Journal of Plant Nutrition and Soil Science
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Innovative methods in soil phosphorus research: A review Abstract Phosphorus (P) is an indispensable element for all life on Earth and, during the past decade, concerns about the future of its global supply have stimulated much research on soil P and method development. This review provides an overview of advanced state‐of‐the‐art methods currently used in soil P research. These involve bulk and spatially resolved spectroscopic and spectrometric P speciation methods (1 and 2D NMR, IR, Raman, Q‐TOF MS/MS, high resolution‐MS, NanoSIMS, XRF, XPS, (µ)XAS) as well as methods for assessing soil P reactions (sorption isotherms, quantum‐chemical modeling, microbial biomass P, enzymes activity, DGT, 33 P isotopic exchange, 18 O isotope ratios). Required experimental set‐ups and the potentials and limitations of individual methods present a guide for the selection of most suitable methods or combinations.
Journal of Plant Nutrition and Soil Science - Tập 178 Số 1 - Trang 43-88 - 2015
Phosphorus bioavailability of biochars produced by thermo‐chemical conversion Abstract Recycling of P is a common strategy in efficient use of P. The aims of our investigation were to study the P extractability of biochars produced by low temperature conversion and to determine the effect of soda application on low‐temperature conversion of organic compounds and the bioavailability of P to rye grass (Lolium perenne L., cv. Grazer). In this study canola cake, dried distillers grains with solubles, and meat‐and‐bone meal were converted to biochars with thermo‐chemical conversion at 400°C. The P availability was measured in terms of solubility in water, 2% citric, and 2% formic acid, and in a pot experiment with rye grass (Lolium perenne L.) which was cut three times. Application of 8% (w/w) soda to the process of thermo‐chemical conversion of canola cake, dried distillers grains with soluble and meat‐and‐bone meal resulted in an increase of water‐, 2% citric‐, and 2% formic‐acid‐extractable P in the biochars. In contrast to the application of soda, addition of 12% wood ash (w/w) to the conversion of dried distillers grains with solubles resulted in a lower increase of water‐soluble P in the corresponding biochar compared to processing biochar without additives. Addition of biochar P (100 mg P [kg soil]–1 ) to a Luvisol resulted in an increase of CAL‐extractable soil P. The P uptake of rye grass from biochars produced with the addition of soda was as effective as basic slag and MgNH4 phosphate fertilizers and even better than rock phosphate.
Journal of Plant Nutrition and Soil Science - Tập 177 Số 1 - Trang 84-90 - 2014
Grazing‐induced alterations of soil hydraulic properties and functions in Inner Mongolia, PR China Abstract Increasing grazing intensities of sheep and goats can lead to an increasing degradation of grasslands. We investigated four plots of different grazing intensities (heavily grazed, winter‐grazed, ungrazed since 1999, and ungrazed since 1979) in Inner Mongolia, PR China, in order to study the effects of trampling‐induced mechanical stresses on soil hydraulic properties. Soil water transport and effective evapotranspiration under “heavily grazed” and “ungrazed since 1979” were modeled using the HYDRUS‐1D model. Model calibration was conducted using data collected from field studies. The field data indicate that grazing decreases soil C content and hydrophobicity. Pore volume is reduced, and water‐retention characteristics are modified, the saturated hydraulic conductivity decreases, and its anisotropy (vertical vs. horizontal conductivity) is influenced. Modeling results revealed higher evapotranspiration on the ungrazed site (ungrazed since 1979) compared to the grazed site (heavily grazed) due to wetter soil conditions, more dense vegetation, litter cover, and decreased runoff and drainage, respectively. Grazing modified the partitioning of evapotranspiration with lower transpiration and higher evaporation at the grazed site owing to reduced root water uptake due to reduced evaporation and a patchy soil cover.
Journal of Plant Nutrition and Soil Science - Tập 172 Số 6 - Trang 769-776 - 2009
Beiträge zur Frage des Basenaustausches und der Aziditäten. II. Vorversuche an Permutiten.
