Sandy Texture Research Articles

The utility of biochar for increasing the fertility of new agricultural lands converted from boreal forests

The agricultural soils of the Happy Valley-Goose Bay (HV-GB) region of Newfoundland and Labrador, Canada are Podzols that are converted from boreal forest and have limited productivity due to their sandy texture, acidity, low soil organic matter (SOM), cation-exchange capacity (CEC), and water and nutrient retention capacity. Although numerous studies advocate biochar for mitigating soil quality problems and enhancing agronomic productivity, there is limited information on managing biochar for boosting the productivity of Podzols under newly converted agricultural lands. A 5 year experiment evaluated the impact of eight biochar rates (0–80 Mg C·ha−1) on soil properties including SOM, CEC, and availability of plant nutrients and metals in agricultural soils of HV-GB. Both immediate and long-term impacts were thus assessed. Biochar generally improved soil fertility indicators. Although the largest rates (40 and 80 Mg C·ha−1) led to the greatest changes, significant changes were also found with rates as low as 10 Mg C·ha−1. Increasing biochar rates had diminishing returns for quality parameters of soil. The impact of biochar decreased with time after application, but the largest rate led to longer lasting effects. Although biochar was incorporated in topsoil, its effects were also measurable in the subsoil, albeit with a temporal delay, usually of 1 year. Thus, given the diminishing returns of increasing biochar rates, and that beneficial effects diminish over years, it is advisable that biochar be added in smaller amounts immediately after conversion, as little as 10 Mg C·ha−1, with regular supplementation as needed.

Nepheline Syenite and Phonolite as Alternative Potassium Sources for Maize

Some silicate rocks are a rich source of potassium (K), with the possibility for use in agriculture. The present study aimed to evaluate the agronomic efficiency index (AEI) of nepheline syenite (NS) and phonolite (PN) rocks in comparison with potassium chloride (KCl) as a K source in maize production. An experiment was conducted in a greenhouse in Ilha Solteira, São Paulo, Brazil. A maize hybrid was grown in 8 L pots filled with 6 kg of soil with a low K concentration and contrasting physical attributes (medium and sandy texture). A completely randomized design in a 3 × 6 factorial scheme was used, consisting of three K sources (NS, PN, and KCl) and six rates (0, 50, 100, 150, 200, and 400 mg kg−1) with four replications. All plants were harvested 45 days after emergence to evaluate biomass production, macronutrient (N, P, K, Ca, Mg, and S) concentration and uptake, stem diameter, and leaf chlorophyll index. After crop harvest, soil was collected for further chemical evaluation, which included organic matter (OM), pH, cation exchange capacity (CEC), H+Al, Al, sum of bases (SB), base saturation (BS), P, K, Ca, Mg, and S. In addition, AEI of NS and PN were also verified in relation to KCl. The application of NS and PN had a similar effect on soil chemical attributes (MO, pH, SB, CEC, and BS) as well as on the concentrations of K, Ca, Mg, and S, in both soils. The increase in NS and PN rates provided linear growth of shoot dry matter. Leaf macronutrient concentrations were similar for NS and PN compared to KCl. All three K sources (NS, PN, and KCl) increased K accumulation in maize plants. Maize treated with KCl had the largest AEI, followed by PN and NS. However, the results indicated similar AEI with both rocks as a K source for maize, especially with application of the highest K rates. This research demonstrated the efficiency of NS and PN as alternative K sources for maize.

KARAKTERISTIK SIFAT FISIK DAN KIMIA TANAH DI KAWASAN HUTAN LINDUNG SENTAJO KABUPATEN KUANTAN SINGINGI, PROVINSI RIAU

Forest is an ecosystem based on the complexity of its components. One of the components of a forest is soil. The importance of soil for human survival and growth for trees. In this ,research we analyzed the physical and chemical characteristics of soil in Sentajo Protected Forest. Soil samples were taken using composite and ring samples techniques. Soil samples were taken from five plot points measuring 20 m x 20 m in two depth level namely, 0-20 cm and 20-40 cm. mixed evenly to get one composite soil mixture. The results of research in Sentajo Protected Forest showed that the land in Sentajo Protected Forest was classified as acidic with a value of 3.68 - 4.34 with organic C content that is classified as low to high and a low KTK value. Moreover, the physical characteristics of the soil in Sentajo Protected Forest were more sandy texture. The values of moisture content, bulk density and porosity at a depth of 0 - 20 cm were higher when compared to a depth of 20 - 40 cm.

