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Soil Management (soil + management)
Selected AbstractsSoil management in pre-Hispanic raised field systems: Micromorphological evidence from Hacienda Zuleta, EcuadorGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 3 2002Clare Wilson Soils-based evidence derived from thin section micromorphology is used to explore contrasts in pre-Hispanic and Hispanic arable land management practices associated with raised fields in an inter-Andean valley of Ecuador. Differences in textural pedofeature characteristics suggest that, where they are found in the same locality, camellón systems were more intensively manured and cultivated than wachu systems. Both, however, were more intensively managed than traditional Hispanic arable fields. The importance of the camellón in pre-Hispanic agriculture is emphasized by soils-based evidence that highlights the efforts made to clear these fields of volcanic ash after the Quilotoa eruption of ca. A.D. 1280. This research suggests that, in an andosol context, pre-Hispanic and Hispanic arable land management practices leave relict and fossil soil micromorphology features that can be used to interpret land use intensities. © 2002 Wiley Periodicals, Inc. [source] Exploitation of food resources by badgers (Meles meles) in the Swiss Jura MountainsJOURNAL OF ZOOLOGY, Issue 2 2005C. Fischer Abstract In our study three badger Meles meles populations separated by only a few km but subjected to different environmental conditions were compared. Differences are especially marked for climatic factors, the three areas being located at different altitudes, and for intensivity of soil use by people. The diet of the three populations was significantly different, with one or two dominant items in each area: mammals and cereals in the mountain, maize in the mid-mountain and in the lowland areas. In the most intensively cultivated area, maize was the most consumed item in autumn and spring, several months after harvesting. Earthworms had only a secondary importance in the diet in the mountainous area, but were negligible in the mid-mountain and lowland areas. Soil management seemed to play a preponderant role, mostly owing to soil quality and topography. Climate seemed to have a secondary effect only. [source] Rainfall variability and hydrological and erosive response of an olive tree microcatchment under no-tillage with a spontaneous grass cover in SpainEARTH SURFACE PROCESSES AND LANDFORMS, Issue 7 2010E. V. Taguas Abstract Most studies on runoff and soil loss from olive orchards were performed on plots, despite the fact that measurements that examine a range of erosive processes on different scales are essential to evaluate the suitability of the use and soil management of this type of land. The main environmental limitations of much of the land used for olive orchards in the Mediterranean are the steep slopes and the shallow soil depth , and this was the case in the study area. Soil erosion and runoff over two hydrological years (2005,2006 and 2006,2007) were monitored in an olive orchard microcatchment of 6·1,ha under no-tillage with spontaneous grass in order to evaluate its hydrological and erosive behaviour. Moreover, soil parameters such as organic matter (%OM), bulk density (BD) and hydraulic saturated conductivity (Ks) were also examined in the microcatchment to describe management effects on hydrological balance and on erosive processes. In the study period, the results showed runoff coefficients of 6·0% in the first year and 0·9% in the second. The differences respond to the impact of two or three yearly maximum events which were decisive in the annual balances. On the event scale, although maximum rainfall intensity values had a big influence on peak flows and runoff, its importance on mean sediment concentrations and sediment discharges was difficult to interpret due to the likely control of grass cover on volume runoff and on soil protection. In the case of annual soil erosion, they were measured as 1·0,Mg,ha,1,yr,1 and 0·3,Mg,ha,1,yr,1. Both are lower than the tolerance values evaluated in Andalusia (Spain). These results support the implementation of no-tillage with spontaneous grass cover for sloping land, although the reduced infiltration conditions determined by Ks in the first horizon suggest grass should be allowed to grow not only in spring but also in autumn. In addition, specific measurements to control gullies, which have formed in the terraced area in the catchment, should be included since it is expected that they could be the main sources of sediments. Copyright © 2010 John Wiley & Sons, Ltd. [source] The concentrations of fatty acids in organo-mineral particle-size fractions of a ChernozemEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 3 2004G. Jandl Summary Fatty acids, the most abundant class of soil lipids, indicate pedogenetic processes and soil management. However, their quantitative