Suitable Soil Research Articles

Cryogenic Pits and Quaternary Glacial Evidence in Central Iran

Quaternary glaciation studies in Central Iran reveal that it is not implausible to anticipate glaciation traces in this region. It is feasible to provide conclusive evidence about the behavior of ice sheets by referring to geomorphological factors and climatic statistical analyses. Factors such as flatness and accidental geographical features contribute to the existence of ice sheets in the Namdan Fars region. The digital reconstruction of past climatic conditions، using the Wright method، along with the absence of lake terraces around Kaftar Lake، signifies the presence of ice instead of water in the lake. The multi-axial morphology of the Namdan Plain، the shape and form of main valleys and passes، and the existence of numerous glacial cirque traces in the surrounding heights are also indicators of this phenomenon. The lack of evidence of ancient settlements in the plain، despite the availability of water and fertile soil، can be attributed to the region's historical thermal conditions. Investigating ancient glaciers helps us understand the natural history of the land. This knowledge can aid planners in devising macro strategies for regional development and water resource management، as glacial performance has always been associated with optimal water levels. Although glacial activities can create aquifers، the movement of ice sheets or ice surfaces does not support the accumulation of sediments required for creating aquifers with sufficient water storage. Instead، their performance leads to the creation of suitable agricultural soil layers. In summary، regional glaciers play a positive role in transforming and creating favorable agricultural soils and can be beneficial in adapting to climatic changes and extending statistical periods.

Spatiotemporal Analysis of Soil Quality Degradation and Emissions in the State of Iowa (USA)

The concept of soil quality (SQ) is defined as the soil's capacity to function, which is commonly assessed at the field scale. Soil quality is composed of inherent (soil suitability) and dynamic (soil health, SH) SQ, which can also be analyzed using geospatial tools as a SQ continuum (SQC). This study proposes an innovative spatiotemporal analysis of SQ degradation and emissions from land developments using the state of Iowa (IA) in the United States of America (USA) as a case study. The SQ degradation was linked to anthropogenic soil (SD) and land degradation (LD) in the state. More than 88% of land in IA experienced anthropogenic LD primarily due to agriculture (93%). All six soil orders were subject to various degrees of anthropogenic LD: Entisols (75%), Inceptisols (94%), Histosols (59%), Alfisols (79%), Mollisols (93%), and Vertisols (98%). Soil and LD have primarily increased between 2001 and 2016. In addition to agricultural LD, there was also SD/LD caused by an increase in developments often through urbanization. All land developments in IA can be linked to damages to SQ, with 8385.9 km2 of developed area, causing midpoint total soil carbon (TSC) losses of 1.7 × 1011 kg of C and an associated midpoint of social cost of carbon dioxide emissions (SC-CO2) of $28.8B (where B = billion = 109, USD). More recently developed land area (398.5 km2) between 2001 and 2016 likely caused the midpoint loss of 8.0 × 109 kg of C and a corresponding midpoint of $1.3B in SC-CO2. New developments are often located near urban areas, for example, near the capital city of Des Moines, and other cities (Sioux City, Dubuque). Results of this study reveal several different kinds of SQ damage from developments: loss of potential for future C sequestration in soils, soil C loss, and “realized” soil C social costs (SC-CO2). The state of IA has very limited potential land (2.0% of the total state area) for nature-based solutions (NBS) to compensate for SD and LD. The results of this study can be used to support pending soil health-related legislation in IA and monitoring towards achieving the Sustainable Development Goals (SDGs) developed by the United Nations (UN) by providing a landscape-level perspective on LD to focus field-level initiatives to reduce soil loss and improve SQ. Future technological innovations will provide higher spatial and temporal remote sensing data that can be fused with field-level direct sensing to track SH and SQ changes.

