EJSS

Eurasian Journal of Soil Science

Eurasian J Soil Sci

2147 - 4249

Federation of Eurasian Soil Science Societies

http://ejss.fesss.org/10.18393/ejss.2053049

10.18393/ejss.2053049

Appraisal of zinc fertilization methods and application timing for grain zinc biofortification in rice

Saleem Maseeh Bhatti smbhatti@sau.edu.pk

Bakhtawar Hingoro

Zohaib ur Rehman Bughio

Ghulam Murtaza Jamro

Nizamuddin Depar

Iqra Sultan Rajput

467-475

2025-10-08

2026-06-04

2026-06-15

2026-10-01

Agronomic biofortification can serve as an important strategy to minimize widespread Zn malnutrition in humans, yet its success depends on many factors including right fertilization method. The present research aimed to evaluate the impact of various Zn fertilization techniques on productivity, Zn concentration and bioavailability in rice grains of NIA-Mehran under the agro-climatic conditions of Tandojam, Sindh, Pakistan. The experiment was arranged in a randomized complete block design (RCBD), with each treatment replicated four times. The treatments included: Control (No Zn), Soil Zn (5 kg Zn ha-1 at 2 weeks after transplanting + 5 kg Zn ha-1 at flowering stage), Soil + Foliar application (5 kg Zn ha-1 at 2 weeks after transplanting in soil + 0.3% Zn through foliar at flowering stage) and Foliar Zn (0.3% Zn at booting, flowering and milky stage). The supplementation of Zn significantly (P< 0.05) influenced most of the growth and yield attributes, the concentration of Zn and phytic acid (PA) in brown rice grains, and Zn bioavailability indices (PA: Zn molar ratio and Total Daily Absorbed Zn [TAZ]). The supplementation of Zn resulted in increment of number of productive tillers to 12.5%, panicle length to 8.1%, thousand grain weight to 6.2%, grain yield to 26.2%, straw yield to 15.2%, Zn concentration to 54.7%, and reduction in PA concentration to 17.9%. A reduction in PA: Zn molar ratio to 45.8% and increment in TAZ values to 45.0% in brown rice grains was also noticed as a function of Zn fertilization. Among various Zn supplementations, foliar fertilization technique produced highest Zn concentration (52.0 ± 0.91 mg kg-1) with higher TAZ values (2.0 ± 0.03 Zn day-1). The required level of PA: Zn (<18) that ensures maximum Zn bioavailability was successfully obtained in rice grains of all Zn fertilized treatments (16.2, 16.3, 14.2). The daily Zn requirement for humans (3 mg Zn day-1) was covered up to 66.7% with ingestion of brown rice grains through foliar application of Zn. Based on these findings, it is suggested that the foliar Zn application should be practiced for selected rice variety (NIA-Mehran) under the agroclimatic conditions of Tandojam, as it significantly increased Zn concentration and its bioavailability in brown rice grains. The consumption of brown rice grains will be an effective tactic to minimize the widespread human Zn malnutrition.

Rice, zinc fertilization, yield, biofortification, zinc bioavailability.

http://ejss.fesss.org/10.18393/ejss.1976329

10.18393/ejss.1976329

Co-application of biochar and inorganic fertilizer improves soil chemical properties without increasing carbon dioxide efflux in Alfisols of Morogoro, Tanzania

