pH Ca Research Articles

Essential oil-containing solutions (mouthwashes) preserve dental enamel with releasing low Ca and P concentrations without morphology alterations: an in vitro study.

Introduction: The use of natural products such as essential oils has been suggested due to their promising pharmacological effects and economic viability. This study aimed to determine hydrogenic potential (pH), titratable acidity (TA), and ion concentrations of five solutions containing essential oils (EO), when used as a EO-containing solutions, and evaluate ion concentrations, enamel surface loss, and morphology alterations in enamel. Materials and methods: The pH, TA, calcium (Ca), potassium (K), and sodium (Na) concentrations of five EO-containing solutions were measured. Bovine enamel specimens were submitted to two daily 30-s immersions in artificial saliva, citric acid, distilled water, BaCloTea (Basil, Clove e Tea Tree), GeLaTeaPep (Geranium, Lavender, Tea Tree and Peppermint), EucaLem (Eucalyptus and Lemon), Cinnamon, or Spearmint solutions for 14 days. Ca, K, Na, and phosphorus (P) were quantified through ions chromatography, enamel surface loss was determined by profilometry, and surface morphology was qualitatively analyzed through scanning electron microscopy. Data were submitted to one-way ANOVA and Tukey (p < 0.05). Results: The five EO-containing solutions presented significantly lower pH values than distilled water (p < 0.05). The GeLaTeaPep group presented a significantly higher TA value than BaCloTea (p < 0.05), which in turn showed a significantly higher TA value than the other solutions (p < 0.05). The distilled water presented significantly higher Ca, K, and Na concentrations than all EO-containing solutions (p < 0.05). The enamel exposed to EO-containing solutions showed lower Ca and P concentrations than artificial saliva (control) as well as significantly higher surface loss; however, the surface morphology was similar to the artificial saliva. Conclusion: EO-containing solutions have low pH, TA, and low concentrations of Ca, Na, and K. Moreover, enamel exposed to these solutions showed low Ca and P concentrations and slight surface loss without morphology alteration.

Calcium isotope fractionation associated with adsorption and desorption on/from δ-MnO2

Small mineral particles present in soils, such as clay minerals and some oxyhydroxides, constitute important nutrient reservoirs. This behavior is due to the negative charges and high specific surface areas of these particles allowing them to adsorb cations such as calcium (Ca), a macronutrient that occupies key physiological and structural functions in plant metabolism. Although the chemical reactivity of clay minerals is rather well-known in the literature, especially toward macronutrients such as Ca, that of oxyhydroxides such as phyllomanganate minerals remains largely unexplored.To enhance our understanding of the mechanisms at the origin of the storage/release of the different isotopes of Ca in a soil solution, the possible fractionation between 40Ca and 44Ca during adsorption and desorption of Ca on a synthetic phyllomanganate, abiotically precipitated in the laboratory [synthetic analog of vernadite (δ-MnO2)], was studied. Experiments were performed in batch (closed system), and several parameters (time, pH of the solution, Ca concentration and nature and concentration of the desorbent) were tested to cover a large range of physicochemical conditions.This study demonstrated that the light 40Ca isotope is preferentially adsorbed on δ-MnO2, with Δ44/40Ca (the apparent fractionation of the aqueous solution at the stationnary state of adsorption compared to the initial one) of the adsorbed Ca that can reach 1.19 ± 0.15‰. The results showed that this isotopic fractionation occurs at chemical equilibrium in a closed system and that the isotopic fractionation measured in this study during Ca adsorption on phyllomanganate is significantly higher than that reported in the literature during Ca adsorption on other soil constituents such as clay minerals. At pH below 4 Ca occupies only the interlayer/basal sites whereas above this pH Ca fills interlayer/basal sites (∼86%) and edges sites (∼14%). By combining the experimental data obtained at different pH values, initial Ca concentrations and interaction times, our results suggest that isotopic signature of the Ca adsorbed on δ-MnO2 is dependent on the nature of the site involved in the adsorption step (i.e., enriched in 40Ca in the interlayer with Δ44/40Ca equal to −0.43‰ and enriched in 44Ca when bound to the edges with Δ44/40Ca equal to +3.5‰). As revealed by surface complexation modeling, such contrasting behavior between the two types of adsorption sites could be due to the bidendate nature of the Ca adsorption occurring on edges and to ion exchange of Ca2+ with H+ in the interlayer sites. Finally, desorption experiments point to total but not instantaneous Ca desorption, probably due to a partial collapse of the interlayer with some ions used to desorb Ca2+ (K+, NH4+, hexaamine-cobalt). This suggests that the amount of bioavailable Ca in soils by simple ion-exchange reactions is highly dependent on the nature of the ions which could desorb Ca present in the soil solution.