Soil and ecological assessment of the technogenically disturbed landscape in the area of a coal mine dump

Study of the soil‐ecological state of technogenic landscapes of Kuzbass through the example of coal mine dumps.Soil samples were taken in places with disturbed landscapes due to the action of the coal industry, namely the external dump on the site of the coal mine in the area of the village of Zarinskoye, Belovsky district, Kemerovo region in the south‐east of Western Siberia. The indicators were determined in accordance with GOST standards.Diagnostics of the surface of the coal mine dump were carried out. The main physical and chemical indicators were determined, according to which the possibility of soil formation and biological reclamation was assessed. In analyzing chemical composition, the following indicators were determined: aqueous pH, hydrolytic acidity, total alkalinity, dry residue, ash content, humus content and ion content (Cl–, SO42–, HCO3–, Ca2, Mg2+, Al3+). Physical indicators of the degree of suitability of soils for reclamation, such as hygroscopic moisture, soil moisture, soil density and soil porosity, were also studied.The results obtained allow us to characterise the technogenically disturbed areas in terms of physical and chemical properties as being limitedly favourable for plant growth, which can be used for biological reclamation following agrotechnical activity.

Land Use Planning by Using GIS Techniques for Land Resource Inventory (LRI)- Northern Dry Zone of Karnataka, India

A study was conducted to determine land capability and to develop suitability map based on soil characteristics and climatic factors of watershed area. Detailed soil survey was carried out for Donur-2 micro watershed which comes under Basavana Bagewadi taluka of Vijayapura district, Karnataka to acquire the comprehensive data related land resources. From the study area, it was observed that based on soil-site characteristics four soil series were identified such as Dadamatti, Karjol, Nidoni and Rampur series and mapped into eight mapping units using GIS techniques. Donur-2 watershed area has been grouped into three land capability classes (LCC) viz., II, III and IV with four subclasses IIes, IIIs, IIIse and IVe. Subclass ‘e’ is due to major limitation of soil property group ‘e’ i.e erosion and slope, subclass ‘s’ is due to major limitations group ‘s’ having parameters like texture, depth and gravelliness. Subclass ‘se’ and ‘es’ are due to limitations of both soil parameters group above mentioned, however se and es are different classes which are based major limitation one of the group and followed by other group. Land capability map was developed using GIS techniques which indicates that out of 324.3 ha study area, LCC class IIIs covering major area i.e. 179 ha (55.12%), followed by class IIs i.e. 109 ha (33.51%), class IVe i.e. 23 ha (7.15%) and minor area of 7 ha (2.15%) area is covered by class IIIse. Soil suitability assessment indicates that majority of land is moderately suitable for agriculture. Class III soils are designated as moderately fertile agricultural land with significant constraints. However, with special conservation practices soils under class III can be used for cultivation of different crops. Class IV soils are categorized as reasonably fertile for intermittent cultivation, characterized by significant restrictions that limit crop options but with careful management practices these can be used for cultivation of arable crops. Therefore, the utilization of a land use planning approach (LUP) is instrumental in formulating tailored land resource management strategies to enhance land productivity, mitigate land degradation and attain sustainability goals.

РАЗРАБОТКА ПРИЕМОВ УПРАВЛЕНИЯ УСТОЙЧИВОСТЬЮ ПЛОДОВЫХ ЦЕНОЗОВ С ИСПОЛЬЗОВАНИЕМ ПЕРСПЕКТИВНЫХ БИОЛОГИЗИРОВАННЫХ МЕТОДОВ

The results of 2023 research on the development of methods for managing the stability of fruit agrocenoses with rational land use are presented. The objects of research are orchard agrobiocenoses under various cultivation conditions. The work used methodological approaches and original techniques developed by the research team. Methods and elements of technologies for increasing the resistance of fruit agrocenoses to a complex of factors with biologized approaches for controlling the development of pathogens and pests, rational formation of the crowns of fruit crops of domestic varieties against the background of the application of biostimulants, techniques for rationing high-quality fruit yield, optimized approaches for optimizing plant nutrition and reproducing soil fertility in biocenotic and molecular levels were developed. The obtained results of scientific research of a fundamental and applied nature are associated with the identification of patterns and disclosure of mechanisms for the formation of the productivity of fruit crops in changing cultivation conditions and create a methodological basis for the development of new elements of technologies for managing the productivity of orchard cenoses, systems for monitoring the resource potential of soils to provide the population with quality products while preserving the environment. New knowledge about the patterns of influence of rootstock genotype on the realization of the production potential of various scion-rootstock combinations of the genus Malus Mill. under conditions of different planting densities, will allow, through the use of the most productive scion-rootstock combinations, to significantly increase the productivity of plantings, make the most efficient use of the garden area, and significantly accelerate the onset of marketable fruiting. New knowledge about the patterns of influence of certain limiting parameters of the soil cover on the condition and productivity of scion-rootstock combinations of fruit crops will be used to develop optimal parameters for assessing the horticultural suitability of soils. The identified features of frost resistance of various pear varieties in terms of the degree of stability of their flower buds under changing weather conditions in different phases of the winter-spring period are the basis for optimizing the placement of pear crops in the North Caucasus zone. Key words: ORCHARD CENOSES, ENVIRONMENTAL STRESS, CHANGES IN WEATHER CONDITIONS, TRANSFORMATION OF SOIL PARAMETERS, SCION-ROOTSTOCK COMBINATIONS, DOMESTIC APPLE VARIETIES, FROST RESISTANCE OF PEAR VARIETIES, NUTRITION OPTIMIZATION, PATHOGENS AND PEST CONTROL

