High Soil Moisture Research Articles

Identification of Environmental Factors Influencing the Population of Endangered Epilobium hirsutum L. in Korea

Epilobium hirsutum has been identified as a Class II endangered species in Korea. Therefore, there is an urgent need to develop habitat conservation and improvement strategies for the protection of E. hirsutum. In this study, we aimed to evaluate the environmental characteristics of E. hirsutum habitats and identify key environmental factors influencing the population size. To this end, we conducted field surveys and performed a spatial data analysis to collect data on 38 environmental characteristics associated with the population size of E. hirsutum. We performed factor and path analyses to identify the environmental factors influencing the population size and the correlations between the population size and environmental factors. The common factors identified in both analyses were the average temperature in March, available P, soil pH, and soil humidity. Therefore, to manage E. hirsutum habitats or create alternative habitats, areas with a low air temperature and high soil moisture must be selected. It is necessary to remove tall plants and amend soils with alkaline fertilizers containing P. Additionally, it may be effective to implement a management strategy that induces vegetative propagation and seed germination by replacing agricultural waterways made of concrete with those made of rock and soil.

Drying characteristics of soil in large-scale rotary kilns: An experimental and CFD-DEM study

Traditional soil thermal desorption often leads to substantial energy loss, particularly with high-moisture soils. A novel approach was proposed, utilizing waste heat from flue gas to pre-dry the soil. A large-scale rotary kiln, with a capacity of 20 t/h, was tested, and the drying process was modeled using CFD-DEM. Results showed the rotary kiln exhibited high stability, enhanced loading capacity, and significant moisture content reduction. Sensitivity analysis indicated that the inlet flue gas temperature had the most significant impact on the outlet moisture content. The rotary kiln’s volumetric heat transfer coefficients ranged from 142.22 to 178.14 W/(m3·°C) and energy utilization rate peaked at 0.81, while the exergy efficiency remained approximately 0.5, demonstrating high energy utilization and exergy efficiency. Detailed analysis of soil particles along the kiln revealed a novel multi-stage drying mechanism. The model effectively describes the drying process, offering valuable insights for future design.

Effect of temperature and moisture on soil pathogen Fusarium solani of lemon in Adjara, Georgia

The research was conducted in the 2022 and 2023 seasons in the agrometerology and plant protection laboratory and citrus greenhouse of Batumi Shota Rustaveli State University, the aim of which was groupe and unit role of temperature and soil moisture (SM) content on aggressive soil pathogen F. solani on lemon, also effects of pathogen density and soil moisture on belowground and aboveground morphological traits. In our study, we could find that the both temperature and soil moisture played a decisive role in influencing the root rot disease scenario. As per the disease susceptibility index (DSI), a combination of high temperature (35°C) and low SM (60%) was found to elicit the highest disease susceptibility in lemon. High pathogen colonization was realized in lemon root tissue at all time-points irrespective of genotype, temperature, and SM. Interestingly, this was in contrast to the DSI where no visible symptoms were recorded in the roots or foliage during the initial time-points. For each time-point, the colonization was slightly higher at 35°C than 25°C, while the same did not vary significantly with respect to SM. Shoot biomass was not affected by either pathogen density or soil moisture. However, the two experimental factors have additive effects on the severity of leaf damage. Leaf damage increased with the density of F. solani in the soil, being significantly higher at 60 CFU/g and 120 CFU/g than in control seedlings. Leaf damage was higher at the two extreme soil moisture levels (15% and 100% WHC) than at the two intermediate levels (40% and 50%). In addition, differential expression studies revealed the involvement of defense-related genes, such as endochitinase and chitinase, in the resistant lemon cultivar Meyer, which contribute to retarding root rot disease progression in lemon. In the early stages of infection, especially with low SM. That can be beneficial for farmers and researchers who involve in Citrus

Rainfall and Soil Moisture Jointly Drive Differences in Plant Community Composition in Desert Riparian Forests of Northwest China

