The Lodi Winegrape District is one of the largest in California and encom- passes a wide diversity of wine-grape varieties, production systems and soils, which complicates grape nutri- ent management. To identify regions within this district that have similar nutrient-management needs, we are developing a soil-landscape model based on soil survey information. Our current model identiﬁ es ﬁ ve regions within the Lodi district with presumed relationships between soil properties and potassium-supplying ability. Region 1 has weakly devel- oped, clay-rich soils in basin alluvium; region 2 has weakly developed, coarser-textured soils on recent al- luvial fans, fl ood plains and stream terraces; region 3 has moderately de- veloped soils on low terraces derived from granitic alluvium; region 4 has highly developed soils on high ter- races derived from mixed alluvium; and region 5 has weakly developed soils formed on undulating volca- nic terrain. Field and lab studies of soils in these regions show that our model is reasonable in concept, but that it must be ﬁ ne-tuned to account for differing degrees of soil vari- ability within each region in order to make realistic nutrient-management predictions.
Resources Centre), Atlas of Ethiopia (IFPRI), the six universities involved, CASCAPE offices (PRA results) and the ISRIC library.
The exploratory survey was conducted through the agricultural lands of the selected kebeles using the base maps (both delineations and content) as hypothesis to verify. Besides exploratory observations made at road cuts and through surficial features like stoniness, colour and vegetation, eight auger point observations were made per kebele (also near trial sites) resulting in a total of some 960 observations. Auger points were georeferenced using Geographic Positioning System (GPS) and described to a depth of 120 cm unless restricted by hard rock or impenetrable layer, using the field form template as prepared by ISRIC (see annex 2b) according to the guidelines for soil profile description (FAO, 2006). Auger points were tentatively classified according to WRB reference soil groups (FAO, 2006b)
soillandscape of Northern Germany [ 28]. Furthermore, lakes (e.g., Kummerower Lake) and river systems (e.g., Peene River, Tollense River, and Trebel River) are tightly connected with the near-surface ground water table. With an altitude range between 0 m and 96 m above sea level (mean 19 m, standard deviation 14 m) and a slope angle between 0° and 61° (mean 1.1°, standard deviation 1.5) , the relief is relatively flat in the north and undulating/hilly with steep slopes in the south. Due to the significant changes in the relief, the parent substrate material, and the distance from the groundwater table, the soil types are spatially variable. The flat and marginal undulating plain is composed of sand-rich areas and glacial-till areas. Cambisols, Luvisols, and Albeluvisols are predominant in the sand-rich area. On the less sandy but more clayey and loamy glacial till, Luvisols, Albeluvisols, and Stagnosols evolved. In hilly terrain, these soils are frequently truncated, and colluvial soils developed from eroded loamy material or deposits over former bogs [28,30,31]. Peaty soils are found in the floodplains. According to the Teterow weather station (34 km west of Demmin), the long-term (1981–2010) mean temperature is 8.7 °C and the mean precipitation is 584 mm/year; these records characterize the present climate of the study area [32,33]. This area is part of the sparsely populated (69 inhabitants per square kilometer), intensively used agricultural state of Mecklenburg- Western Pomerania, which consists of 80.3% farmland, 19.5% grassland/pastureland and 0.2% other agrarian land use. In 2012, cereal crops (55.5%), feed crops (19.3%), oleaginous fruits (18.6%), root crops (3.6%), legume crops (0.4%), and others (2.6%) were cultivated . In general, the study area is located within the TERENO-NE, which is managed by the German Research Centre for Geosciences Potsdam (GFZ) .
This way of blending field observations (e.g. point observations or existing soil maps) with statistical spatial prediction techniques has created a new branch of research in soil science called Digital Soil Mapping (DSM). DSM enables us to predict soil taxonomic units or specific soil proprieties (organic carbon, texture, bulk density, etc.) in areas where information is required by spatially extending point observations of individual soil properties using mathematical and statistical techniques as well as estimating the uncertainty of such predictions. DSM, by formalising the relationship between soil forming factors and the landscape, aims to capture and model the intrinsic spatial variability naturally observed in soils. After more than twenty years of intensive research and applications, DSM has emerged as a credible alternative to traditional soil mapping (Carre et al., 2007) due to its low costs and fast deployment in comparison to conventional surveying methods. Despite its short history, the development of DSM has consisted of a rapid series of advancements (improvements in data mining and knowledge discovery, better selection of terrain attributes and ancillary data, etc.) as soil scientists expanded the scope and prediction power of their modelling. However, one of the fundamental concerns since the foundation of this technique, that still remains unsolved, is the issue of scale (Addiscott, 1998, Lagacherie, 2008). Thomson et al. (2001) have also suggested that this will become increasingly important with the fast development and implementation of regional soil- landscape models.
