Asian Soil Research Journal

GPS based two pedons- one each from up and medium land during dry season, studied in the field & analysis done in the laboratory. The difference in properties between two pedons was mostly due to lateritic and basaltic parent material in pedons. The morphology of mineral soils explains the evolution that occurs in the soil body during the process of soil formation, which is predominantly influenced by the parent material and climate. Determination of epipedon and endopedon of diagnostic horizons through description and interpretation of soil profile properties is the basis of land classification, as the knowledge of soil properties, capabilities, and utilization. The results of the study found that, based on its morphological and chemical characteristics, the soil in pedon 1 had brighter colors, higher micronutrient availability, and a thicker horizon compared to the soil in pedon 2. Meanwhile, the pedon 1 is light texture, crumb structure and pedon 2 is heavy texture and sub angular blocky structure. Both the form of density in two pedons was increasing downwards & the value were of a typical mineral soils, but the pore space showed a reverse trend on confirming the compactness and aging of soils towards subsurface horizons. Same results tendency found in micronutrients analysis where pedon 1 rich in micronutrients as compare to pedon 2.

Fluvisols in urban wetlands in Bamenda Municipality Cameroon play a vital role in vegetable production but they are under immense pressure. Seven representative soil profiles and 21 surface soil samples were morphologically and/or physico-chemically characterized to classify the soils, evaluate their agro-utilization constraints, and to provide adequate data for planning sustainable land management. The soil samples were analyzed using standard procedures. Critical levels established for tropical crops and vegetables were used to declare deficiency of soil nutrients. The coefficient of variation were used as an index of soil variability, while sources of soil variation and subsequent grouping into management units were identified using principal component analysis. The soils, classified as Humi-umbric fluvisols are developed from young alluvio-colluvial material of granitic origin. Like other physico-chemical properties, organic matter varied irregularly down the profile. Except of pH which was slightly (CV<15%) variable, most soil properties were moderately (CV=15-35%) to highly (CV>35%) variable. Some correlation coefficients between the soil parameters were highly significant (p<0.01) ranging - 0.95 to 0.99, but most of them have correlation values less than 0.5. Six principal components (PCs) grouping soils in management units explained 96.2% of the variations observed in the soil properties. The PCs were: base status, organic matter, weathering and moisture retention, acidity, dispersal and N-mineralization, and mineral neo-synthesis factors. We recommend that a detailed mapping of soil properties be carried out for the establishment of a soil fertility map; and individual soil management practices defined for identified units instead of a common management for all units in the municipality.

The soils of Agoi-Ibami in central Cross River State of Nigeria were evaluated for their mechanical and textural compositions in the field. The objective was to present to small scale, subsistence farmers, with limited access to external farm-inputs for time consuming and expensive laboratory analysis, soil data for on-site and field land use and management decisions. Three profile pits were sunk, along three well defined and selected toposequences, on three landscape elements of crest, middleslope and valley bottom in three land use types of forest (FS), rubber (RS), and arable (AS). Relevant environmental properties were inventorized and the profiles described in the moist state. Their textures were determined by the feel method in the field among other morphological properties. The field investigation showed the soils to be predominatly loamy soils. After the field investigation, soil samples were collected from the morphogenetic horizons for determination of their mechanical composition in the laboratory to supplement the field investigation. Their loamy textures and mechanical composition inferred from their loamy texture impact unique physical and chemical properties like good water holding capacity, good drainage, fertile and productive soils and good for irrigation. Loamy soils exhibit properties intermediate between sandy and clayey soils. Loamy soils are considered best for agricultural production because they hold more water and nutrients than sandy soils and have better drainage, aeration and tillage properties than clayey soils. They have slight plastic and sticky workable properties ideal for crop growth and crop productivity. Therefore knowing the texture of soils and their mechanical composition in the field their properties can be inferred and land use and management decisions can be taken on-site without recourse to expensive and time consuming laboratory analyses which are beyond the capacity of resource poor small-scale and subsistence farmers in developing countries and or sub-Saharan Africa. The land use and management decisions are taken after mutual adaptation and adjustments of the description of the land use and the increasingly known soil qualities in the field.

