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Litter decomposition is a vital part of the carbon cycle and is thoroughly studied both in the field and with models. Although temporally and spatially limited, litterbag decomposition experiments are often used to calibrate and evaluate soil models, coupled to land models, that are intended for use on large scales. We used the microbially explicit soil decomposition model MIMICS+ to replicate two high-latitude litterbag decomposition experiments of different spatial and temporal scales. We investigated how well the model represented observed mass loss in terms of the controlling factors of climate and litter quality and their relative importance with time. In addition to default model forcing, we used measured and site-specific model-derived microclimatic variables (soil moisture and temperature), hypothesizing that this would improve model results. We found that MIMICS+ represented mass loss after 1, 3, and 6 years well across a climatic gradient of Canadian sites but had more variable results for 1-year mass loss across a climate grid in southern Norway. In terms of litter quality, the litter metabolic fraction had more influence on modeled mass loss than the carbon-to-nitrogen ratio of the litter. Using alternative microclimate sources led to up to 23 % more mass remaining and down to 22 % less mass remaining compared to the simulations using default model inputs. None of the input alternatives significantly improved results compared to using the default model setup. We discuss possible causes for our findings and suggest measures to better utilize short-term field experiments to inform microbially explicit decomposition models. [ABSTRACT FROM AUTHOR]

The relationship between plant aboveground biomass and diversity typically follows a unimodal pattern, showing a positive correlation in resource‐poor habitats and a negative correlation in resource‐rich environments. Precipitation is a crucial resource for both plant biomass and diversity in terrestrial ecosystems. However, the impact of precipitation changes on the relationship between plant biomass and diversity remains unclear. We conduct a water addition field experiment in a semiarid grassland and identify a unimodal relationship between plant biomass and species richness under ambient conditions. Water addition delays the declining phase of this unimodal curve and shift it upward compared to ambient conditions. Our meta‐analysis of water addition experiments conducted across major biomes worldwide (grassland, shrubland, desert, and forest) supports this finding, while water reduction does not alter the biomass–diversity relationship. Water addition increases biomass in all climate but only increases species richness in arid and semiarid climate. Similarly, water reduction decreases biomass in all climate but only reduces species richness in arid and semiarid climate. Species richness in dry subhumid and humid climate does not change significantly. Furthermore, our field experiment shows that water addition increases plant diversity while decreasing soil inorganic nitrogen levels. The increase in one resource, such as water, leads to the scarcity of another, such as nutrient, thus postponing the declining phase of the plant biomass–diversity relationship typically observed in resource‐rich habitats. Our research contributes to predicting the plant biomass–diversity relationship under changing precipitation conditions and highlights the complex interplay between water availability, nutrient level, and plant diversity. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Natural Hazards & Environment (JNHE) / Doğal Afetler ve Çevre Dergisi (DACD) is the property of Artvin Coruh University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Belowground parameters, e.g. root production and dynamics, play a pivotal role in evaluating the restoration degree of degraded grasslands. However, it remains unclear how roots respond to the combined restoration measures. To investigate root responses to different restoration treatments, a field experiment was conducted in a degraded Songnen meadow from 2013 to 2014. The treatments included: free grazing (FG), no ploughing (NP), only ploughing (OP), ploughing and fertilizer (PF), ploughing and mulching (PM), ploughing with fertilizer and mulching (PFM). Our results showed the seasonal dynamics pattern of roots was a unimodal pattern, which mainly was influenced by precipitation rather than restoration measures. The impacts of different restoration measures on root production were dependent on precipitation. In 2013, compared with FG, only PFM significantly increased root production by 242.34% (0–10 cm) and 90.8% (10–20 cm), which was mainly attributed to the increase of aboveground net primary production, soil moisture and root numbers. However, restoration measures had minor effects on root production in 2014. Root turnover ranged from 0.47 to 0.78 yr−1 and was not significantly changed by different restored measures. This is because the dominant annual species, Chloris virgata , exhibited relatively small changes in root turnover across different plots. Moreover, PFM improved soil conditions, leading to increased root lifespan and survival rate. Our results suggest that the combined measures are an effective way to accelerate belowground restoration in the degraded Songnen meadow. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the response to water deficit of different ecotypes and a variety of Lotus corniculatus on growth, productivity, and yield components, through seasonal times. A randomized block experimental design in a 2 × 5 factorial arrangement with three replicates was used. The first variation factor was soil moisture contents: field capacity (FC) was 26.5% ± 1.5, and water deficit (WD) was 85% of FC (22.5% ± 1.5); the second variation factor was the ecotypes identified with the codes 255301, 255305, 202700 and 226792 and of the variety Estanzuela Ganador. The best responses in plant cover and weight of accumulated fresh biomass were obtained in the ecotype 202700 under WD, with values of 1649.0 cm2 and 583.7 g plant−1, and 1661.2 cm2 and 740.1 g plant−1 in ecotype 255305 under FC. The leaf clover was the main component of yield during the summer and autumn seasons. Ecotype 226792 was tolerant to low temperatures during the winter season with better leaf development. Ecotype 202700 is the best option for forage clover production when water is limited, and ecotype 255305 when water is not resource-limited, but these preliminary conclusions need to be confirmed in field studies. [ABSTRACT FROM AUTHOR]

