Soil Moisture Regimes Research Articles

Investigating Light and Water Optimization for Early Seedling Establishment in Albizia lebbeck (L.) Benth

Seedling growth, development, and establishment are vulnerable stages for trees, greatly influenced by two important environmental factors: light availability and soil moisture regime. This study investigated the interactive effects of light intensity and water availability on key early vegetative growth parameters of collar diameter, height, and the number of leaves in seedlings of the tropical legume tree Albizia lebbeck. The experiment utilized a 4×3 factorial design with four light intensity levels (L1 (75%), L2 (50%), L3 (25%), and L4 (100% as control)) and three watering frequencies (daily (W1), every three days (W2), weekly (W3)) in a nursery greenhouse. Measurements were recorded biweekly for ten weeks. The results showed that moderate light intensity of 50% coupled with adequate moisture supply by daily watering (L2W1) led to optimal seedling growth. This treatment combination resulted in the greatest mean collar diameter (3.62 mm), plant height (41.88 cm), and number of leaves (11). Growth was restricted under full light (L4) and insufficient light (L3). Limited water availability by watering weekly (W3) also suppressed growth metrics. However, there was no significant difference between daily watering (W1) and moderate watering frequency (W2). Strong intrinsic synchronization was observed between the collar diameter and plant height growth trajectories over time, reflecting coordinated lateral and vertical stem expansion regulated by developmental processes. Leaf proliferation showed partially decoupled dynamics from stem growth, indicating specialized control over leaf traits. Collar diameter, height, and the number of leaves were inherently intercorrelated, highlighting their co-dependence in generating resources and signals needed to sustain growth and development. The findings suggest that 50% light intensity and adequate moisture by watering every 1-3 days are optimal for nursery establishment of A. lebbeck seedlings to maximize early vegetative growth.

Genotype by environment interaction across water regimes in relation to cropping season response of quinoa (Chenopodium quinoa).

Genotype × environment (GxE) interaction effects are one of the major challenges in identifying cultivars with stable performance across agri-environments. In this study we analysed GE interactions to identify quinoa (Chenopodium quinoa) cultivars with high and stable yields under different soil moisture regimes, representing control conditions, waterlogging and drought. Waterlogging and drought treatments were artificially induced using normoxia, a combination of hypoxia-normoxia, and 10% PEG (Polyethylene glycol) under hydroponic growth conditions, respectively. Both waterlogging and drought conditions significantly reduced the plant height (PH), number of leaves (NoL) and number of branches (NoB), stem diameter (SD), leaf area (LA) and dry weight (DW) of quinoa genotypes. The genotype, water regime, and genotype by water regime effects all significantly affected the measured quinoa traits. Based on the additive main effects and multiplicative interaction (AMMI) model for DW, the genotypes G18, Puno, Q4, 2-Want, Puno, Real1 x Ruy937 and Titicaca were found to exhibit tolerance and were stable across water regimes. A second-stage evaluation was conducted to test genotype × environment interaction effects in crop production field trials, selecting two contrasting seasons based on soil moisture conditions involving a diverse set of genotypes (58 varieties in total). Our results demonstrate significant variations in both growth and yield among the quinoa genotypes across the cropping seasons. The GGE analysis for grain yield indicate that field conditions matched to G × E under hydroponic experimental conditions and the cultivars G18, Q1, Q4, NL-3, G28, 42-Test, Atlas and 59-ALC were classified within a range of high productivity. Our findings provide a basis for understanding the mechanisms of wide adaptation, while identifying germplasm that enhances the water stress tolerance of quinoa cultivars at early growth stages.

Effect of Soil Moisture on Future Heatwaves Over Eastern China: Convection‐Permitting Regional Climate Simulations

