Tashkent State Agrarian University

Afforestation, an ecological restoration measure to mitigate climate change and the greenhouse effect, plays a crucial role in carbon sequestration in soil (Csoil) and vegetation (Cveg) in terrestrial ecosystems. This study presents a rainwater harvesting and supplementary irrigation (RHSI) method to alleviate rainfed drought and then combines the DeNitrification-DeComposition (DNDC) model with multiple regression analysis to quantify the carbon sink benefits of RHSI application. Eventually, a multi-objective optimization algorithm was used to determine the optimal RHSI technical parameters under various climate and soil conditions. The sensitivity analysis and Monte Carlo uncertainty analysis of the revised Gash model and the DNDC model demonstrated robust performance in predicting canopy interception (Ic) and carbon sink benefits. Meanwhile, a decoupled relationship was observed between ΔCsoil and ΔCveg. Comparative evaluation based on hypervolume (HV), inverted generational distance (IGD) and spacing indicated that the non-dominated sorting genetic algorithm II (NSGA-II) performed excellently in convergence and solution distribution, highlighting its suitability for optimizing RHSI technical parameters (catching board area, A, and flow rate of ceramic emitters, q). The results of two case studies in Yangling and Lhasa indicated that the optimal values of A were 0.157 m2 and 0.391 m2, and the optimal values of q were 0.077 L h−1 and 0.060 L h−1, respectively. Compared to CK, RHSI maintained a relatively adequate supply of soil moisture during rainfall, with Csoil and Cveg increasing by at least 2.67% and 1.43%, respectively, and a global warming potential of 672 kg CO2-e ha−1 in Yangling. The findings not only advance the theoretical foundation for modeling carbon sequestration under optimized RHSI in rainfed afforestation but also offer valuable insights into RHSI optimization strategy suitable for local climate and soil conditions.

The optimization of crop production in the context of agricultural land use and production inputs is a strategic element of sustainable development. Fertilization and irrigation are vital components of agricultural engineering, driving crop quantity and quality. The objective of the study discussed here was to assess greenhouse gas emissions from carrot cultivation depending on the variant of the fertilization and irrigation processes. One tonne of marketable carrot yield was selected as the functional unit. A controlled field experiment in a split-plot configuration was carried out to deliver the objective. Calculation of the total quantity of greenhouse gases emitted from the crop was carried out according to ISO 14040 and ISO 14044. Boundaries of the system encompassed the production and use of fertilizers and pesticides, the consumption of energy for agro-engineering activities and irrigation, as well as GHG emissions from soil resources and crop residue. The reference unit for the study was an object (plot) irrigated according to production practice in the area where the study was conducted. Under those conditions, greenhouse gas emissions totaled 75.68 kg CO2 . t(-1) of the commercial product. Optimization, involving precise irrigation and fertilization using slow-release fertilizers, reduced the carbon footprint to 54.33 kg CO2 . t(-1) of the commercial product. GHG emissions were thus reduced by 30%. The use of slow-release fertilizers resulted in a reduction of total greenhouse gas emissions per unit of marketable yield by 15% for non-irrigated crops and by 17% for irrigated crops. Irrigation, in turn, resulted in a reduction of total GHG emissions by 8% for conventional fertilization and by 11% for slow-release fertilization.