Contamination and suitability of soils for growing bio products in Russia

The area of impact zones of industrial contamination, oil and oil products spills, motor vehicle emissions, radioactive substances, as well as pesticides and mineral fertilizers application on agricultural lands of the Russian Federation is calculated. The share of the territory under consideration in the total area of agricultural lands of the country does not exceed 3%. Soils in the zone of contamination influence are considered to be potentially polluted and should be included in the monitoring program of agricultural land. Soils outside the zone of influence of pollutant dissemination are uncontaminated. Regular monitoring of contamination of these soils should not be carried out, which will reduce the costs of monitoring. More than 97% of the Russian agricultural land is represented by uncontaminated soils and is suitable for the production of bio products. Regular monitoring of contamination of these soils should not be conducted, which will reduce the cost of the survey, including sample collection, preparation and analysis. In view of the lack of soil contamination, the transition to the cultivation of bio products should be based on declarative approach. In this case, bio production should meet the requirements of special cultivation technologies and the product quality standards.

ДИКОПЛОДОВЫЕ ПОРОДЫ НА НАРУШЕННЫХ ЗЕМЛЯХ СЕВЕРНОГО КАВКАЗА

Wild fruit species on disturbed lands grow in degraded areas and have the ability to quickly restore the ecosystem. Restoration of disturbed lands in mountain and piedmont areas plays a big role and is a significant resource in the national economic potential of the region, an important reserve for agricultural production. The article provides an overview of the disturbed lands of the North Caucasus as a result of mining. For the purpose of biological rehabilitation, a classification of technogenic landscapes has been developed. The state of wild fruit and berry plants in disturbed areas has been revealed, which depends on the types of substrate, topography, climate, parts of the slopes and their steepness. Eleven wild fruit species grow naturally in quarries in the study region. Among them, sea buckthorn and dog rose stand out. They tolerate drought well and are resistant to low soil fertility. Cherry plum, common hazel and hawthorn prefer better moisture conditions. The degree of root growth in different parts of the slope has been established, which makes it possible to determine the suitability of soil and hydrological conditions for wild fruit species and to plan appropriate measures. It has been confirmed that the moist parts of the lower slopes are the most favorable for the growth and development of plants. The individuality of the formation of wild fruit and berry plantings according to the exposures at each deposit separately is noted. The prospects of wild fruit breeds capable of producing root shoots are substantiated. It was revealed that the spread of root suckers occurs more intensively on light soils, despite the fact that moisture is better on clay; this is not the main criterion for the spread of suckers. An assortment of wild fruit plants has been developed to create protective plantings in various environmental conditions. Measures are proposed to restore disturbed lands. Key words: WILD FRUIT SPECIES, DISTURBED LANDS, SLOPE, QUARRY, REHABILITATION, ROOT OFFSPRING, ASSORTMENT

Conversion of metal-enriched magnetite mine tailings into suitable soil for vegetation by phytoremediation process with Bougainvillaea glabra under the influence of Thiobacillus ferroxidance