Melkizedeck F. Dunda melkizedeck.dunda@sua.ac.tz

Boniface H. Massawe

Salim M. Maliondo

476-488

2026-01-30

2026-06-12

2026-06-22

2026-10-01

Combining biochar with inorganic fertilizers has gained global significance as a strategy for improving soil fertility; however, the agronomic and biogeochemical responses of soil remain inconsistent across environments and are further underexplored in Sub-Saharan Africa. This study evaluated the interactive effects of biochar and inorganic fertilizer on soil chemical properties and soil CO₂ efflux in Alfisols of Morogoro, Tanzania. A 3 × 3 factorial field experiment was conducted using three biochar rates (0, 5, and 10 t ha⁻¹) and three NPK fertilizer rates (0, 50, and 100 kg ha⁻¹). The efflux was measured using an EGM-5 infrared gas analyzer at 101, 108, 115, 122, and 129 days after biochar application. Selected soil properties: Electrical Conductivity, organic carbon, total nitrogen, available phosphorus, exchangeable potassium, and calcium were measured before and after treatment application. Results showed treatments had no statistically significant effects on soil CO₂ efflux (p > 0.05). Biochar at 10 t ha⁻¹ combined with 50 kg ha⁻¹ fertilizer significantly increased available phosphorus, exchangeable calcium, and electrical conductivity. The combination of 5 t ha⁻¹ biochar with 50 kg ha⁻¹ fertilizer significantly improved total nitrogen, while 5 t ha⁻¹ biochar with 100 kg ha⁻¹ fertilizer significantly improved exchangeable potassium. Principal component analysis revealed treatment-related patterns in soil chemical properties and CO₂ efflux, with B2F1 and B1F2 generally associated with higher organic carbon, total nitrogen, and Cation Exchange Capacity along PC1. Overall, combined biochar and fertilizer treatments tended to separate from low-input treatments in the multivariate space, suggesting distinct soil response patterns.

Biochar, fertilizer, CO₂ efflux, chemical properties, Field factorial experiment.

http://ejss.fesss.org/10.18393/ejss.1976355

10.18393/ejss.1976355

Interplay of soil characteristics and elevation influences performance of widespread plant species in the Himalaya

Mohammad Aadil Dar aadildar45@gmail.com

Pervaiz A. Dar

Jonas J. Lembrechts

Manzoor A. Shah

489-502

2026-02-07

2026-06-15

2026-06-22

2026-10-01

The climate change–driven reshuffling of floristic elements has recently gained attention, yet the mechanistic bases of these shifts remain poorly understood. Here, we examined how variation in soil chemical characteristics associated with an elevational gradient influences the early performance of lowland widespread plant species under controlled conditions. We tested the performance of two plant species (Trifolium pratense L. and Sisymbrium loeselii L.) using soil samples collected from different elevational zones of the Kashmir Himalaya in a greenhouse experiment. We observed limited trait development in S. loeselii under greenhouse conditions, which reduced the strength of interspecific comparisons; therefore, most trait responses, except plant height, were primarily driven by T. pratense. Generalized linear mixed models indicated that soil origin along the elevational gradient and associated nutrient variation, especially phosphorus, were linked to delayed germination, reduced leaf count, and lower plant height, whereas nitrogen, potassium, and sulphur showed trait-specific associations with measured plant responses. Overall, early plant performance tended to decline in soils originating from higher elevations under controlled greenhouse conditions. These findings suggest that soil nutrient variation may influence early plant performance across contrasting elevational soils, while highlighting the need for field-based studies to evaluate the ecological relevance of these patterns under natural environmental conditions.

Soil chemical properties, elevational gradient, plant functional traits, soil–plant interactions, widespread species, greenhouse experiment

http://ejss.fesss.org/10.18393/ejss.1977905

10.18393/ejss.1977905

Variation of soil physical properties under tea gardens along an alluvial toposequence in Northern Vietnam