Coconut fiber biochar alters physical and chemical properties in sandy soils

This work aimed to characterize the biochar produced from residues of coconut fruit and to evaluate how it might beneficially alter the retention capacity of water and nutrients in soils with a sandy texture. The biochar was produced in a retort furnace and later analyzed to determine its chemical and physical characteristics. Experiments to analyze the retention potential of the biochar for water and nutrients were performed in PVC columns filled to a 400 mm depth, with the upper 300 mm receiving treatments that consisted of 0, 1, 2, 3, 4, and 5% (p p-1) biochar mixed with soil. For the nutrient retention experiment, in addition to the biochar concentrations, the treatments received the same NPK fertilization. The experiments were performed in a completely randomized design with four replications. The water retention in the upper 300 mm, as well as the pH, effective cation exchange capacity (ECEC) of the substrate, base saturation, and concentrations of P and K, increased with increasing biochar concentration. Coconut biochar demonstrated potential for increasing water retention and improving nutrient retention in sandy soils.

Clandestine gold mining and pollution risks of sediments from Bagoue river (Niger watershed, Cote d’Ivoire)

Mercury used in gold amalgamation is a global concern and a major source of contamination and dispersion in environmental aquatic of Cote d’Ivoire, mainly in the North where clandestine gold mining activities are a local interest. The aim of this study was to assess the level of total mercury (Hg-T) contamination of sediments from Bagoue River. Water and sediments samples were collected during wet and dry seasons from six stations differently impacted. Spatial and seasonal variations in physical and chemical parameters were assessed. Results revealed that the level of Hg-T in water was 0.68±0.03 µg.L-1 and in the sediments, dry weight concentration was 0.064±0.01 mg.kg-1. The Hg-T concentration in sediments was significantly higher (p< 0.05) during the dry season (0.089±0.053 mg.kg-1) than that recorded in the wet season (0.064±0.039 mg.kg-1). Ultimately, strong and positive correlations have been observed between Hg-T in sediments and sandy sediments (r = +1), as well as suspended materials (r = +0.85). The pollution status of mercury in sediments according to the geo-accumulation index was uncontaminated (- 47.03) at all the seasons whereas enrichment factor has been moderate over climatic seasons at downstream stations heavily impacted by gold mining. The sandy texture of the River sediments favours the infiltration of mercury and its accumulation in groundwater. As a rate, the health risks associated with the consumption of these waters are potentially high.

Petrographic, morpho-structural and geophysical study of the quartzite deposit in the central part of Pouma, Littoral-Cameroon

The characterization of the Pouma-Cameroon quartzite deposit with the aim of determining its lateral extension along the Douala-Yaoundé axis required, among other things, the examination of the petrographic and morpho-structural domain as well as the determination of the electrical properties of the formations in the study area. 24 vertical electrical sounding points were carried out using a Schlumberger type electrode configuration; also, 7 manual auger boreholes were carried out, these resulted on one hand in the following types of curves: KH, QH, AKH, H, HK, AK, HA, A; and on the other hand to lithological logs with a clayey sandy texture, gravelly clayey sand to lateritic. The calculation of the densities as well as the petro-structural studies made it possible to confirm the geological context of the study area. The various results obtained permitted us to locate the fresh quartzite formation at the center of the study area. It stretches along the Douala-Yaoundé axis over 1871.4 m for the fresh formation and 1991 m for the slightly altered formation.

Metazoan activity facilitates passive sediment trapping in modern supratidal microbialites: Revealed using µ-CT-scanning and microscopy.