AbstractSoil moisture deficiencies exacerbate heatwaves through soil moisture‐temperature feedback, an effect that is expected to intensify with climate change, resulting in critical impacts on society and ecosystems. This study aims to investigate the evolving soil moisture‐heatwave relationship over eastern China in the future, using a convection‐permitting (CP, ∼4 km) regional climate model (RCM). The CP‐RCM model simulates historical (1998–2007) and future (2070–2099) climates over eastern China, with three pseudo‐global warming (PGW) experiments conducted under the RCP2.6, RCP4.5, and RCP8.5 scenarios. Results indicate a substantial increase in heatwave frequency (HWF) and magnitude (HWM) over eastern China, particularly under the RCP8.5 scenario. The largest HWF (up to 23 days) is expected in South China (SC), and the largest HWM (up to 3.25°C) is expected in Loess Plateau (LP) and North China Plain (NCP), indicating a pronounced future risk of heatwave in the region. Antecedent soil moisture exhibits a negative correlation with heatwave indices (HWM and HWF) in most areas of eastern China, suggesting its role in mitigating heatwaves. Quantile regression analysis shows that antecedent soil moisture exerts a stronger effect on the upper quantile of the HWF/HWM than on the lower quantile. With global warming, the amplifying effect due to soil moisture deficiency on future heatwaves is expected to expand spatially and become more pronounced. Increased soil moisture control on heatwaves can be attributed to reduced energy limitation and intensified water limitation. A comprehensive investigation across five sub‐regions reveals the role of various soil moisture regimes in modulating heatwaves over eastern China.

Responses of Khao Dawk Mali 105 and Pathum Thani 1 Rice to Different Soil Moisture Regimes on Physiological Traits and Productivity

Khao Da wk Mali 105 (KDML105) and Pathum Thani 1 (PTT1) are two popular rice cultivars in Thailand; KDML105 is known for its unique texture and fragrance and PTT1 for its high yield and ability to be grown year-round in various conditions. This research aimed to (1) study the morphological and physiological processes of two rice cultivars KDML105 and PTT1 under six levels of soil moisture including 20, 30, 40, 50, 60, and 70% available water holding capacity (AWHC) in clay soil and sandy clay loam soil (SCL); (2) identify the critical soil moisture content (CMC) using the physiological response to drought. All physiological traits decreased with reduced soil moisture levels across all growth stages and soil types. The 20% AWHC maximum reduced plant height (1.61-folds), predawn leaf water potential (LWPpd, 3.07-folds), net photosynthesis rate (3.26-folds), stomatal conductance (17.00-folds), chlorophyll fluorescence (1.28-folds), dry matter (2.70-folds), grain yield (3.91-folds) in flowering stage. All physiological traits positively correlated with dry matter and grain yield in both cultivars and both soils, but the highest correlation was found between LWPpd with dry matter (0.884–0.961**) and grain yield (0.790–0.936**) in PTT1, or dry matter (0.883-0.973**) and grain yield (0.818–0.945**) in KDML105. Therefore, LWPpd was used to evaluate the CMC from the linear regression between LWPpd and soil moisture contents. At the seedling stage, the CMCs of PTT1 were at 60% AWHC in both soils, while KDML105 was at 60 and 70% AWHC in clay and SCL soils, respectively. At the tillering and flowering stages, the CMCs of both cultivars were at 70% AWHC in both soils. The results indicate that CMC values vary with soil texture, rice cultivar, and growth stage. This information is crucial for optimizing irrigation practices, such as implementing alternate wetting and drying systems tailored to specific soil textures and rice cultivars.

Evaluation of cabbage growth using quadratic distribution under soil moisture regimes

Evaluation of cabbage growth using quadratic distribution under soil moisture regimes

Impact of Long Term Tillage and Soil Moisture Regime on the Sulphur, Organic Carbon, DOC, MBC and MBN of Soil under Mung Bean-Wheat and Sorghum-Wheat Cropping System

Impact of Long Term Tillage and Soil Moisture Regime on the Sulphur, Organic Carbon, DOC, MBC and MBN of Soil under Mung Bean-Wheat and Sorghum-Wheat Cropping System

Wood decay and Norway spruce vulnerability to wind-inflicted mortality in monospecific and mixed stands in hemiboreal forests