Hoang Huu Chien hoanghuuchien@tuaf.edu.vn

503-516

2026-02-11

2026-06-22

2026-06-24

2026-10-01

Soil structural and hydraulic properties are fundamental for regulating water retention, aeration, saturated hydraulic conductivity (Ks), and root development in perennial cropping systems. This study evaluated the spatial variability of soil physical properties in tea plantation systems developed along contrasting alluvial geomorphic settings in northern Vietnam. The study was conducted along a representative alluvial toposequence in Tan Cuong commune, Thai Nguyen province, including riverside lowlands, previous dikes, and older hillslope positions. Three tea garden sites (TB1, TB2, and TB3) and two adjacent forest sites planted with Acacia spp. (FB1 and FB3) were investigated along the toposequence. An additional tea garden site (TS1) located in Dong Hy commune was included as a comparative site representing a less favorable tea-growing environment developed on different parent materials. Soil samples were collected at two depths (0–10 and 20–30 cm) in triplicate using undisturbed and bulk soil samples for the determination of bulk density, three phase distribution, Ks, aggregate stability expressed as mean weight diameter (MWD), and soil water retention characteristics. The results revealed pronounced differences among sites, depths, and land-use types. Riverside alluvial soils (TB1 and FB1), developed from coarse-textured quartz-rich deposits, exhibited lower MWD values, weaker water retention, and lower structural stability. In contrast, soils located on previous dikes and weathered hillslopes (TB2, TB3, FB3, and TS1) showed higher aggregate stability, more differentiated pore systems, and greater water-holding capacity. At the 20–30 cm depth, TB3 exhibited significantly higher Ks, MWD, and plant-available water than TB1 and TB2 (p < 0.05), indicating more favorable structural and hydraulic conditions. Forest soils generally maintained higher aggregate stability and greater gaseous porosity than adjacent tea soils. The findings demonstrate that soil structural and hydraulic properties in tea plantation systems were closely associated with geomorphic position, pedogenic development, and land use along tropical alluvial toposequences.

Aggregate stability, Ks, soil water retention, tea plantation systems, Vietnam.

http://ejss.fesss.org/10.18393/ejss.1990628

10.18393/ejss.1990628

Influence of rhizosphere and soil properties on antioxidants in selected Western Ghats medicinal plants

Abitha Benson

Kiyoon Kim

Melvin Joe Manoharan micromelvin@gmail.com

Muniappan Ayyanar

Govindaraj Kamalam Dinesh

Balathandayutham Karthikeyan

Denver I.. Walitang

Tongmin Sa

517-528

2026-01-28

2026-06-23

2026-07-09

2026-10-01

Soil physicochemical properties and rhizosphere microbial attributes may be associated with plant growth, metabolic activity, and the accumulation of bioactive compounds in medicinal plants. The phytochemical profiles of Sida rhombifolia, Phyllanthus rheedei, Hellenia speciosa and Arisaema tortuosum were assessed, and rhizosphere microbial activities and soil physicochemical properties were compared to explore possible associations among plant–site combinations. The differences observed here likely result from a combination of soil type, location, and plant species. Because species and sampling sites are confounded, these results indicate broad associations rather than effects unique to specific plant species. Endophytic Achromobacter, Cupriavidus, Acinetobacter, and Sphingomonas strains isolated from these plants were found to be positive for most of the plant growth-promoting traits. Alkaloid concentrations of the studied medicinal plants ranged from 0.3 to 0.6 g kg⁻¹ and flavonoid levels ranged from 1.2 to 1.7 g kg⁻¹. Differences in ABTS and DPPH radical scavenging capabilities were noted among the plant and location combinations that were sampled. The highest ABTS radical scavenging activity was observed in P. rheedei and was statistically comparable to H. speciosa. Lower DPPH IC₅₀ values were observed in A. tortuosum and H. speciosa, indicating comparatively higher DPPH radical scavenging capacity in these extracts. Important bioactive components such as 2-methoxy-4-vinylphenol, 9,12-octadecadienoic acid, and 2-heptanol were detected by GC–MS analysis. Although principal component analysis (PCA) showed associations among soil characteristics, microbial activity, and phytochemical accumulation, these findings should be considered exploratory rather than conclusive.

Medicinal plants, Rhizosphere, GC-MS analysis, Western Ghats, Principal component analysis, Secondary metabolites.

http://ejss.fesss.org/10.18393/ejss.2005074

10.18393/ejss.2005074

Elemental sulfur and Thiobacillus culture alter nutrient availability and maize growth in compost-amended calcareous soil