A Study of Oral Health Parameters and the Properties and Composition of Saliva in Oncological Patients with and without Medication-Related Osteonecrosis of the Jaw Who Take Bisphosphonates.

Background and Objectives: The aim of this study was to examine how the status of the oral cavity, composition and properties of saliva change in oncological patients with and without Medication-Related Osteonecrosis of the Jaw (MRONJ) undergoing bisphosphonate therapy. Materials and Methods: A retrospective case-control study of 49 oncological patients using bisphosphonates (BPs) was conducted. The study population was divided into two groups-Group I consisted of 29 patients with MRONJ and Group II of 20 patients without MRONJ. The control group consisted of 32 persons without oncological history and without antiresorptive therapy. Standard dental examination included the assessment of the number of teeth remaining, teeth with caries and fillings, Approximal Plaque Index (API) and Bleeding on Probing (BOP). In terms of MRONJ, localization and stage were assessed. Laboratory tests of saliva included determination of pH and concentrations of Ca and PO4 ions, total protein, lactoferrin, lysozyme, sIgA, IgA, cortisol, neopterin, activity of amylase at rest, and stimulated saliva. The buffering capacity and microbiological tests (Streptococcus mutans, Lactobacillus spp. load) of stimulated saliva were also determined. Results: There were no statistically significant differences between the selected oral parameters and saliva of Group I and Group II. Significant differences were found between Group I and the control group. BOP, lysozyme and cortisol concentration were higher, while the number of teeth with fillings, Ca and neopterin concentrations were lower in comparison to the control group. In Group I, a significantly higher percentage of patients with a high colony count (>105) of Streptococcus mutans and Lactobacillus spp. was also found. The significant differences between Group II and the control group concerned the concentrations of lysozyme, Ca ions, sIgA, neopterin and the colony count of Lactobacillus spp. In the Group I patients who received a significantly higher cumulative dose of BP compared to the Group II, a significant positive correlation was found between the received BP dose and the BOP. Most MRONJ foci were stage 2 and were mainly located in the mandible. Conclusions: Among oncological patients with and without MRONJ undergoing BP therapy compared to the control group, there are statistically significant differences in the dental, periodontal and microbiological status and in the composition of the saliva. Particularly noteworthy are the statistically significant differences in the decreased level of Ca ions, the increased level of cortisol and the elements of saliva related to the immune response (lysozyme, sIgA, neopterin). Additionally, a higher cumulative dose of BPs may affect the susceptibility to the development of osteonecrosis of the jaws. Patients undergoing antiresorptive therapy should receive multidisciplinary medical care, including dental care.

Composition and Properties of Saliva in Patients with Osteoporosis Taking Antiresorptive Drugs

The study population consisted of 38 patients with osteoporosis using AR drugs (Group I) and 16 patients with osteoporosis who had never used AR drugs (Group II). The control group consisted of 32 people without osteoporosis. Laboratory tests included determination of pH and concentrations of Ca, PO4, total protein, lactoferrin, lysozyme, sIgA, IgA, cortisol, neopterin, activity of amylase at rest, and stimulated saliva. The buffering capacity of stimulated saliva was also determined. There were no statistically significant differences between the saliva of Group I and Group II. No statistically significant correlation was found between the amount of time using AR therapy (Group I) and the tested parameters of the saliva. Significant differences were found between Group I and the control group. The concentrations of PO4, lysozyme, and cortisol were higher, while concentrations of Ca ions, sIgA, and neopterin were lower, in comparison to the control group. The significant differences between Group II and the control group were smaller, and they concerned only the concentrations of lysozyme, cortisol, and neopterin. The saliva of people with osteoporosis subjected to AR therapy and those not subjected to AR therapy did not show statistically significant differences in terms of the examined parameters of the saliva. However, the saliva of patients with osteoporosis taking and not taking AR drugs was significantly different compared to the saliva of the control group.