Developing potato varieties that have enhanced tolerance to soil moisture and high‐temperature stress could improve household food and nutrition security in drought and heat prone areas. A field experiment was conducted at two locations in Ethiopia to evaluate the effectiveness of some stress tolerance indices for the identification of drought and heat tolerant potato genotypes. Treatments consisted of two irrigation regimes and 23 potato genotypes. The experiment was laid out as a split‐plot design in a factorial arrangement with three replications. Irrigation regimes were the main plot factor and genotypes were the sub‐plot factor. Stress tolerance indices were calculated based on the tuber yield under stress (Ys) and non‐stress (Yp) conditions of each genotype. To determine the most desirable stress tolerant genotypes, all indices mean rank (R) and standard deviation of the R were computed. Genotypes Cl‐12(CIP‐304371.67), Cl‐13(CIP‐304383.80), Cl‐2(CIP‐302499.30), Cl‐34(CIP‐397079.6), Cl‐15(CIP‐304394.56), and Cl‐14(CIP‐304387.39) were found to have had top mean ranks and higher tuber yield under drought and heat stress. Ranking methods using all indices best determined desirable drought, heat, and combined drought‐heat tolerant genotypes that consistently coincided with the yield rank of genotypes under a given stress condition. This implies that these indices (stress tolerance index, geometric mean productivity, mean productivity, yield stability index, and tolerance index) could be used in combination to differentiate stress tolerances and susceptible potato genotypes. It is recommended that genotypes that exhibited higher drought and/or heat stress tolerance in this study could be further evaluated in drought and heat prone areas for the development of tolerant potato varieties. Core Ideas: Different potato genotypes (International Potato Center collections, improved varieties, and local cultivar) were evaluated for drought and heat.Promising genotypes tolerant to drought, heat, or combination of both were identified.Stress tolerance indices were used to identify drought and heat tolerant and susceptible genotypes.Stability of the genotypes under different environments were tested.Stress tolerance indices mean rank standard deviation used to group genotypes to stress tolerant and susceptible. [ABSTRACT FROM AUTHOR]

Backgrounds: Climate change is well-known to alter the structure and function of grassland ecosystems, and multifunctionality contributes to a comprehensive understanding of the impacts of climate change on ecosystem functions. Warming and humidification are predicted to be the climate change trend on the northeastern Qinghai-Tibetan Plateau. However, understanding of how long-term warming and increased precipitation affect ecosystem multifunctionality in alpine meadows is still limited. Methods: Here, we conducted an 8-year field experiment involving warming and increased precipitation in an alpine meadow to explore how warming, increased precipitation, and their interaction affect ecosystem multifunctionality. Results: The results indicated that increased precipitation had a positive effect on ecosystem multifunctionality. However, warming and the interaction of warming and precipitation had no significant effects on it. Warming decreased species richness and plant coverage. Increased precipitation enhanced aboveground carbon (C), nitrogen (N), and phosphorus (P) pools of plant community, and soil moisture, but decreased soil pH. Aboveground P and N pools of plant community and microbial biomass nitrogen (MBN) were important predictors of ecosystem multifunctionality. Conclusion: This study demonstrated long-term increased precipitation can enhance ecosystem multifunctionality by indirectly affecting the individual functions (aboveground P and N pools of plant community and MBN), soil moisture, and pH in an alpine meadow. These findings highlighted that increased precipitation is more critical than warming for enhancing ecosystem multifunctionality in semi-arid alpine meadows. [ABSTRACT FROM AUTHOR]