Extreme rainfall and soil moisture play important roles in the survival, community composition, and ecosystem function of desert plants. This study focused on arid desert riparian forests ecosystems in the Ebinur Lake Basin of Xinjiang, China. We analyzed the effects of rainfall and soil moisture on species composition, indicator species, β diversity, species turnover, and nestedness using three consecutive years of community surveys. A zero-model combined with a Bayesian framework was used to explore the response of species turnover and nestedness to soil moisture and rainfall, and variance decomposition was used to quantify the relative importance of spatial distance, rainfall, and soil factors in determining species composition. The results indicated the following: (1) when rainfall was high, the richness and abundance of annual herbaceous plants increased. The proportion of the community based on richness (32%) and abundance (58.1%) of annual herbaceous plants in 2016 was higher than that in 2015 and 2017. The Jaccard, Bray–Curtis, and Chao indexes of the community in years with higher rainfall were significantly higher than in years with lower rainfall; however, a lag effect was also observed. (2) Soil factors explained 5% of the changes in community composition, rainfall explained 12% of the changes in community composition, and spatial distance, soil factors, and rainfall jointly explained 32% of the changes in community composition. (3) We also showed that high soil moisture leads to greater β diversity than low soil moisture. Rainfall had the greatest explanatory power on the measured values of β diversity (19.6%) and species turnover (38%), and the factor with the greatest explanatory power for species nestedness was the interaction between rainfall and soil moisture (26.2%). Our findings indicate that drought and rainfall drive differences in plant community composition, with rainfall playing a dominant role. These results provide a basis for understanding the impact of extreme rainfall events on arid ecosystem functions.

High resolution soil moisture mapping in 3D space and time using machine learning and depth functions

Soil moisture is a key factor in hydrological, biological, and chemical processes, and plays a critical role in maintaining ecosystem balance. To generate high-resolution soil moisture maps at regional scales, researchers primarily employed in-situ observation-based spatial interpolation and remote sensing-based downscaling methods. However, direct comparisons between these methods are scarce. Additionally, remote sensing techniques are limited to the topsoil layer, and in-situ observations often have large depth intervals, thereby constraining the vertical resolution of subsurface soil moisture mapping. To address these challenges, we utilized an equal-area spline depth function combined with machine learning to map high spatial-vertical-resolution daily soil moisture across the Qinghai-Tibet Plateau. The performance of spatial interpolation and downscaling methods in mapping surface soil moisture at 0–5 cm depth were also compared. The results revealed that both spatial interpolation and downscaling methods produced unbiased predictions. However, prediction accuracy was lower in the peripheral subareas of the study area which had lower sampling density. Maps generated through the spatial interpolation method better captured detailed environmental covariates, whereas those obtained with downscaling methods were smoother. The fitting of depth functions introduced only small errors, but caution is still needed when predicting at unobserved depths. For subsurface soil moisture mapping using depth functions combined with spatial interpolation, validation results at two depth intervals showed improvements over surface predictions, with a root mean squared error (RMSE) reduced by 6.45 % to 17.2 % and unbiased RMSE by 5.95 % to 19.04 %. Furthermore, the analysis of variable importance highlighted the critical role of time-varying covariates. Future research should focus on optimizing depth functions and combining data-driven with knowledge-driven approaches. This study serves as a reference for mapping soil moisture with fine spatial-vertical-resolution in large-scale study areas.

Effects of nitrification and urease inhibitors on nitrous oxide emissions and concentrations driven by soil moisture in sandy soils