Soil fungal and bacterial community structure in monocultures of fourteen tree species of the temperate zone

Knowledge about the effects of tree species on the soil environment is crucial for implementation of sustainable forest management. The aim of our study was thus to compare the effects of 14 tree species with contrasting traits and origin in Poland and/or Europe on fungal and bacterial diversity in soils. To reduce confounding factors such as differences in topography, microclimate, the age of the tree stand, the admixture of other tree species and soil type, we used a common garden experiment, comprising 14 tree species planted 50 years ago as monoculture plots. We examined soil microbial communities via metabarcoding of bacteria and fungi, including arbuscular mycorrhizal fungi, followed by Illumina sequencing. The highest fungal species richness was found under Acer pseudoplatanus, whereas Carpinus betulus and Quercus rubra were characterized by the lowest species richness. Acer pseudoplatanus and Tilia cordata were associated with the highest species richness of bacteria, followed by Acer platanoides. Fungal composition was mainly explained by the tree species identity, while bacterial composition was explained by soil chemical properties, namely pH and contents of exchangeable Ca, K and Mg. Interaction between tree species identity and soil chemical properties was also important. Tree species belonging to the same genus tended to harbor microbial communities with similar structures, while we did not observe a clear difference between broadleaf and coniferous trees, and between native and alien species. We suggest using admixtures of Acer spp. and T. cordata to improve soil microbial diversity in the process of afforestation of new areas and in restoration of degraded lands.

The effects of chemical conversion parameters on morphology and corrosion performance of calcium phosphate coating on AZ31 alloy

To improve the corrosion resistance of magnesium alloy, Ca–Ph coatings were prepared on AZ31 alloy substrates by chemical conversion. The treatment time and temperature have been adjusted to prepare the coatings with various morphologies, compositions, and properties. The surface morphologies and chemical compositions were investigated using a scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS), and the phase structure was investigated using X-ray diffraction (XRD). The corrosion performance of the coatings was investigated by an electrochemical test and immersion test. All the coatings showed significant corrosion protection to the substrate in the simulated body fluid (SBF) solution. The coating prepared at 5 h duration was thicker than other coatings but with the lowest corrosion current density in the electrochemical test and weight loss studies after being immersed in the SBF solution for 7 days had the slightest loss. The results showed that higher temperatures favored the presence of hydroxyapatite and that the coating thickness had an enhanced influence on the corrosion performance.

Increasing yield of paddy rice on peat soil using steel slag

Peat soil is one marginal soil having the potential for paddy rice cultivation. Peat soil has a low content of total Si and available copper and zinc. Steel slag is the typical source of Si elements. Two experiments were carried out to determine steel slag supplementation effects on the growth and development of paddy rice on peat soil. Experiment 1 was a greenhouse pot experiment to evaluate three steel slag dosages (i.e., 0.0, 2.5, and 5.0 %). Experiment 2 was a field experiment to validate the effects of five steel slag dosages (i.e., 0, 2.5, 5.0, 7.5, and 10-tons ha−1). In experiment 1, applying steel slag at 2.5 and 5.0 % dosages significantly increased paddy rice development. In experiment 2, paddy rice development was significantly increased with steel slag. Grain yield increased from 65 to 96 % with steel slag 2.5 to 10 tons ha−1. The response of paddy rice on peat soil to steel slag in experiments 1 and 2 was associated with increasing soil pH and availability of Si, Mg, and Ca.

