Low Soil Quality Research Articles

Accounting for Climate and Inherent Soil Quality in United Nations (UN) Land Degradation Analysis: A Case Study of the State of Arizona (USA)

Climate change and land degradation (LD) are some of the most critical challenges for humanity. Land degradation (LD) is the focus of the United Nations (UN) Convention to Combat Desertification (UNCCD) and the UN Sustainable Development Goal (SDG 15: Life on Land). Land degradation is composed of inherent and anthropogenic LD, which are both impacted by inherent soil quality (SQ) and climate. Conventional LD analysis does not take into account inherent SQ because it is not the result of land use/land cover change (LULC), which can be tracked using remote sensing platforms. Furthermore, traditional LD analysis does not link anthropogenic LD to climate change through greenhouse gas (GHG) emissions. This study uses one of the indicators for LD for SDG 15 (15.3.1: Proportion of land that is degraded over the total land area) to demonstrate how to account for inherent SQ in anthropogenic LD with corresponding GHG emissions over time using the state of Arizona (AZ) as a case study. The inherent SQ of AZ is skewed towards low-SQ soils (Entisols: 29.3%, Aridisols: 49.4%), which, when combined with climate, define the inherent LD status. Currently, 8.6% of land in AZ has experienced anthropogenic LD primarily because of developments (urbanization) (42.8%) and agriculture (32.2%). All six soil orders have experienced varying degrees of anthropogenic LD. All land developments in AZ can be linked to damages from LD, with 4862.6 km2 developed, resulting in midpoint losses of 8.7 × 1010 kg of total soil carbon (TSC) and a midpoint social cost of carbon dioxide emissions (SC-CO2) of $14.7B (where B = billion = 109, USD). Arizona was not land degradation neutral (LDN) based on an increase (+9.6%) in the anthropogenic LD overall and an increase in developments (+29.5%) between 2001 and 2021. Considering ongoing climate change impacts in AZ, this increase in urbanization represents reverse climate change adaptation (RCCA) because of the increased population. The state of AZ has 82.0% of the total state area for nature-based solutions (NBS). However, this area is dominated by soils with inherently low SQ (e.g., Entisols, Aridisols, etc.), which complicates efforts for climate change adaptation.

Variability of soil chemical properties and rice productivity in salt-affected soil in the north coastal rice field of Central Java, Indonesia

A coastal rice field is generally characterized by salt-affected soil and low soil quality for rice cultivation. Identifying soil chemical properties in these areas is necessary to determine soil management options for rice production. Therefore, soil samples were collected from 33 sampling points in the Wedung Sub-district of Demak Regency in the late dry season of 2021 to evaluate the variation among soil chemical characteristics in a coastline rice field. Soil samples were obtained beneath the topsoil (0-20 cm soil depth) and observed for electrical conductivity, exchangeable potassium, sodium, calcium, magnesium, and cation exchange capacity. Soils in the research field were categorized as slightly salty (0.75-2 dS m-1) to lightly salty (2.0-4.0 dS m-1) with very high sodium (>2 cmol(+) kg-1). Exchangeable potassium was dominated by moderate (0.3-0.7 cmol(+) kg-1) and low categories (0.2-0.3 cmol(+) kg-1). Based on soil calcium-to-magnesium ratios, around 6% of all samples were classified as calcium-deficient. The range of soil cation exchange capacity was 22-30 cmol(+) kg-1 and classified as high soil cation exchange capacity. Rice productivity in the salt-affected soil was around 4 t ha-1. Strategies for soil and controlling plants, such as soil amelioration and salt-tolerant rice cultivars, should be pursued to support plant growth and enhance rice productivity in the salt-affected soil, particularly in the coastal area.