Pathogen-caused stem and root decay are becoming increasingly common in Norway spruce (Picea abies (L.) H. Karst) which is believed to contribute to greater stand instability and susceptibility to wind-inflicted damage. Thus, this study aims to assess the effect of root and stem decay on Norway spruce vulnerability to wind-inflicted mortality in monospecific and mixed stands, to widen our base of knowledge on potentially more resilient spruce forest management approaches in hemiboreal forest zone. In this study we used data from: i) the National Forest inventory (NFI), ii) 34 observation plots established in wind-affected stands, iii) two transects (9200 m long, 36.8 ha inspection area combined), iv) and monospecific spruce plantation thinning experiment (five thinning intensities with two repetitions of each) affected by wind. We found that the total mortality of spruce during the NFI four five-year re-measurement cycles (2003–2007, 2008–2012, 2013–2017, 2018–2022) was 2.28 %, during which the main disturbance-causing agents were wind at 0.86 %, pests at 0.41 %, intra/interspecific competition at 0.37 %, and diseases at 0.36 %. NFI data-based multinomial logistic regression model revealed that the probability of wind-inflicted spruce mortality is dictated by soil moisture regime, stand age, stand stocking level, and tree decay presence. Results from the 34 established observation plots show that wood decay is a potential risk factor associated with wind damage occurrence in spruce stands. In a spruce stand, when a group of trees are damaged by wind the proportion of undecayed trees increases. Whereas a single tree is more likely to be attributed to decay caused wind damage.Results point towards deciduous broadleaf admixture having a positive effect on mitigating wind damage among non-decayed spruce trees: however, decayed trees, are more likely to be affected in such stands. The thinning experiment portion of this study suggests that increasingly intensive thinning in monospecific spruce stands will lead to an increasing spread of root and stem decay and thus the risk of wind damage. Therefore, from this perspective, the main goal is to reduce the root and stem decay presence in the stand and thus increase wind stability. We suggest further research to be directed into finding the optimal initial spruce seedlings density with a combination of coniferous and deciduous broadleaf species in order to mitigate root and stem decay presence and wind-inflicted spruce mortality in the forest stands.

Effect of Long Term Tillage and Soil Moisture Regime on the Chemical Properties of Soil under Mung Bean-Wheat and Sorghum-Wheat Cropping System

Effect of Long Term Tillage and Soil Moisture Regime on the Chemical Properties of Soil under Mung Bean-Wheat and Sorghum-Wheat Cropping System

Impact of soil moisture regimes on greenhouse gas emissions, soil microbial biomass, and enzymatic activity in long-term fertilized paddy soil

Two potent greenhouse gases that are mostly found in agricultural soils are methane and nitrous oxide. Therefore, we investigated the effect of different moisture regimes on microbial stoichiometry, enzymatic activity, and greenhouse gas emissions in long-term paddy soils. The treatments included a control (CK; no addition), chemical fertilizer (NPK), and NPK + cattle manure (NPKM) and two moisture regimes such as 60% water-filled pore spaces (WFPS) and flooding. The results revealed that 60% water-filled pore spaces (WFPS) emit higher amounts of N2O than flooded soil, while in the case of CH4 the flooded soil emits more CH4 emission compared to 60% WFPS. At 60% WFPS higher N2O flux values were recorded for control, NPK, and NPKM which are 2.3, 3.1, and 3.5 µg kg−1, respectively. In flooded soil, the CH4 flux emission was higher, and the NPKM treatment recorded the maximum CH4 emissions (3.8 µg kg−1) followed by NPK (3.2 µg kg−1) and CK (1.7 µg kg−1). The dissolved organic carbon (DOC) was increased by 15–27% under all flooded treatments as compared to 60% WPFS treatments. The microbial biomass carbon, nitrogen, and phosphorus (MBC, MBN, and MBP) significantly increased in the flooded treatments by 8–12%, 14–21%, and 4–22%, respectively when compared to 60% WFPS. The urease enzyme was influenced by moisture conditions, and significantly increased by 42–54% in flooded soil compared with 60% WFPS while having little effect on the β-glucosidase (BG) and acid phosphatase (AcP) enzymes. Moreover DOC, MBC, and pH showed a significant positive relationship with cumulative CH4, while DOC showed a significant relationship with cumulative N2O. In the random forest model, soil moisture, MBC, DOC, pH, and enzymatic activities were the most important factors for GHG emissions. The PLS-PM analysis showed that soil properties and enzymes possessed significantly directly impacted on CH4 and N2O emissions, while SMB had indirect positive effect on CH4 and N2O emissions.

Advancements in Soil Organic Carbon Mapping and Interpolation Techniques: A Case Study from Lithuania’s Moraine Plains