Sholpan Muminova

Baglan Makhamedova baglan.makhamedova@kaznaru.edu.kz

Khansulu Kuspangaliyeva

Liza Zhussupova

Gulzhan Zhaksybayeva

Zukhra Mussina

Ashirali Smanov

Bakhytkul Kenzhaliyeva

529-537

2026-03-12

2026-07-19

2026-07-28

2026-10-01

Elemental sulfur can improve nutrient availability in calcareous soils, but its effectiveness depends on oxidation conditions, soil buffering, and associated organic and microbial amendments. A controlled greenhouse experiment evaluated seven elemental sulfur rates (0, 250, 500, 750, 1000, 1250, and 1500 kg ha⁻¹) combined with either sterile water or a live Thiobacillus thioparus culture treatment in a compost-amended calcareous clay soil. Each of the 14 treatment combinations had three replicate pots. All pots received mature composted cattle manure at 20 Mg ha⁻¹ on a dry-matter basis, and one hybrid maize plant was grown per pot for 86 days. Increasing sulfur rate lowered post-harvest soil pH and increased available P, S, Fe, Cu, Zn, Mn, and B. The lowest pH (6.68), highest available P (12.8 mg kg⁻¹), and highest available S (205 mg kg⁻¹) occurred at 1500 kg S ha⁻¹ with the culture treatment. Post-harvest total N declined as shoot N removal increased, whereas available K changed little. Total aboveground dry biomass increased from 466–478 g pot⁻¹ at 0 kg S ha⁻¹ to 744–812 g pot⁻¹ at 1500 kg S ha⁻¹. Uptake of all measured macro- and micronutrients followed a similar increasing pattern. The greatest responses within the tested range occurred at 1500 kg S ha⁻¹, particularly in culture-treated pots. These results show that micronized elemental sulfur, under adequate moisture and warm greenhouse conditions, can substantially alter nutrient availability and maize performance in compost-amended calcareous soil. The highest tested rate should not be interpreted as a field optimum without multi-soil and field validation.

Alkaline soil, calcareous soil, composted cattle manure, elemental sulphur, nutrient uptake, Thiobacillus thioparus.

http://ejss.fesss.org/10.18393/ejss.2005110

10.18393/ejss.2005110

Isolation of indigenous soil bacteria with potential application for diuron removal

Berk Emre Engin

Hilal Yılmaz

Esra Meşe Erdoğan

Melek Özkan mozkan@gtu.edu.tr

538-552

2026-02-16

2026-07-16

2026-07-28

2026-10-01

Diuron is a widely used herbicide in sugarcane, cotton, coffee, and citrus production and is classified as a priority pollutant. Physical and chemical remediation of pesticide-contaminated sites is often technically complex and costly. Microorganism-mediated bioremediation offers an environmentally compatible and cost-effective alternative, particularly when pollutant-specific indigenous microorganisms are used. In this study, microorganisms were isolated from diuron-amended soil microcosms, and their diuron removal capacities were evaluated under different pH and temperature conditions. Fourteen bacterial isolates were initially screened, of which six capable of growing in diuron-supplemented medium were selected. Isolates 2 and 6 achieved the highest removal efficiencies, reaching 53% and 51%, respectively, within 3 days. A mixed microbial culture achieved 60% removal, suggesting potential complementary interactions among the isolates. Based on 16S rRNA gene sequencing, isolate 2 showed 97–99% sequence identity to Bacillus sp., whereas isolate 6 showed 97–99% identity to Cellulomonas sp. The study aimed to identify bacterial strains with potential application in future pesticide bioremediation. Indigenous isolates with high pollutant-removal capacity may improve bioremediation performance in their native environments because they are adapted to prevailing local conditions.

Bio-removal, Cellulomonas, diuron, indigenous soil microorganisms, pesticides.

http://ejss.fesss.org/10.18393/ejss.2005188

10.18393/ejss.2005188

Pedological and geochemical characteristics of highly weathered soils derived from ophiolitic rocks in Samar, Philippines