Tracing the fate of hay meadows with haylofts in Slovakia: A geographical perspective

Abstract The paper focuses on the historical distribution of haylofts in Slovakia, geographical conditions related to hay meadows with haylofts, and land cover changes of former hayloft localities. Moreover, the current state of preserved haylofts and the land use of their surrounding area were documented at a regional scale, during the field research. A map of the historical occurrence of haylofts was digitised based on the Czechoslovakian military topographic maps from 1952–1957 (1:25,000). Altogether, 9,742 haylofts were recorded. The haylofts were usually built in mountain and sub-mountain areas on places with low soil quality, mostly at higher elevations, on moderate or moderately steep slopes and in more distant and isolated areas. About half of former hayloft meadows now exist as meadows or pastures with different intensity of grassland management. Forest or shrubs already cover the other 38% of the sites. To a lesser extent, the areas have been converted into arable land or recreational areas. Only a few haylofts have survived to this day; for example, in Upper Liptov Region, it is only 1% of their former abundance in this area (48 haylofts). Apart from a few positive cases where they have been restored or preserved, those that have survived continue to decay.

Hazard estimation in urban home garden soils in an industrial area using microarthropods, soil properties and GIS modelling: an integrated approach.

The use of soil microarthropods as indicators of soil pollution in home gardens of an industrial area has been covered in this study. Soil samples were collected from 25 home gardens in three zones in Eloor during summer and North East monsoon from 2014 to 2018, for the study of soil microarthropods, soil properties, soil nutrients, and trace elements. The relationships among QBS-ar, microarthropod abundance, soil properties, and soil nutrients, were used to estimate the pollution hazard of the industrial area. The microarthropods present in the study area were Coleoptera, Hymenoptera, Diplopoda, and Araneae. A prominent study area feature was the absence of Collembola and Acari. The QBS-ar index score in these regions showed that the home gardens located adjacent to the industrial area showed low soil quality, with soil quality class values ranging from 1 to 2 throughout the study period. Discriminant analysis of soil nutrients with soil properties and microarthropod abundance showed that in Zone 1 and Zone 2, the data in 2018 was very well discriminated compared to other years. The hazard assessment in the Eloor region showed various levels of hazard zonation: Zone 1 with high-hazard and medium-hazard areas, Zone 2 with medium-hazard areas, and Zone 3 with low- and medium-hazard areas. The study is one of the first kinds that have used QBS-ar scores and soil properties along with soil nutrients and trace elements for estimating the level of hazard in home garden agroecosystems and thus points to an easy, simple, and practical approach in the monitoring and management of soil ecosystems.

Strength and Compressibility Characteristics of An Expansive Soil with addition of GGBS and Alkali Activated Slag

Abstract: The phenomenal development in civil engineering infrastructure in developing countries like India, soil stabilization has emerged as à key problem in the engineering industry. Engineers have been attempting to enhance the engineering properties of low-quality soil due to their negative impact on project performance. With increasing awareness of environmental issues, there has been a remarkable shift towards green and sustainable technologies. Reuse of waste materials have been advocated for quite a while to improve the properties of poor soils open up to new avenue and double advantage of waste management. In the project investigation an attempt to evacuate the Plasticity characteristics, Strength characteristics and Compressibility characteristics were conducted on selected soil as per Indian Standards using GGBS and Alkali Activated Solution (AAS) with different percentages and curing for 0,3,7,14, and 28 days to analyze the variation of engineering properties. From the results combination of (GGBS + AAS) proved to increase of strength and reduce compressibility characteristics. The combination of GGBS + AAS is cost effective, non-destructive, low energy demanding and ecofriendly than GGBS to the selected expansive soil.

Role of Genome Sequences of Major and Minor Millets in Strengthening Food and Nutritional Security for Future Generations

Millets are small-seeded cereals belonging to the family Poaceae. They are considered to be climate-resilient and future nutritional food cereals for humans. Millets are resistant to biotic and abiotic stressors compared to other major cereals and thrive in low-quality soils with little maintenance and less rainfall. The importance of millets is still not well known to many people due to the lack of popularity and cultivation in semi-arid tropics of Asia and Africa. The United Nations has declared 2023 as the International Year of Millets (IYM 2023) to promote millet cultivation and popularize their health benefits globally. A few years ago, the application of molecular biology was in its infancy in millets due to the unavailability of genome sequences. Genome sequences are available for most of the millets on NCBI and Phytozome databases. In this review, we discuss the details of genome sequences for millets, candidate genes identified from the native genome of millets. The current status of quantitative trait loci and genome-wide association studies in millets are also discussed. The utilization of millet genome sequences in functional genomics research and translating the information for crop improvement will help millet and non-millet cereals survive harsh environments in the future. Such efforts will help strengthen food security and reduce malnutrition worldwide in 2050.