When estimating field‐scale average soil moisture from sensors measuring at fixed positions, spatial variability in soil moisture leads to "measurement errors" of the spatial mean, which may persist over time due to persistent soil moisture patterns resulting in autocorrelated measurement errors. The uncertainty of parameters that are derived from such measurements may be underestimated when they are assumed to be independent. Temporal autocorrelation models assume stationary random errors, but such error models are not necessarily applicable to soil moisture measurements. As an alternative, we propose a mechanistic error model that is based on the spatial variability of the water retention curve and assumes a uniform water potential. We tested whether spatial soil moisture variability and its temporal covariance could be predicted based on (1) mean soil moisture, (2) water retention variability, and (3) (co)variances of the van Genuchten parameters using a first‐order expansion of the retention curve. The proposed models were tested in a numerical and a field experiment. For the field experiment, in situ sensor measurements and water retention curves were obtained in a field plot. Both experiments showed that water retention variability under a uniform water potential is a good predictor for spatial soil moisture variability, and that soil moisture errors are strongly correlated in time and neglecting them would be an incorrect assumption. The temporal error covariance could be predicted as a function of the mean moisture contents at two observation times. Further research is required to assess the impact of these temporal correlations on soil moisture predictions. Core Ideas: Soil moisture is spatially variable, and spatial variations are correlated in time.Due to spatial variability, the estimated average soil moisture from a limited number of measurements is uncertain.The error of the spatial mean estimated from a limited number of sensors at fixed positions is correlated in time.A mechanistic error modeling approach is presented based on the spatial variability of the water retention curve.Such a model can predict measurement variability and error covariance in time as a function of mean soil moisture. [ABSTRACT FROM AUTHOR]

The relevance of the new forms of ecologically safe, stable in composition, in functional activity, biodegradable preparations development with a complex positive effect on plants remains high and the presented work is devoted to acquaintance with the generalized results of interdisciplinary studies for the effect on the system of soil (soil substitute)—cultivated plants by nanocompositions created based on carbon (water-soluble polyhydroxylated, carboxylated and amino acid derivatives of fullerene C60) nanostructures with additions of trace elements in certain concentration ratios. Based on the previously identified concentration ranges of the tested fullerene derivatives with a positive effect on plants when treating their seeds, introducing them into the soil, other root habitats and foliar exposure, their compositions with salts of trace elements were developed and in a series of vegetation and field experiments under controlled favorable conditions and when modeling oxidative stress caused by UV-B irradiation, deficiency of soil moisture, deficiency of nutrients, phytopathogens, as well as in the natural conditions of the Leningrad region, the main mechanisms of positive impact (regulatory on vital systems, adaptogenic, immunomodulatory, protective) of the created nanocompositions on plants and the prospects of their application in plant growing are shown. [ABSTRACT FROM AUTHOR]

The phenology has gained considerably more attention in recent times of climate change. The transition from vegetative to reproductive phases is a critical process in the life history of plants, closely tied to phenology. In an era of climate change, understanding how environmental factors affect this transition is of paramount importance. This study consisted of field surveys and a greenhouse experiment on the reproductive biology of Northern pipevine (Aristolochia contorta Bunge). During field surveys, we investigated the environmental factors and growth characteristics of mature A. contorta, with a focus on both its vegetative and reproductive phases. In its successful flowering during the reproductive phase, A. contorta grew under the conditions of 40% relative light intensity and 24% soil moisture content, and had a vertical rhizome. In the greenhouse experiments, we examined the impact of increased CO2 concentration on the growth and development of 10-year-old A. contorta, considering the effect of rhizome direction. Planted with a vertical rhizome direction, A. contorta exhibited sufficient growth for flowering under ambient CO2 concentrations. In contrast, when planted with a horizontal rhizome direction, it was noted to significantly impede successful growth and flowering under elevated CO2 concentrations. This hindered the process of flowering, highlighting the pivotal role of substantial vegetative growth in achieving successful flowering. Furthermore, we observed a higher number of underground buds and shoots under the conditions of elevated CO2 concentration and a horizontal rhizome direction instead of flowering. Elevated CO2 concentrations also exhibited diverse effects on mature A. contorta's flower traits, resulting in smaller flower size, shorter longevity, and reduced stigma receptivity, and pollen viability. The study shed light on elevated CO2 concentrations can hinder growth, potentially obstructing sexual reproduction and diminishing genetic diversity. [ABSTRACT FROM AUTHOR]