Soil moisture and nitrogen (N) fertilizer control the balance between nitrous oxide (N₂O) production and consumption in soil. However, the impact of nitrification and urease inhibitors on soil N₂O production and consumption under varying soil moisture levels remains insufficiently understood. In this study, a soil column experiment was conducted to investigate N₂O concentrations and accumulation at different soil depths (0, 5, 15, 30, and 60 cm) in sandy soil over two months. The soil was collected from a drip-irrigated field subjected to long-term cotton cultivation in an arid region. Four fertilizer treatments were applied: urea, urea + nitrification inhibitor (Dicyandiamide, DCD), urea + nitrification and urease inhibitors [N-(n-butyl) thiophosphoric triamide, NBPT], and an unfertilized control. These treatments were tested under three soil moisture levels [23%, 46%, and 70% water-filled pore space (WFPS)]. The results showed that treatments with inhibitors significantly reduced cumulative surface N₂O emissions by 33.2%–58.2% compared to urea alone. Notably, the treatment with both DCD and NBPT achieved the greatest reductions in surface emissions and in N₂O concentrations at 5 cm and 15 cm soil depths at 70% WFPS. Additionally, across all N fertilizer sources, 70% WFPS led to increased N₂O concentrations in the soil profile compared to lower soil moisture levels. Column N₂O accumulation was positively correlated with surface cumulative N₂O emissions under all three moisture conditions. Our study highlights that under high soil moisture conditions, DCD and NBPT can significantly mitigate intense N₂O emissions in sandy soils. This emission reduction is likely attributed to enhanced nitrification within the 0–15 cm soil layer rather than reduced N₂O diffusivity and denitrification along the soil profile. Therefore, we recommend applying nitrification and urease inhibitors under high soil moisture conditions as an effective strategy to reduce N₂O emissions in sandy soils.

Divergent Drivers of Declining Urban Vegetation Productivity and Transpiration During Heatwaves

AbstractHeatwave events, characterized by high vapor pressure deficit (VPD) and low soil moisture (SM), considerably disrupt the regional carbon and water cycle. However, research pertaining to the impact of heatwaves on vegetation productivity (VPu) and vegetation transpiration (VTu), along with their underlying drivers, particularly in urban areas, remains limited. This study investigates the response of VPu and VTu to heatwave events across 895 global cities from 1990 to 2022. The analysis reveals a notable upward trend in the average heatwave frequency, intensity, and duration across the global cities. Heatwave events demonstrate a detrimental impact on VPu and VTu, resulting in an average decrease of 28% and 26%, respectively, during heatwave occurrences. The attribution analysis reveals divergent driving factors for the decline in VPu and VTu during heatwaves. The decrease in VPu is primarily influenced by SM, contributing 60% to the downward trend of VPu during heatwaves. Notably, VPu displays a sharp downward trend when SM falls below 0.38 m3/m3. In contrast, the primary driver of VTu decline is VPD, contributing more than 66% to the downward trend of VTu during heatwave events. VTu exhibits a significant downward trend when VPD exceeds 1.35 kPa. The results of this study show the important effects of increasingly frequent heatwaves on vegetation transpiration and productivity, and that can be used as quantitative factor to be evaluated when investigating policy measures for the resilience of urban areas.

Phosphorus leaching in high-P soils under maize silage and interseeding cover crop system

Managing soil phosphorus (P) in agroecosystems with high P levels is crucial to mitigate P loss in water sources without compromising yields. The objective of this study was to assess maize silage (Zea mays L.) + interseeding cover crop of annual ryegrass (Lolium multiforum) or using a relay cover crop and starter P (P0, P10, and P20) on (i) P leaching, (ii) changes in soil P status, and (iii) maize yield, cover crop biomass and P uptake. A six-year study was conducted between 2018 and 2023 in two sites. Leachate samples were collected every two weeks between 2021and 2023. The concentration of P in leachate exceeded 0.5 mg L–1 indicating a high risk of P leaching at the current levels of soil P. High concentration of P in leachate with a peak at 0.9 mg L–1 in August and 1.45 mg L–1 in October during 2021 and 2022 was pronounced under interseeded compared to relay cover crop system due to improve water infiltration contributing to the downward movement of P. In contrast, the concentration of P in leachate was high under relay cover crops in February and March particularly in 2023, which could be attributed to the delay in cover crops establishment and growth in early spring. The concentration of P extracted using anion exchange membranes (PO4AEMs) increased with increasing starter P rate during the first weeks after planting maize silage. There were spikes of PO4AEMs, reaching 1.18 and 1.73 µg cm–2 d–1 during the 4th, 7th, and 8th weeks after planting maize which coincided with high soil moisture content occurring after irrigation or rainfall events. The lack of dry matter yield response to starter P at harvest was due to high initial soil P. The soil P status remained significantly high averaging 196.6 mg kg–1 as Mehlich-3 P, despite negative cumulative P budgets. A close observation of the relationships among soil P indicators shows a trend of rapidly decreasing water extractable P under interseeding compared with relay cover crops. It is possible that the production of high biomass under interseeding cover crops increased the amount of P taken up from the soil. We conclude that interseeding cover crops within cash crops in high P soils could be effective at decreasing soil P, but could enhance P leached in the first years of cropping due to high water infiltration along the soil profile.