Integrated Soil–Crop System Management Promotes Sustainability of Intensive Vegetable Production in Plastic Shed Systems: A Case Study in the Yangtze River Basin, China

Excessive fertilizer input, low nutrient use efficiency, soil quality, and environmental degradation hinder greenhouse vegetable production. Integrated agronomic strategies of soil, crop, and nutrient management are needed to sharply improve the vegetable yield and simultaneously maintain sustainable production. A three-season field experiment was conducted from 2015 to 2018, aiming to evaluate the effect of integrated soil–crop system management (ISSM) on the agronomy, environment, and economy of greenhouse vegetable systems in the Yangtze River Basin, China. Three treatments were included in the experiment: (1) farmers’ current practice (FP), based on a local farmers’ survey; (2) soil remediation treatment (SR), the application of soil conditioner and compost fertilizer instead of chicken manure; (3) ISSM, a combination of soil conditioner, reducing plant density, and using formula fertilizer as well as increasing the fertilization times. The results indicated that ISSM (47.7 Mg ha−1) improved the pepper yield by 17% relative to farmers’ current practice (FP, 40.7 Mg ha−1). Soil remediation (SR), as a single approach, mainly made a contribution to improving the yield (by 6.9%) and nutrient use efficiency while reducing apparent nitrogen (N) losses. Higher yields were mainly attributed to increasing the fruit number per plant. On average, apparent N losses were reduced by 245 kg N ha−1 per season for ISSM compared to FP. In addition, higher net profits were obtained under SR and ISSM relative to FP. Overall, both SR and ISSM have advantages for the agronomy, environment, and economy in greenhouse vegetable production, but ISSM would be the optimal choice to achieve higher yields with lower environmental impacts.

Composition of the weed flora in sugar beet cultivation in Germany – nationwide trials 1995–2022

Long-term data from 449 herbicide trials across Germany from 1995–2022 were used to characterise the weed composition in sugar beet cultivation. The assessments of 1782 untreated control plots showed local weed species composition and weed pressure. The most common weeds were Chenopodium album (82.3% of all plots), Polygonum convolvulus (52.2%) and Galium aparine (25%). The average number of weed species in the field trials decreased from 4.9 in 1995 to 2.6 in 2022, significantly influenced by trial location and year. The occurrence of the most frequent weeds has also changed. C. album and P. convolvulus increased while G. aparine and Matricaria chamomilla decreased. Possible reasons for these changes are different tillage systems and intensities as well as changes in crop rotation with decreased crop diversity. Herbicide treatments and different active ingredients also affect the occurrence and proportion of weeds. The trial sites were assigned to clusters accounting for climate attributes and soil properties to identify regional differences in weed infestation. Regions with low soil quality, high temperatures and low precipitation had higher weed diversity, presumably due to low crop cover and, thus, lower weed suppression. The proportion of C. album was very high in all regions because it can grow under a wide range of environmental conditions. For P. convolvulus, significant regional differences existed in its proportion of total weed infestation. Its importance was lower in regions with poorer soils.

Evaluation of soil quality and land suitability in different management systems

ABSTRACT This study aimed to evaluate the effect of management systems on soil quality in rangeland and agricultural lands (smallholder, total owner, and Binaloud Company) in Neyshabur plain, northeastern Iran. Twenty-one soil profiles were described and sampled. The weighted and additive soil quality indices (SQI) of surface soil and soil profile (0–100 cm) were calculated. The minimum data set (MDS) was determined using principal component analysis (PCA) and expert opinion (EO) methods. The land index (LI) for alfalfa was calculated using the FAO method. In all management systems, the EO-weighted SQI was the highest for surface soil and soil profile. The relationship between the EO-weighted SQI and alfalfa yield was the strongest in the total owner and Binaloud Company. The LI showed a better relationship with the alfalfa yield than the SQI. The SQI of soil profile provides more comprehensive information regarding the different soil management systems. The LI, which considers crop requirements, could be useful in comparing the soil quality for a specific plant. The lower soil quality in smallholder system is an early warning sign of soil degradation in the area. Furthermore, the SQI has sufficient capability to reveal the effects of the land exploitation systems on soil quality.