We review results from field experiments that simulate drought, an ecologically impactful global change threat that is predicted to increase in magnitude, extent, duration and frequency. Our goal is to address, from primarily an ecosystem perspective, the questions 'What have we learned from drought experiments?' and 'Where do we go from here?'.Drought experiments are among the most numerous climate change manipulations and have been deployed across a wide range of biomes, although most are conducted in short‐statured, water‐limited ecosystems. Collectively, these experiments have enabled ecologists to quantify the negative responses to drought that occur for most aspects of ecosystem structure and function. Multiple meta‐analyses of responses have also enabled comparisons of relative effect sizes of drought across hundreds of sites, particularly for carbon cycle metrics. Overall, drought experiments have provided strong evidence that ecosystem sensitivity to drought increases with aridity, but that plant traits associated with aridity are not necessarily predictive of drought resistance. There is also intriguing evidence that as drought magnitude or duration increases to extreme levels, plant strategies may shift from drought tolerance to drought escape/avoidance.We highlight three areas where more drought experiments are needed to advance our understanding. First, because drought is intensifying in multiple ways, experiments are needed that address alterations in drought magnitude versus duration, timing and/or frequency (individually and interactively). Second, drivers of drought may be shifting—from precipitation deficits to rising atmospheric demand for water—and disentangling how ecosystems respond to changes in hydrological 'supply versus demand' is critical for understanding drought impacts in the future. Finally, more attention should be focussed on post‐drought recovery periods since legacies of drought can affect ecosystem functioning much longer than the drought itself.We conclude with a call for a fundamental shift in the focus of drought experiments from those designed primarily as 'response experiments', quantifying the magnitude of change in ecosystem structure and function, to more 'mechanistic experiments'—those that explicitly manipulate ecological processes or attributes thought to underpin drought responses. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Purpose: Nitrogen (N) enrichment through either artificial N application or atmospheric N deposition often increases ecosystem aboveground net primary productivity (ANPP). Therefore, results from N addition experiments have been used to assess the effects of atmospheric N deposition on ecosystems. However, the frequency of atmospheric N deposition is higher than that of artificial N addition. Whether the frequency of N addition alters the long-term response of ecosystem ANPP remains unclear. Methods: We conducted a N addition frequency experiment from 2010 in a temperate grassland, northern China. Plant community ANPP was collected in 2019 and 2020, and soil physicochemical properties were measured in 2020. Results: Plant community ANPP was significantly enhanced by N addition, whereas these increments declined with the frequency of N addition. The responses of the grasses ANPP were similar to those of the plant community ANPP. Forbs ANPP was not significantly altered. Meanwhile, soil ammonium and nitrate (NO3−–N) concentrations decreased with increasing N addition frequency, while the soil water content (SWC) and pH were similar among the frequencies of N addition. Regardless of the frequency of N addition, SWC and soil NO3−–N jointly promoted grasses ANPP, ultimately increasing the plant community ANPP. Conclusion: Our findings demonstrate that the frequency of N addition affects plant community biomass production through altering soil nitrate concentration in the semi-arid grassland. Therefore, this study illustrates that a higher frequency of N addition is more suitable for assessing the long-term impacts of atmospheric N deposition on ecosystems. [ABSTRACT FROM AUTHOR]

In plantation areas, soil conditions affect the crop’s quality. One of the crucial elements in the soil for plant survival is soil water content (SWC). Radar system has advantages that can be implemented for measuring SWC in plantation areas. A radar system operates by utilizing electromagnetic waves to obtain the dielectric characteristics of the soil. However, the presence of tea plants has become an obstacle to the radar wave propagation toward the soil layer. Reflected signal, which is influenced by the presence of vegetation, makes the estimation of SWC inaccurate. Consequently, the estimation of SWC needs to consider the vegetation’s effect. This study uses an FMCW radar system, which operates at a frequency of 24 GHz. A layer medium propagation model is proposed in this study to prove the relationship between the reflected signal and the SWC. The reflection coefficient extracted from the radar signal is used to estimate the SWC. The vegetation propagation constant was obtained from the average field measurement results. The gravimetric method is used to validate the SWC estimation in vegetation’s presence using the radar system. The results of the field experiments showed that the proposed method succeeded in estimating the SWC by considering the presence of vegetation with an average error of 3.57%. The proposed method has the potential to be applied to plantation areas. [ABSTRACT FROM AUTHOR]