Jertz Vlyn D. Escala jertzescala@gmail.com

Ian A. Navarrete

Marvin D. Cascante

Victor B. Asio

553-567

2026-03-17

2026-07-20

2026-07-28

2026-10-01

Limited information is available on the pedology of highly weathered soils derived from ophiolitic rocks in the Philippines. This study evaluated red, highly weathered soils across the ophiolitic landscape of Eastern Samar. Five soil profiles were described and sampled for laboratory analysis. The geochemical composition of the parent materials ranged from mafic to ultramafic. The soils were acidic [pH(H₂O) = 4.97–6.45; pH(CaCl₂) = 3.95–5.96] and contained low concentrations of available P (trace–1.14 mg kg⁻¹), exchangeable K (trace–0.23 cmolc kg⁻¹), Ca (trace–12.66 cmolc kg⁻¹), and Na (trace), together with low Ca/Mg ratios (0.1–41.7). Profile 2 had comparatively high exchangeable Ca concentrations, particularly in deeper horizons. Ca/Mg ratios increased with depth in Profiles 2 and 3 but decreased in Profile 5. In Profiles 1 and 4, Ca/Mg ratios were very low and could not be calculated in several subsurface horizons because exchangeable Ca and/or Mg occurred at trace levels. Extractable Ni concentrations ranged from 0.16 to 22.40 mg kg⁻¹, with the highest concentration occurring in the Bo2 horizon of Profile 4, indicating contributions from ultramafic materials, Ni accumulation, and adsorption onto Fe (oxyhydr)oxides during weathering. The warm, humid climate, highly weatherable ophiolitic parent material, stable, well-drained topography, and original rainforest vegetation promoted the formation of highly weathered Ultisols and Oxisols. Low OM (0.36%–3.60%) and total N (0.04%–0.25%) contents may reflect anthropogenic effects, particularly periodic burning associated with shifting cultivation. The CIA (55.56–99.31), CIW (55.63–99.58), MWPI (0.14–7.44), and Vogt ratio (1.08–63.95) indicated advanced weathering and substantial losses of major cations. These findings demonstrate that ophiolitic soils under humid tropical conditions undergo intense weathering and leaching, resulting in marked profile-scale variation during pedogenic development.

Geochemistry, soil characteristics, ophiolites, ultramafic soils, Oxisols, Ultisols.

http://ejss.fesss.org/10.18393/ejss.2010187

10.18393/ejss.2010187

Repeated foliar zinc applications enhance shoot biomass, zinc accumulation, and mineral composition of sorghum across contrasting soil-moisture regimes in a calcareous soil

Ibadulla Tautenov

Serik Bekzhanov ser.bekzhanov@mail.ru

Laura Tokhetova

Nurali Nurgaliyev

Karlygash Kaimoldaeva

Samalbek Kossanov

Ainur Demesinova

568-579

2026-04-02

2026-07-27

2026-08-03

2026-10-01

Water deficit and low zinc (Zn) availability frequently co-occur in calcareous soils, constraining sorghum growth and tissue mineral status. This greenhouse study evaluated whether the timing and repetition of foliar Zn application improved aboveground biomass, whole-shoot Zn accumulation, and mineral composition of grain sorghum (Sorghum bicolor (L.) Moench) cv. Tagamdyk-2017) under contrasting soil-moisture regimes. A completely randomized 3 × 8 factorial experiment with three replicates combined soil moisture maintained continuously from sowing to harvest at 100% (T1), 75% (T2), or 50% (T3) of field capacity with eight foliar schedules: a water-sprayed control (D0); single applications at the 4–5-leaf (D1), panicle-initiation (D2), or flowering-initiation (D3) stage; three two-stage combinations; and a three-stage D1+D2+D3 program. After 105 d, soil moisture and foliar Zn schedule significantly affected fresh and dry biomass (P < 0.01), whereas their interaction was nonsignificant. Mean dry biomass declined from 34.3 ± 0.5 g pot⁻¹ at T1 to 27.9 ± 0.4 and 20.4 ± 0.3 g pot⁻¹ at T2 and T3, respectively. Across moisture regimes, D1+D2+D3 produced the highest mean fresh biomass (133.0 ± 3.2 g pot⁻¹), dry biomass (29.9 ± 0.8 g pot⁻¹), shoot Zn concentration (34.0 ± 0.8 mg kg⁻¹), and Zn uptake (1.04 ± 0.03 mg pot⁻¹), compared with 114.2 ± 2.5 g pot⁻¹, 25.5 ± 0.6 g pot⁻¹, 14.2 ± 0.3 mg kg⁻¹, and 0.37 ± 0.01 mg pot⁻¹, respectively, in D0. The soil-moisture × foliar-Zn interaction was significant for shoot Zn concentration (P < 0.05) and Zn uptake (P < 0.01). Repeated Zn application was also associated with higher shoot N, P, K, Fe, Cu, and Mn concentrations but did not eliminate the adverse effects of severe soil-moisture limitation. Under the conditions of this pot experiment, repeated foliar Zn application improved whole-shoot Zn status and mineral composition, while soil moisture remained the dominant determinant of biomass production.