Landform elements (LFEs) are commonly used in soil science to demarcate pedological boundaries and as a first indication of soil spatial variability. A novel LFE classification system known as geomorphons, has been shown to be able to overcome limitations of other automated LFE classifiers. The pattern recognition algorithm classifies the 10 most common LFEs, is computationally efficient, and is robust to changes in scale. However, due to their novelty, research into geomorphons has been limited. This study aimed to stratify the soillandscape through an aggregated geomorphon at the farm-scale (1:25 000) in the Western Cape, South Africa (33.25° S and 18.20° E). Twenty-four geomorphons were created at different resolution and their association with soil classes were compared. The best fitting geomorphon was aggregated into a 5-unit system corresponding to the South African national resource inventory. The aggregation was based on a decision tree corresponding to soil type. The 5-unit system was evaluated on how well the system stratified soil associations, soil lightness, soil electrical conductivity (EC), soil organic carbon, effective rooting depth (ERD), depth to lithology, gravel, sand, silt, and clay. The prediction potential was compared between the original geomorphon, the aggregated geomorphon, and a manually delineated LFE system. It was found that the aggregated geomorphon stratified all soil attributes except EC. Additionally, the aggregated geomorphon predicted 6 out of 9 soil properties with the lowest RMSE. This study shows that aggregating geomorphons can stratify the soillandscape even at the farm- scale and can be used as an initial indication of the soil spatial variability. This has implications in resource poor areas where an additional soil survey is not feasible or can be used to aid in the disaggregation of existing soil-terrain datasets.
Some evident examples of this potential are given in liter- ature on the relationships between soil (soil architecture) and rainfall/runoff processes. Amongst others, Lin et al. (2008) analysed the contributions of hydropedology to the under- standing and modelling of surface/subsurface runoff pro- cesses at microscopic (macropores and aggregates), meso- scopic (horizons and pedons) and macroscopic (hillslopes and catchments) scales; Bouma et al. (2008) showed the high potential of hydropedology in addressing end user multiscale land use problems; Bouma (1981) and Ritsema et al. (2005) related preferential flow paths to soil morphology and soil hydrophobicity, respectively; Coppola et al. (2009) studied the effects of a bimodal pore-size distribution and its vari- ability on a hillslope water balance. In an attempt to con- ceptualize the relationships between hydrology and pedol- ogy, Lin et al. (2008) and Lin (2010) have (i) framed hy- dropedology in the more general domain of earth’s criti- cal zone; (ii) created a hierarchical framework for bridging soil type distribution (forms) and soil processes (functions) in hydropedology; (iii) emphasised soil structural complex- ity at different scales (aggregates, horizon, profile, catena, etc.); and (iv) defined the Hydrologic Functional Unit (HFU) as the soil-landscape mapping unit with similar pedologic and hydrologic functions (Lin et al., 2008). Despite these
Although the static controls on soil moisture and their seasonality observed in this study are similar to those re- ported by others (Grayson et al., 1997; Western et al., 1999; G´omez-Plaza et al., 2001; Grant et al., 2004; Tromp-van Meerveld and McDonnell, 2006), the reasons for signifi- cance are strongly associated with static influences on snow distribution and melt. Significant correlations of soil mois- ture with aspect and topography variables during wet-up can be explained by the influence of these characteristics on early season snowmelt and sub-surface soil water routing in the northern portion of the catchment. Wetter soil mois- ture conditions that developed in the north-central portion of the catchment (sub-surface source area) during this period (Fig. 6) resulted in hydrological processes commonly ob- served in more humid to semi-humid environments (Ander- son and Burt, 1977; Beven and Kirkby, 1979; O’Loughlin, 1981; Burt and Butcher, 1985; Moore et al., 1988; Barling et al., 1994; Brocca et al., 2007). Significant negative cor- relations of soil moisture with northing, elevation, and dis- tance to the stream and positive correlations with distance to divide, snowpack variables, and soil depth during the ensu- ing wet-high flux period are explained by the distribution of available water (snowpack and soil water storage). Snow- pack, soil depth and available soil water (sub-surface source area) were generally greater at lower elevations (decreasing northings) and farther from the slope divide. Positions near the slope divide are often windswept of snow or experience early season melt due to intense solar radiation. The ability of the distance to divide variable in this study to represent available water input throughout the year, both the early sea- son lateral flow and the late season snow water input, storage, and lateral flow, explains its more significant correlation with overall soil moisture trends as compared with snow and soil variables. These correlations suggest the spatial domain of the dynamic influence of snowmelt on soil moisture patterns is dependent on how static variables like slope position and orientation influence snowpack development and retention of snow and early season meltwater (Litaor et al., 2008).