The effect of low-temperature straw-degrading microbes on winter wheat growth and soil improvement under straw return.

The application of straw-degrading microbes (SDMs) with straw returned to the field is an effective measure to improve soil quality, increase yield, and maintain soil microorganisms. However, the utilization of SDMs in winter in north China is limited by the poor effects at low temperatures. This study investigated the effects of a new compound SDM, including a novel low-temperature fungus Pseudogymnoascus sp. SDF-LT, on winter wheat yield, soil improvement, and soil microbial diversity. A 2-year field experiment was conducted in two different soil textures of wheat-maize rotation fields with full corn straw return and application of SDMs at an amount of 67.5 kg hm-2. After 2 years of continuous application of SDMs, the winter wheat yield increased significantly, reaching 9419.40 kg hm-2 in Ningjin (NJSDM) and 9107.25 kg hm-2 in Mancheng (MCSDM). The soil properties have been significantly improved compared with the single straw return group, especially the sandy loam soil, whose quality is relatively low. The analysis of soil microbial diversity showed that SDMs significantly reduced the Chao1, Shannon, Simpson, and observed species of the sandy loam soil in the MCSDM group. The Simpson and Shannon indexes of fungi diversity in the two experimental sites were significantly increased by SDMs. The negative correlation of fungi increased from 47.1 to 48.85% in the SDM groups. The soil-dominant microbes changed in the SDM groups, in which the interactions between microbes were enhanced. These results suggested that the SDMs changed the the soil microbial community structure and its diversity and complexity, which is beneficial for crop growth. Our study provided sufficient evidence for the utilization of low-temperature SDMs with straw return in cold winter, which plays a role in soil improvement, especially for low-quality soils, to increase crop yield.

Assessment of Nutritional Potential and Methane Mitigation Efficacy of Napier Grass Cultivars

Napier grass is cultivated as a high-yielding forage crop and widely utilized in the nutrition of grazing animals such as cattle and goats due to its rapid growth rate, expansive leaf surface, and ability to thrive even in low-quality soils, making it a valuable animal feed option. In this study, the chemical compositions, in vitro gas (GP) and methane (CH4) production, metabolizable energy (ME), organic matter digestibility (OMD), true digestible dry matter (TDDM), microbial protein (MP), partitioning factor (PF), microbial protein synthesis efficiency (MPSE, and relative feed values (RFV) of the grasses Packhong1 (Penisetum purpureum x Penisetum americanum), Chinese Pennisetum (Penisetum purpureum x Penisetum alopecurides), and Dwarf Elephant (Pennisetum purpureum cv. Mott) were investigated. Significant differences were found in the chemical contents of napier varieties used in the study (p

Response of growth performance and yield of butternut squash(Cucurbita moschata Duch Ex Poir) cultivar Waltham under differentdosages of bokashi application

Butternut squash, also known as Cucurbita moschata, is a variety of pumpkin with promising commercial potential. However,most of the soils in the tropics are acidic and lack organic matter.The addition of organic material such as bokashi is essential inimproving the low soil pH and soil quality. Therefore, this study aimed to elucidate the effects of different rates of bokashi application on the growth performance and yield of butternut squash cultivated on tropical acid soil. A planting experiment was carried out from July until October 2022. A total of 36 planting beds were prepared, and each bed was constructed in 100 cm x 400 cm, consisting of 8 plants bed-1. The experiment was arranged in a Randomized Complete Block design. A total of three different rates of bokashi were applied to the soil prior to planting, namely 0 (control), 4,000, and 8,000 kg ha-1. A 12,000 kg ha-1 of commercial peat moss (Holland Free Peat) was also applied to compare bokashi and peat moss (the common planting medium used in most planting activities). The maximum plant height growth and leaf production for butternut squash was around 7-8th week. Application rate of 8,000 kg ha-1 bokashi contributed to significantly highest plant height (352.1 cm), number of leaves (86 leaves), and yield of Waltham butter squash per plant (1.5 kg plant-1). Multiple planting cycles should be carried out further to elucidate the bokashi's residual effect on nutrient supply to butternut squash cultivation.