Cut-off walls alter nitrogen loads and fluxes in small islands

The measure of constructing cut-off walls in coastal islands has been tested effective to upgrade the freshwater lenses (FWL). Meanwhile, cut-off walls can also affect the FWL quality by changing the loads and fluxes of nitrogen (N). Previous research has been focused on the effects of cut-off walls on the N fluxes in groundwater (like, e.g., nearshore denitrification), assuming a constant N source while changes of the N loads and fluxes associated to the N source in shallow soils have only rarely been considered. In this study, we numerically simulated seawater intrusion and transport of land-sourced nitrate on a 2D, vertically oriented island equipped with a cut-off wall. A simplified framework was used to simulate the N fate in the shallow soil. We selected different aquifer permeability and the depth of cut-off wall. The cut-off wall effect on the N loads and fluxes in soil and groundwater, and on the nitrate concentration within the FWL, was quantitatively assessed. The results show that cut-off walls can considerably reduce the soil N load in high permeability islands (> 10−11.5 m2), because of the increased potential crop uptake due to the increased groundwater level and higher soil moisture. The opposite effect was observed in low permeability islands (< 10−11.5 m2) due to the smaller N leaching fluxes from soil to groundwater under the reduced groundwater flow rate. For the high and low permeability islands the leaching flux can generally be reduced by up to 63 %; for the intermediate permeability islands (10-11.5 m2 ≤ k ≤ 10-11 m2), however, the leaching is increased by up to 38 %. Highly depending on how the leaching changes, cut-off walls can reduce the groundwater N load and the nitrate concentration of FWLs, and thus improve the FWL quality in many cases except for the intermediate permeability islands. Therefore, special caution and investigation are required for constructing cut-off walls on islands with intermediate permeability. As a first attempt to assess the influence of cut-off walls on N loads and fluxes considering the N source dynamics, our study is important for the management of FWL quality and coastal environments.

Process and mechanism analysis of typical permafrost area surface deformation at two sites along the Qinghai-Tibet highway based on long-term leveling observation

Surface deformation indicates permafrost changes and multi-year surveys can reflect its characteristics and causes. In this study, surface deformations in Wudaoliang (WDL) and Xidatan (XDT) were determined based on long-term leveling measurements, hydrothermal data, precipitation and soil sampling. In-situ observations can be used to study the influence of hydrothermal changes in the active layer on the surface. The amplitude and onset date of seasonal deformation are different due to the soil moisture (SM) and soil texture in the two permafrost regions. High SM and fine-grained soils can cause significant seasonal surface deformation. A good correlation existed between the freeze-thaw front migration rate and deformation in the active layer with a uniform distribution of SM. The inter-annual subsidence rate in the WDL was higher than in the XDT, owing to the different rates of ground ice thawing near the permafrost table. The long-term subsidence rate positively correlates with the increased seasonal deformation amplitude, especially in fine-grained soils.

