Salt content of lateritic profiles in the Darling Range, Western Australia

Soil Research ◽  
1974 ◽  
Vol 12 (2) ◽  
pp. 63 ◽  
Author(s):  
GM Dimmock ◽  
E Bettenay ◽  
MJ Mulcahy
Keyword(s):  
Soil Salinity ◽  
Agricultural Land ◽  
Surface Soil ◽  
Unit Area ◽  
Salt Content ◽  
Annual Rainfall ◽  
Mining Operations ◽  
Bauxite Mining ◽  
The Past ◽  
Forested Areas

Soil cores from some 40 complete laterite profiles as deep as 40 m in the Darling Range, W.A., have been examined for salt content, and in some cases, pH. The sites cover a range of topographic situations from divides to valley floors, and of rainfall from 560 to 1350 mm per annum. Increases in surface soil salinity and in the salt concentration of water yields following clearing of the native hardwood forest are related to the amounts of soluble salts stored in the lateritic pallid zones. Storage increases as rainfall decreases in all slope situations. In low rainfall areas (<800 mm per annum) the salt stored under unit area of landscape in the profile down to bedrock is five times greater than in high rainfall areas (≫1000 mm per annum). One area with an annual rainfall of 600 mm has an estimated storage of nearly a million kg of total salts per ha and marked increases in surface soil salinity have occurred within 10 years of clearing. Although in the past, increasing soil salinity has mainly affected agricultural land, the present emphasis on bauxite mining in the forested areas of the Darling Range, particularly in the drier parts, poses new problems in revegetating the exposed saline and acid pallid zone clays after mining operations have ceased.

Estimation of salt storage in the deep lateritic soils of the darling plateau, Western Australia

Soil Research ◽  
1985 ◽  
Vol 23 (4) ◽  
pp. 533 ◽  
Author(s):  
EN Tsykin ◽  
GC Slessar
Keyword(s):  
Western Australia ◽  
Nonlinear Regression ◽  
Soil Salinity ◽  
Salt Content ◽  
Drainage Density ◽  
Regression Equation ◽  
Annual Rainfall ◽  
Regression Equations ◽  
Statistical Relationship ◽  
Drilling Data

The salt content of soils in the principal bauxitic area of the Darling Plateau is broadly known from drilling. Soil salinities averaged over 15 km2 grid blocks bear a strong statistical relationship to a number of easily measured parameters, including distance from the Darling Scarp, mean annual rainfall and drainage density. We have used a nonlinear regression equation (r=0.96) to prepare maps showing soil salinity isopleths estimated with two levels of reliability. Similar regression equations have been used to estimate average soil salt contents over selected depth intervals. These regression equations and maps provide a useful means of estimating average soil salinities in areas where no drilling data are available.

FEATURES OF MONITORING OF DEGRADED LANDS TO ASSESS POSSIBILITIES FOR THEIR REHABILITATION

2020 ◽  
pp. 37-43
Author(s):  
B.I. KORZHENEVSKIY ◽  
◽  
N.V. KOLOMIYTSEV ◽  
G.YU. TOLKACHEV
Keyword(s):  
Agricultural Land ◽  
Meteorological Data ◽  
Morphological Characteristics ◽  
Energy Reserves ◽  
Land Restoration ◽  
Degraded Land ◽  
Degraded Lands ◽  
The Past ◽  
Unused Land ◽  
Restoration Work

Putting out of using large areas of agricultural lands in the central region over the past years has led to worsening the prospects of their purposed use, although the problem of the relevance of their restoration still remains. For many years the unused land was exposed to both natural exogenous processes such as erosion, suffusion, etc. and biological and chemical changes, usually for the worse for agriculture. There are considered elements of monitoring aimed at assessing the prospects or lack of perspectives of rehabilitation of degraded lands. An energy approach to assessing the state of slopes and soils located within these slopes is presented. The main factors of natural and anthropogenic character in assessing the prospects for land restoration are their steepness, excess relative to local bases of erosion other morphological characteristics of slopes which in general is reduced to an assessment of the energy provision of slopes and soils. So the higher the energy capacity of slopes – they are less promising for development, for soils – there is a reverse picture – the higher their energy reserves, the more promising is their use. Approaches to zoning the territory for monitoring from larger taxons of natural and anthropogenic genesis to the sites of special surveillance within which the prospects for rehabilitation of the agricultural land are evaluated. The most important factor is the material expediency of such actions, i.e. before starting the restoration work it is necessary to assess the profitability or loss of the proposed event. In cases of the material expediency it is feasible as further actions to include energy assessments of slopes and soils; zoning of the object according to the steepness and oriented characteristics of soil washout; and the possibility of obtaining agronomic and meteorological data on a timely basis. The result of the work is a forecast assessment of the prospects for restoring degraded land for the intended purpose using modern databases and WEB-systems.