Microbialites are formed through two processes, the trapping and binding of sediment grains and mineral precipitation. Sediment trapping and binding result in coarse sandy textures, whereas fine micritic textures are produced by mineral precipitation. Although well-studied modern microbialites (e.g. Bahamas and Shark Bay) are formed through the former process, purely trapped-and-bound examples are rare throughout the geologic record and limited to shallow-marine environments. Through the use of conventional microscopy and 3D micro-computed tomography (µ-CT) scanning, this study found that South African coastal microbialites have a primarily mineral precipitated texture, although detrital material is included sporadically. Furthermore, these modern microbialites exhibit both micritic and fibrous layering with high porosity. The novel use of 3D microtomography rotational scans has revealed that microbialites are extensively burrowed by metazoan activity and was also able to distinguish the occurrence and distribution of heavy minerals and detrital shell material in the samples. Some of the detrital grains appeared to be accidental/random inclusions, while in other cases the metazoan burrows provided space for the accumulation of sediment once abandoned. In both cases, sediment was incorporated as a product of intermittent accumulation, rather than systematic trapping and binding. The microfabric texture of South African microbialites is therefore a function of both biological (e.g. microbially mediated precipitation) and environmental (e.g. sporadic sediment deposition and inorganic cementation) influence. Overall, the findings presented here highlight the importance of these systems regarding microbialite formation, ichnology and taphonomy.

Changes in soil salinity under treated wastewater irrigation: A meta-analysis

In view of water shortages, the development and utilization of unconventional water resources have been studied extensively. Treated domestic or industrial wastewater used for agricultural irrigation is an unconventional water resource utilization method. Due to the particularities of water sources, previous studies have mainly focused on changes in soil heavy metals, microorganisms, and organic substances and crop responses to toxic elements; thus, attention to soil salinity is of secondary importance. After selecting qualifying research, a meta-analysis was performed to statistically analyze the data of seven variables (potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), electrical conductivity (EC), pH, and yield) to 1) estimate the mean effects of treated wastewater (TWW) irrigation on the soil salinity, soil pH and crop yield; and 2) identify the wastewater treatment grade (primary treated wastewater (PTW), secondary treated wastewater (STW), and tertiary treated wastewater (TTW)) and soil texture (sandy texture, loamy texture and clayey texture) that benefit TWW irrigation. The results showed that TWW irrigation caused a significant accumulation of soil salinity, and the increase in cation content from high to low was K (90.1%), Na (59.9%), Mg (25.2%) and Ca (17.3%). EC also increased significantly by approximately 57.2%, while there was no significant change in pH, and even the crop yield presented an average reduction of nearly 6.5%. PTW contributed to the largest salt accumulation, followed by TTW and STW. STW showed a significant increase in EC but did not show a significant change for the four ions. In terms of yield, STW can increase yield, while TTW has the opposite effect. In general, the sandier the soil texture, the higher is the salt content detected, although the retention of salt in loamy textured soil may differ depending on the ions. The yield of crops grown increased in the clayey textured soil and decreased in the loamy textured soil. Our study elucidated the response of soil salinity accumulation under TWW irrigation and could provide a reference for unconventional water resource utilization.

Screening and Optimization of Zinc Removal Potential in Pseudomonas aeruginosa-HMR1 and its Plant Growth-Promoting Attributes.

The soil samples of old Zawar mine sites were sandy texture, basic, electric conductivity range from 16 to 59 dSm-1 with a high content of heavy metals of Zn, Pb, Cd, and Fe, indicating poor soil-health. Two bacterial isolates Pseudomonas aeruginosa HMR1 and P. aeruginosa HMR16 (GenBank-accession-number KJ191700 and KU174205, respectively), differed in the Phylogenetic tree based on 16S-rDNA sequences. HMR1 isolate showed the high potential of Plant growth-promoting attributes like IAA, Phosphate-solubilization, Exopolysaccharide production, and Proline activities at high concentration of Zn augmented nutrient media after 24h, followed by HMR1 + HMR16 and HMR16. Both isolates were survived at 100ppm Zn (w/v) concentration, followed by Pb, Cd, and Fe. Linear RL value from Langmuir and Freundlich isotherms revealed that the suitable condition of Zn adsorption by HMR1 was at pH8 with 40°C. The value of r2 from pseudo-second-order kinetics and Transmission-Electron-Microscopic analysis confirmed Zn adsorption by HMR1.