Abstract: Soil water dynamic is considered an important process for water resource and plantation management in Horqin Sand Land, northern China. In this study, soil water content simulated by the SWMS-2D model was used to systema- tically analyse soil water dynamics and explore the relationship between soil water and rainfall among micro-landforms (i.e., top, upslope, midslope, toeslope, and bottomland) and 0–200 cm soil depths during the growing season of 2013 and 2015. The results showed that soil water dynamics in 0–20 cm depths were closely linked to rainfall patterns, whereas soil water content in 20–80 cm depths illustrated a slight decline in addition to fluctuations caused by rainfall. At the top position, the soil water content in different ranges of depths (20–40 and 80–200 cm) was near the wilting point, and hence some branches, and even entire plants exhibited diebacks. At the upslope or midslope positions, the soil water content in 20–80 or 80–200 cm depths was higher than at the top position. Soil water content was higher at the toeslope and bottomland positions than at other micro-landforms, and deep caliche layers had a positive feedback effect on shrub establishment. Soil water recharge by rainfall was closely related to rainfall intensity and micro-landforms. Only rainfalls > 20 mm significantly increased water content in > 40 cm soil depths, but deeper water recharge occurred at the toeslope position. A linear equation was fitted to the relationship between soil water and antecedent rainfall, and the slopes and R 2 of the equations were different among micro-landforms and soil depths. The linear equations generally fitted well in
DOI: 10.4236/ojss.2018.87013 171 Open Journal of Soil Science grassland which stresses the importance of sampling deeper in the soil profile. To continue improving our understanding of land use change effects on SOC stocks future research should focus on how fast and slow pools of SOC are im- pacted by land use conversion. Also, isotopic natural abundance methods could potentially shed light on the underlying mechanisms driving the changes seen in SOC stock by allowing for comparisons of d13C levels of SOC to those of plant- and microbial-derived carbon. Given that demand for arable land will likely lead to an increase in the conversion of marginal lands it is important that we have a thorough understanding of land use change effects so we can make informed land management decisions.
Abstract. We propose the implementation of the Soil and Landscape Evolution Model (SaLEM) for the spatiotempo- ral investigation of soil parent material evolution following a lithologically differentiated approach. Relevant parts of the established Geomorphic/Orogenic Landscape Evolution Model (GOLEM) have been adapted for an operational Ge- ographical Information System (GIS) tool within the open- source software framework System for Automated Geoscien- tific Analyses (SAGA), thus taking advantage of SAGA’s ca- pabilities for geomorphometric analyses. The model is driven by palaeoclimatic data (temperature, precipitation) represen- tative of periglacial areas in northern Germany over the last 50 000 years. The initial conditions have been determined for a test site by a digital terrain model and a geological model. Weathering, erosion and transport functions are calibrated using extrinsic (climatic) and intrinsic (lithologic) parame- ter data. First results indicate that our differentiated SaLEM approach shows some evidence for the spatiotemporal pre- diction of important soil parental material properties (partic- ularly its depth). Future research will focus on the validation of the results against field data, and the influence of discrete events (mass movements, floods) on soil parent material for- mation has to be evaluated.