In the study carried out in 8 villages and 27 cotton parcels of Mardin Province Artuklu and Kızıltepe Districts, ambient humidity and temperature values in the field were measured and recorded with data logger devices at 6-hour intervals. The data obtained from the data loggers were analyzed with the Sentinel-1 and Landsat-8 satellite data prepared in the Google Earth Engine (GEE) environment and the relationship between them was examined. While a high correlation was found between ambient humidity (ON) values and VV (R²=0.63), VV-VH (R²=0.68), Soil Moisture Index (SMI) (R²=0.84), low correlation was found between VV (R²=0.51), VH (R²=0.06), VV-VH (R²=0.49), LEE_VH (R²=0.09), LEE_VV (R²=0.49), GAMMA_VH (R²=0.11, GAMMA_VV (R²=0.08), MALIK_VH (R²=0.08), MALIK_VV (R²=0.49), SMI (R²=0.50). A high correlation was found between ambient temperature (OS) values and Land Surface Temperature (LST) (R²=0.80**). However, a low correlation was found between ambient temperature (OS) and VV (R²=0.51), VH (R²=0.06), VV-VH (R²=0.49), LEE_VH (R²=0.09), LEE_VV (R²=0.49), GAMMA_VH (R²=0.11, GAMMA_VV (R²=0.08), MALIK_VH (R²=0.08), MALIK_VV (R²=0.49), SMI (R²=0.50). In large-scale field studies; VV, VV-VH and SMI index in estimating ambient humidity values; as it was concluded that the LST band can be used with high accuracy in estimating ambient temperature values, it has been recommended. [ABSTRACT FROM AUTHOR]

Past studies described several dominant factors responsible for minimum runoff-generating areas (MRGAs) which are seldom backed by field observations. Here, soil moisture and runoff data for 45 rainfall events were collected from a small (21.62 ha) agricultural watershed in Ontario, Canada, using a remotely operated wireless sensor network system. The relationship developed between MRGA and basin moisture index (M) indicated that MRGAs are insensitive up to the threshold M value of 25 cm. A higher M leads to an exponential increase in the MRGA. Various factors (e.g. rainfall amount) affecting the spatiotemporal variability of MRGA were then identified. Statistical analyses (e.g. F-test) indicated a strong seasonal influence and showed that MRGA during spring, summer, and fall seasons was 34.3%, 8.0%, and 13.6%, respectively. The relationship of MRGA with rainfall amount, initial soil moisture content and rainfall intensity was the strongest for the summer season followed by fall and then spring. [ABSTRACT FROM AUTHOR]

Available soil moisture is thought to be the limiting factor for most ecosystem processes in the cold polar desert of the McMurdo Dry Valleys (MDVs) of Antarctica. Previous studies have shown that microfauna throughout the MDVs are capable of biological activity when sufficient soil moisture is available (~2–10% gravimetric water content), but few studies have attempted to quantify the distribution, abundance, and frequency of soil moisture on scales beyond that of traditional field work or local field investigations. In this study, we present our work to quantify the soil moisture content of soils throughout the Fryxell basin using multispectral satellite remote sensing techniques. Our efforts demonstrate that ecologically relevant abundances of liquid water are common across the landscape throughout the austral summer. On average, the Fryxell basin of Taylor Valley is modeled as containing 1.5 ± 0.5% gravimetric water content (GWC) across its non-fluvial landscape with ~23% of the landscape experiencing an average GWC > 2% throughout the study period, which is the observed limit of soil nematode activity. These results indicate that liquid water in the soils of the MDVs may be more abundant than previously thought, and that the distribution and availability of liquid water is dependent on both soil properties and the distribution of water sources. These results can also help to identify ecological hotspots in the harsh polar Antarctic environment and serve as a baseline for detecting future changes in the soil hydrological regime. [ABSTRACT FROM AUTHOR]