Heavy Metal Content and Physico-Chemical Analyses of Soils under the Litter of some Medicinal Taxa in the Luki Biosphere Reserve, Democratic Republic of the Congo

Aim: The aim of this study was to compare the texture, mineral element and heavy metal content of the soil under the litter of different selected species in relation to the plan of their pedogenesis.&#x0D; Methods: The granulometric analysis of the various samples based on laser diffraction, measurements of Total Nitrogen and Total Organic Carbon were performed using the Elemental Analyzer, the Organic Matter content is estimated by the loss of ignition method using a Salvis furnace, In order to estimate the CaCO3 content. The same samples were heated in the oven at 1000°C for 60 minutes and reweighed. The carbonate content is estimated by the loss in mass during this second firing, multiplied by 2.274 which is the molecular weight ratio between CaCO3 and CO2. The heavy metal and mineral composition was evaluated by ICP-AES and AAS.&#x0D; Results: The granulometric analyses show a sandy texture, according to the FAO classification. The organic matter content thus observed in the soils under the litter of these four species did not show any significant difference. The concentration of major mineral elements recorded in soils under the litter of Blighia welwitchii, Oncoba welwitschii, Zanthoxylum gilletii and Harungana madagascariensis did not show any significant difference. However, potassium, phosphorus, and magnesium have a high concentration compared to calcium and sodium. This study showed that the levels of cadmium, lead, arsenic and aluminum in the various samples of litter soils of all plant species including nickel for B. welwitschii are above the standards set by the Canadian Council of Ministers of the Environment for soil quality. Pollution factors for aluminum are the highest. This indicates that aluminum is the most polluting metal. The low pollution factors for lead and nickel are due to the low fixation of these metals by soils.&#x0D; Conclusions: Our study took place in the Luki Biosphere reserve and showed that the different soils under litter are polluted by very toxic and persistent heavy metals such as cadmium, lead, aluminum, arsenic and nickel. This study has revealed new aspects of heavy metal pollution. This pollution represents a serious threat to the environment in general and to humans in particular through the food chain.

The wells of the underground water in Al-Aatha area south of Al-Miqdadiya District and its Agricutural uses

Al-Aatha area is located in the south of AL Muqdadia district in Diyala province. its unreclaimed lands. It was natural pastures distributed among peasants and farmers on contracts after the imposition of the Economic Blockade on Iraq in 1990. This area contains alot of hills, sand-dunes and arable lands. It covers two agricultural territories with an area of (55034) Dunams. These are rain irrigated iands and the underground water provides their needs for water in Agriculture. The Wells water is affected by many natural factors which led to agglomeration under this area such as geological structure, sandy texture, soil and natural vegetation. The wells of this area are characterized by huge amounts of water through the permanent supply of water which goes on for about 14 hours aday. This means that the level of water does not fall much and this proves that it contains ahuge under ground water reservoir. This case encouraged use the extensive agriculture with winter crops such as wheat depending on these Wells. So the farming of this crop is about (9173) Dunams acope with agricultural plan for the present season (2019-2020) The irrgation of two methods. The first one by surface irrigation with an area about (8531) Dunams and the other is the modern system is called sprangler irrigation. The region contains five advance methods with an area about (642) Dunams.

Interpreting regolith data to infer groundwater potential contamination in Piracicaba, Brazil

Interdisciplinary concepts have been used to manage the environmental crisis of the 21st century. Ecological problems and solutions require an increasingly comprehensive soil study and this has been carried out in order to consider the entire regolith profile. Regoliths are the entire column of materials above the fresh rock, whether this is saprolite (literally “rotten rock”) or soil, material with intense biological and chemical process. Groundwater contamination is particularly enhanced in shallow, porous regolith profiles, due to the easiness of surface water flow into the groundwaters. This is particularly critical in the Guarani aquifer, which waters supplies 15 million people in 4 countries. Several morphological, chemical, physical and mineralogical analyses were applied to samples collected in three regolith profiles to infer, based on weathering and pedogenesis characteristics, their susceptibility to allow groundwater contamination. A particular challenge was that most of the weathering indices were proposed for igneous rocks, and the studied profiles had sedimentary rocks as parent materials. The most weathered profile (P2) had the least potential for groundwater contamination due to its higher cation exchange capacity (CEC) and clay activity, differentiated structure and consistency in the Bi horizon that can favor the lateral flow and the greatest thickness. Profile P1 had sandy texture, small CEC and thickness that facilitate the passage of soluble contaminants towards the groundwater. Some anox features in the Cr layer suggest the existence of a physical limitation that may delay infiltration or diverge water flow to surface outlets. The profile P3 had the greatest potential for groundwater contamination because it had low CEC, weathering degree and thickness. The only feature to prevent the polluted infiltration water to reach groundwaters in this profile was its sub-horizontal structure and transition from soft/very friable consistency in CA layer to very hard/unbreakable consistency in Cr layer, which also may diverge or delay the vertical infiltration of water. However, no anox features were found in it. Results indicate the importance of understanding the soil weathering and relate with their potential on underground water contamination, and thus, to bring light to public environmental monitoring policies.