Factors that influence the migration of sorbed pesticides in polyethylene and biodegradable mesoplastics

Trifluralin, Chlorpyrifos, and Procymidone migration performance from polyethylene (PE) and biodegradable (Mater-Bi: M-B) mulching films was examined. Desorption of pesticides from PE and M-B was studied using soil-plastic microcosms, considering temperature, soil humidity, and mulching film type as experimental variables. Trifluralin and Chlorpyrifos desorption was higher for PE than for M-B under all experimental conditions. In both cases, as the temperature increased from 25º C to 40º C, pesticide migration also increased, whereas as the soil humidity raised from 30% to 60%, pesticide desorption decreased. In the case of Procymidone, migration from PE and M-B at 25º C was similar under both soil moisture conditions. Migration percentages were similar for both mulch films at 40ºC and 30% soil humidity. However, at higher soil moisture (60%), migration from M-B was greater than from PE. A linear relationship was observed between the percentage of migration and the vapor pressure of the pesticides. In all cases, migration increased with higher vapor pressure, indicating a possible migration mechanism in the vapor phase. Pesticide migration increased at high temperatures (40º C). The effect of soil humidity in reducing pesticide migration was more significant at lower levels (30%).In addition, the mesoplastic sorption of pesticides in soil columns was studied using PE and M-B films. While the recoveries for Trifluralin, Chlorpyrifos, and Procymidone in the PE films were 0.05% ± 0.01%, 0.13% ± 0.03%, and non-detectable, the recoveries for M-B were: 0.49% ± 0.07%, 0.31% ± 0.09%, and 0.17% ± 0.10%, respectively, indicating that M-B was a better adsorbent than PE in all cases. This behavior should be considered in combination with the lower migration percentages observed for this type of mulching film in the microcosm experiments. These results could indicate a potential carrier effect of pesticide on biomesoplastic in the environment.

In-Vivo and In-Vitro Investigation of Germination Rate of Buried Sclerotia, and Variability in Carpogenic Germination Among Sclerotinia sclerotiorum Isolates

The sclerotia of Sclerotinia sclerotiorum serve as a primary inoculum source for initiating infections. This study aimed to evaluate the effects of environmental factors on sclerotial germination under field conditions by establishing sclerotia depots to monitor apothecia appearance over four consecutive years. Additionally, the effects of soil moisture content (25%, 50%, 75%, and 95%), air temperature (10 °C/10 °C, 14 °C/10 °C, and 18 °C/10 °C), and light conditions (white and UV light) on sclerotial germination and apothecial formation were investigated under controlled conditions with a 17 h day/7 h night regime. Furthermore, variability in carpogenic germination among S. sclerotiorum isolates was examined. From 2021 to 2024, significant differences were observed in both the sclerotia germination rate and timing of germination within the season. High soil moisture, particularly prolonged wetness, and soil temperatures between 10 and 14 °C were key factors for apothecial formation under field conditions. Under controlled conditions, higher soil moisture levels (75% and 95%) accelerated sclerotial germination, with sclerotia incubated at 14 °C/10 °C germinating earlier after 38 days than those at 10 °C/10 °C or 18 °C/10 °C. Additionally, the type of light significantly affected apothecial formation, which was observed only in treatments exposed to a combination of white and UV light. Furthermore, significant variations were also found in the duration until sclerotia of different S. sclerotiorum isolates produced the first stipe and the first apothecium, indicating that the genetic characteristics of each isolate affect carpogenic germination.

Отглеждане на соя при висока почвена влажност

The aim of this work is to study the biological and economic effect of growing soybeans at high soil moisture. The experiment is two-year and was conducted in the experimental field of AU - Plovdiv in 2009 and 2010. The variants are: 1) No irrigation, 2) Irrigation at 80% FC (field capacity), 3) Irrigation at 90% FC. When maintaining higher pre-irrigation moisture, the number of irrigation applications increases by an average of 3, and irrigation rates decrease by between 22 and 53%. The duration of the irrigation period increases by ten days. According to the results, the maintenance of high soil moisture for soybean is unjustified from a biological point of view, since the increase in the productive potential of the plants is not realized in reality. It can be considered that regardless of the irrigation method, the pre-irrigation humidity should be no higher than 80% FC for the soil layer 0-60 cm. When maintaining high soil moisture (above 90% FC), production costs increase by an average of 11%, without increasing the cost price and hardly affecting the net income, and the results for this indicator are not unidirectional.