Magnetite mining is a significant contributor to land deterioration as well as HM-based soil contamination. The characteristics of magnetite mine tailing were examined in the present study, in addition to the positive and sustainable restoration strategy with Bougainvillaea glabra under the influence of Thiobacillus ferroxidance. The traits of test soil analysis findings demonstrated that the majority of the parameters exceeded the allowable limits (For instance: HMs such as Cr, Cu, Zn, Pb, Fe, and Co were found to be 208 ± 2.3, 131.43 ± 1.6, 185.41 ± 3.3, 312 ± 5.11, 956 ± 5.3, and 26.89 ± 2.43 mg kg−1 respectively). T. ferroxidance exhibited impressive HMs tolerance for as much as 800 g mL−1 concentrations of Cr, Cu, Zn, Pb, Fe, and Co. To prevent HMs toxic effects, the HMs contents in test soil were decreased by diluting with normal soil in the ratios of Ex-3 and Ex-2. A typical greenhouse study was carried out to assess the phytoremediation ability of B. glabra across six setups for experiments (Ex-1 to Ex-6). According to the findings of this research, the HMs tolerant T. ferroxidance from Ex-3 and Ex-2 had an outstanding impact on the growth, biomolecules level (such as chlorophylls: 65.84 & 41.1 mg g−1, proteins: 165.1 & 151.1 mg g−1, as well as carbohydrates: 227.4 & 159.3 mg g−1) as well as phytoremediation potential of B. glabra on magnetite mine soil. These findings indicated that a mixture of B. glabra as well as T. ferroxidance might serve as a valuable sustainable agent for removing HMs from contaminated soil.

Changes in Growth Parameters, C:N:P Stoichiometry and Non-Structural Carbohydrate Contents of Zanthoxylum armatum Seedling in Response to Five Soil Types

Zanthoxylum armatum (Z. armatum) is an economic crop widely planted for both spice and medicinal purposes in Southwest China. Soil is a key environmental condition that affects seedling growth and development, and screening suitable soil types is of great significance for the large-scale cultivation of crops. This study designed growth experiments of Z. armatum seedlings in red soil (RS), yellow soil (YS), acidic purple soil (ACPS), alkaline purple soil (ALPS), and alluvial soil (AS) to screen for more suitable soil types. The growth traits of Z. armatum seedlings and the carbon (C), nitrogen (N), phosphorus (P), C:N:P stoichiometry, and non-structural carbohydrate (NSC) content of different organs were comparatively analyzed. The results showed that the morphological indexes of Z. armatum seedlings cultured in AS were better than those in the other four soils.AS and RS may be beneficial for the culture of Z. armatum seedlings due to higher nutrient levels in three organs. Two-factor ANOVA and PCA analysis showed that C, N, and P and their proportions would affect the uptake and distribution of NSC in various organs of Z. armatum seedlings. These results showed that soil types and plant organs significantly affected the accumulation and distribution of N, P, and NSC in Z. armatum seedlings. These results are conducive to screening soil types suitable for the growth and development of Z. armatum and provide data support for further large-scale cultivation of Z. armatum in suitable areas.

Optimal Soil, Climate, and Management Factors for Maximizing Crop Yield and Soil Nutrients in a Rice–Oilseed Rotation System with Straw Return

Straw return (SR) has been widely recommended as a conservation agricultural practice in China. However, the effects of SR on crop yield and soil properties are inconsistent across studies of rice–oilseed rape cropping systems in China. This study aimed to investigate the effects of SR on crop yield and soil nutrient content in a rice–oilseed rotation system, and to understand the mechanism of straw return on the difference in yield increases between rice and oilseed rape. Additionally, suitable climate factors, soil properties, and agricultural practices were identified to achieve maximum increases in yield and soil nutrients in a rice–oilseed rotation under SR. This paper is based on a meta-analysis of 1322 observations from 83 peer-reviewed studies to evaluate the effects of climate, initial soil conditions, and agricultural management practices on rice and oilseed rape yields and soil nutrients under SR. The results showed that the responses of oilseed rape and rice yield remained positive, with 12.37% and 6.54% increases, and were significantly higher under SR than the control (no SR). Moreover, SR significantly increased the contents of several soil nutrients (soil organic carbon (SOC), total nutrients, available nutrients) and microbial biomass carbon (MBC) and nitrogen (MBN). Interestingly, the increase in crop yields was attributed to the increase in SOC, total nitrogen, and available potassium. Additionally, the increase in yields was mainly affected by climate factors, initial soil properties, and agronomic practices. For example, both mean annual temperature (MAT) and mean annual precipitation (MAP) had a positive correlation with crop yield increases under SR (p < 0.01). Initial soil conditions such as low SOC and total nitrogen content were more suitable for increased rice yield under SR, while the opposite was true for increased oilseed rape yield. Without fertilization, the SR did not significantly improve crop yield and soil nutrients, while it was more pronounced with N fertilization at 150–180 kg hm−2. The positive effect of SR on crop yields is more evident with plowing tillage, whereas the SR caused the highest increase in soil nutrients with the no-tillage condition. These findings have important implications for further improving crop yield, SOC, and soil nutrients in the Chinese rice–oilseed cropping system through straw return.