Evaluating the Trend of Changes in Bed Sediments Gradation over the Sistan River

Sediment movement in rivers is one of the most important indicators to evaluate the health of an ecosystem. Bed load different specification such as shape, dimensions and other statistical parameters of this sediment reflect the hydraulic and hydrological conditions governing them, directly. To investigate the changes of particle aggregation of Sistan river bed, four sediment samples were collected from the Sistan river. After aggregation of sediments in the laboratory, sediment diameter (D50) and uniformity coefficient (Cu) was calculated, and using inverse distance weighting (IDW) method, the mentioned parameters for the Sistan river from Jarikeh up to the AfzalAbad plugs place were interpolated and parameters using ARC-GIS software was zoning along the river. Results showed that Sistan river bed material is sand and silt, 3 km to the beginning and at end of the study interval based on the English standard classification it is silty texture and the rest of bed is sandy texture. 11 kilometers beginning and the end of the river also from 20 +721 kilometer up to about 12 kilometers has also a good aggregation. The entire river except for the middle section of river from the 13 +244 km to extent of 4 km river bed has non-uniform soil.

Testing Taylor’s Power Law association of winter wheat variation with mean yield at two contrasting soils

Previous research has found that, based on Taylor’s Power Law (TPL), the coefficient of variation (CV) of yield data may functionally be related to the mean, with an exponential mean yield decline with increasing CV. Recent proposals have been made how this scale-dependency can be removed in order to allow a scale-independent assessment of stability. The theoretical background of the hypothesis was studied in wheat (Triticum aestivum L.) throughout data obtained from two fields of the farm of the Mendel University of Brno, Czech Republic. Soils of the two fields were of the contrasting loamy and sandy textures. Yield variation was intense in the sandy field representing a low-input agro-ecosystem. TPL became more obvious when the two fields were considered together, so as to enlarge the range of means and CVs. On the simple correlation between logarithms of variances and respective means, there was a systematic dependence of yield variance on mean yield when the within-block CV was considered. Conversion of variance to remove dependence on mean did not validate the CV ∼ yield negative relationship meaning that caution is needed when interpreting the CV of yield as a stability index. On the other hand, when the genotype CV for yield was considered variance was independent of the mean indicating agronomic essence in the CV∼ yield relationship, and coupled with the POLAR statistic, based on the negative residuals from the linear TPL regression that reflect low variability, revealed genotype cases exhibiting both high yield and stability. The findings corroborated that TPL is not always valid depending on scales and factors structuring the data. Interpreting crop variation via CV may entail a risk of bias due to variance dependence on mean, whereas the POLAR index offers an alternative stability measure that allows straight-forward interpretation providing the basis for developing more stable cropping systems. A trade-off between yield and stability does not exclude genotype cases of simultaneous occurrence of both, pinpointing realism in the pursuit of stable varieties without compromising yield.