Sorghum bicolor, calcareous soil, drought stress, foliar zinc, mineral composition, zinc uptake.

http://ejss.fesss.org/10.18393/ejss.2010205

10.18393/ejss.2010205

Variation in soil phosphorus adsorption and desorption characteristics across agro-ecological zones in Central Nepal

Dinesh Khadka dinesh.khadka92@gmail.com

Keshab Raj Pande

Bhaba Prasad Tripathi

Roshan Man Bajracharya

580-598

2026-05-03

2026-07-28

2026-08-03

2026-10-01

Phosphorus (P) adsorption and desorption regulate P availability, soil fertility, and the risk of P loss from terrestrial ecosystems; however, these processes remain poorly characterized in Nepalese soils. Despite their significance, there is limited understanding of these processes in Nepalese soils. This study aimed to explore how P adsorption and desorption vary across agro-ecological zones in central Nepal. A total of 225 soil samples, equally distributed among the high-hills, mid-hills, and Terai regions (75 from each), were collected across diverse locations. Isothermal P adsorption and desorption experiments were conducted to evaluate these behaviors, employing Langmuir, Freundlich, and Temkin models to assess P adsorption-desorption characteristics. Adsorbed P was highest in the high-hills (28.67–525.91 µg g⁻¹), followed by the Terai (28.57–494.68 µg g⁻¹) and mid-hills (25.63–422.14 µg g⁻¹). Similarly, P desorption was also highest in high-hills (3.39 to 69.38 µg g-1), followed by the Terai (5.15 to 56.00 µg g-1) and mid-hills (3.14 to 47.91 µg g-1). The P adsorption and desorption parameters, namely P adsorption capacity, bonding energy, maximum P buffering capacity (MPBC), P sorption index (PSI), P desorption capacity, maximum P desorption capacity, standard P requirement (SPR), external P requirement (EPR) were highest in the high-hills, while lowest in the mid-hills. However, maximum P adsorption capacity and P desorption capacity were highest and lowest, respectively, in the Terai. Moreover, the P desorption intensity, readily desorbable P (RDP), degree of P saturation (DPS), and P eutrophication risk index (PERI) were highest in the mid-hills, while lowest in the Terai. In contrast, the P buffering capacity (PBC) did not significantly differ among zones. These contrasting patterns demonstrate the need for zone-specific P management: the high-hills and Terai have comparatively greater fertilizer-P requirements, whereas the mid-hills exhibit higher laboratory-derived indicators of potential P loss. This study offers valuable insights for developing improved soil P management strategies for sustainable agriculture in diverse agro-ecological zones.

High-hills, Isotherm models, Mid-hills, Phosphorus adsorption, Phosphorus desorption, Terai.

http://ejss.fesss.org/10.18393/ejss.2016780

10.18393/ejss.2016780

Exploratory profiling of soil bacterial communities and fertility in tropical maize amended with diatomaceous earth