Kondisi habitat mangrove di Kelurahan Mapane Kecamatan Poso Pesisir Kabupaten Poso

The aim of this study is to assess the mangrove habitat condition in Mapane Village, Poso Coastal District, Poso Regency. Field surveys were conducted to determine representative mangrove habitat conditions (physical and chemical) in Mapane Village. Soil and water samples were collected to assess mangrove habitat conditions, using purposive sampling method with 3 repetitions. The soil and water quality in the research area is still conducive for mangrove growth, with suitable soil texture for Rhizophora sp. and stable salinity at 34‰. Although soil pH is slightly below standard, it remains suitable for mangrove growth (pH 6-7). Water quality parameters approach quality standards, albeit some below, remaining productive according to previous studies. The optimal pH for mangrove growth is neutral (pH 6.6-7.5). In conclusion, the soil and water quality in the research area strongly support mangrove growth. Despite slightly below-standard soil pH, it remains suitable for mangrove growth. Previous studies indicate the optimal soil pH for mangroves ranges from 6-7, while water pH approaches quality standards, remaining productive despite some below, and below pH levels.

Multivariate analysis and GIS approaches for modeling and mapping soil quality and land suitability in arid zones

Assessing soil quality marks the initial step in precision farming and agricultural management. Developing countries like Egypt face numerous hurdles in ensuring food security due to increasing populations and limited agricultural resources. A geographic information system (GIS) and multivariate analysis were utilized in the current work to evaluate and map a soil quality index (SQI). Moreover, the land suitability of the land for two plantations of the tree's oak (Quercus robur), and pine (Pinus silvestris), respectively was assessed using a parametric approach. A total of 82 soil profiles were selected to fulfill the objectives of the study. Based on the samples' PC scores, and agglomerative hierarchical clustering (AHC, the data was divided into two clusters: Cluster I and Cluster II, which collectively account for approximately 57% and 43% of the total data, respectively.. . The findings indicated that land suitability for planting Q. robur planted identified 2.14% of the research area as highly suitable (S1), 37.98% as moderately suitable (S2), and 59.89% as not suitable (N). Furthermore, the assessment of suitability for P. silvestris indicated that 50.88% of the investigated area was classified into: S1, 48.73% as S2, and 0.39% as N, which means it is not suitable for conservation activities. The research identified that soil depth beside excessive salinity and calcium carbonate as the primary soil constraints in the area in both clusters. The average soil depth, ECd and CaCO3 were 113.62 ± 12.41, 17.27 ± 10.23, 16.83 ± 6.57 in Cluster 1 and 45.43 ± 15.21, 22.42 ± 12.43, 21.55 ± 5.63 in Cluster II. The study demonstrates that integrating multivariate analysis with GIS enables a precise and streamlined assessment of the Soil Quality Index (SQI). Soil suitability modelling underscores the importance of implementing efficient management practices to attain agricultural sustainability in arid regions, particularly amidst intensive land utilization pressures