Synthesis and Evaluation of Starch-Grafted-Poly[(Acrylic Acid)-Co-Acrylamide] Based Nanoclay Polymer Composite Fertilizers for Slow Release of Nitrogen in Soil.

Nitrogen (N) losses from conventional N fertilizers contribute to environmental degradation and low N use efficiency. Highlighting the need for slow-release fertilizers (SRFs) to mitigate these problems, this study aims to develop slow-release N fertilizers using starch-grafted-poly[(acrylic acid)-co-acrylamide] based nanoclay polymer composites (NCPCs) and investigate their efficacy for slow N delivery in soil. Three types of NCPCs, NCPC(A) (poly [(acrylic acid)-co-acrylamide]), NCPC(W) (wheat starch-grafted-poly[(acrylic acid)-co-acrylamide), and NCPC(M) (maize starch-grafted-poly[(acrylic acid)-co-acrylamide) were prepared and characterized using FTIR spectroscopy and X-ray diffraction techniques. N-release behaviour of the products was assessed under two distinct soils, i.e., Assam (Typic Hapludults, pH 4.2) and Delhi (Typic Haplustepts, pH 7.9) soils. Additionally, the effects of varying soil moisture and temperature levels on N release were studied in the Assam soil. The N-release kinetics of the synthesized fertilizers were assessed using zero-order, first-order, Higuchi, and Korsmeyer-Peppas models. Degradability of the NCPCs was evaluated by measuring evolved CO2-C under various soil conditions as an indicator of microbial degradation. The results indicated that NCPC fertilizers significantly slowed down the release of N compared to urea. According to the R2 values obtained, it was evident that the first-order kinetic model most accurately describes the N release from both urea and NCPC-based N fertilizers in the studied soils. Among the formulations, NCPC(A) exhibited the lowest N release (42.94-53.76%), followed by NCPC(M) (51.05-61.70%), NCPC(W) (54.86-67.75%), and urea (74.33-84.27%) after 21 days of incubation. The rate of N release was lower in the Assam soil compared to the Delhi soil, with higher soil moisture and temperature levels accelerating the release. Starch addition improved the biodegradability of the NCPCs, with NCPC(W) showing the highest cumulative CO2-C evolution (18.18-22.62 mg g-1), followed by NCPC(M) (15.54-20.97 mg g-1) and NCPC(A) (10.89-19.53 mg g-1). In conclusion, NCPC-based slow-release fertilizers demonstrated a more gradual N release compared to conventional urea and the inclusion of starch enhanced their degradability in the soil, which confirms their potential for sustainable agricultural applications. However, soil properties and environmental factors influenced the N release and degradation rates of NCPCs.

Spatial downscaling of SMAP soil moisture to high resolution using machine learning over China’s Loess Plateau

Soil moisture (SM) is a critical physical parameter in land surface processes that affects the atmospheric and hydrological cycles. Soil Moisture Active Passive (SMAP) mission produces high-quality global SM data, but its low spatial resolution limits the applications at a regional or local scale. In this study, we developed a novel method to select optimal factors from 34 candidate downscaling factors for each month using three machine learning methods (Back Propagation Neural Network (BPNN), Support Vector Machine (SVM) and Random Forest (RF)) to produce monthly time series SM products at a spatial resolution of 1 km for the entire Loess Plateau in China from 2015 to 2023. 11 in-situ SM measurements distributed in Loess Plateau and precipitation data were used to evaluate the downscaling performances of the three machine learning approaches. The results show that the spatial trends of the three downscaled SM were essentially the same as the SMAP SM, with similar spatial patterns, and all three downscaled SM can provide more spatial information and texture features than SMAP SM. Among the three types of downscaled SM, the RF downscaled SM reached the highest R (0.654) and the smallest unbiased Root Mean Square Error (ubRMSE) (0.044 m3m−3), better than the BPNN and SVM downscaled SM, and most closely matched the in-situ measurements. The dynamics of SM were successfully captured by RF downscaled SM, which exhibited strong temporal consistency with the in-situ SM and responded well to precipitation events, with significant increases in SM values in the month of high precipitation and subsequent months. In conclusion, the RF model has the best downscaling effect and it can be used to provide high spatial resolution SM data for applications at a regional or local scale across the Loess Plateau.