distribution in organo-mineral particle-size fractions is unknown. The concentrations of n -C10:0 to n -C34:0 fatty acids both in whole soil samples and in the organo-mineral particle-size fractions of the Ap horizon of a Chernozem were determined (i) to evaluate the effects of long-term fertilization and (ii) to investigate their influence on the aggregation of organo-mineral primary particles. Quantification by gas chromatography/mass spectrometry (GC/MS) showed that long-term fertilization with nitrogen, phosphorus and potassium (NPK) and farmyard manure (FYM) led to larger concentrations (25.8 µg g,1) of fatty acids than in the unfertilized sample (22.0 µg g,1). For particle-size fractions of the unfertilized soil, the fatty acid concentrations increased from the coarse silt to the clay fractions (except for fine silt). Fertilization with NPK and FYM resulted in absolute enrichments of n -C21:0 to n -C34:0 fatty acids with a maximum at n -C28:0 in clay (×2.2), medium silt (×2.0), coarse silt (×1.8) and sand (×2.9) compared with the unfertilized treatment (the factors of enrichment are given in parentheses). New evidence for the aggregate stabilizing function of n -C21:0 to n -C34:0 fatty acids was shown by the characteristic pattern in size-fractionated, disaggregated and aggregated samples. Highly significant correlations of fatty acid concentrations with organic C concentrations and specific surface areas are interpreted as indicators of (i) trapping of fatty acids in organic matter macromolecules and (ii) direct bonding to mineral surfaces. This interpretation was supported by the thermal volatilization and determination of fatty acids by pyrolysis-field ionization mass spectrometry (Py-FIMS). [source] Projected changes in the organic carbon stocks of cropland mineral soils of European Russia and the Ukraine, 1990,2070GLOBAL CHANGE BIOLOGY, Issue 2 2007JO SMITH Abstract In this paper, we use the Rothamsted Carbon Model to estimate how cropland mineral soil carbon stocks are likely to change under future climate, and how agricultural management might influence these stocks in the future. The model was run for croplands occurring on mineral soils in European Russia and the Ukraine, representing 74 Mha of cropland in Russia and 31 Mha in the Ukraine. The model used climate data (1990,2070) from the HadCM3 climate model, forced by four Intergovernmental Panel on Climate Change (IPCC) emission scenarios representing various degrees of globalization and emphasis on economic vs. environmental considerations. Three land use scenarios were examined, business as usual (BAU) management, optimal management (OPT) to maximize profit, and soil sustainability (SUS) in which profit was maximized within the constraint that soil carbon must either remain stable or increase. Our findings suggest that soil organic carbon (SOC) will be lost under all climate scenarios, but less is lost under the climate scenarios where environmental considerations are placed higher than purely economic considerations (IPCC B1 and B2 scenarios) compared with the climate associated with emissions resulting from the global free market scenario (IPCC A1FI scenario). More SOC is lost towards the end of the study period. Optimal management is able to reduce this loss of SOC, by up to 44% compared with business as usual management. The soil sustainability scenario could be run only for a limited area, but in that area was shown to increase SOC stocks under three climate scenarios, compared with a loss of SOC under business as usual management in the same area. Improved agricultural soil management will have a significant role to play in the adaptation to, and mitigation of, climate change in this region. Further, our results suggest that this adaptation could be realized without damaging profitability for the farmers, a key criteria affecting whether optimal management can be achieved in reality. [source] Spatial patterns of suspended sediment yields in a humid tropical watershed in Costa RicaHYDROLOGICAL PROCESSES, Issue 12 2001Jagdish Krishnaswamy Abstract An Erratum has been published for this article in Hydrological Processes 16(5) 2002, 1130,1131. Humid tropical regions are often characterized by extreme variability of fluvial processes. The Rio Terraba drains the largest river basin, covering 4767 km2, in Costa Rica. Mean annual rainfall is 3139±419sd mm and mean annual discharge is 2168±492sd mm (1971,88). Loss of forest cover, high rainfall erosivity and geomorphologic instability all have led to considerable degradation of soil and water resources at local to basin scales. Parametric and non-parametric statistical methods were used to estimate sediment yields. In the Terraba basin, sediment yields per unit area increase from the headwaters to the basin mouth, and the trend is generally robust towards choice of methods (parametric and LOESS) used. This is in contrast to a general view that deposition typically exceeds