Camilo Alexander Mestanza Uquillas cmestanza@uteq.edu.ec

Diana Verónica Véliz Zamora

Ángel Virgilio Cedeño Moreira

John Jairo Pinargote Alava

599-608

2026-06-16

2026-08-07

2026-08-12

2026-10-01

Soil bacterial communities are sensitive indicators of biological condition in tropical agroecosystems, yet field information from acidic maize soils in Ecuador remains scarce. This study provides an exploratory profile of soil bacterial communities and fertility indicators in maize amended with diatomaceous earth under field conditions. A randomized complete block field experiment was established with three treatments and five replications: untreated control without fertilization or diatomaceous earth (T1), conventional fertilization (T2), and conventional fertilization plus diatomaceous earth (T3). Grain yield was measured from replicated plots, whereas soil chemistry and 16S rRNA bacterial profiles were obtained from composite analytical profiles and interpreted descriptively. One composite baseline soil profile was obtained before treatment differentiation, and one composite profile per treatment was obtained at 60 and 120 days after sowing. Soil was sampled from the 0-30 cm layer in the inter-row zone. The diatomaceous earth product was applied edaphically at 12 kg ha-1 and contained 73.60% w/w SiO2 according to the product certificate. The 16S rRNA V3-V4 region was sequenced using an Illumina workflow, and raw FASTQ files were deposited in NCBI SRA. Grain yield differed among treatments (F = 18.18; P = 0.0011), with T2 and T3 statistically similar and both higher than T1. Bacterial profiles were dominated by Acidobacteria, Actinobacteria, Proteobacteria, Firmicutes and Verrucomicrobia. T3 at 120 DAS showed the highest numerical Shannon index and provider-reported species-level classifications among treatment-time profiles, but these patterns were not tested inferentially. The study offers a transparent baseline for future replicated microbiome work in tropical acidic maize soils.

16S rRNA, acidic soil, diatomaceous earth, Ecuador, soil fertility, tropical maize.

http://ejss.fesss.org/10.18393/ejss.2016819

10.18393/ejss.2016819

Field response of corn and cotton to a cotton-linter-based superabsorbent polymer in salt-affected sierozem under arid irrigation

Gulnara Tastanbekova

Abdugani Azimov

Zhenisbek Abdraimov

Zhanybek Akbar

Marat Atemov

Gulfairuz Beisenova

Amangeldy Abilov

Zhainagul Yertayeva jain_0404@mail.ru

609-618

2026-04-12

2026-08-12

2026-08-17

2026-10-01

Water scarcity and soil salinity jointly constrain irrigated crop production in the arid regions of Central Asia. This field study evaluated an experimental cotton-linter-based superabsorbent polymer (SAP) as a soil amendment for corn and cotton grown in salt-affected sierozem in Otyrar District, southern Kazakhstan, during 2025. The SAP was produced by grafting acrylic acid onto purified cotton linter, with sodium hydroxide as the neutralizing agent, ammonium persulfate as the initiator, and N,N′-methylenebisacrylamide as the crosslinker. Corn and cotton formed the main plots, and SAP rates of 0, 30, 40, and 50 kg ha⁻¹ formed the subplots in a split-plot randomized complete block design with four blocks. The polymer was incorporated into the seed zone at sowing. Seasonal rainfall was only 12.3 mm, while soil electrical conductivity increased from 3.2 dS m⁻¹ at 0–20 cm to 5.1 dS m⁻¹ at 80–100 cm. Across the tested rate range, crop establishment, yield components, marketable yield, and irrigation water productivity increased progressively with SAP application. Corn grain yield rose from 2.69 Mg ha⁻¹ in the control to 3.60, 5.40, and 6.30 Mg ha⁻¹ at 30, 40, and 50 kg ha⁻¹, respectively; corresponding irrigation water productivity increased from 0.60 to 1.40 kg m⁻³. Seed-cotton yield increased from 2.90 to 4.20, 4.99, and 5.46 Mg ha⁻¹, while irrigation water productivity increased from 0.29 to 0.55 kg m⁻³. Lint percentage remained nearly unchanged, indicating that higher lint yield primarily reflected improved stand establishment and boll production. Post-harvest soil bulk density varied little among SAP rates, with within-depth differences generally not exceeding 0.02 g cm⁻³. Thus, the short-term agronomic response was substantially greater than the measured structural response. Yield, yield-component, and irrigation-water-productivity responses to hydrogel rate were statistically significant (P < 0.05) based on split-plot analysis of variance across four field blocks. The findings provide field evidence that cotton-linter-based SAP can improve corn and cotton productivity under arid, saline–alkaline conditions; multi-season trials, soil-water monitoring, economic evaluation, and full polymer characterization are still required before an optimum rate or long-term environmental performance can be established.