Journal of Plant Nutrition and Soil Science - Tập 16 Số 2 - Trang 184-204 - 1930
Beiträge zur Frage des Basenaustausches und der Aziditäten
Journal of Plant Nutrition and Soil Science - Tập 15 Số 4 - Trang 329-342 - 1930
Placing soil‐genesis and transport processes into a landscape context: A multiscale terrain‐analysis approach Abstract Landforms and landscape context are of particular importance in understanding the processes of soil genesis and soil formation in the spatial domain. Consequently, many approaches for soil generation are based on classifications of commonly available digital elevation models (DEM). However, their application is often restricted by the lack of transferability to other, more heterogeneous, landscapes. Part of the problem is the lack of broadly accepted definitions of topographic location based on landscape context. These issues arise because of: (1) the scale dependencies of landscape pattern and processes, (2) different DEM qualities, and (3) different expert perceptions. To address these problems, we suggest a hierarchical terrain‐classification procedure for defining landscape context. The classification algorithm described in this paper handles object detection and classification separately. Landscape objects are defined at multiple scales using a region‐based segmentation algorithm which allows each object to be placed into a hierarchical landscape context. The classification is carried out using the terrain attribute mass‐balance index across a range of scales. Soil genesis and transport processes at established field sites were used to guide the classification process. The method was tested in Saxony‐Anhalt (Germany), an area that contains heterogeneous land surfaces and soil substrates. The resulting maps represent adaptation degrees between classifications and 191 semantically identified random samples. The map with the best adaptation has an overall accuracy of 89%.
Journal of Plant Nutrition and Soil Science - Tập 171 Số 3 - Trang 419-430 - 2008
Nitrogen and genotype effects on root growth and root survivorship of spring wheat Abstract The nitrogen (N) fertilization of wheat (Triticum aestivum L.) is important for stable and high grain yield. However, the effect of N on root growth and survivorship is poorly understood. The objectives of this study were (1) to determine the effect of varying N availability on the growth and survivorship of roots and (2) to determine whether genotypic variation in N‐related traits are linked to root growth and survivorship. In a two‐year study, two spring wheat cultivars (Albis and Toronit) and an experimental line (L94491) were grown under low (20 kg N ha–1 ) and high N supply (270 kg N ha–1 ) in lysimeters equipped with minirhizotrons. The genotypes showed significant differences in N‐related traits: total shoot N content, grain N yield, N harvest index, and rate of decline in flag‐leaf greenness. However, there were relatively weak and inconsistent genotypic effects on the time course of root density, root growth during grain filling, and root survivorship. The level of N supply was the factor that most influenced the establishment, growth, and survivorship of roots; the high N supply, depending on the year and genotype, increased growth and survivorship of roots from 0% to 68% and 24% to 34%, respectively.
Journal of Plant Nutrition and Soil Science - Tập 176 Số 4 - Trang 561-571 - 2013
Effects of hydrochar application on the dynamics of soluble nitrogen in soils and on plant availability Abstract Before hydrochars can be applied as soil amendments in agriculture, information about how hydrochar application affects soil nutrient cycles and plant growth are necessary. In this study, incubation experiments were performed to investigate hydrochar effects on N concentrations (NO$ _3^- $ , NH$ _4^+ $ ) in soils with different N pools (soil N, fertilizer N). A set of pot trials with three crop species (barley, phaseolus bean, leek) was conducted to determine hydrochar effects on plant N availability and biomass production after mineral‐N fertilization. Results of the incubation experiments show that hydrochar reduced the concentration of mineral N in soil within the first week after incorporation, especially that of nitrate. This was particularly evident, when hydrochars with high C : N ratio, high DOC and low mineral‐N contents were applied. Hydrochars promoted biomass production of barley and phaseolus bean in pot trials, which can be partly attributed to an increase in soil pH after hydrochar incorporation. Dry‐matter yield of leek tended to decrease after hydrochar application. Hydrochars with high C : N ratio decreased the plant's N content, an effect that was strongest with increased hydrochar concentration. Hydrochars with low C : N ratio did not affect the crop's N uptake. Our results show that the use of hydrochars as amendment in arable field or horticultural pot production will require an adjustment of N‐mineral‐fertilization strategies.