Landslide Monitoring and Warning System Based on Wireless Sensor Network

Landslides are common in Indonesia, often caused by factors like heavy rainfall and high soil moisture levels. The Batubrak mini hydro power plant intake area in Lampung province of Indonesia has experienced landslides, prompting the need for an early warning system. This study presents the development of a cost-effective and efficient real-time landslide monitoring and warning system. The system incorporates sensors to measure accelerometer and vibration parameters, enabling real-time data display through a wireless sensor network and SCADA software. Early warnings are issued when triggers are activated. Three sensor nodes were deployed in the intake area for testing, demonstrating their ability to detect, collect, process, and transmit accelerometer and vibration data to the gateway node.

Spatial Aggregations of the Grey Field Slug Deroceras reticulatum Are Unstable Under Abnormally High Soil Moisture Conditions.

Deroceras reticulatum in arable fields display spatio-temporally stable slug patches that have been well documented under typical soil moisture conditions. The effect of abnormally high soil moisture on slug patch stability, however, is unknown. In this study, stepped gradient choice tests comparing soil moisture levels of 50-125% soil capacity showed slug preferences for levels in a range near to 125%. Activity became erratic, however, when given a choice of high moisture levels (125-370%), potentially because slugs searched for preferred conditions. Slug spatial aggregation was investigated in 21 commercial fields in 2023/24, a season of extreme rainfall, and then compared to years exhibiting typical rainfall (2015-2018). Slug patches occurred in 27.2% of assessment visits to fields during 2023/24 compared to 96.4% in typical years, suggesting weather conditions leading to abnormally high soil moisture are significantly associated with the breakdown of slug spatial aggregation behaviour. Random forest models identified the weather predictors (precipitation, relative humidity, temperature) with the highest impact on slug distribution and relative abundance, with the assessment date and region also related to relative abundance. However, a complex of environmental parameters affects soil moisture content, and no statistically significant effects of individual weather predictors emerged. The results are discussed in relation to slug behaviour in the context of their impact on targeted slug treatments.

Glacier melting promotes methane emission via increased methanogenic activity in the foreland alpine meadow

Annual glacier melting alters hydrothermal conditions of the foreland alpine meadows, and causes significant fluctuations in methane (CH4) flux. Previously we found that Tibetan glacier foreland alpine meadow shifts to CH4 source from sink during the melting season, but the potential mechanisms remain unclear. This study, via combination of in-situ measurement of seasonal CH4 flux and survey of microbial species that may involve in CH4 metabolism, explores the causes of glacier melting on CH4 flux in a glacier foreland alpine meadow on Tibetan Plateau. We determined a pronounced CH4 emission (13.95 μg·m−2·h−1) in August (melting season) but CH4 uptake in June (−3.76 μg·m−2·h−1) and October (−17.77 μg·m−2·h−1), and 1.4-fold higher soil moisture in August than the other two months. This showed a direct correlation of CH4 flux with glacier melting increased soil water. Additionally, glacier melting caused more CH4 fluxes increase in hollows than in hummocks. Amplicon sequencing determined 126-fold higher abundance of mcrA, the methanogenic marker gene, in August than in June and October, and a higher relative abundance of a fungal phylum Mortierellomycota and syntrophic bacteria that convert the fatty acids, the degradation intermediates of organic complexes to CO2 and acetate, the methanogenic substrates like in August. However, no seasonal variation of pmoA, the marker gene of aerobic methanotrophs, was observed. It appears that glacier melting promotes the CH4 producing but not the consuming microorganisms, thus leading to increased CH4 emission. The findings of this work indicate that global warming resulted glacier melting would increase global CH4 emissions, and in turn worsens global warming, so an alarming positive feedback loop.