Monitoring soil organic carbon (SOC) is essential for assessing the sustainability of soil usage. This study explores the spatial variability and mapping of SOC in Lithuania’s Nevėžis Plain using various interpolation methods, with an emphasis on understanding the impacts of soil typological units, moisture regimes, and erosion on SOC distribution. A total of 275 soil samples were collected from agricultural croplands at depths of 0–10 cm, supplemented by 38 samples from previous studies. The SOC map was created based on the contours of the Lithuanian soil geodatabase. Statistical analysis revealed that the distribution of SOC in the studied area was significantly influenced by soil moisture and the degree of erosion. Based on these findings, SOC mapping was conducted according to the contours of Lithuanian soils. Comparing the interpolation methods that were analyzed, it was found that the kriging, RBF, and EBK methods fail to adequately capture the minimum and maximum values of SOC, while the IDW fails to adequately capture only the minimum values. In summary, the integrated geographical approach is complex but applicable to SOC mapping. This method facilitates the creation of adaptable SOC maps that are both geographically and pedologically informed. Key principles to apply this approach for future research and practical application should include establishing a statistically reliable data foundation, categorizing samples based on contrasting soil moisture regime, degrees of erosion, and land use patterns, and developing contouring principles along with a criteria algorithm that enables accurate spatial interpolation of average SOC values.

Organic carbon in Mollisols of the world − A review

Mollisols represent 29 % of agricultural land and they are considered to be one of the most fertile soils in the world. Here, we compare soil organic carbon (SOC) concentrations and pools of Mollisols for the globe, the USA and Poland, and review how differences are caused by climate, land use, and key environmental factors. Globally, the mean thickness of the A horizon in Mollisols is 50 cm. At 0–30 cm the mean SOC concentration is 2.3 %, SOC pool is 84 t ha−1, and clay content calculated at 0–50 cm soil depth is 21 %. Mollisols in the USA have an A horizon thickness of 36 cm and have a mean clay content of 27 % (0–50 cm). SOC concentrations are 2.0 and 1.7 % and SOC pools are 85 and 116 t ha−1 at 0–30 and 0–50 cm soil depth, respectively. Mollisols in Poland have SOC concentrations of 1.8 and 1.5 % at 0–30 and 0–50 cm soil depth, respectively, and lower clay content (17 %) at 0–50 cm depth. The SOC pool at 0–30 cm depth is 74 t ha−1 whereas it is 106 t ha−1 at 0–50 cm. At the global scale, the highest SOC concentrations and pools are in Mollisols from Eastern Europe (including Ukraine and Western Russia) and Asia, while the lowest SOC pools are found in Mollisols from South America. The Mollisols in Western and Central Europe and North America have similar SOC pools, although Mollisols in North America have higher SOC concentrations and lower A horizon thickness. Globally, the mean pH value of Mollisols is 7.1, and the pH is slightly lower in Mollisols of the USA (6.9 ± 0.9). The SOC concentrations and pools are strongly and positively correlated with clay content. Soil moisture and temperature regimes determine SOC concentration and pools in Mollisols, and higher SOC concentrations and pools are in Mollisols with frigid and frigid-cryic soil temperature regimes as well as aquic, xeric, and aridic soil moisture regimes. Mollisols under grassland have the largest SOC pools compared to those cultivated or under forest. The important environmental factors on SOC concentrations and pools in Mollisols worldwide are soil texture, land use, and soil temperature regime.

Performance of ACCase-Resistant and ACCase-Susceptible Phenotypes of Sterile Oat Avena sterilis subsp. ludoviciana (Durieu) Nyman under Drought Conditions in the Greenhouse

Climate change might benefit water-stress-adapted weeds, further impairing their management. To evaluate the impact of soil moisture regimes on the growth and reproductive behaviour of ACCase-resistant and ACCase-susceptible phenotypes of sterile oat (Avena sterilis subsp. ludoviciana (Durieu) Nyman), a greenhouse experiment was carried out in 2020 and 2021. The factors were soil moisture regimes (100% field capacity (FC) as well-watered, 75% FC, 50% FC, and 25% FC) and ACCase-resistant and ACCase-susceptible phenotypes of sterile oat. Increased drought stress conditions reduced the number of tillers per plant by 34, 55, and 83% and the number of seeds per plant by 36, 61, and 89% in the 75% FC, 50% FC, and 25% FC conditions, respectively, compared to the well-watered treatment. Notably, both phenotypes reacted similarly to water stress, with no interactions between the two factors. Regardless of water stress, the resistant phenotypes produced fewer seeds per plant, indicating fitness costs. However, due to their high plasticity, both phenotypes will still produce seeds even when facing severe water stress conditions. Thus, sterile oat is expected to continue infesting crop fields in the near future, but with ACCase-resistant phenotypes being less successful than susceptible ones in the absence of herbicide application.