Eficiencia técnica en la ganadería de carne bovina en Uruguay

Livestock farming is the agricultural activity with the greatest individual land-use, but it faces competition from other sectors for land, and is criticized for its environmental footprint. In this global context, Uruguay emerges as an important case study, boasting a long tradition and significance in the beef export sector. Enhancing livestock productivity is imperative to mitigate environmental impacts, and bolster farm competitiveness and food production. This study delves into the technical efficiency of cattle ranches focused on cow-calf production in Uruguay during the 2011 agricultural year, with nationwide and mandatory data coverage. Using data from the 2011 General Agriculture Census we estimate a translog stochastic production frontier model encompassing key inputs (livestock units, grazing area, and labor), along with control variables such as soil suitability and infrastructure improvements. Our findings underscore the potential to augment Uruguay's beef production by an average of 26.4%, harnessing existing resources and technology while improving ranch management. Moreover, variables like the extent of reliance on livestock farming as the primary source of income of the ranch, the use of outsourced services, foreign cattle ownership ratios, and agronomic and veterinary consultation exert noteworthy significant impacts on TE.

Modelling Soil Erosion Using RUSLE and GIS for Kadalundi River Basin in Kerala, India

The main objective of the study was to estimate the potential average annual soil loss from Kadalundi river basin using RUSLE model and to prepare the spatial distribution map of soil erosion hazard using GIS to suggest suitable soil conservation and management measures for the basin. The individual factor maps for each factor in the RUSLE equation were prepared and multiplied in raster calculator to obtain the spatial distribution map of soil erosion with the help of ArcGIS. The daily rainfall data, basic soil data, Digital Elevation Model (DEM) and satellite imageries were used as the input data for the calculation of rainfall erosivity factor, soil erodibility factor, topographic factor, cover management factor and conservation practice factor. The results indicated an average annual erosion of 5.48 t·ha-1·yr-1 in the basin during the period of 2001 to 2021. The total quantity of soil washed away from the basin was 694836.60 t·yr-1. The estimated values of R-factor ranged from 938.97 MJ·mm·ha-1·h-1·yr-1 to 1102.65 MJ·mm·ha-1·h-1·yr-1, and the computed erodibility factor values varied between 0.0075 to 0.025 t·h·MJ⁻1·mm⁻1. The topographic factor value of the basin was found between 0 to 9.07. The basin had C-factor values of 0.08 to 1.10 and the P-factor values varied from 0.1 to 1. The spatial distribution map of erosion suggest that major part of the basin is under slight erosion class and only a minor part is under very severe erosion class. Areas in the very severe erosion class is characterised by moderate to steep slopes, or in other words areas with less slope is having slight erosion. As most of the area of the basin is having slight erosion, simple agronomical measures can be adopted for the mitigation purposes.

BIOCHAR AS A POTENTIAL SOIL CONDITIONER IN SALINE PRONE COASTAL AREA OF BANGLADESH

In the coastal areas of Bangladesh, salinity restricts normal crop production and increases with the desiccation of the soil. Recently, biochar has received great attention as a soil amendment to mitigate the detrimental effects of salinity stress. In this respect, a field experiment was conducted to examine the effects of biochars on soil properties and growth of okra (Abelmoschus esculentus L.) and to identify a suitable biochar amendment for salt-affected soils in coastal areas of Bangladesh. The experiment was conducted in a randomized complete block design (RCBD) with five replications. Three types of biochar (rice straw biochar, sawdust biochar and water hyacinth biochar) were applied @ 10 t ha-1 in a silt loam soil along with the control. Results showed that biochar application to the soil enhanced plant height, leaf number, leaf area, shoot fresh weight, shoot dry weight and yield of okra as well as improving the soil quality e.g. field capacity (FC), CEC, OC, total N, available P, S, K, and Ca. The application of water hyacinth biochar improved almost all of the growth and yield attributes of okra along with most of the soil properties than that of others. The results suggest that water hyacinth biochar might be recommended as a suitable soil amendment for better crop growth and soil quality. Moreover, water hyacinth biochar had significantly (P<0.001) higher surface area (205.40 m2g-1); consequently, higher capacity in salt and water adsorption which might prevent soil desiccation. Side by side, it significantly (P<0.001) increased the soil Ca content which might replace Na+ in the root rhizosphere minimizing the Na+ uptake by plants. Taken together, water hyacinth biochar could also be the best choice of organic amendments to reduce the suppressing effect of salinity stress in coastal areas of Bangladesh.