Remote sensing analysis of desert sensitive areas using MEDALUS model and GIS in the Niger River Basin

Environmental degradation is a dynamic issue that requires ongoing monitoring to ensure ecological repair and environmental management for sustainable development. This study employed remote sensing techniques to ascertain the desertification sensitivity areas in the Niger River Basin (NRB) using the MEDALUS Model. The indicators for the model were divided into three categories: vegetation quality,climate quality, and soil quality index. The net primary productivity, estimated by the Carnegie Ames Stanford Approach model was substituted in the vegetation quality index. Each quality index was computed by calculating the geometric mean of selected sub-indices, while the geometric mean of the three quality indicators was utilized to determine the Environmental sensitivity to desertification in the study area. A total of 26.10% of the study area had low soil quality, while 26.16% and 17.41% of the study area had low vegetation and climate indicators, respectively. The study revealed that about 36.56% of the study area is highly sensitive while 27.65% and 35.78% are moderately and less sensitive respectively, to desertification in the NRB. The desertification-sensitivity index map shows that the northern part of the study area is highly susceptible to desertification and is encroaching southwards. The findings reveal that climate variables are major influencers in the study area. Our research is of importance to the Niger Basin Authority, planners, and other government agencies in charge of protecting the environment, to ascertain the sensitive areas to desertification, and to help cushion the effect of land degradation in the NRB.

Niche construction by two ectomycorrhizal truffle species (Tuber aestivum and T. melanosporum)

Niche construction by biota has been frequently reported for animals and plants, but fungi have received less attention. For mycorrhizal fungi, mutualistic niche construction has been proposed where partners construct niches for each other. However, few eco-evolutionary mechanisms leading to mutualistic symbiotic feedback have been described. Here we report niche construction by two ectomycorrhiza-forming species of truffles, Tuber aestivum and T. melanosporum. The soils of 263 spots of these Tuber, which create bare patches (brûlés), have been monitored (9–10 years) in natural forests to analyze whether they meet the criteria to satisfy the mutualistic niche construction process. Soil habitat modification by these Tuber can be seen in their brûlés, where the vegetation of arbuscular mycorrhizal plants and soil organisms are largely suppressed. Tuber melanosporum brûlés were smaller more productive, and with lower vegetation cover than T. aestivum. Interactions among soil carbonates, pH, and brûlé size are associated with increased carpophore productivity, indicating positive feedback between habitat modification and fungal fitness. Both species modified the habitat differentially. Tuber aestivum brûlés had higher pH and lower total carbonate than soils outside. Tuber melanosporum brûlés had lower total carbonate and higher exchangeable Ca2+ and active carbonate than soils outside. In conclusion, brûlés show a mutualistic niche construction process because modifies their soil environment and increases the fitness of both Tuber spp. Enhanced carbonate weathering by truffles resulted in lower soil quality with a negative impact on plants, indicating that mutualistic niche construction does not equally benefit both partners.

Characterization of black cotton soil by using granulated blast furnace slags

Soil stabilization is the best way to enhance the characteristics of low-quality soil. The properties may include, permeability, compressibility, strength, durability, etc. It is required when there is a need for construction on the poor sub-soils that are not suitable for that particular construction. Black cotton soil (BC) has a high clay content and is also considered as compressible soil with shrinkage and swelling characteristics and a constrained bearing capacity. It expands during the rainy season due to water absorption and contracts during the summer, which gives rise to serious structural deterioration. This study targets to stabilize this black cotton soil using ground granulated blast furnace slags (GGBS). It is a by-product of iron found in the blast furnace. It is extremely cementitious and contains a large amount of calcium silicate hydrates that increase its durability, strength, and appearance. In this study, GGBS is used at different percentages such as 5 %, 10 %, 15 %, 20 % and 25 %. Sodium hydroxide is also added in various dosages from 0.5 M, 1 M, 2 M, 4 M and 6 M. The major goal of this study is to investigate how GGBS affects the engineering parameters such as Atterberg’s limit, differential free swell (DFS), Compaction characteristics (i.e., maximum dry density (MDD) and optimum moisture content (OMC)) and unconfined compressive strength (UCS). The durability characteristics of soil-GGBS mixtures are also studied. Results show that as compared to virgin soil, adding 25 % of GGBS to BC soil resulted in an increase in MDD of around 16.5 % and a decrease in OMC of about 29 %. Further, it is also found that compared to (Soil + 20 % GGBS), the UCS value of the (Soil + 20 % GGBS + 4 M NaOH) mixture increased by roughly 36.5 %. Finally, the optimum concentration of GGBS content is found as 20 % while treated with 4 M NaOH solution.