Bentonite clay combined with organic amendments to enhance soil fertility in oasis agrosystem

Soils in arid and semi-arid lands are vulnerable to climate change, erosion, and mismanagement practices that contribute to organic matter depletion and nutrients imbalances. Oasis agrosystems are considered one of the major farming systems in some parts of these lands in the Middle East and North Africa region. However, oases soils are inherently low in organic carbon due to their sandy texture which retains little water and binds low organic matter contents, and the accelerated decomposition rates of organic matter under high temperature, which makes its accumulation difficult. Traditional farming practices in oasis agrosystems have always integrated organic matter derived from livestock to enhance organic carbon (OC) and total nitrogen (TN) stocks in the soil. This study is aimed to examine the potential effects of a new mixture of organic amendments and bentonite clay on organic carbon and total nitrogen stock accumulation in the soil. Five amendments were applied including sand and compost (SC), sand and manure (SM), sand, bentonite, and compost (SBC), sand, bentonite, and manure (SBM), and sand mixed with bentonite (SB). These treatments were compared to untreated soil (U). The results showed that OC and TN stocks increased significantly (p<0.05) in all three depths of the five treatments compared to the untreated soil. Higher organic carbon stocks (2862±3.4 g m−2) were detected in SBM treatment. The combined organic and mineral amendment retarded OC and TN decomposition. After two years of the amendments’ application, 30% of OC remained in the soil for SBC treatment. In conclusion, the mixed mineral and organic amendment is a better choice to preserve OC and, thus, maintain oasis soil fertility.

Vertical distribution of different forms of potassium and their relationship with different soil properties in Haryana soil

Distribution of different forms of potassium in soils in Haryana was studied by exposing profiles. Most of the soils were light in texture and ranged from sand to clay. They were neutral to slight alkaline in nature. The organic carbon in Kaul soil varied from 0.19 to 0.54%. In majority of the soils, the organic carbon content showed a decreasing trend with depth. The distribution of the different forms of the potassium i.e. water soluble, exchangeable, non-exchangeable and total potassium in these soils ranged from 6.26 to 24.93 kg ha-1, 28.09 to 160.25 kg ha-1, 25.05 to 1273.10 kg ha-1 and 2.17 to 1.15%, respectively. The highest amount of the available and total potassium were found in Kaul soil, whereas, Balsamand soil with sandy texture showed the lowest amount. No definite trend of different forms of potassium was observed with respect to depth in these soils. Correlation study showed that the different forms of potassium were positively and significantly correlated with organic carbon, silt and clay content of the soils. They were negatively correlated with sand content. The different forms of potassium were positively and significantly correlated among themselves.

Physicochemical and rheological properties of lentil milk/inulin blend—A feta cheese analogue

AbstractIn recent years, due to nutritional conditions and increasing consumer awareness, the tendency of using healthy food has been necessary. Besides, much consideration is given to use of the legumes protein and fat in dairy products due to their low cost and healthy benefits. Indeed, by increasing obesity and cardio‐vascular diseases, and consideration of consumers to nutritional health, the demand for healthy products has increased. The present study is based on achieving a good formulation by replacing a part of cow's milk with lentil milk to produce vegetable functional cheese with good flavor and texture and acceptable appearance from the point of view of consumers. Inulin was used to improve the texture and organoleptic properties. The applied lentil milk was 0%, 10%, and 20%, and inulin was 0%, 3.5%, and 7.0% in nine formulations. The results revealed that the high level of lentil milk (20%) lead to a sandy texture. The formulation which contained 10% and 3.5% of lentil milk and inulin, respectively, obtained the best texture and sensory score.

Impact of European Beech Forest Diversification on Soil Organic Carbon and Total Nitrogen Stocks–A Meta-Analysis

Drought-sensitive European beech forests are increasingly challenged by climate change. Admixing other, preferably more deep-rooting, tree species has been proposed to increase the resilience of beech forests to drought. This diversification of beech forests might also affect soil organic carbon (SOC) and total nitrogen (TN) stocks that are relevant for a wide range of soil functions and ecosystem services, such as water and nutrient retention, filter functions and erosion control. Since information of these effects is scattered, our aim was to synthesize results from studies that compared SOC/TN stocks of beech monocultures with those of beech stands mixed with other tree species as well as monocultures of other tree species. We conducted a meta-analysis including 38 studies with 203, 220, and 160 observations for forest floor (i.e., the organic surface layer), mineral soil (0.5 m depth) and the total soil profile, respectively. Monoculture conifer stands had higher SOC stocks compared to monoculture beech in general, especially in the forest floor (up to 200% in larch forests). In contrast, other broadleaved tree species (oak, ash, lime, maple, hornbeam) showed lower SOC stocks in the forest floor compared to beech, with little impact on total SOC stocks. Comparing mixed beech-conifer stands (average mixing ratio with regard to number of trees 50:50) with beech monocultures revealed significantly higher total SOC stocks of around 9% and a smaller increase in TN stocks of around 4%. This equaled a SOC accrual of 0.1 Mg ha−1 yr−1. In contrast, mixed beech-broadleaved stands did not show significant differences in total SOC stocks. Conifer admixture effects on beech forest SOC were of additive nature. Admixing other tree species to beech monoculture stands was most effective to increase SOC stocks on low carbon soils with a sandy texture and nitrogen limitation (i.e., a high C/N ratio and low nitrogen deposition). We conclude that, with targeted admixture measures of coniferous species, an increase in SOC stocks in beech forests can be achieved as part of the necessary adaptation of beech forests to climate change.