The Effect of pH and Mineral Content of Fe, Ca, Mg, And Cl On The Growth of Koi Fish (Cyprinus carpio) in Aquariums with Water Sources of The Tuntungan River in Medan

The effect of pH and mineral content of Fe, Ca, Mg and Cl on the growth of koi fish (Cyprinus carpio) in an aquarium with water sources of the Tuntungan Medan river has been studied. Cultivate koi fish in the aquarium with water from the Tuntungan river had various pHs between 5 to 10. NaH2PO4 is used to reduce pH level, while NaHCO3 is used to elevate pH level. Before the fish was placed, the mineral content of Fe, Mg, Ca, and Cl in the water after pH arrangement was analyzed. The initial weight of the fish that will be incorporated into each aquarium was weighed. After ten days, the fish were weighed, and the mineral content of Ca, Mg, and Cl were determined by titration method, whereas Fe mineral was determined using the Visible Spectrophotometry method. The same thing is done on days 20, 30, 40, and 50. The results showed maximum growth at 120.50% of fish in the river water aquarium pH = 8.5 with high levels of iron (Fe) which fluctuated between 0.4343 mg / L - 0.6020 mg / L, the level of calcium (Ca) which fluctuated between 7.76 mg / L - 15.52 mg / L, the levels of magnesium (Mg) which fluctuated between 120.28 mg / L - 157.14 mg / L, and levels of chloride (Cl) which fluctuated between 27.99 mg / L - 32.48 mg / L. Minimum growth in amount of 88.02% found in the river water aquarium pH = 5.5 with the levels of iron (Fe) which fluctuated between 0.2246 mg / L - 0.5610 mg / L, the level of calcium (Ca) which fluctuate between 7.76 mg / L - 27.93 mg / L, the levels of magnesium (Mg) which fluctuated between 80.71 mg / L - 108.64 mg / L, and levels of chloride (Cl) which fluctuated between 17.99 mg / L - 39.98 mg / L. Water with pH = 9.5 is not suitable as a medium for the cultivation of koi fish.

Contrasting Adaptation Mechanisms of Golden Camellia Species to Different Soil Habitats Revealed by Nutrient Characteristics

Golden Camellia species are highly specific to certain soil environments. Most species are only native to calcareous soils in karst regions, except for a few that grow only in acidic soils. Our aim is to elucidate the adaptation mechanisms of the species of calcareous-soil golden Camellia (CSC) and acidic-soil golden Camellia (ASC) to habitat soils through plant–soil nutrient characteristics and their relationships. We investigated 30 indices for soils and plants. Compared with ASC, CSC had more fertile soil, while their plant tissues exhibited stronger Ca, P, and Mn and weaker K storage, which may be important mechanisms for adapting to habitat soils. However, ASC showed a higher biological absorption coefficient (BAC) for nutrients, which may contribute to the adaptation of ASC to relatively barren acidic soils. Both CSC and ASC showed much higher BAC and accumulation of Ca than other nutrients. We also found that the concentrations of nutrients in the different tissues varied considerably between species. Correlation analysis revealed 135 significant relationships between the 30 indices, with the soil pH and soil Ca levels being the most important factors influencing the nutrient uptake network. This information helps in understanding the adaptation mechanisms of karst plants to habitat soils.

Investigation of soil properties and pesticide intensity in crop lands at Tangail region of Bangladesh

The study was conducted to investigate the soil properties and pesticide intensity in rice, banana and brinjal growing agricultural land of Delduar and Sakhipur upazila of Tangail district during July 2019 to June 2020. Forty five soil samples were collected from different crop land at the study area and analyzed in the Soil Resource Development Institute to determine the soil properties as pH, total organic matter (OM), total nitrogen (N), available phosphorus (P), available sulfur (S), available zinc (Zn), exchangeable potassium (K), exchangeable magnesium (Mg) and exchangeable calcium (Ca). However, pesticide used intensity was also evaluated through questionnaire survey with farmers and stakeholders in the study area. Results showed that pH, OM, available N, exchangeable Ca and exchangeable Mg content were significantly higher in rice growing land than banana and brinjal. On the other hand, available P, exchangeable K and available Zn content were substantially higher in brinjal growing land than rice and banana. The OM showed significant positive correlation with soil pH, available N, available S, exchangeable Mg and exchangeable Ca (r=0.37, 0.99, 0.31, 0.59 and 0.63, respectively), indicated rice growing land built up these soil properties through increasing soil OM. The available P showed significant and positive correlation with K and Zn (r=0.55 and 0.74, respectively), but negative correlation with exchangeable Mg and exchangeable Ca (r=-0.53 and -0.32, respectively). The exchangeable K showed significant and positive correlation with available Zn (r=0.45) but negative correlation with exchangeable Mg (r=-0.37). The Mg showed significant negative correlation with available Zn (r=-0.45) but positive correlation with exchangeable Ca (r=0.87). Results also revealed that pesticide used intensity was higher in brinjal followed by banana and minimum in rice crop. Study suggests that farmers require up-to-date information on soil nutrient status so that they may use the proper utilization of fertilizers and avoid using excessive amounts of fertilizers and pesticides in their crop land. Int. J. Agril. Res. Innov. Tech. 11(2): 85-94, Dec 2021