Crop yield increments will enhance soil carbon sequestration in coastal arable lands by 2100

Coastal lands are crucial arable land reserves that play a vital role in ensuring future global food security. In arable coastal lands, low soil quality often results in limited crop yield and soil organic carbon (SOC), making them promising sites for enhancing both soil carbon sequestration and agricultural production. However, a scarcity of long-term site experiments has led to a research gap regarding SOC sequestration in coastal arable lands, leaving potential uncertainties due to variations in planting systems, crop yields, and the influence of climate change. In this study, we focused on the Yellow River Delta (YRD) in China, which is a typical coastal agricultural area. We verified the adaptability of the Denitrifcation-Decomposition (DNDC) model in coastal farmlands based on an 11-year long-term observation experiment and continuous sampling survey data. We further explored the spatiotemporal changes of regional SOC stocks under two Shared Socio-Economic Pathways (SSPs) scenarios based on five Global Climate Models (GCMs) derived from the Coupled Model Intercomparison Project Phase 6 (CMIP6), along with three yield increase scenarios from 2020 to 2100. The results indicated that promoting single-cotton cultivation in coastal saline–alkali lands would result in at least 88.2% of farmland being converted into carbon sinks. In contrast, promoting the cultivation of a wheat–maize rotation system can promote regional SOC sequestration as a whole, with a maximum increase of 31.90 Mg C ha−1. By 2100, the SOC stocks decreased in cotton and wheat–maize rotation farmland by 3.9% and 11.6%, respectively, in the SSP585 scenario compared with that in the SSP126 scenario. Except for farmlands with wheat-maize rotation cropping system under the SSP126 scenario, the SOC stocks in all other scenarios are projected to reach their theoretical maximum values before 2050. Additionally, when reaching the North China Plain (S1) and national (S2) high-yield levels of farmland, the SOC stocks in cotton farmland by 2100 increased by 16.7% and 21.6%, respectively, whereas the SOC stocks in wheat-maize farmland increased by 1.8% and 4.8%, respectively. Our study revealed the mutually beneficial relationship between yield increment and SOC sequestration in coastal farmlands under climate change, as well as the potential for future SOC sequestration. We provided scientific support for land management and climate change mitigation strategic decision-making in coastal saline–alkali farmlands.

Assessment of soil quality in an arid and barren mountainous of Shandong province, China

Forest soils are important components of forest ecosystems, and soil quality assessment as a decision-making tool to understand forest soil quality and maintain soil productivity is essential. Various methods of soil quality assessment have been developed, which have occasionally generated inconsistent assessment results between soil types. We assessed the soil quality of five communities (herb, shrub, Quercus acutissima, Pinus thunbergii, and Q. acutissima–P. thunbergii mixed plantation) using two common methods of dry and barren mountains in the Yimeng Mountain area, China. Sixteen soil physical, chemical and biological properties were analysed. The soil quality index was determined using the established minimum data set based on the selection results of principal component analysis and Pearson analysis. Silt, soil total phosphorus (P), soil total nitrogen (N), L-leucine aminopeptidase, acid phosphatase and vector length were identified as the most representative indicators for the minimum data set. Linear regression analysis showed that the minimum data set can adequately represent the total data set to quantify the impact of different communities on soil quality (P < 0.001). The results of linear and non-linear methods of soil quality assessment showed that the higher soil quality index was Pinus forest (0.59 and 0.54), and the soil quality index of mixed plantation (0.41 and 0.45) was lower, which was similar to the herb community (0.37 and 0.44). Soil quality was mostly affected by soil chemical properties and extracellular enzyme activities of different communities, and the different reasons for the low soil quality of mixed plantations were affected by soil organic carbon (C) and total C. Overall, we demonstrate that the soil quality index based on the minimum data set method could be a useful tool to indicate the soil quality of forest systems. Mixed plantations can improve soil quality by increasing soil C, which is crucial in ecosystem balance.