Pore unit cell network modeling of the thermal conductivity dynamics in unsaturated sandy soils: Unveiling the role of spanning‐wetting phase cluster

AbstractAs the world struggles with climate change and energy crises, understanding the role of soil in the food–water–energy nexus becomes increasingly critical. Accurately estimating the soil thermal conductivity drying curve is essential for assessing the impacts of temperature on soil biota and crop growth, environmental changes due to forest fires and global warming, and for designing geo‐energy extraction techniques such as geothermal energy piles. Existing empirical models often fail to accurately estimate the soil thermal conductivity (TC), particularly in pendular soil moisture regimes where they do not capture sharp changes in TC. This study introduces a novel approach using a pore unit cell network model to more accurately describe the dynamics of TC in variably saturated soils. A quadratic parallel scheme within each soil pore unit cell links the TCs of solid, water, and air to the overall effective conductivity. By modeling air invasion in the pore network model and employing the proposed equation, we determined the unsaturated soil TC based on varying local conductivities. The model effectively captures the significant decrease in conductivity in the pendular saturation regime, associated with the shrinkage of the spanning‐wetting cluster. Quantitative analyses showed a substantial improvement in prediction accuracy compared to existing models, especially under varying moisture conditions. Our findings have significant implications for better characterizing soil thermal and hydraulic properties, which are crucial for resource management in a changing climate and advancing geo‐energy technologies.

Evaluation of Soil Quality of Pingliang City Based on Fuzzy Mathematics and Cluster Analysis

Pingliang City has a complex topography and diverse soil types. To realize the improvement of soil according to local conditions and the reasonable and sustainable use of soil resources, an evaluation of soil quality in Pingliang City was carried out, based on the soil distribution situation in Pingliang City, adopting a method combining fuzzy mathematics and cluster analysis of the main evaluation factors, such as soil organic matter, topsoil depth, soil erosion intensity, soil moisture regime, effective soil thickness, soil texture, soil profile structure, soil nutrient status and topographical parts, to carry out a comprehensive evaluation. A comprehensive evaluation of soil quality was conducted in seven counties under the jurisdiction of Pingliang City, and the evaluation results were compared and analyzed against the national standard, “Cultivated land quality grade”, to provide a basis for the selection of scientific soil improvement methods. The results of the arable land quality grades indicate that the quality of farmland in Pingliang City is divided into three to ten grades, and the average quality grade of farmland is 6.83, which is in the middle–lower level, and the overall grade distribution shows the characteristics of low in the middle and high in the east and west. The results of fuzzy mathematics combined with cluster analysis indicated the following trends in soil quality for the 12 soil genera: Chuan black gunny soil > yellow moist soil > sandy soil > silt soil > mulching helilu soil> loessal soil> loamy soil > slope loessal soil > arenosol > tillage leaching gray cinnamon soil > calcareous gray cinnamon soil > red clay soil. The results of the combination of fuzzy mathematics and clustering were significantly correlated with the results of the evaluation of the soil quality of arable land; the correlation coefficient was 0.884. This indicates that the method can accurately and objectively review the advantages and disadvantages of arable land soil and can be effectively applied to the evaluation of the soil quality of agricultural soils in other regions. It is a complement to the existing evaluation of the soil quality of arable land and at the same time provides a reference for the improvement of soil quality in agricultural regions.

Active Soil Organic Carbon Pools Decrease with Increased Time since Land-Use Transition from Rice Paddy Cultivation to Areca Nut Plantations under the Long-Term Application of Inorganic Fertilizer

Many croplands in the tropics of China have been converted over the last decades into areca nut plantations due to their high economic returns. This land-use transition was accompanied by changes in agricultural practices such as soil moisture regimes and fertilizer inputs, which may affect soil organic carbon (SOC) and its fractions, especially in tropical soils with low fertility and high nitrogen loss. Yet, how the time since land-use transition from rice paddy cultivation to areca nut plantations affects soil carbon dynamics and their underlying mechanisms in the tropics of China remains elusive. Here, areca nut plantation soils with different ages (2, 5, 10, 14, and 17 years) and paddy fields in the tropical region of China were investigated. The study result indicates that the contents of dissolved organic carbon (DOC), particulate organic carbon (POC), easily oxidized organic carbon (EOC), light organic carbon (LFOC), and microbial biomass carbon (MBC) decreased significantly with increased time since land-use transition from rice paddy cultivation to areca nut plantations. Similarly, the ratios of DOC/SOC, MBC/SOC, POC/SOC, LFOC/SOC, and EOC/SOC decreased significantly with increased time since land-use transition. Compared with the paddy soil, the carbon pool management index decreased by 36.6–76.7% under the areca nut plantations, concluding that increasing the time since land-use transition from rice paddy cultivation to areca nut plantations with high application rates of chemical fertilizers resulted in reduced soil active carbon fractions and SOC supply capacity. Therefore, agricultural practices such as the use of organic fertilizers should be applied to improve the soil’s ability to supply organic carbon in managed plantation ecosystems in the tropics of China.