Pine cone ash stabilization of expansive soils

<p>The use of appropriate waste materials to stabilize problematic soils, such as expansive soils that are responsible for geotechnical damage, is a common practice in geotechnical engineering. This study presents the use of pulverized ash from the combustion of pine cone (PC) waste as a stabilizing agent to improve the engineering properties of expansive soils. A series of laboratory tests were carried out to examine the effect of different percentages of pine cone ash (PCA) content (3%, 5%, 7%, and 10%) on the Atterberg limits, swelling potential (Sp), linear shrinkage, compressibility, and unconfined compressive strength (qu) of naturally occurring swelling soils and the PC ash-treated soils. The results showed that PC ash contents of 5% and 7% contributed to a significant reduction in the swelling and shrinkage potential and an improvement in the coarsest texture, brittleness behavior, compaction properties, and compressive strength of the treated soils. Conversely, PC ash contents below 3% and above 7% showed minimal changes in the index and engineering properties of the PC ash-treated soils. In particular, the PC ash content of 5% resulted in optimal mitigation of the poor properties of the treated soils. The use of pine cone ash as a stabilizing agent represents a suitable and complementary subgrade soil material for expansive soils on which lightweight structures are built.</p>

Estimation of Water Yield and Soil Erosion in Samanalawewa Watershed in Sri Lanka using GIS-based InVEST Model

Ecosystem services (ES) are a group of tasks performed by the earth's ecosystems that are required to support life and offer benefits to humanity. Thus, this study explores two of the water-related ecosystem services, water yield, and soil retention that were distributed in the Samanalawewa Watershed (SW) and its eight sub-watersheds in Sri Lanka, over 20 years (2000-2020) with five- year time intervals. Soil and water conservation and water yield play an important role in ecosystem management. Hydrological balance is a crucial component of the hydrological ecosystem services. Assessing water yield and soil erosion are pivotal for watershed management. Thus, this study estimated and mapped the water yield and soil erosion, using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST 3.9.2) Annual Water Yield (AWY) and Sediment Delivery Ratio (SDR) model respectively. According to the obtained results, in 2000, 2005, 2010, 2015 and 2020, the estimated mean annual water yield was 2.62x105, 2.6x105, 3.5x105, 3.58x105 and 2.75x105 m3 ha-1year-1, respectively. Furthermore, the estimated mean annual soil erosion rates for the above- mentioned years were 53.2, 52.9, 69.7, 87.7 and 70.2 t ha-1 year-1. The estimated soil loss values of the SW are 10 to 18 times greater than the soil erosion tolerance (5 t ha-1 year-1) in Sri Lanka. The results show that the years 2015 and 2005 have the highest and the lowest water yield and total soil loss values, respectively. The upper part of the watershed has relatively moderate water yield and soil loss values than the lower part. These findings would be beneficial in developing watershed management strategies and in the implementation of suitable soil and water conservation techniques within the watershed. 
 Keywords: Ecosystem services, InVEST, Samanalawewa watershed, Soil erosion, Water yield

Experimental Study on the Soil Conditions for Rapeseed Transplanting for Blanket Seedling Combined Transplanter

To address the lack of available information on the soil physical conditions suitable for rapeseed blanket-shaped seedling transplanting, as well as the lack of protocols for the optimisation of soil tillage components in the utilisation of an integrated rapeseed blanket seedling combined transplanter, the physical parameters of different soil conditions and their impact on the growth of rapeseed after transplanting were investigated in this study. The aim was to determine the suitable soil physical parameters for rapeseed blanket-shaped seedling transplanting. First, the changes in soil firmness, soil bulk density, and soil moisture content during the installation of the rapeseed blanket seedling combined transplanter were tested and analysed, providing preliminary data for subsequent research. Using the variables of soil firmness and soil moisture content in the micro-environment around the roots and stems (30–50 mm) after rapeseed seedling transplantation and indicators such as the survival rate, root diameter, seedling height, and dry weight, an experiment on the growth of rapeseed blanket-shaped seedlings was conducted based on the furrow cutting transplanting principle. The results indicated that during the initial stage of rapeseed transplanting, the soil moisture content significantly influenced the vitality of the rapeseed plants. Under a high soil moisture content, the typically lengthy seedling period was shortened, and the effect on vitality was good, with minimal influence from the soil firmness. After seedling establishment, the rapeseed growth was significantly affected by the soil firmness. When the soil moisture content was less than 20%, increasing the soil firmness to 500 kPa was beneficial for moisture retention and rapeseed seedling growth. At a soil moisture content ranging from 20 to 25%, a soil firmness of 400 kPa was most suitable for both rapeseed vitality and late-stage growth. When the soil moisture content exceeded 25%, reducing the soil firmness to 300 kPa was beneficial for rapeseed growth, as an excessively high moisture content may lead to soil compaction, affecting seedling development. This study provides a theoretical basis for optimizing the design of soil tillage components in the application of an integrated rapeseed blanket seedling combined transplanter and for the high-yield management of rapeseed after transplanting.