In farmland ecosystems, phosphorus and water have crucial roles. To elucidate the effects of phosphorus concentration and water management on arbuscular mycorrhizal fungi (AMF), field experiments were conducted in a farmland ecosystem (China). We examined the effects of different treatments, including drought and normal phosphorus, normal water and normal phosphorus, drought and low phosphorus, and normal water and low phosphorus, on the AM fungal biomass, diversity, and community. Results showed great differences in the AMF under different water and phosphorus concentrations. When under a suitable drought treatment, the AMF became more abundant and more conducive to plant growth. The abundance of AMF varied with different phosphorus treatments, and the abundance of AMF in low-phosphorus treatments was higher, which is more suitable for plant growth. In conclusion, as water and phosphorus concentrations change, the community structure of AMF constantly changes. Only under the appropriate water and phosphorus concentration processing can AMF play its role well. Understanding the influence of different phosphorus concentrations and the moisture contents of AMF can play a role in the agricultural production of AMF, and it can also provide improved theoretical support. [ABSTRACT FROM AUTHOR]

The effect of key ecological and anthropic factors on the recruitment of the common yew (Taxus baccata L.) in Sardinia (Italy) has been analyzed. After bibliographic and cartographic research, followed by field surveys, we found 232 sites where yew grows in Sardinia (as opposed to 69 previously reported in the literature). Among them, we selected 40 sites, located in 14 different mountain chains, characterized by a number of individuals ranging from 11 to 836 adult yews with an average diameter at breast height (DBH) from 13 to 130 cm. By means of generalized linear modeling, we investigated and weighted the effect of ecological, structural, and anthropic factors on the amount of T. baccata recruitment. Our analyses showed that stand recruitment was positively correlated to shrub cover and soil moisture. In particular, shrub cover had a stronger effect, clearly showing that a thicker shrub layer, both bushy and/or spiny, corresponded to a higher number of yew seedlings and saplings. Secondarily, moister sites had a higher number of seedlings and saplings, showing that habitat suitability improved with higher humidity. On the contrary, recruitment was negatively correlated to browsing (both from livestock and wild animals). Our data confirm that the presence of a protective layer of shrubs is a crucial factor for seedling and sapling survival, mostly in relation to protection from summer drought and the browsing of large herbivores. Finally, guidelines for the conservation and restoration of T. baccata communities, referred to as the EU priority habitat 9580* (Mediterranean Taxus baccata woods), have been outlined. [ABSTRACT FROM AUTHOR]

Fractures are the dominant conditions for rainfall infiltration into slopes, which can aggravate the instability of landslides. However, few studies have been conducted to analyze in detail the instability and deformation characteristics of creeping landslides with fractures. In view of this, this study investigated a landslide in Fu'ao Village, Wencheng County, Zhejiang Province in China to determine how fractures affect landslide deformation and instability during heavy rainfall through an in situ simulation experiment. In the experiment, three consecutive days of rainfall were set up based on Typhoon Megi in 2016, and two conditions were simulated, namely, rainfall + water filling fractures and rainfall + filled fractures (also referred to as the first and second conditions, respectively). The changes in the volumetric water content (VWC), pore water pressure (PWP), and deep displacement of the landslide at a depth of less than 5 m under the two conditions were observed using field monitoring instruments. The simulation results were as follows: (1) The volumetric water content of the shallow soil showed a more sensitive time-varying response to rainfall, while that of the soil at a depth of more than 200 cm showed a lagged response to rainfall, with a lag of about 10 h, which decreased significantly in the case of the unfilled fractures; (2) Under the first condition, the pore water pressure at different depths showed almost the same changing amplitude of 5 kPa or less. Under the second condition, the pore water pressure increased significantly with depth during the rainfall, with the changing amplitude reaching 30 kPa; (3) The displacement of the borehole equipped with the inclinometers near the front of the slope was higher than that at the borehole equipped with the inclinometers near the rear of the slope. The displacement under the first condition was up to 6 mm, which was significantly greater than that under the second condition. Therefore, fractures have significant effects on the instability of landslides induced by typhoon-triggered rainstorms, and one important measure to prevent and control this type of landslides is to fill fractures in the landslides in time. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Groundwater recharge is a key component of the hydrological cycle, yet its direct measurement is complex and often difficult to achieve. An alternative is its inverse estimation through a combination of numerical models and transient observations from distributed soil water monitoring stations. However, an often neglected aspect of this approach is the effect of model predictive uncertainty on simulated water fluxes. In this study, we made use of long-term soil water content measurements at 14 locations from the Austrian soil water monitoring program to quantify and compare local potential groundwater recharge rates and their temporal variability. Observations were coupled with a Bayesian probabilistic framework to calibrate the HYDRUS-1D model and assess the effect of model predictive uncertainty on long-term simulated recharge fluxes. Estimated annual potential recharge rates ranged from 44 to 1319 mm a -1 with a relative uncertainty (95 % interquantile range/median) in the estimation of between 1 % and 39 %. Recharge rates decreased longitudinally, with high rates and lower seasonality at western sites and low rates with high seasonality and extended periods without recharge at the southeastern and eastern Austrian sites. Higher recharge rates and lower actual evapotranspiration were related to sandy soils; however, climatic factors had a stronger influence on estimated potential groundwater recharge than soil properties, underscoring the vulnerability of groundwater recharge to the effects of climate change. [ABSTRACT FROM AUTHOR]