Reconstruction of a deep-time critical zone in southern patagonia (mid-high paleolatitude) during the mid-cretaceous greenhouse

The mid-Cretaceous was a period characterized by a global greenhouse climate. Paleosols can be used to reconstruct Critical Zones of the Earth́s past and enhance our comprehension of such greenhouse conditions. Through macro- and micromorphological, clay-mineralogy, and bulk geochemical analyses of the paleosols, we conducted a deep-time Critical Zone reconstruction at mid-high paleolatitudes of the mid-Cretaceous Puesto El Moro Formation in the southern Patagonia (Austral-Magallanes Basin). Paleosols were classified as hydromorphic Histosol-like paleosols (Kachaike pedotype), Alfisols like-paleosols (La Lila pedotype), and Vertisol like-paleosols (La Bernarda pedotype). The analysis of these paleosols facilitated the reconstruction of the deep-time Critical Zone and enables us to infer the four scientific spheres (lithosphere, hydrosphere, biosphere, and atmosphere). Different types of paleosols developed under different parent materials with specific soil-moisture regime and drainage class. Overall, paleosols took place during temperate and humid conditions with a marked seasonality of the precipitations. The paleoclimate reconstruction obtained here provides new data from mid-high paleolatitudes and agrees with the current mid-Cretaceous climate reconstructions in the context of a greenhouse world.

Effects of microbial biofertilizer on growth, physio-biochemical traits, fruit yield, and water productivity of okra under drought stress

Drought poses a major challenge to global agricultural crop production, as it is considered one of the most severe abiotic stresses. Understanding the effects of exogenous microbial biofertilizer on okra [Abelmoschus esculentus (L.) Moench] under drought stress can lead to new strategies for coping with drought conditions. The objective of the study was to examine the effects of microbial biofertilizer on growth, physio-biochemical traits, fruit yield, and water productivity of okra under drought stress. A factorial pot experiment, consisting of eight biofertilizer treatments applied as a soil drench (autoclaved inoculum [control], and inoculation with arbuscular mycorrhizal fungi [AMF], phosphate-solubilizing fungi [PSF], plant growth-promoting rhizobacteria [PGPR], AMF + PSF, AMF + PGPR, PGPR + PSF, and AMF + PSF + PGPR) and three soil moisture regimes (50%, 75%, and 100% field capacity [FC]), was carried out. The results indicated that decreasing soil moisture level severely affected growth and fruit yield of okra. The application of microbial biofertilizer effectively enhanced growth, fruit yield, and physio-biochemical traits of okra under different soil moisture levels. Among the biofertilizer treatments considered, the combined application of AMF and PGPR showed remarkable efficacy in enhancing growth and productivity of okra plants under both 75% and 100% FC conditions. This co-inoculation significantly boosted shoot dry matter by 51%, root dry matter by 73%, fruit yield by 113%, and irrigation water productivity by 122% compared with plants grown without inoculation, irrespective of soil moisture levels. Furthermore, the plants treated with AMF and PGPR exhibited a noteworthy decrease in free proline accumulation by 31% compared with their non-inoculated counterparts. The results suggest that application of both AMF and PGPR biofertilizer to soil is an effective strategy to alleviate moderate drought stress. It is recommended to apply AMF and PGPR in combination to improve okra yield and water productivity under drought stress.

Investigation of Yield and Physio-Morphological Characteristics of Wheat Grown Under Varied Soil Moisture Regimes

Wheat (Triticum aestivum L.) is a vital crop globally, and its production is influenced by various environmental factors, including soil moisture. This review synthesizes existing research on the impact of varying soil moisture regimes on wheat yield and physio-morphological characteristics. The review encompasses studies examining the effects of water stress and excess moisture on wheat growth, development, and yield. Keywords: Wheat, Soil Moisture, Yield, Physio-Morphological Characteristics, Climate Change.