scholarly journals Correction of Eddy Covariance Based Crop ET Considering the Heat Flux Source Area

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 281
Author(s):  
Stuart L. Joy ◽  
José L. Chávez
Keyword(s):  
Heat Flux ◽  
Eddy Covariance ◽  
Agricultural Land ◽  
Flux Measurement ◽  
Source Area ◽  
Mean Bias Error ◽  
Bias Error ◽  
Crop Water ◽  
The Past ◽  
Measurement Results

Eddy covariance (EC) systems are being used to measure sensible heat (H) and latent heat (LE) fluxes in order to determine crop water use or evapotranspiration (ET). The reliability of EC measurements depends on meeting certain meteorological assumptions; the most important of such are horizontal homogeneity, stationarity, and non-advective conditions. Over heterogeneous surfaces, the spatial context of the measurement must be known in order to properly interpret the magnitude of the heat flux measurement results. Over the past decades, there has been a proliferation of ‘heat flux source area’ (i.e., footprint) modeling studies, but only a few have explored the accuracy of the models over heterogeneous agricultural land. A composite ET estimate was created by using the estimated footprint weights for an EC system in the upwind corner of four fields and separate ET estimates from each of these fields. Three analytical footprint models were evaluated by comparing the composite ET to the measured ET. All three models performed consistently well, with an average mean bias error (MBE) of about −0.03 mm h−1 (−4.4%) and root mean square error (RMSE) of 0.09 mm h−1 (10.9%). The same three footprint models were then used to adjust the EC-measured ET to account for the fraction of the footprint that extended beyond the field of interest. The effectiveness of the footprint adjustment was determined by comparing the adjusted ET estimates with the lysimetric ET measurements from within the same field. This correction decreased the absolute hourly ET MBE by 8%, and the RMSE by 1%.

scholarly journals Linking Long-Term Changes in Soil Salinity to Paddy Land Abandonment in Jaffna Peninsula, Sri Lanka

Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 211
Author(s):  
Tharani Gopalakrishnan ◽  
Lalit Kumar
Keyword(s):  
Sri Lanka ◽  
Soil Salinity ◽  
Agricultural Land ◽  
Sea Water ◽  
Land Use Changes ◽  
Soil Salinization ◽  
Landsat Images ◽  
Paddy Land ◽  
Semi Arid Region

Soil salinity is a serious threat to coastal agriculture and has resulted in a significant reduction in agricultural output in many regions. Jaffna Peninsula, a semi-arid region located in the northern-most part of Sri Lanka, is also a victim of the adverse effects of coastal salinity. This study investigated long-term soil salinity changes and their link with agricultural land use changes, especially paddy land. Two Landsat images from 1988 and 2019 were used to map soil salinity distribution and changes. Another set of images was analyzed at four temporal periods to map abandoned paddy lands. A comparison of changes in soil salinity with abandoned paddy lands showed that abandoned paddy lands had significantly higher salinity than active paddy lands, confirming that increasing salts owing to the high levels of sea water intrusion in the soils, as well as higher water salinity in wells used for irrigation, could be the major drivers of degradation of paddy lands. The results also showed that there was a dramatic increase in soil salinity (1.4-fold) in the coastal lowlands of Jaffna Peninsula. 64.6% of the salinity-affected land was identified as being in the extreme saline category. In addition to reducing net arable lands, soil salinization has serious implications for food security and the livelihoods of farmers, potentially impacting the regional and national economy.

scholarly journals Comparison of Different Interpolation Methods for Prediction of Soil Salinity in Arid Irrigation Region in Northern China

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1535
Author(s):  
Tonggang Fu ◽  
Hui Gao ◽  
Jintong Liu
Keyword(s):  
Soil Salinity ◽  
Subsurface Layer ◽  
Salt Content ◽  
Spatial Prediction ◽  
Northern China ◽  
Sodium Adsorption Ratio ◽  
Interpolation Methods ◽  
Distance Weighting ◽  
Total Salt Content ◽  
Inverse Distance

Numerous methods have been used in the spatial prediction of soil salinity. However, the most suitable method is still unknown in arid irrigation regions. In this paper, 78 locations were sampled in salt-affected land caused by irrigation in an arid area in northern China. The geostatistical characteristics of the soil pH, Sodium Adsorption Ratio (SAR), Total Salt Content (TSC), and Soil Organic Matter (SOM) of the surface (0–20 cm) and subsurface (20–40 cm) layers were analyzed. The abilities of the Inverse Distance Weighting (IDW), Ordinary Kriging (OK), and CoKriging (CK) interpolation methods were compared, and the Root Mean Square Error (RMSE) was used to justify the results of the methods. The results showed that the spatial distributions of the soil properties obtained using the different interpolation methods were similar. However, the surface layer exhibits more spatial heterogeneity than the subsurface layer. Based on the RSME, the nugget/sill value and range significantly affected which method was the most suitable. Lower nugget/sill values and lower ranges can be fitted using the IDW method, but higher nugget/sill values and higher ranges can be fitted using the OK method. These results provide a valuable reference for the prediction of soil salinity.

