Nutrient management and fertilizer application are influential elements for high yield and preferred grain quality. Negligible information is available regarding fertilizer application in the paddy fields in Afghanistan. This research elucidates the efficacy of different fertilizers’ application on growth attributes, yield potential, and grain quality of rice. The treatments included the traditional application rate of nitrogen and phosphorus (RD), animal manure (AM), animal manure with 50% nitrogen and phosphorus of the traditional application rate (AMRD), sawdust (SD), and sawdust with 50% nitrogen and phosphorus of the traditional application rate (SDRD). Growth parameters, grain yield and its components, physicochemical properties, and morphological observation using scanning electron microscopy were recorded. The results revealed that the greatest panicle number, spikelet number, and grain yield were recorded in AMRD and SDRD treatments. Both AMRD and SDRD treatments increased the percentage of protein, amylose, and lipid contents, as well as the percentage of perfect grain compared to the RD treatment. Rice grain in RD treatment had very few protein bodies and their traces (pits), as well as the formation of amyloplasts and starch granules, were normal. However, AMRD and SDRD increased the number of protein bodies and their pits in the rice endosperm. The shapes of the amyloplasts were round and polyhedral with diverse sizes. Starch granules were polygonal with sharply defined edges. This research encourages farmers to adopt the combined application of manures and fertilizers to decrease the dependence on inorganic fertilizers.

Background: The projected increase in global temperature is expected to negatively impact food production in many regions. Rice exposure to heat stress can limit plant growth in different stages, especially at the seedling stage. In this experiment, two Indica parental lines N22 (heat tolerant) and BIM (heat sensitive) along with their F₂ hybrid were elucidated under different high temperatures (28 °C, 35 °C, and 42 °C) at the seedling stage. Results: The results indicated that the F₂ hybrid inherited the heat tolerance rate from the male heat-tolerant N22 parent. Based on phenological and physiological attributes, the F₂ hybrid exhibited excessive-performance as compared to its BIM parent under different high-temperature conditions. Specifically, absorbing the ample available water through the long-rooted system enabled rice seedlings to carry out high transpirational cooling. Furthermore, there was a strong relationship (r = 0.89, p < 0.01) between root length and transpiration rate under 42 °C. The temperature 35–42 °C caused a significant reduction in seedlings’ growth, chlorophyll content, and survival rate (18–20%), while the relative heat injury percentage and leaf temperature increased in heat-sensitive BIM parent as compared to F₂ hybrid. Conclusion: This study suggests that the breeding of heat-tolerant hybrid rice plays an important role in the production of a resilient rice plant through heat-tolerant seedlings at the initial vegetative growth stage.

Heat stress is a critical limiting factor in rice production, and a comprehensive understanding of the physiological traits contributing to yield under such conditions remains incomplete. This study evaluated the effects of heat stress on six rice varieties: Nagina22 (N22), NERICA4 (NER), Nipponbare (NPB), IR64, Berenj-I-Mahin (BIM), and Berenj-I-Luk (BIL) exposed to maximum temperatures exceeding 40 °C from flowering to the grain-filling stage. Results demonstrated a strong correlation between the photosynthetic rate and both 1000-grain weight and transpiration rate at the flowering stage across all varieties. Under heat stress, NER, BIM, BIL, and IR64 exhibited elevated levels of malondialdehyde, indicative of oxidative damage, and sustained significant heat injury compared to ambient conditions. Heat stress notably impaired pollen viability and spikelet fertility, reducing crop yields. In contrast, the heat-tolerant variety N22 maintained the highest spikelet fertility rate, effectively regulated transpiration cooling, and significantly enhanced yield by maintaining a lower leaf temperature. The findings indicate that photosynthetic efficiency and oxidative stress during the flowering stage critically influence spikelet fertility and overall yield in rice under heat stress. This research provides valuable insights for rice breeders and agronomists, encouraging the development of heat-tolerant varieties and adaptive strategies to mitigate the adverse impacts of elevated temperatures during critical reproductive stages.