A field experiment was carried out at Khaled Ibn El-waleed village, Sahl El-Hussinia, El-Sharkia Governorate, Egypt, during two summer seasons 2019 and 2020 to study the effect of NPK nanofertilizers, biofertilizers and humic acid combined with or without mineral fertilizers different at rates on some soil physical properties and soybean productivity and quality under saline soil conditions. The treatments consisted of: NPK-chitosan, NPK-Ca, humic acid, biofertilzer and control (mineral NPK only). In both seasons, the experiment was carried out in a split plot design with three replicates. The results indicated a significant increase in the soybean yield parameters as compared to control. There was also a significant increase in dry and water stable aggregates in all treatments as compared to control. The treatment NPK-Chitosan was the best in improving dry and stable aggregates. Also, hydraulic conductivity and total porosity values were significantly increased in all treatments due to increase in soil aggregation and porosity that led to increase in values of hydraulic conductivity. Values of bulk density were decreased, the lowest values of bulk density were found in NPK-chitosan treatment as a result of the high concentration of organic matter resulted from NPK-chitosan is much lighter in weight than the mineral fraction in soils. Accordingly, the increase in the organic fraction decreases the total weight and bulk density of the soil. Concerning soil moisture constants, all treatments significantly increased field capacity and available water compared to control. This increase was due to improvement of the soil aggregates and pores spaces which allowed the free movement of water within the soil thereby, increasing the moisture content at field capacity.

Heavy metals (HM) have been a global concern for its toxic and detrimental effect on the environment especially when it exceeds the permissible limit through anthropogenic activities like kaolin mining. Kaolin mining has improved the economic wellbeing of the local people through employment and otherwise; and at the same time attached with environmental consequences that threatens the livelihood of the community members. This study was carried out to ascertain the concentrations of selected heavy metals in kaolin mined soils and water body and its pollution density using single pollution indices such as contamination factor (CF), geo-accumulation (Igeo) and ecological risk factor (E^r ). Soil sample were collected from three different kaolin mined sites labelled (A,B and C) also surface water samples were collected from upper and down streams of Iyi-ugbohoroAmaudara, both samples were digested and elemental analysis was carried out using Atomic Absorption Spectrophotometer (AAS UNICAM 919 model). The concentration of the metals in three different kaolin mined soil samples ranges from Pb(40.00, 52.00 and 55.09 mg/kg) Cr(45.01, 70.00 and 71.00 mg/kg) Ni( 32.10, 50.50 and 51.00 mg/kg) Cd( 2.16, 6.25 and 6.15 mg/kg) Co( 19.68, 57.06 and 56.00 mg/kg) Se(1.06, 0.50, and 1.00 mg/kg) Mn(0.001, 0.01 and 0.01 mg/kg) Hg( 2.01, 2.00 and 2.50 mg/kg) As( 1.07, 1.10 and 1.05 mg/kg) and Cu(33.01, 60.00 and 57.5 mg/kg). Results from single pollution indices used for the selected heavy metals from kaolin mined soil, samples (A,B and C) showed that Mn, As, Cr, Ni and Cu indicated low to moderate contamination factor while Cd, Se, Co and Hg indicated high to very high contamination factor in all the samples. The distribution trend of heavy metals concentrations in the upper and down streams of the river body during wet season, showed that there were significant difference between upper and down streams while dry season showed variations in significant differences between the upper and down streams of some of the heavy metals. The study therefore concludes that kaolin soils are contaminated with heavy metals as a result of kaolin deposit and its mining activities. The single pollution indices used for the study pointed out that Cd, Se, Co and Hg are very high in the kaolin soils. The surface waters of Iyi-ugbohoroAmaudara River at the study area are polluted with heavy metals as a result of kaolin mining activities in the area; more especially during wet season of the study. Consequently, these outcomes would pose a toxic effect to both fauna and flora and possibly threatens the aquatic lives and the local populace.