ANALISE COMPARATIVA DOS FRAGMENTOS DE CERRADO NOS MUNICÍPIOS DE CAMPO MOURÃO E JAGUARIAÍVA, PARANÁ, BRASIL

The Cerrado (Savannah) is one of the six Brazilian morphoclimatic domains and although it has its core area located in Brazil’s central region, fragments of this vegetation are observed in the state of Paraná and that, even, they have already occupied 1,700 square kilometers. Currently, however, the Cerrado is restricted only to isolated islands in cities such as Arapoti, Campo Mourão, Cianorte, Jaguariaíva, Sabáudia, Sengés and Tuneiras do Oeste. In the light of these considerations, this article aims at presenting the comparative characterization of the Cerrado areas in Campo Mourão and Jaguariaíva by highlighting the geographical elements observed there. For the accomplishment of the research, fieldwork was done, as well as comparative analyzes throughcartographic and bibliographical material. From the research survey, it was evidenced that: a) both analyzed fragments are in different climates; b) the soil in the area studied in Jaguariaíva presents sandy texture in shallow soil, while in Campo Mourão the soil can be described as Lactosoil with clayey texture; c) both soils, although distinct, have low natural fertility and high acidity; d) the botanical families that compose the studied’s area vegetation are correlated.

Runoff and leaching of dissolved phosphorus in streams from a rainfed mixed cropping and grazing catchment under a Mediterranean climate in Australia

Managing phosphorus (P) is a global priority for environmental water quality due to P lost from agricultural land through leaching, runoff and subsurface flow. In Western Australia (WA), following decades of P fertiliser application to crops and pastures in low rainfall regions, questions have been raised about this region's contribution to environmental P loss. This study was conducted on the Fitzgerald River catchment in the south Western Australia (WA) with mixed cropping and grazing land uses and a Mediterranean climate with low mean rainfall (~350 mm yr−1). Phosphorus forms were monitored continuously over a three-year period in five separate streams, each draining a defined sub-catchment. The P concentrations in streams consistently exceeded Australian and New Zealand Environment Conservation Council (ANZECC) trigger values throughout the monitoring period. Of the measured total P concentration, ~75% was dissolved P (DRP; <0.45 μm) and 80% of that fraction was in the filterable reactive form (FRP). These water quality measurements and other independent soil investigations at this site, suggest that transport of dissolved P rather than erosion of sediment-bound P was dominant in this environment. Based on extractable soil P (Colwell P) and the P buffering index (PBI), predicted concentrations of dissolved reactive P (DRP) in soil solution in topsoils (0–10 cm) across this catchment, generally exceeded ANZECC's values of 0.07 mg PL−1. The level of exceedance was spatially variable. Streams draining areas with the lowest predicted DRP concentrations also had the lowest measured FRP concentrations. Elsewhere stream water FRP concentrations depended on both DRP concentration and the PBI of the land being drained. Our findings suggest that deployment of practices that physically filter runoff, for example riparian vegetation, would be ineffective in restricting P transport into stream in this environment. This conclusion is consistent with previous findings of the ineffectiveness of riparian buffers on coarse textured sandy soils in higher rainfall areas of southwest WA. A reduction in DRP losses without yield loss could be achieved by following evidence-based fertiliser advice from soil testing to limit losses of legacy P”.