sediment delivery with increase in basin size. The specific sediment yield increases from 112±11·4sd t km,2 year,1 (at 317·9 km2 on a major headwater tributary) to 404±141·7sd t km,2 year,1 (at 4766·7 km2) at the basin mouth (1971,92). The analyses of relationships between sediment yields and basin parameters for the Terraba sub-basins and for a total of 29 basins all over Costa Rica indicate a strong land use effect related to intensive agriculture besides hydro-climatology. The best explanation for the observed pattern in the Terraba basin is a combined spatial pattern of land use and rainfall erosivity. These were integrated in a soil erosion index that is related to the observed patterns of sediment yield. Estimated sediment delivery ratios increase with basin area. Intensive agriculture in lower-lying alluvial fans exposed to highly erosive rainfall contributes a large part of the sediment load. The higher elevation regions, although steep in slope, largely remain under forest, pasture, or tree-crops. High rainfall erosivity (>7400 MJ mm ha,1 h,1 year ,1) is associated with land uses that provide inadequate soil protection. It is also associated with steep, unstable slopes near the basin mouth. Improvements in land use and soil management in the lower-lying regions exposed to highly erosive rainfall are recommended, and are especially important to basins in which sediment delivery ratio increases downstream with increasing basin area. Copyright © 2001 John Wiley & Sons, Ltd. [source] RING CHARACTERIZATION OF QUALITY INDICES IN BUTTERHEAD LETTUCE CULTIVATED UNDER MULCH AND BARE SOILJOURNAL OF FOOD QUALITY, Issue 4 2010MARÍA G. GOŃI ABSTRACT Butterhead lettuce was characterized by physical, microbiological and nutritional quality indices as a function of plant zoning and soil management (bare soil and mulch). Quality indices were measured in all the rings from the external toward the internal ratio. Assayed indices were: relative water content, water content, free and bound water, and the ratio between free water and total water, leaf area and color, total microbial counts (TMC) and ascorbic acid content (AA). The lettuce characterization by rings showed a remarkable plant zoning as a function of leaf age and development; also, some initial indices were affected by the soil management employed. Plastic mulches affect the microclimate around the plant, resulting in better plant water status. However, the use of black plastic covers could absorb sunlight therefore increasing soil temperature and causing lower AA and higher TMC in lettuce tissue. PRACTICAL APPLICATIONS During lettuce development, each leaf had a different level of exposure to environmental conditions, such as light, humidity, nutrients absorption and temperature affecting the quality indices of the raw material and introducing a source of variability in the physico-chemical, biochemical, nutritional and microbiological indices within the plant. In this way, the location of the leaf within the whole plant is an important factor to be considered. Moreover, during lettuce heads trading, it is a common practice to remove the external leaves as storage advances. These leaves are more perishable than middle and internal ones because of their direct exposure to environmental conditions. Understanding the way in which physical, microbiological and nutritional indices were distributed in the whole lettuce plant could be of interest, to know the value of the losses of regular green grocers' practices, from a nutritional and a safety point of view. [source] United States Department of Agriculture,Agricultural Research Service research on pest biology: weeds,,PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 6-7 2003Frank Forcella Abstract Over 125 permanent full-time scientists conduct research within the USDA Agricultural Research Service (ARS) on issues related to weeds. The research emphasis of most of these scientists involves ecology and management or biological control of weeds. Many scientists perform research on weed biology as components of their primary projects on weed control and integrated crop and soil management. Describing all ARS projects involved with weed biology is impossible, and consequently only research that falls within the following arbitrarily chosen topics is highlighted in this article: dormancy mechanisms; cell division; diversity of rangeland weeds; soil resources and rangeland weeds; poisonous rangeland plants; horticultural weeds; weed traits limiting chemical control; aquatic and semi-aquatic weeds; weed/transgenic wheat hybrids; seedbanks, seedling emergence and seedling populations; and weed seed production. Within these topics, and others not highlighted, the desire of ARS is that good information on weed biology currently translates or eventually will translate into practical advice for those who must manage weeds. Published in 2003 for SCI by John Wiley & Sons, Ltd. [source] | ||||||||||||||||