Arid agriculture, cotton, corn, irrigation water productivity, saline soil, superabsorbent polymer.

http://ejss.fesss.org/10.18393/ejss.2016846

10.18393/ejss.2016846

How soil sampling reflects DTPA-extractable micronutrients and their spatial variability in a cultivated field

Coşkun Gülser cgulser@omu.edu.tr

619-627

2026-04-09

2026-08-12

2026-08-17

2026-10-01

This study investigated the spatial variability of DTPA-extractable Fe, Mn, Zn, and Cu in a cultivated field, their relationships with selected soil properties, and the optimum number of samples required to estimate mean micronutrient concentrations precisely. Forty-nine soil samples were collected at 5-m intervals from a square grid within a 30 × 30 m cultivated plot. Mean DTPA-extractable concentrations were 71.80 mg kg⁻¹ for Fe, 350.26 mg kg⁻¹ for Mn, 2.58 mg kg⁻¹ for Zn, and 4.11 mg kg⁻¹ for Cu. The coefficients of variation were higher for Fe (20.6%) and Zn (19.2%) than for Mn (11.8%) and Cu (8.4%). Spatial variability was best described by spherical models for Fe and Mn and exponential models for Zn and Cu. The spatial correlation ranges followed the order Zn (67 m) > Cu (17 m) > Fe (15 m) > Mn (8 m). Nugget-to-sill ratios indicated strong spatial dependence for Fe (0.039%), Mn (8.03%), and Cu (11.32%) and moderate spatial dependence for Zn (42.86%). In principal component analysis, Fe, Cu, and soil organic matter (OM) had high negative loadings on PC1, whereas Zn contributed most strongly to PC2. Fe was positively correlated with soil OM and negatively correlated with Mn, Zn, pH, Ca, and Na. Mn was positively correlated with Zn and Cu, whereas Zn was positively correlated with silt and pH. Cu was negatively correlated with pH, Ca, Mg, and K. The numbers of samples required to estimate mean concentrations within allowable errors of 5%, 10%, and 20% followed the order Fe (69, 17, and 4) > Zn (59, 15, and 4) > Mn (23, 6, and 2) > Cu (11, 3, and 1), respectively. Thus, greater spatial variability in a micronutrient requires a larger sample size to estimate its field mean precisely.

Soil properties, Fe, Mn, Zn, Cu, spatial dependence, sampling intensity.

http://ejss.fesss.org/10.18393/ejss.1010998

10.18393/ejss.1010998

Garib Mammadov and the development of soil science and ecology in Azerbaijan: A biographical tribute

Irada Mammad Huseynova i.huseynova@imbb.science.az

628-632

2026-06-12

2026-09-28

2026-10-01

Academician Garib Shamil oglu Mammadov is one of the leading figures in the development of modern soil science, agroecology, ecological land evaluation and land administration in Azerbaijan. Over more than five decades, he has combined fundamental research, higher education, scientific institution building and public service. His early investigations of pasture soils on the Mil Plain developed into a broad research programme encompassing soil bonitation, ecological assessment, soil fertility modelling, land cadastre, monitoring, cartography and the sustainable management of soil resources. He contributed to major national soil and ecological atlases, helped establish academic programmes in soil science and ecology, and supervised successive generations of researchers. His public responsibilities during Azerbaijan’s land reforms also enabled him to connect scientific knowledge with legislation, cadastre, geodesy and land-use policy. This biographical tribute reviews the principal stages of his career and considers the enduring importance of the scientific school that formed around his work. Mammadov’s legacy is found not only in his extensive publications and maps, but also in the institutions, professional networks and trained specialists through which soil science continues to serve society.

Azerbaijan, ecological soil assessment, land cadastre, soil bonitation, soil mapping, scientific school.