According to Schaefer, C. N. et al. (2004) bryophytes are adapted to environments with higher humidity, which can be either saline or eutrophic. The humic horizons, formed by the cycling of the biomass of mosses, serve as reservoirs of nutrients in organic colloids (Allen et al., 1967), which de- pend on the contribution of the elements via precipitation and snow melt channels. The concentrations of elements in moss samples often reflect the biogeochemical nature of soils and rocks rather than atmospheric input of elements (Bargagli, 2005). According to Allen et al. (1967), rainfall inputs are the dominant source of nutrient supply to moss carpets grow- ing on deep peat. However, on Potter Peninsula the nutrient content of precipitation is not high and survival depends on the capacity of living mosses and organic matter in colloidal forms to retain nutrients. In this area, as elsewhere in Antarc- tica, climate and landscape-soil stability play a dominant role in controlling both the establishment of vegetation and soil development.
The performance of CCs at different topographic positions was affected by the variability caused by inherent differences in topography. In general, N uptake in the CC biomass was higher at the shoulder position compared to the footslope positions due to better establishment of CCs. However, a N reduction in the vadose zone was generally only seen at the footslope position in CC watersheds compared to no CC watersheds. The results of the study are important for implementing economically viable management decisions for the farmers. At the watershed scale, the cost of implementing CCs can increase due to the area targeted under CCs and the poor establishment of CCs at this scale, which can result in significant loss off time, money, and efforts involved by the CC user. Therefore, dividing fields into different management zones based on topographic positions would allow micromanagement of watersheds. Multiple goals can be setup in an individual watershed to achieve the benefits of using CCs depending on the management zones. If the goal of a CC user is to get a reduction in soil solution N concentrations on the non-tile drained watersheds, then site specific CC planting targeting footslope topographic positions can be implemented. In our study, only footslope positions showed a reduction in soil solution N concentrations. Farmers can plant CCs on the footslope or the areas that are near to a headwater stream to manage N loss. If the goal of CC user is to prevent soil erosion on highly erodable topographic positions, such as backslopes, then CC species that establish well during winter and accumulate greater biomass can be adopted. Lastly, if the goal is obtaining an N benefit, then legume CCs can be planted at shoulder positions that can result in higher cash crop yields during normal precipitation years and can compensate for yield losses that are observed in the areas that may yield less. Cover crops at the watershed scale should be practiced and promoted; however, it is critical to keep in mind what kind of CC is to be implemented. Long-term research projects where different CCs and CCs mixes are planted on different topographic positions at the watershed scale are needed to further evaluate the potential of this BMP.
Sampling and data collection Soil samples were collected 2
from the 3 subplots of 1.0 m selected to represent each land use system in the June, 2012. Within each subplot 12-15 soil cores were collected at random and bulked. Thus, 3 replicates for each land use were collected for both 0-0.15 m and 0.15-0.30 m depths, totaling 24 soil samples for laboratory analysis. Water infiltration field tests were conducted by double ring infiltrometer method in the subplots chosen for sample collection, which consists of 2 galvanized rings of 0.30 and 0.80 m diameter with 0.30 m height. Infiltration rate was recorded every 5 minutes (ASTM 2003). In each subplot infiltration measurement was taken for 30 minutes. Soil bulk density (BD) was estimated by core method after oven-drying the soil cores collected with a core cutter of 0.05 m height (Gradwell & Birrell 1979). Soil analysis Soil samples were air-dried, ground and sieved with a 2 mm sieve prior to chemical analysis. Samples were analyzed at the soils laboratory of National Agricultural Research Institute (NARI) in Port Moresby. Total nitrogen content was determined by Kjeldahl digestion method (Blakemore et al. 1987), extractable phosphorus by Bray-1 method (Bray & Kurtz 1945), exchangeable potassium by neutral normal ammonium acetate extraction method (Blakemore et al. 1987), soil organic carbon by Walkley- Black method (Ogle et al. 2003), and soil pH were recorded by dipping a glass electrode in a 1:2.5 (w/v) soil-water
As the percent change in soil organic carbon fractions reflects the difference in soil organic carbon from one land use to another, it can be regarded as an indication of the degree of soil organic carbon deterioration or improvement. The positive value shows improvement of the soil organic carbon, whereas negative value indicates deterioration of the soil organic carbon. Across the three sites, there has been greater reduction in soil organic carbon fractions when forest land use is converted to agricultural land use. Clearing and cultivation of forest lands resulted in deterioration of soil organic carbon compared to soils under forest, Acacia and Gliricidia land uses. Cultivated soils showed low soil organic carbon fractions. Total organic C, light fraction C, particulate organic C and silt+clay organic C fractions were all reduced. Improvement of total organic C, light fraction C, and particulate organic C under planted forest land use at Matturie site indicates that planting of well-adapted and fast-growing tree species can gradually improve soil quality and regenerate degraded lands. The study has revealed that soil organic carbon is best protected in the silt+clay fraction under grassland use, and the incorporation of residues during tillage could increase soil organic matter fractions in soils of the Njala series. The level of crop residue addition should be increased in order to increase the level of soil organic matter. A further research is needed to determine the Microbial Biomass Carbon, KMnO4 soluble carbon, water soluble carbon and KMnO4 soluble carbon. The results of such research can be compared with the current results to see if they show any correlation. There is need for faster organic matter restoration through the addition of organic residues in the Njala landscape.