Journal of Plant Nutrition and Soil Science - Tập 177 Số 1 - Trang 48-58 - 2014
Nitrous oxide emissions from agricultural land use in Germany— a synthesis of available annual field data Abstract The nations that have ratified the Kyoto Protocol must set up an appropriate national inventory on N2 O emissions from agricultural land use, in order to report properly on the achievements made in reducing greenhouse‐gas emissions. The search for the appropriate method is a controversial topic as it is subject to high uncertainty in particular associated to the upscaling from site measurements. In this study, all available data from Germany on annual N2 O‐emission rates derived from field experiments of at least an entire year are summarized. From each study, only differences in soil properties on N input qualified as an individual data set. Under these premises, 101 treatments from 27 sites were found equally spread across Germany. The annual N application ranged from 0 to 400 kg N ha–1 and the annual emission rates from 0.04 to 17.1 kg ha–1 . Annual emission factors (EFs), uncorrected for background emission, varied considerably from 0.18% to 15.54% of N applied. There was no nationwide correlation found for the relationship between N2 O losses and N application, soil C, soil N, soil texture, or soil pH. However, site‐specific trends in the relationship between emission factor and mean soil aeration status, as expressed by the soil type and/or mean climatic conditions, were revealed. Regularly water‐logged soils were characterized by low emission factors as were soils from the drier regions (<600 mm y–1 ), whereas well‐aerated soils from the frost‐intensive regions showed exceptionally high emission factors. Since purely physical and chemical parameterization failed to describe N2 O emissions from agricultural land use on the national scale, there must be a biological adaptation to mean site conditions, i.e. , different microbial communities react differently to similar actual conditions in terms of N2 O dynamics. Regardless of the point of view, the chapter on N2 O soil dynamics cannot be closed yet, and new additional model concepts, process studies, and field measurements are needed.
Journal of Plant Nutrition and Soil Science - Tập 169 Số 3 - Trang 341-351 - 2006
Relationship between water and nitrogen uptake in nitrate‐ and ammonium‐supplied <i>Phaseolus vulgaris</i> L. plants Abstract Sole ammonium supply provokes negative effects on dry‐mass formation, leaf growth, and water uptake of ammonium‐sensitive plants. To study the effects of N form on nutrient and water uptake and aquaporin expression, French bean plants were grown in a split‐root system. Five treatments were compared: homogeneous nitrate (NN) and ammonium (AA) supply; spatially separated supply of nitrate and ammonium (NA); and half of the root system supplied with N‐free nutrient solution, the other half with either nitrate (N0) or ammonium (A0). Ten days after onset of treatments, root dry mass (DM) and water‐uptake rate (WUR) were significantly reduced under ammonium compared to nitrate supply. WUR from nitrate‐supplied vessels was 80% higher than that from N‐free nutrient solution, while WUR from N‐free nutrient solution was 130% higher than that from ammonium‐supplied vessels. Potassium uptake was lower under ammonium supply and the ratio of N : K uptake of treatment AA was significantly higher compared to others. High K uptake from N‐free nutrient solution of A0 plants resulted in a ratio of N : K uptake comparable to nitrate‐supplied plants, but shoot growth resembled that to plants under sole ammonium supply. Within 24 h after onset of treatments, expression of aquaporin was lower under ammonium compared to nitrate supply. From these data, it can be concluded that reduced root water transport under ammonium supply is directly related to aquaporin activity.
Journal of Plant Nutrition and Soil Science - Tập 170 Số 1 - Trang 73-80 - 2007
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