Effect of Sowing Dates and Seed Priming on Agrometeorological Indices and Soil Moisture Regimes of Chickpea in North Central Plateau Zone NCPZ of Odisha

Background: field experiment entitled “Effect of sowing dates and seed priming on agrometeorological indices and soil moisture regimes of Chickpea in NCPZ of Odisha” was conducted at RRTTS, Keonjhar, Odisha, during the Rabi season for two consecutive years i.e., 2021-22 and 2022-23. Method: The field experiment was laid out in factorial RBD design with three replications and two factors. There were 3 dates of sowing in Factor A (D1-25 November, D2-5 December, D3- 15 December) and 5 moisture conservation practices in Factor B (M1- Control, M2- Seed priming with water for 8 hours, M3- Osmopriming (Seed priming with CaCl2 solution @0.5% for 8 hours), M4- Straw mulch@ 5t/ha and M5- Straw mulch@ 5t/ha +Seed priming with CaCl2 solution @0.5% for 8 hours). Seed priming controls the hydration of seeds that helps in the pre germinative metabolic activity of the seeds. So even if the soil has less moisture that will not affect the uniform and proper germination of the seeds. All together there were 15 treatment combinations. The test crop variety taken was JAKI-9218. Among the three dates of sowing, D2 (5th Dec) sowing recorded the tallest plants (41.47 cm). but were recorded in D1 (25 Nov) sowing. Early sowing on 25th November recorded the maximum number of primary and secondary branches and required a greater number of days to 50% flowering (41.8 days) and days to physiological maturity (101.1 days). Results: Among the moisture conservation practices, M5 (Straw mulch@ 5 t/ha+Seed priming with CaCl2 solution @ 0.5% for 8 hours) recorded the tallest plants, maximum number of primary and secondary branches, maximum number of days taken to 50% flowering (40.7 days) and days taken to physiological maturity (100.1 days), maximum number of pods per plant (44) and number of seeds per pod (3.62), grain yield (1812 kg/ha) and straw yield (218 kg/ha). This treatment recorded the minimum consumptive use of water (203.5 mm) and rate of moisture use (1.36 mm/day) but the moisture use efficiency was maximum (12.34 kg/ha-mm). Treatment M5 recorded the maximum growing degree days (2182°C day), heliothermal unit (15077°C day hrs), photothermal unit (22595°C day hrs) and heat use efficiency (0.94 kg/ha/°C) to reach maturity. Chickpea when combined with suitable date of sowing and moisture conservation practices for proper utilization of carry-over residual soil moisture in the rice fallows gives higher yield.

Assessing corn recovery from early season nutrient stress under different soil moisture regimes.

Corn (Zea mays) biomass accumulation and nutrient uptake by the six-leaf collar (V6) growth stage are low, and therefore, synchronizing nutrient supply with crop demand could potentially minimize nutrient loss and improve nutrient use efficiency. Knowledge of corn's response to nutrient stress in the early growth stages could inform such nutrient management. Field studies were conducted to assess corn recovery from when no fertilizer application is made until the V6 growth stage, and thereafter, applying fertilizer rates as those in non-stressed conditions. The early season nutrient stress and non-stress conditions received the same amount of nutrients. As the availability of nutrients for plant uptake is largely dependent on soil moisture, corn recovery from the early season nutrient stress was assessed under different soil moisture regimes induced via irrigation scheduling at 50% and 80% field capacity under overhead and subsurface drip irrigation (SSDI) systems. Peanut (Arachis hypogaea) was the previous crop under all conditions, and the fields were under cereal rye (Secale cereale) cover crop prior to planting corn. At the V6 growth stage, the nutrient concentrations of the early season-stressed crops, except for copper, were above the minimum threshold of sufficiency ranges reported for corn. However, the crops showed poor growth, with biomass accumulation being reduced by over 50% compared to non-stressed crops. Also, the uptake of all nutrients was significantly lower under the early season nutrient stress conditions. The recovery of corn from the early season nutrient stress was low. Compared to non-stress conditions, the early season nutrient stress caused 1.58 Mg ha-1 to 3.4 Mg ha-1 yield reduction. The percent yield reduction under the SSDI system was 37.6-38.2% and that under the overhead irrigation system was 11.7-13%. The high yield reduction from the early season nutrient stress under the SSDI system was because of water stress conditions in the topsoil soil layer. The findings of the study suggest ample nutrient supply in the early season growth stage is critical for corn production, and thus, further studies are recommended to determine the optimum nutrient supply for corn at the initial growth stages.