Management of Soil Acidity and Its Relations With Soybean Productivity in Brazilian Savanna

The soils of Brazilian Savanna, naturally, present acidity problems, making correction practices fundamental to ensure production. Even with so many years since the introduction of agriculture, some soil correction practices are still misused. Thus, the objective was to evaluate soybean yield and chemical changes in a Red Oxisol in the Brazilian Savanna with the use of limestone, associated or not with gypsum, applied superficially and incorporated by harrow and moldboard plow. The experiment was conducted under field conditions, in Rio Verde-GO, cultivating soybeans in the 2015/2016 and 2016/1017 harvests. The experimental design was in randomized blocks, with four replications, with treatments arranged in a 3 &amp;times; 3 factorial scheme. The first factor refers to the application of superficial limestone and incorporated by harrow and moldboard plow. The second factor was the presence or absence of limestone and/or gypsum (0 + 0; 0.875 + 0 and 0.875 + 1.75 t ha-1). Plant height, number of pods per plant, productivity, pH, Al, CTC, Ca, Mg and V were evaluated, in soil depths of 0-0.2 and 0.2-0.4 m. In the 2016/2017 harvest, the characteristics of pH, CTC, V and contents of Ca, Mg and Al were influenced by the methods of application of limestone and by its use, associated or not with gypsum. There was an increase in pH on the soil surface with the use of limestone and on the subsurface with the use of limestone and gypsum. The moldboard plow provided increases in the contents of Ca and Mg in the soil in comparison to surface application. The moldboard plow incresed in soybean yield, in the second crop, with and without association of gypsum with limestone.

Effect of Biochar and PGPR on the Growth and Nutrients Content of Einkorn Wheat (Triticum monococcum L.) and Post-Harvest Soil Properties

Limited availability of nutrients to crops is a major agricultural concern. Deteriorated soil health and poor fertility status decrease the bioavailability of essential nutrients to the plants. Consequently, organic soil amendment biochar is gaining attention due to its potential benefits. Rhizobacterial inoculation, are also documented as an effective technology for mobilization of immobile nutrients in soil. However, limited literature is available on combined use of rhizobacteria and biochar. Therefore, this study was carried out to examine the changes in the nutrient content of einkorn wheat and the change in some soil properties during the application of plant growth-promoting rhizobacteria (PGPR) with biochar. Four doses of biochar (0, 2.5, 5, and 10%) were applied with and without PGPR in the study. Biochar increased the growth criteria such as plant fresh weight (PFW), plant dry weight (PDW), root fresh weight (RFW), root dry weight (RDW), number of tillers, germination rate (GR) and potassium (K), calcium (Ca), sodium (Na), iron (Fe), copper (Cu), zinc (Zn), manganese (Mn), and nickel (Ni) elements. While PGPR application increased soil pH, dry and fresh weight of root, R/S, K, Ca, Mg, Fe, and Ni contents, and it caused a decrease in PH, PFW, tillers, GR, P, Cu, and Zn values. Combined biochar applications and PGPR had a significant effect on the pH, RFW, R/S, P, Na, and Cu. In conclusion, the combination of biochar and PGPR applications has shown a positive effect in terms of soil properties, plant growth, and element contents of einkorn wheat.