Effective and sustainable photocatalysts are crucial for removing persistent pharmaceutical antibiotics from wastewater systems. The present work reports the successful synthesis of NdFeO3 (NFO), Ce-Mn co-doped NdFeO3 (NCFMO), and Ce-Mn co-doped NdFeO3/g-C3N4 (NCFMO/g-CN) nanocomposites through a facile hydrothermal and ultra-sonication route to examine the cerium and manganese dual-doping and g-C3N4 (g-CN) incorporation. The structural, morphological, electrical, magnetic, optical, and photolytic features were studied using XRD, FTIR, SEM, BET, VSM, EIS, UV-Vis, and PL analyses. The structural and morphological studies confirmed the perovskite type orthorhombic phase in consort with Ce and Mn dual-doping and g-CN incorporation in pure NFO having average grain size in the 20-40 nm range. The magnetic and electrical analysis via VSM, I-V and EIS demonstrated enhancement of the electrical conductivities (6.2 & times; 10-4 S center dot m-1 to 98.27 S center dot m-1) and magnetic behaviour of the Ce-Mn co-doped NCFMO. Optical band gap revealed narrowing of the band gap (2.17 to 1.94 eV) and a red shifting in absorption of the visible light upon co-doping and g-CN integration. The photocatalytic performances of the as-fabricated materials were investigated via degradation of levofloxacin (LVF) and lomefloxacin (LMF) antibiotics under visible light irradiation. The Ce-Mn co-doped NCFMO/g-CN composite achieved superior photocatalytic activity with degradation efficiencies of 96.8% for LVF and 94.5% for LMF within 70 min, compared to 85.2% and 82.6% for Ce-Mn co-doped NCFMO and 64.6% and 61.2% for pure NFO, respectively. The improved activity of the NCFMO/g-CN hybrid catalyst was accredited to combine effects of Ce-Mn co-doping and g-CN addition, which efficiently forms heterojunction with NCFMO, which improved light harvesting, delayed charge partition, and effective creation of active species. The NCFMO/g-CN nano-hybrid demonstrated outstanding stability and reusability, retaining 88.7% efficiency after 4 consecutive cycle runs, highlighting its potential for wastewater remediation.

Zea mays L. (maize) is a globally important cereal crop whose productivity is highly vulnerable to abiotic stresses, particularly drought and salinity. Biochar (BC) and plant growth regulators such as gibberellic acid (GA3) have been proposed as sustainable strategies to enhance crop performance under adverse conditions; however, evidence for their combined effects under controlled stress environments remains limited. This pot experiment (10 kg soil per pot) was conducted under a Completely Randomized Design to evaluate BC and GA3, alone and in combination, under drought stress (40

Heavy metal (HM) contamination of agricultural soils by cadmium (Cd2+) and lead (Pb2+) pose a serious risk to the crop productivity and food security. However, a workable solution is required to reduce the impact of HM contamination in soils and improve productivity. Therefore, the current study aimed to investigate the tolerance of different canola varieties against the contamination of Cd2+ and Pb2+ under field conditions. The experimental site was previously contaminated with Cd2+ (6ppm) and Pb2+ (600ppm) where canola varieties were cultivated under the randomized complete bock design (RCBD) with three replicates of each treatment. The current study evaluated the growth, biomass accumulation, chlorophyll content and biochemical attributes of canola varieties. The results of this study revealed significant variability among varieties in response to the metal stress. Under Cd2+ contaminated conditions Oscar attained highest plant height (71.42 cm), root length (33.62 cm), shoot length (34.25 cm) however under Pb2+ contaminated soil Super Raya showed maximum plant height (39.43 cm), root length (13.45 cm) and shoot length (26.34). In contrast varieties like rainbow and Sandal Canola showed inhibited growth with a significant reduction in the root, shoot length and decline in the antioxidant enzyme activity. In addition, highest superoxide dismutase (SOD) 6.63 U/g Protein, catalase (CAT) 2.87 U/g Protein, peroxidase (POD) 43.26 U/g Protein, Malondialdehyde (MDA) 76.10 nmol /g FW, Ascorbate Peroxidase (APX) 74.20 U/g Protein, Ascorbic Acid (ASA) 70.52 µg/g FW and Glutathione (GSH) 73.71 µmol/g FW activity by Oscar under Cd2+ contaminated soil. In Pb2+ contaminated soil CONII represent its potential by showing highest SOD (5.78 U/g Protein), CAT (2.81 U/g Protein), POD (52.57 U/g Protein), MDA (72.77 nmol /g FW), APX (68.24 U/g Protein), ASA (74.49 µg/g FW) and GSH (72.76 µmol/g FW) activity. In conclusion, canola varieties exhibit differential tolerance to Cd²⁺ and Pb²⁺ contamination under field conditions, with certain varieties i.e., Oscar and Super Raya demonstrating superior growth and enhanced antioxidant defense mechanisms, making them suitable candidates for cultivation in heavy metal–contaminated soils.