The excess presence of calcium carbonate (CaCO₃) in soil poses challenges for production of horticultural crops, including tomatoes. This condition is prevalent in arid and semi-arid regions of Afghanistan. The objective of this study was to evaluate the effects of elevated concentrations of CaCO₃ on growth, physiology, and quality attributes of tomato. Seedlings were exposed to different concentrations of CaCO₃ (0%, 2.5%, 5%, 10%, and 20% w/w) in soil. The results showed that elevated concentrations of CaCO₃ (10% and 20%) significantly increased soil electrical conductivity (EC) and pH, and subsequently affected growth, physiology, and quality of tomato. CaCO₃ effects resulted in an increase in leaf electrolyte leakage, leaf calcium content, root respiration rate, root ethylene production, fruit firmness, total soluble solids, ascorbic acid, and organic acids, as well as a decrease in plant height, leaf length, leaf magnesium content, leaf SPAD value, number of leaves per plant, root weight and length, and root activity. At higher concentrations, CaCO₃ decreased number of flowers and fruit per plant, as well as fruit weight and diameter, consequently affecting yield production. Although elevated concentrations of CaCO₃ is characteristic of soils in Afghanistan, limited information is available about this topic. These findings enhance our understanding of soil conditions in the country and provide valuable insights for farmers.

The reproductive stage of rice is vulnerable to heat stress, which reduces spikelet fertility and yield. Auxin significantly influences reproductive development, hence the research aimed to enhance spikelet fertility and grain attributes in rice plants by exploring the application efficiency of Indole-3-acetic acid (IAA) and 1-naphthaleneacetic acid (NAA) under heat stress. This study investigated the effects of IAA (10 μmol L⁻¹) and NAA (100 μmol L⁻¹) on spikelet fertility rate in six rice genotypes during the flowering stage. Compared to the heat stress (HS) treatment, the spikelet production rate and grain yield per plant were higher by 61.16%, 37.25%, and 33.07%, and 72.84%, 44.48%, and 32.71% in control, HS + NAA, and HS + IAA treatments, respectively. In addition, panicle weight, primary branches number panicle⁻¹, and 1000-grains weight were significantly (p < 0.05) improved with HS + IAA and HS + NAA application under heat stress conditions. Auxin application enhanced photosynthetic and transpiration rate, while contrarily, leaf temperature diminished. The higher photosynthetic rate showed positive relationships with spikelet fertility (r = 0.64) and yield plant⁻¹ (r = 0.63). Additionally, leaf temperature had a strongly negative correlation (r = −0.81) with the spikelet fertility rate. The application of auxin increased the number of filled grains panicle⁻¹, which showed a positive relationship (r = 0.75) with grain yield plant⁻¹. The variation of spikelet fertility rate among genotypes was dependent on the variety tolerance rate. Overall, these findings indicate that exogenous auxin application can mitigate the negative impact of heat stress on rice and improve spikelet fertility and grain yield.

In this study, we propose quantifying the Amu River riverbank erosion with the modelled river discharge in Kaldar District, Balkh Province of Afghanistan from 2004 to 2020. We propose a framework synergizing multi-source information for modelling the erosion area based on three components: (1) river discharge, (2) river width, and (3) erosion area. The total river discharge for the watershed shared by Afghanistan and Tajikistan was modelled using hydrological parameters from the European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis v5 (ERA5) data through multivariate linear regression with ground station data. The river width was determined manually using the Normalized Difference Water Index (NDWI) derived from Landsat data. The riverbank erosion area was derived from the digital shoreline analysis using the NDWI. The digital shoreline analysis showed that, between 2008 and 2020, the average riverbank erosion area in Kaldar District is about 5.4 km² per year, and, overall, 86.3 km² during 2004–2020 due to flood events. The significantly higher land loss events occurred at 10 km² bank erosion during the years 2008–2009 and 2015–2016, and 19 km² peak erosion occurred during 2011–2012. A linear relation between the erosion area with respect to the discharge intensity and the specific stream power was observed with an R² of 0.84 and RMSE of 1.761 for both.