This work presents results from a field experiment which was focused on the impact of the drought period on microbial activities in rhizosphere and non-rhizosphere soil. To demonstrate the effect of drought, the pot experiment lasted from 2012 to 2015. Fifteen lysimeters (plastic containers) were prepared in our area of interest. These lysimeters were filled with the subsoil and topsoil from this area and divided into two groups. The first group consisted of two variants: V1 (control) and V2 (84 kg N/ha), which were not stressed by drought. The second group consisted of three variants, V3 (control), V4 (84 kg N/ha), and V5 (84 kg N/ha + 1.25 L lignohumate/ha), which were stressed by drought every year of the experiment for 30 days. Changes in the soil moisture content caused by drought significantly affect the growth of Deschampsia caespitosa L., the microbial activity, and the soil's capacity to retain nutrients. The measured basal respiration and dehydrogenase activity values confirm the significant effect of drought on microbial activity. These values were demonstrably higher in the period before drought simulation by more than 60%. On the other hand, significant differences between microbial activities in the rhizosphere and non-rhizosphere soil were not found. We did not find a clear effect of drought on the formation of soil water repellency. [ABSTRACT FROM AUTHOR]

Field experiments are subjected to spatial variability due to factors such as soil moisture, fertility, pH, and structure, as well as the pressure of diseases and pests. Soybean yields are highly variable across fields. Controlling spatial variability could decrease the risk of erroneous inferences in breeding trials. This study aims at evaluating the spatial variability of furrow-irrigated soybean for seed yield, wilting, and maturity under four different irrigation levels. The field experiment was conducted in four environmzents (location-year combination). A total of 165 soybean lines of similar relative maturity (maturity group 5) along with commercial checks were planted in an augmented strip plot design. Irrigation treatment decisions were triggered using an atmometer based on a threshold at a designated growth stage. Data were analyzed via Analysis of Variance as a linear mixed model using a blocking structure (block model) and spatial covariances using range and column. Two different spatial models were used: exponential and Gaussian. Results showed that the spatial models displayed better data fitting (lower AIC and/or BIC) than the block model in each different irrigation level across different environments and traits. Indeed, genotype ranking for seed yield was different between the block model and the best spatial model, suggesting that spatial adjustment may be necessary for soybean breeding operations under furrow irrigation. Further validation in a breeding yield trial demonstrated similar results of the effectiveness in terms of AIC and/or BIC of the spatial model compared to the block model for soybean seed yield. [ABSTRACT FROM AUTHOR]