Effect of Charcoal on the Properties, Enzyme Activities and Microbial Diversity of Temperate Pine Forest Soils

Relict charcoal hearths (RCHs) increases soil fertility in forest ecosystems. However, the effects of RCHs on the activity and abundance of soil microorganisms remain unknown. In this paper, we analysed the impact of relict charcoal production on the soil enzymatic activity and composition of soil bacterial and fungal communities in Scots pine forests of the Manowo Forest District in northern Poland. Moreover, we determined the effect of relict charcoal production on the soil properties. Our research was conducted by comparing the physical, chemical, enzymatic and microbiological properties of charcoal-enriched and charcoal-free soils. Significant differences in physical properties were found between these two soil types in terms of their structure and water holding capacity. As expected, horizons enriched with charcoal were characterised by a significantly higher organic carbon content (4.7% on average compared to 2.2% in control horizons), and also by a considerably higher content of available phosphorus (an average of 64.07 mg·kg−1 compared to 36.21 mg·kg−1 in the control). Similarly, RCH horizons displayed a higher pH and higher contents of Ca and Na cations. These results indicated that RCH soils provided more favourable conditions for the soil microbiome, as reflected by the higher enzymatic activity and diversity of the microorganisms. Moreover, bacterial and fungal communities in RCH soils were more diverse and had greater species/genera richness, especially in the case of fungi. Members of the genus Rhodoplanes dominated the bacterial community at both RCH and non-RCH sites, followed by Streptomyces, Burkholderia, Skermanella, Tsukamurella and Candidatus Solibacter. Both culture- and next generation sequencing (NGS)-based analyses showed that soil fungal communities were dominated by Ascomycota, with Penicillium as the most abundant genus. Our results showed that hearth soils may represent a significant C pool in the forest ecosystem. This study supports the strategy of safeguarding such charcoal-enriched soils as precious C reservoirs and ecologically important biodiversity hotspots. Moreover, the application of charcoal may effectively increase the microbial diversity of forest soils, especially during the reforestation or re-cultivation of disturbed habitats.

The role of calcium metabolism disorders in the formation of different density calculi with calcium oxalate nephrolithiasis

Objective To investigate the relationship between calcium metabolism disorders, stone formation inhibitor levels and stone density in primary and recurrent calcium-oxalate nephrolithiasis.Material and Methods Sixty nine patients with urolithiasis were examined, their average age was 41,4 ± 9,5 years. Two main groups were distinguished: Group 1 – primary calcium-oxalate nephrolithiasis (PN), Group 2 – recurrent calcium-oxalate nephrolithiasis (RN). Then each group was divided into two subgroups – A and B according to stone density: 500–1000 HU and from 1000–1500 HU, respectively. Stone density was determined by computed tomography (CT). PTH (parathormone), PTHrP (parathyroid hormone related protein), vitamin D, total blood calcium (Ca), ionized blood Ca, total blood protein, Ca and urine pH were also examined. After the examination, patients underwent surgical removal of the stones.Results It was found that 41.9% of group 1 and 46.9% of group 2 patients had grade I obesity. Average creatinine level in group 2 was 9.7% higher than in group 1 (p &lt; 0.05). Urea level in both groups was not statistically significantly different. Glomerular filtration rate (GFR) was comparable. Groups 2A and 2B had higher PTHrP values (77.61 and 76.98 pg/mL, respectively) combined with relatively high PTH levels (2A – 4.4 pg/mL and 2B – 5.1 pg/mL), relatively low osteopontin concentration (2A – 0.044 pg/ mL, 2B – 1.106 pg/mL), compared to those in group 1 (p &lt; 0.05). Pairwise unidirectional differences between groups 1A and 2A, 1B and 2B were found to correlate positively with density values: for osteopontin: r = 0.992 (p &lt; 0.05); for vitamin D: r = 0.831 (p &lt; 0.05); for blood Ca2+ ions: r = 0.836 (p &lt; 0.05); for urine pH: r = 0.863 (p &lt; 0.05). There was a negative correlation with the daily concentration of urinary calcium ions with the density of concrements: r = -0.663; p &lt; 0.05. The concentration of osteopontin was significantly higher in Group 1B and 2B patients, and it was significantly lower in patients with stones of &lt; 1000 HU density. Higher values of osteopontin concentration were noted in groups 1B and 2B in relation to groups 1A (p &lt; 0.05) and 2A (p &lt; 0.05). The increase of blood Ca2+ ions in patients in groups 1B and 2B in relation to groups 1A (p &lt; 0.05) and 2A (p &lt; 0.05) was also accompanied by higher values of vitamin D.Conclusion Patients with denser stones showed high values of osteopontin and PTHrP in serum and low values of urinary calcium ions, which may lead to the formation of concrements on the matrix with an organic base. Determination of calcium metabolism makes it possible to predict recurrence of KSD in primary calcium oxalate nephrolithiasis and assess the severity of mineral metabolism disorders in recurrent calcium oxalate nephrolithiasis.

