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The ability to predict long-term plant-availability of soil P provides an additional management tool for sustainable agriculture. Our objective is to present a methodology using P fractionation data for predicting long-term plant-availability of soil P. Soil samples were collected (0-30 cm) in 1975, 1985, and 1992 from two continually cropped field trials. Soils were a Norfolk loamy sand and a Davidson...
Chemical fractionation and 31 P nuclear magnetic resonance (NMR) spectroscopy of humic acids (HA) and fulvic acids (FA) were used to characterize the forms of phosphorus and their changes within a toposequence of alpine soils at the Mt. Malaya Khatipara (Teberda reserve, northwestern Caucasus). Sodium hydroxide extracted 66-82% of total phosphorus from A horizons and 28-51% from B horizons...
Phosphate adsorption and desorption studies provide insight for developing P management strategies. Very few studies have concentrated on P desorption which provides information on the reversibility of adsorbed P. Phosphate adsorption and desorption studies were carried out on seven rice-growing soils from three countries in West Africa, with the objective of relating these processes to P management...
X-ray microanalysis was used to determine the localisation and the distribution of sewage sludge when mixed with a calcareous soil at high doses. The first part of this study was aimed at optimising this technique in order to accurately detect the sludge present in soil. Phosphorus was used as a marker of sludge because this element has shown itself to be the one that best defined the distribution...
Phosphorus (P) reserves and related characteristics of soil horizons were studied in two clay (Inceptisols) and two coarse-textured (Inceptisol, Spodosol) cultivated soils in Finland. The soils were young and they all had been formed of multiple parent materials, the deposition of which were linked to the evolutionary stages of the Baltic Sea. In all C horizons, the content of total P and measured...
The concentration of phosphorus (P) in overland and subsurface flow is related to the concentration and release rate of P in soil. To more accurately describe soil P loss to runoff water, we investigated P species controlling P release, and the kinetics of P release in three soils ranging in Olsen P from 9 to 159 mg kg -1 . Using solubility diagrams and P fractionation data, soil P release...
How has soil quality changed in California over the past 60 years? Using the known locations of archived samples collected by the soil survey staff in the 1940s and 1950s, we resampled 125 locations in California from the Imperial Valley in the south to Tehama county in the north and analyzed samples for properties important to plant production. We collected three samples from the 0- to 25-cm depth...
The evergreen Nothofagus betuloides and deciduous Nothofagus pumilio live close together in Tierra del Fuego. The fact that these two species rarely form mixed forests suggests that the soil factor can contribute to the distribution of two species on a local scale. Most of these forests are undisturbed; therefore, soil characteristics may reflect both the influence of the species and of the dominant...
A fraction of P in eroded sediments is attached to Fe oxides (Fe-related P). Reduction of Fe oxides in the bottom of water reservoirs is considered to mobilize P bound by poorly crystalline Fe oxides, which is supposed to be the main Fe(III) form available for microbial reduction in anoxic environments. The main objective of this work was to compare Fe and P extracted from suspended sediments of representative...
Mesquite trees in desert grasslands create localized distributions of soil N, C, and P, through N fixation, nutrient uptake, and subsequent litterfall. Fires may prevent or reverse this accumulation, but the results of this process are poorly understood. Our objectives were to (1) characterize temporal and spatial variation in velvet mesquite litter mass and C, N, and P concentration; (2) characterize...
Long-term high resolution measurements of precipitation, soil water budget, surface runoff, and sediment transport as well as rainfall simulations at plot scale have been accomplished on a non-vegetated lignite mining dump (Germany, Lusatia, Schlabendorf-North), completed by measurements of infiltration and water drop penetration time. The investigations revealed that the distribution of hydraulic...
Rate of phosphorus (P) release from solid to solution phase may control the lability of P in soil environments. Kinetics of P release from Iranian calcareous soils at upper-, mid-, and lower-slope positions of two arid and two semiarid landscapes were determined and relations between the P release rate parameters and P uptake by wheat were investigated. The kinetic data was best described by simple...
Agriculture is a significant contributor to the diffuse loading of phophorus (P) in fresh water systems. At the landscape level, source areas and targeted surface waters are connected through different hydrological pathways. One of these pathways, P removal through surface runoff, may increase in relative importance when storm events occur and in wet seasons. With Digital Elevation Models (DEMs) it...
Cultivation of native land can reduce the quality of soil by decreasing topsoil contents of organic carbon, total nitrogen, and phosphorus in the semiarid Pampas of Argentina. The objective of this study was to analyze the changes produced by cultivation on organic carbon (OC), total nitrogen (TN) and phosphate (inorganic and organic fractions) in two aggregate sizes of three different semiarid soils...
Little attention has been given to the influence of freezing on P cycling in wetlands. The purpose of this study was to explore the effects of freeze–thaw treatments on the P sorption properties of wetland soils, and to determine possible further impact on P retention in wetland soils. In laboratory incubations, six surface soils with varying amounts of P added (0–320 mg P L −1 ), was continuously...
Hybrid geostatistical prediction methods incorporate (i) spatially-explicit soil observations and exhaustive grids of ancillary environmental variables (e.g. derived from remote sensing), (ii) spatial autocorrelation, (iii) spatial covariation, and/or (iv) combinations of the above. In numerous studies of terrestrial soils it has been shown that hybrid geostatistical methods outperform univariate...
Soil phosphorus distribution and cycling in the McMurdo Dry Valleys is poorly understood despite its importance for contemporary Antarctic ecosystem processes. We present data from sequential chemical extractions of phosphorus pools from dry valley soils and sediments on tills across a gradient of surface exposure ages, and across potential weathering gradients in stream channels. The geologically...
The availability of native phosphorus (P) in Zambian Alfisols, Ultisols and Oxisols, the dominant agricultural soils in the country, is relatively low. Given that crop production in the country is dominated by low external input practices, native P remains important to plant P nutrition in many locations. There is a dearth of knowledge about soil P distribution, transformations and fertility in Zambia...
Two native shrubs (Piliostigma reticulatum and Guiera senegalensis) commonly coexist with crops in fields throughout the Sahel but aboveground residue is annually coppiced and burned. An alternative, with potential to improve soil quality, would be non-thermal return of residues to soils but information is needed on the potential of residues’ to provide nutrients before such systems can be adopted...
In order to find common distribution and relationship patterns between soil properties a statistic methodology is applied and discussed; the aim is to validate conceptual distribution models of soil constituents. Solum (A and Bt horizonts) data of five profiles located in the Chacopampeana Plain of northwest Argentina were studied; the variables under analysis were the sampling depth (SD) and the...
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