microbial community structure under various water levels in a wetland and provide instructive information for assessing wetland function. Soil samples were collected from sampling plots under different hydrological conditions. Soil parameters, including total nitrogen (TN), available nitrogen (AN), total phosphorus (TP), available phosphorus (AP), soil organic carbon (SOC), and dissolved organic carbon (DOC), were utilized to identify the effect of different hydrological conditions on soil properties. The quantity and abundance of phospholipid fatty acid (PLFA) and enzyme activities (alkaline phosphatase, urease, and invertase) were utilized to evaluate variation of microbial community. The PLFA of bacteria, fungi, and actinomycetes accounted for 80.64–85.09%, 9.09–12.23%, and 5.06–6.02% of the total PLFA in wetland soil, respectively. Soil water content showed significant correlation with microbial PLFA and enzyme activities. Long-term inundation led to substantial alteration in the microbial biomass and structure. The redundancy analysis (RDA) identified that AN and AP were the critical factors impacting the structure of microbial community, and AP and SOC were principal factors to soil enzyme activities. Soil water content was the principal controlling factor in the formation of special environment for microbial community. The perennial flooded condition stimulated the increase of bacteria, fungi, and actinomycetes through changing AN and AP levels. Thus, the relation between microbial community and hydrological gradients was significantly impacted by soil nutrition.

Soil chemical properties and geographical distance exerted effects on arbuscular mycorrhizal fungal community composition in pear orchards in Jiangsu Province, China

Arbuscular mycorrhizal fungi (AMF) are considered to be natural biofertilizers because they provide the host with mineral nutrients, particularly phosphorus. However, there is insufficient information on AMF community compositions and their determining factors in pear orchard soils. In this study, hypotheses tested were that both soil characteristics and geographical distance influence the variation in AMF community composition. The community composition and diversity of AMF were examined using MiSeq sequencing in nine pear orchard soils in Jiangsu Province, China. Our data showed that a total of 108 operational taxonomic units (OTUs) were identified, with the majority belonging to Glomus (>90%). Nonmetric multidimensional scaling (NMDS) plots and PERMANOVA based on Bray-Curtis distance showed a clear separation of soil samples, suggesting significant dissimilarities in the AMF communities among the nine sampling sites. Distance-decay relationship (DDR) curves revealed that both geographical distance and soil chemical properties affect AMF community composition. Canonical correspondence analysis (CCA) and forward selection were used to examine the significance of environmental factors in more detail, and found that soil chemical properties and geographical distance correlated with AMF community composition. Particularly, pH, available phosphorus (AP) and Cu were the most significant soil properties that affected AMF communities. Partial CCA demonstrated that soil chemical properties exerted the primary influence on the assembly of the AMF communities in pear orchard soils, while geographical distance was less influential, which was supported by a partial Mantel analysis. Overall, we concluded that soil chemical properties and geographical distance were important parameters that affected AMF communities in Jiangsu Province, China, and the soils with moderate level of AP and low contents of heavy metals may preserve diverse AMF communities.

The effect of enzyme and protein source on laying hens performance, eggshell and bone traits

The aim of the study was to investigate the interaction between exogenous phytase with protease and protein source in laying hens diet. A completely randomised design study with a 2 × 4 factorial arrangement was conducted to observe effects of protein source (soybean vs. yellow lupine seeds diet) and enzyme addition (no enzyme vs. phytase or protease or both) on laying hens performance, bone mineralization and some egg traits. One hundred sixty Hy-Line Brown hens at the age of 18 weeks were weighed and randomly assigned to 10 treatments, each with 16 birds. According to the producer recommendation in diets containing enzymes reduced the level of available phosphorus (50% reduction) and digestible amino acids - 5% reduction. The egg production during the entire experiment was similar in all groups without significant differences. The egg weight was also on an equal level in all treatments and it was about 58g. Birds fed different protein source were characterized by similar feed intake and feed conversion ratio during the whole experiment. The feed conversion ratio (FCR) was about 1.9-2.0 in all groups. Tibia ash was affected by enzymes supplementation. There was an interaction between protein source and enzymes addition. Birds from treatments fed with yellow lupine meal (YLM) diets reached highest tibia ash level in a group with phytase addition and in groups with SMB in a group with phytase and protease mix. The inclusion of enzymes improved the thickness of the shell. There was an interaction between protein source and enzyme inclusion. It was an interaction between experimental factors in shell breaking strength. Stronger eggshell was laid by hens from groups fed with the inclusion of yellow lupine meal. Addition of phytase had a positive impact on increasing the strength of eggshell. Only inclusion of enzymes affected significantly on shell elastic deformation in part I of eggs. Eggs from hens fed diets with inclusion of protease and phytase mix were most resistant to elastic deformation.