Effects of Management Practices on Soil Properties and Plant Nutrition in Hay Meadows in Picos de Europa

Fertilization and mowing affects the physico-chemical properties of soils, as well as the characteristics of the plants growing on them. Changes in the management techniques are causing semi-natural grasslands to disappear all over Europe. These grasslands host a great amount of diversity, thus their conservation is a top priority. This work studies whether the kind of management has an influence on the soil properties and the foliar content in macronutrients in 25 hay meadows located in Picos de Europa (10 in Asturias, 10 in Castilla y León and 5 in Cantabria). Soils at a 0–20 cm depth showed a high content of organic matter and a low C/N ratio. Effective cation exchange capacity was adequate for a texture, which varied from sandy clay loam to loam, with an average clay content of 17%. Mean values of foliar nutrient concentrations showed a deficiency in K. In this study, management practices were shown to affect some properties of the soils, namely pH, sand percentage and exchangeable K and Ca, to different extents. The highest values of pH and exchangeable Ca were significantly correlated with the least intensive management.

Farm use of calcium hydroxide as an effective barrier against pathogens

Livestock farming is affected by the occurrence of infectious diseases, but outbreaks can be prevented by proper sanitary control measures. Calcium hydroxide (Ca(OH)2), commonly called slaked lime, powder is traditionally used as a disinfectant to prevent infectious diseases in livestock. Since Ca(OH)2 can inactivate a wide variety of pathogens, has a small environmental impact, does not require a disinfection tank (i.e., can be spread directly on the ground) and is produced inexpensively worldwide, it is used for the prevention of epidemics on farms worldwide. Water is essential for the strong alkalinity that underlies its disinfecting effect, but it is unknown how much water is required under field conditions. In addition, Ca(OH)2 reacts with carbon dioxide in the environment, reducing its pH, but it is unclear how long its degradation takes under actual field use. Thus, we measured the water adsorption ability of Ca(OH)2-based disinfectants and its relation to disinfectant activity, as assessed by colony counts and live/dead staining and observation. We found that 15–20% (w/w) water in Ca(OH)2 was necessary for disinfection to occur in practice. Moreover, we found that the pH of Ca(OH)2 decreased within about two weeks to one month under actual use in practical conditions and lost its ability to disinfect. We further showed that granules prepared from Ca(OH)2 and zeolite maintained high alkalinity more than twice as long as calcium powder. These findings will help to establish a suitable method of applying Ca(OH)2 to protect farms from infectious diseases.

Geochemical alkalinity and acidity as preferential site-specific for three lineages liverwort of Aneura pinguis cryptic species A

The study focused on the verification of the preferential site-specific concept hypothesizing, that mineral elements could be playing an initiating role in the biological speciation within Aneura pinguis cryptic species. A. pinguis species A and soil materials were collected from three ecological sites of Poland. They underwent genetic (Aneura pinguis) and chemical analyses (soil materials) for pH, total and water soluble (active) forms of Ca, Mg, K, Na fractions. Data revealed trends in the site preference of three genetic lineages (A1, A2 and A3) of A. pinguis cryptic species A. Lineage adaptability index Ca/(Mg + K + Na) reflecting the dynamic character of site pH implied, that lineages A1 and A2 were both calciphilous. The A3 lineages were intrinsically acidophilous and this characteristics was also observed at some A1 lineages. Site concentrations of Ca and in some cases Mg too were crucial in shaping pH, but this process could have been controlled by each mineral element, individually. Calciphilous or acidophilous A. pinguis species may be “remotely” attracted by high or low Ca (or Mg) concentrations, for alkalinity or acidity emergence, respectively. Mineral richness at investigated ecological sites has possibly initiated opportunistic and specific site colonisation by A. pinguis lineages.