Financial Feasibility of Cucumber Cultivation in Polyhouse: A Case Study from Jaipur, Rajasthan, India

Cucumber (Cucumis sativus L.) is one of the popular vegetable crops grown broadly throughout the world. Cucumber crop grows successfully under conditions of high light, high humidity, high soil moisture, temperature, and fertilizers in the greenhouse. Aim of the Study: The present study was carried out to evaluate financial matrix such as payback period or net present value benefit cost ratio and internal rate of return of polyhouse by cucumber cultivation financial metrics evaluated, for 2023-24. Sampling Design: A multistage sampling design were used for the study of Cucumber cultivation in a polyhouse in the Jaipur district of Rajasthan for the 2023-24. Two tehsils were selected purposively based on the highest number of polyhouse from Jaipur district, namely Jhotwara and Jobner. A sample of 60 farmers were selected for the study from these two tehsils. Results: The finding of the study revealed that the payback period of polyhouse by cucumber cultivation, for small farmers was favorable after covering the subsidy i.e. 0.75 years. The net present worth of polyhouse for small farmers was ₹ 14222249.12, for 20-year expected life at a 7.5 percent discount rate. It was ₹ 13406743.12 for large farmers and ₹ 11164102.12 for assumed non-subsidized farmers. The benefit-cost ratio for the subsidized small farmer was 10.41 and it was 6.76 for the subsidized large farmer. The benefit-cost ratio for the assumed non-subsidized farmer was 3.44 for the cucumber cultivation in polyhouse. The Internal Rate of Return was 133 percent, 84 percent, and 36 percent for the small, large, and non-subsidized cucumber-cultivating polyhouse farmers. Thus, result of the study in all three condition shows profitability of polyhouse by cucumber cultivation.

Soil climate underpins year effects driving divergent outcomes in semi‐arid cropland‐to‐grassland restoration

AbstractConverting croplands to grasslands can restore ecosystem functions and services, but there is uncertainty about why some restoration treatments succeed and others do not. One likely explanation for variation in restoration outcomes is that interannual variation in the drivers of community assembly, or “year effects,” is often overlooked in restoration planning. Existing restoration strategies tailor species compositions of seed mixes according to long‐term climate means and hardiness zones. However, individual years typically deviate from average climate norms such that restoration activities may be better informed by recent conditions than by climate averages. We monitored a 109‐ha field in northeastern Colorado that was converted from a winter wheat‐fallow rotation to native perennial grassland via seeding. The same seed mix was used to seed 6 of 12,120‐m strips in 2013 (drier) and 6 in 2014 (wetter). In the strips seeded in 2013, only one native grass and one shrub species from the seed mix established widely, whereas in 2014, all native grasses established. Higher soil moisture preceding seed application was positively associated with perennial grasses, while rhizomatous grasses, shrubs, and introduced annuals were associated with other variables. After seeding, high summer soil moisture was positively associated with a rhizomatous C3 grass, while the planted C4 bunchgrasses were negatively associated with high summer soil moisture and positively associated with high fall soil temperatures. We found evidence of facilitatory interactions between grasses and forbs, as well as antagonistic interactions between native perennial grasses and non‐native annuals. Our results suggest that the conditions immediately before and after planting govern community assembly and leave a lasting legacy and should be considered in planning treatments. We suggest composing seed mixes that are tailored to commonly encountered extremes of temperature and moisture availability. Land managers can also use split‐seeding or repeated seeding approaches, within or between years as bet‐hedging strategies. The development of more flexible funding mechanisms could allow for regional go/no‐go climate thresholds to avoid wasting resources.