The agronomic effectiveness of reactive phosphate rocks 1. Effect of the pasture environment

1997 ◽  
Vol 37 (8) ◽  
pp. 921 ◽  
Author(s):  
P. W. G Sale ◽  
R. J. Gilkes ◽  
M. D. A. Bolland ◽  
P. G. Simpson ◽  
D. C. Lewis ◽  
...  
Keyword(s):  
North Carolina ◽  
Phosphate Rock ◽  
Surface Soil ◽  
Annual Rainfall ◽  
Triple Superphosphate ◽  
Agronomic Effectiveness ◽  
P Sorption ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock ◽  
Very High

Summary. The agronomic effectiveness of directly applied North Carolina reactive phosphate rock was determined for 4 years from annual dry matter responses at 26 permanent pasture sites across Australia as part of the National Reactive Phosphate Rock Project. Fertiliser comparisons were based on the substitution value of North Carolina reactive phosphate rock for triple superphosphate (the SV50). The SV50 was calculated from fitted response curves for both fertilisers at the 50% of maximum yield response level of triple superphosphate. The reactive phosphate rock was judged to be as effective as triple superphosphate in the 1st year (and every year thereafter) at 4 sites (SV50 >0.9), and was as effective by the 4th year at 5 sites. At another 9 sites the reactive phosphate rock was only moderately effective with SV50 values between 0.5 and 0.8 in the 4th year, and at the final 8 sites it performed poorly with the 4th year SV50 being less than 0.5. Pasture environments where the reactive phosphate rock was effective in the 1st year were: (i) those on sandy, humic or peaty podsols with an annual rainfall in excess of 850 mm; (ii) those on soils that experienced prolonged winter inundation and lateral surface flow; and (iii) tropical grass pastures in very high rainfall areas (>2300 mm) on the wet tropical coast on North Queensland. The highly reactive North Carolina phosphate rock became effective by the 4th year at sites in southern Australia where annual rainfall exceeded 700 mm, and where the surface soil was acidic [pH (CaCl2) <5.0] and not excessively sandy (sand fraction in the A1 horizon <67%) but had some phosphorus (P) sorption capacity. Sites that were unsuitable for reactive phosphate rock use in the medium term (up to 4 years at least) were on very high P-sorbing krasnozem soils or high P-sorbing lateritic or red earth soils supporting subterranean-clover-dominant pasture, or on lower rainfall (< 600 mm) pastures growing on soils with a sandy A1 horizon (sand component >84%). No single environmental feature adequately predicted reactive phosphate rock performance although the surface pH of the soil was most closely correlated with the year-4 SV50 (r = 0.67). Multiple linear regression analysis found that available soil P (0–10 cm) and the P sorption class of the surface soil (0–2 cm), together with annual rainfall and a measure of the surface soil"s ability to retain moisture, could explain about two-thirds of the variance in the year-4 SV50 . The results from this Project indicate that there are a number of specific pasture environments in the higher rainfall regions of Australia where North Carolina reactive phosphate rock can be considered as an effective substitute P fertiliser for improved pasture.

Prospects for increasing the volume of agricultural production for export due to the expansion and intensification of the use of Russian land resources

2021 ◽  
pp. 40-47
Author(s):  
Gennadiy A. Polunin ◽  
Keyword(s):  
Agricultural Production ◽  
Agricultural Land ◽  
Arable Land ◽  
Agricultural Products ◽  
Land Resources ◽  
The Past ◽  
Federal Districts ◽  
Near Future

The article is devoted to substantiating the prospects for increasing the marginal volumes of agricultural production for export in the next four years. Two scenarios of such production are considered: 1) expansion and 2) intensification of the use of land resources. As part of the development of the first scenario, an analysis of the distribution of unused agricultural land, including arable land, by federal districts was carried out. Also, based on the forecast of the introduction of additional annual volumes of acreage in the subjects of the Federation, the calculation of additional volumes of agricultural production, which can be expected in the next four years, was carried out. The analysis of data on the increase in the yield of export-oriented crops over the past five years has been carried out, in the framework of the second scenario, the calculation of the projected additional yield due to the intensification of agriculture is presented. The results of the study indicate that the intensification of agriculture will have the greatest impact on the growth of production and export of agricultural products in the near future.