Surface-applied or incorporated biochar and compost combination improves soil fertility, Chinese cabbage and papaya biomass

Many Hawaiian agricultural soils are acidic with low-nutrient retention; therefore, organic soil amendments are often used to improve soil properties and increase yields. Amendments can be incorporated for annual crops, but perennial orchards need surface application to avoid damaging surface roots. Pot trials compared responses to incorporated (IBC) or surface-applied (SBC) combination of hardwood biochar and chicken manure compost (4% v/v of each amendment) added to an Andisol and Oxisol. Soil pH was increased by 0.4–1.1 units in IBC and by 0.2–0.5 for SBC in the 0–10 cm soil layer. Both SBC and IBC increased soil total N, extractable P, Ca and Mg in the 0–10 cm soil layer. Soil pH, total C and extractable Ca were also higher in the 10–20 cm soil layer for IBC soil, indicating movement and/or leaching of amendments. Chinese cabbage biomass was 18–70% higher in the IBC and 14–47% higher in the SBC than that in the unamended soil, while papaya biomass was 23% and 19% higher in SBC and IBC, respectively. There was a greater response in the more acidic Andisol soil, with larger improvements in soil pH, plant nutrient uptake and root biomass than the Oxisol. Surface application was as effective in increasing plant growth as the incorporated amendment, providing evidence for farm scale assessment. Biochar and compost are recommended for use in tropical soils, and surface application may be beneficial to annual and perennial crops.

Phosphorus mobilization from intact soil monoliths flooded under simulated summer versus spring snowmelt with intermittent freeze-thaw conditions.

Enhanced phosphorus (P) release from flooded, anaerobic soils has been extensively studied under summer temperatures but not under cold temperatures with intermittent freeze-thaw events. We investigated the temperature and freeze-thaw effects during flooding on the release of P to floodwater from soil monoliths (15-cm depth) collected from eight agricultural fields in Manitoba. Soil monoliths were flooded with reverse osmosis water and incubated for 56 d under simulated summer flooding (SSF; 22±1°C) or snowmelt flooding with intermittent freeze-thaw (IFT; 4±1°C with intermittent freezing) in triplicates. Redox potential (Eh), pore water and floodwater dissolved reactive P (DRP) concentrations, pH, and concentrations of Ca, Mg, Fe, and Mn were determined weekly. In seven soils, Eh decreased rapidly with days after flooding (DAF) under SSF to values<200mV but not under IFT. Both pore water and floodwater DRP concentrations significantly increased with DAF in all soils under SSF and in seven soils under IFT. Although DRP concentrations were consistently greater under SSF than IFT in four soils, other soils had similar concentrations at certain DAF. Significant relationships between ion concentrations and redox status that fitted both IFT and SSF data in most soils suggest that similar redox-driven mechanisms are responsible for the P release; however, less P was released under IFT than under SSF because soils were not severely reduced under IFT. Substantial P release in a few soils under IFT appeared to be unrelated to redox status, suggesting other P release mechanisms that are not redox driven.

Effects of Solanum mauritianum Scopoli (bugweed) invasion on soil and vegetation in Vhembe Biosphere Reserve, South Africa

AbstractThis study examined the effects of Solanum mauritianum Scopoli (bugweed) invasion on soil properties and vegetation diversity and cover on three paired invaded and uninvaded sites in Vhembe Biosphere Reserve, Limpopo Province of South Africa. Soils were analysed for pH, total P, C, N and exchangeable cations of Na, K, Ca and Mg. In addition, soil moisture content, penetration resistance levels and soil water repellency were measured over three months. Vegetation diversity and cover were surveyed in plots measuring 10 × 10 m in both invaded and uninvaded sites. Results showed that soil pH, nutrient concentrations of total P, N, C, cations of K, Ca and Mg, soil penetration resistance levels and water repellency were significantly (P &lt; 0.01) higher in the invaded than uninvaded sites. Soil moisture were significantly (P &lt; 0.001) higher in the uninvaded than invaded sites. Vegetation diversity and cover were significantly (P &lt; 0.01) lower in the invaded than uninvaded sites. Results indicate that bugweed invasion alters some soil properties and negatively impact native species diversity and cover. These results provide the first evidence in South Africa that bugweed invasion contributes to soil changes and vegetation displacement, therefore, the need to manage it through clearing.