Assessment of soil quality in hanzhong city based on risk management of heavy metal pollution

In the present study, Hanzhong City was taken as an example, and the classification of soil heavy metal pollution risks was performed based on the evaluation of soil fertility status with soil physical and chemical properties as the main indicators. Results showed that the coefficients of variation of soil physical and chemical indicators in the study area were in the descending order: the soil fertility status showed a trend of increasing with decreasing terrain and increasing rivers. The high fertility areas were mainly distributed in the northwest and northeast of the plain area, while the low fertility areas were mainly distributed in the southeastern hilly and mountainous areas and in the western low-lying areas, and the transitional areas surrounded the low-fertility areas. At least 88.89% of the Cd samples and 98.61% of the Cr samples out of the eight heavy metals, Cd, Hg, As, Pb, Cr, Ni, Cu, and Zn, belonged to the priority protection class, while 11.11% of the Cd samples and 1.39% of the Cr samples belonged to the safe use class. The overall distribution of soil quality was similar to that of soil fertility status, while the distribution range of low-quality soil in the southeastern part was smaller and more concentrated. The above research results indicate that the introduction of the classification results of soil pollution risk control types generally reduces the soil fertility status correction and changes the spatial distribution pattern of the original soil fertility status to some extent. Bangladesh J. Bot. 52(2): 659-669, 2023 (June) Special

Assessment of soil quality in hanzhong city based on risk management of heavy metal pollution

In the present study, Hanzhong City was taken as an example, and the classification of soil heavy metal pollution risks was performed based on the evaluation of soil fertility status with soil physical and chemical properties as the main indicators. Results showed that the coefficients of variation of soil physical and chemical indicators in the study area were in the descending order: the soil fertility status showed a trend of increasing with decreasing terrain and increasing rivers. The high fertility areas were mainly distributed in the northwest and northeast of the plain area, while the low fertility areas were mainly distributed in the southeastern hilly and mountainous areas and in the western low-lying areas, and the transitional areas surrounded the low-fertility areas. At least 88.89% of the Cd samples and 98.61% of the Cr samples out of the eight heavy metals, Cd, Hg, As, Pb, Cr, Ni, Cu, and Zn, belonged to the priority protection class, while 11.11% of the Cd samples and 1.39% of the Cr samples belonged to the safe use class. The overall distribution of soil quality was similar to that of soil fertility status, while the distribution range of low-quality soil in the southeastern part was smaller and more concentrated. The above research results indicate that the introduction of the classification results of soil pollution risk control types generally reduces the soil fertility status correction and changes the spatial distribution pattern of the original soil fertility status to some extent. Bangladesh J. Bot. 52(2): 659-669, 2023 (June) Special

Assessment of the desertification sensitivity of Northwestern El Minya Governorate, Egypt using MEDALUS model

Desertification leads to a decline in land production, resulting from biophysical interaction and human factors with temporal and spatial changes. This paper aims to evaluate the desertification sensitivity using Mediterranean Desertification and Land Use (MEDALUS) approach in the Northwestern El Minya Governorate in Egypt. The study area is one of the promising and important areas for land reclamation and developmental projects. Four indicators; climate, vegetation, management, and soil, were used in this study. Landsat 8 (OLI) satellite image 2021 was processed to calculate NDVI index to assess vegetation quality index. Then, it was classified into land cover classes to calculate the management quality index. ASTERDEM satellite data and the climate data were used in the climate quality index. Seventy soil samples were collected and analyzed for chemical and physical properties to be used for the retrieval of soil quality index. These indicators were integrated and used as input criteria in the model of desertification sensitivity. The physiographic unit extraction indicated that significant landforms were included in the study area namely; Old wadi Sediments, Peniplain, old river terraces, Shoulders, Sand sheets, Rock outcrops, and Sand dunes, Erosional Plains, Hill and Plain out wash. The obtained results showed that the severely sensitive area to desertification was represented by 86.7 % of the study area. The main factors affecting the sensitivity were climate conditions (arid, semi-arid), low soil quality and management in addition to the low vegetation cover. Furthermore, about 3% of the study area was located in the moderate sensitive class while the low sensitive area exhibits 1.06 %. Present study supports decision makers to reduce the constraining environmental conditions.