Non-Chernozem land: problems and ways of rational use

2020 ◽  
pp. 5-20
Author(s):  
G. A. Polunin ◽  
V V. Alakoz
Keyword(s):  
Agricultural Land ◽  
Arable Land ◽  
European Part ◽  
Agricultural Land Use ◽  
Agricultural Producers ◽  
The Real Estate ◽  
The Past ◽  
The Russian Federation ◽  
Agricultural Organizations ◽  
Land Economic

The results of scientifi c research on the state of agricultural land use in the subjects of the Russian Federation included in the Non-Chernozem Economic Zone of the European part of the country are considered in this article. The paper consists of data on distribution of currently unused arable land; the area of land plots in common shared ownership, the boundaries of which are not available in the Real Estate Cadastre; information about especially valuable productive agricultural land; economic prerequisites for the use of land by agricultural producers on the basis of lease or ownership, as well as changes over the past fi ve years in sown areas, the productivity of arable land in farms of all categories, data on the level of profi tability of agricultural organizations, unprofi table agricultural organizations etc.

Natural nanoclays: applications and future trends – a Chilean perspective

Clay Minerals ◽  
2009 ◽  
Vol 44 (2) ◽  
pp. 161-176 ◽  
Author(s):  
M. Calabi Floody ◽  
B. K. G. Theng ◽  
P. Reyes ◽  
M. L. Mora
Keyword(s):  
Agricultural Land ◽  
Clay Fraction ◽  
Barrier Properties ◽  
Clay Nanocomposites ◽  
Volcanic Soils ◽  
Gas Barrier ◽  
Important Species ◽  
The Past ◽  
Organically Modified ◽  
Water And Wastewater

AbstractBecause of their large potential for agricultural, industrial and medicinal applications, nanomaterials have been the focus of much research during the past few decades. Nanoclays are natural nanomaterials that occur in the clay fraction of soil, among which montmorillonite and allophane are the most important species. Montmorillonite is a crystalline hydrous phyllosilicate (layer silicate). Organically-modified montmorillonites or ‘organoclays’, formed by intercalation of quaternary ammonium cations, have long been used as rheological modifiers and additives in paints, inks, greases and cosmetics and as carriers and delivery systems for the controlled release of drugs. Perhaps the largest single usage of organoclays over recent years has been in the manufacture of polymer-clay nanocomposites. These organic–inorganic hybrid materials show superior mechanical, thermal and gas-barrier properties. Organoclays are also useful in pollution control and water treatment. Allophane is a non-crystalline aluminosilicate derived from the weathering of volcanic ash. A large proportion of the agricultural land in Chile is covered by volcanic soils,the clay fraction of which is dominated by allophane. Consisting of nanosize (3.5–5.0 nm) hollow spherules, allophane is a suitable support material for enzyme immobilization. Allophane is also effective at adsorbing phenolic compounds and colour from kraft mill effluents and phosphate from water and wastewater.

scholarly journals The history and characteristics of the 1980–2005 Portuguese rural fire database

2011 ◽  
Vol 11 (12) ◽  
pp. 3343-3358 ◽  
Author(s):  
M. G. Pereira ◽  
B. D. Malamud ◽  
R. M. Trigo ◽  
P. I. Alves
Keyword(s):  
Urban Areas ◽  
Unit Area ◽  
Fire Regime ◽  
Minimum Area ◽  
Burnt Area ◽  
Forested Areas ◽  
Large Fires ◽  
Burnt Areas

Abstract. We focus here on a mainland Continental Portuguese Rural Fire Database (PRFD) that includes 450 000 fires, the largest such database in Europe in terms of total number of recorded fires in the 1980–2005 period. In this work, we (a) list the most important factors for triggering and controlling the fire regime in mainland Continental Portugal, (b) describe the dataset's production, (c) discuss procedures adopted to identify and correct different fire data inconsistencies, creating a modified PRFD which we use here and make available as Supplement, (d) explore some basic temporal and completeness properties of the data. We find that the dataset's minimum measured burnt areas have changed with time between AF = 0.1 ha (1980–1990), AF = 0.01 ha (1991–1992), and AF = 0.001 ha (1992–2005), with varying degrees of completeness down to these values. These changes in minimum area measured are responsible for greater numbers of fires being recorded. A relatively small number of large fires in the PRFD are responsible for the majority of the burnt area. For example, fires with AF > 100 ha represent about 1% of all fire records but 75% of total burnt area. Finally, we consider for each Continental Portugal district and for the 26-yr period, the total number of rural fires and area burnt in forests and shrublands, each normalized by district areas. We find that the highest numbers of fires per unit area are in highly populated districts, and that the largest fraction of burnt area is in forested areas, coinciding with large parcels of continuous forests (predominantly rural and moderately urban areas).

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