scape from the ecological impact and sustainabil- ity of agriculture point of view. The ﬁ rst time proﬁ le chosen was the agriculture socialization period 1950–1960 when uniform agricultural cooperatives originated but their member land base was not sta- ble yet and therefore o en varied (Fig. 2). The se cond time proﬁ le is the period of the years 1970–1980 (Fig. 3). This period features formation of land blocks and forced merging of cooperatives by aggregation of several thousands hectares of land area. The aim was a maximum utilization of land fund for agricul- tural production. To a signiﬁ cant extent in this pe- riod a land image which exists at the present form was being created. The third proﬁ le is the period of the years 1990–2000 when in terms of restitution of agrarian land, the land was being returned into the hands of private farmers. The last time proﬁ le is the present state of landscape.
insignificant the news and economy make people feel these days. The promised freedom/salvation that the capitalised land represents is the only land for many to work toward. For millions it is now the only option. This ubiquitous new land that heavyly self promotes, colonises the imagination of the viewer, and therefore, as I have been arguing above, colonises, claims and reforms the locating landscape. The multi-coded effect of this colonising process simultaneously advertises the purchasable 'freedom' of the new and better, whilst promoting a sense of lack, confinement and inadequacy of the place of the present. This simulacrum of effect seducing with an imagined location of freedom. (Capitalism, the Saviour?
Schmidt J, Hong N, Dellinger A, Beegle D, Lin H. Hillslope variability in maize response to nitrogen linked to in-season soil moisture redistribution. Agronomy Journal 2007;99:229. Schulte L, Liebman M, Asbjornsen H, Crow T. Agroecosystem restoration through strategic integration of perennials. Journal of Soil and Water Conservation 2006;61:164a.
Setting a regional or local system of land use regimes presents a separate problem in which the principles of legal conventionality, preference of broad public interests, insurance of landscape quality, functional convergence and planning hierarchy must be kept. The strictest regime systems are always deﬁned as territories predomi- nated by most valuable protected areas. It is important that accord- ing to the new edition of the Lithuanian Law of Territorial Planning in 2004, the solutions of landscape management tasks became ob- ligatory for all levels of general (master) plans. A useful experience in landscape management by many countries was gained, as usual, in the sphere of planning of protected areas, national and regional parks in particular. The Standard Territorial Regime System for Diﬀerent Landscape Management Zones (Saugomų..., 2004) was adopted in Lithuania by its Government in 2004 on the basis of ex- perience in the planning of protected areas.
The term landscape has several connotations and interpretations. Knudsen et al. (1995) clarify that landscape cannot be the same for two individuals because each of them has a different interaction with the landscape and their knowledge of landscape differs. Therefore, they do not suggest any universal definition for the landscape. nevertheless, some defi- nitions of landscape can be found in the literature, international documents and also in the national legislative. The European Landscape convention and Explanatory report defines landscape as follows: “ Landscape means an area, as perceived by people, which character is the result of the action and inter- action of natural and/or human factors” (council of Europe 2000, article 1). in the czech republic, the term landscape is defined in the Act no. 114/1992 coll, on the protection of nature and landscape as: “a part of earth surface with characteristic relief, which is created by functional connection of ecosystems and civilizing elements”. in literature, there can be found other definitions, for example Valenta (2008) in his work connects landscape with aesthetical values and defines it as follows: “Landscape represents de- terminate space, this space used to be determine by