Mapping of soil suitability for medicinal plants using machine learning methods

Inadequate conservation of medicinal plants can affect their productivity. Traditional assessments and strategies are often time-consuming and linked with errors. Utilizing herbs has been an integral part of the traditional system of medicine for centuries. However, its sustainability and conservation are critical due to climate change, over-harvesting and habitat loss. The study reveals how machine learning algorithms, geographic information systems (GIS) being a powerful tool for mapping and spatial analysis, and soil information can contribute to a swift decision-making approach for actual forethought and intensify the productivity of vulnerable curative plants of specific regions to promote drug discovery. The data analysis based on machine learning and data mining techniques over the soil, medicinal plants and GIS information can predict quick and effective results on a map to nurture the growth of the herbs. The work incorporates the construction of a novel dataset by using the quantum geographic information system tool and recommends the vulnerable herbs by implementing different supervised algorithms such as extra tree classifier (EXTC), random forest, bagging classifier, extreme gradient boosting and k nearest neighbor. Two unique approaches suggested for the user by using EXTC, firstly, for a given subregion type, its suitable soil classes and secondly, for soil type from the user, its respective subregion labels are revealed, finally, potential medicinal herbs and their conservation status are visualised using the choropleth map for classified soil/subregion. The research concludes on EXTC as it showcases outstanding performance for both soil and subregion classifications compared to other models, with an accuracy rate of 99.01% and 98.76%, respectively. The approach focuses on serving as a comprehensive and swift reference for the general public, bioscience researchers, and conservationists interested in conserving medicinal herbs based on soil availability or specific regions through maps.

A novel index for vegetation drought assessment based on plant water metabolism and balance under vegetation restoration on the Loess Plateau

Vegetation is vital to the ecosystem, contributing to the global carbon balance, but susceptible to the impacts of climate change. Monitoring vegetation drought remains challenging due to the lack of widely accepted drought indices. This study focused on vegetation, and simulated the vegetation suitable water demand and soil available water supply (calculated by Remote-sensing-based Water Balance Assessment Tool model). The standardized Vegetation Water deficit Index (SVWDI) was established by calculating the vegetation water deficit, which reflects the response of vegetation to drought. We examined the spatiotemporal evolution of vegetation drought on the Loess Plateau and evaluated the applicability of standardized vegetation water deficit index. Our findings revealed that the standardized vegetation water deficit index demonstrated an overall upward trend across different time scales from 1991 to 2020. Drought conditions were concentrated in the first 20 years of the study period, but vegetation drought on the Loess Plateau has been alleviated in the past decade. Moreover, as the time scale extended, the trend of SVWDI generally decreased, with approximately 49.50 % (1-month scale), 46.66 % (3-month scale), 47.08 % (12-month scale), and 32.16 % (24-month scale) of the grid areas experiencing increased SVWDI. The correlation between SVWDI and tree-ring width index (TRWI) performed well under all precipitation gradients, but the Palmer drought severity index (PDSI) was only highly correlated with TRWI in regions with low precipitation. In terms of the relationship with vegetation health, SVWDI demonstrated the highest correlation with the normalized difference vegetation index (NDVI) across different time scales, followed by PDSI and standardized precipitation evapotranspiration index (SPEI). This study provides insights into the evolution of vegetation drought in response to climate change. The findings can guide initiatives such as returning farmland to forest and grassland on the Loess Plateau to aid climate change adaptation strategies.