Green stem disorder (GSD), characterized by delayed stem senescence during seed maturation, complicates harvesting in soybean production. Although GSD is associated with a sink – source imbalance, a rapid and precise evaluation of GSD has not been established. In sink-limited soybean plants, vegetative storage protein (VSP) accumulates. In this study, pot and field experiments were conducted to reevaluate the relationship between GSD, sink – source imbalance caused by soil moisture change, and VSP accumulation as a possible indicator of GSD in Kyoto, Japan over two years. Drought treatment for four weeks from R1 (beginning flowering), R3 (beginning pod), or R5 (beginning seed) growth stage in pots using the short growth-period cultivar Yukihomare reduced sink size in both years, but reduced relative sink mass (pod weight/shoot weight) and increased GSD severity only in 2017, suggesting that sink-source imbalance, affected by soil moisture, can induce GSD. Soil moisture change from around R3 or R5 to maturity in fields using trench-filled or unfilled water tended to change GSD severity but not VSP accumulation in the uppermost fully expanded leaves from R5 (2018) or 15 days before R5 (2019) to 28 days after R5. GSD and VSP responses, however, differed between the two contrasting cultivars, Tachinagaha and Touhoku 129, suggesting the potential usability of VSP for GSD evaluation. [ABSTRACT FROM AUTHOR]

Mixed plantations have emerged as a promising approach to improve soil health and contribute to sustainable land management. Despite the numerous field experiments conducted so far, there is no clear consensus on the impacts of mixed plantations on soil physicochemical properties due to the wide range of findings. This meta-analysis synthesizes findings from 252 studies across China to provide a comprehensive evaluation of these effects within both monoculture and mixed plantation contexts. We quantified the effects of mixed versus monoculture plantations on key soil physicochemical properties, including soil moisture content, bulk density, pH, and nutrient indicators such as soil organic matter, total nitrogen, available nitrogen, total phosphorus, available phosphorus, total potassium, and available potassium. Additionally, we identified the primary drivers of these changes, focusing on factors such as initial soil pH, elevation, mixing proportion, and plantation age. Compared to monocultures, mixed plantations significantly enhanced key soil physicochemical properties, with available potassium, soil organic matter, and available phosphorus each increasing by 18 %. However, soil pH only increased by 1 %. The magnitude of the response varied significantly across different analytes, influenced by factors including initial soil pH, elevation, mixing proportion, and plantation age, underscoring the complex interactions that affect soil dynamics under different plantation management strategies. • Mixed plantations significantly reduce soil bulk density. • Mixed plantations increased soil organic matter (SOM) by 44.91 %. • Mixed plantations increased soil available potassium and phosphorus by 17.72 % and 17.64 %. • A positive correlation between SOM and soil moisture and total N has been identified. [ABSTRACT FROM AUTHOR]

• Quantified the effect of discharge on erosion and morphology characteristics. • The impact of rill depth on cumulative sediment yield was greater than that of rill width. • Unit stream power can be used to describe dynamic mechanisms of eroding rill. • Rill erodibility parameters for eroded rill were 0.574 × 10−3 s m−1. Field experimental studies on the erosion characteristics and dynamic mechanisms of rills that have already eroded (eroded rills) when rainfall occurs are limited, especially compared to the dynamics of those rills that have experienced erosion for the first time (eroding rills). The field runoff scouring experiments included two intermittent sub-experiments: flow discharge of 9, 13, 17, 21, 25, and 29 L min−1 (E1) with a scour duration of 60 min and flow discharge of 6, 9, 12, 15, 18, and 21 L min−1 (E2) with a scour duration of 10 min. Two antecedent soil moistures (15 % and 25 %) were used for the runoff plot (18 × 1 m) before starting E1. The results from E1 indicated that flow discharge and antecedent soil moisture increased the average runoff rate (19.46 % with discharge, 4.63 % with soil moisture), soil loss rate (63.94 % with discharge, 58.80 % with soil moisture), rill width (16.49 % with discharge, 4.66 % with soil moisture) and rill depth (13.40 % with discharge, 6.60 % with soil moisture). The average flow velocity varied from 0.231 to 0.344 m s−1, and the flow regimes were basically subcritical turbulent flows. The impact of rill depth on cumulative sediment yield was greater than that of rill width. Moreover, the critical values of flow velocity, shear stress, stream power, unit stream power, and unit energy under eroded rills were 0.183 m s−1, 7.532 Pa, 1.278 W m−2, 0.032 m s−1 and 0.007 m from E2, respectively, and the rill erodibility parameters for E1 and E2 were 0.252 × 10−2 and 0.574 × 10−3 s m−1, respectively. The flow unit stream power and stream power could be effectively used to simulate the dynamic mechanism under conditions E1 and E2, respectively. The study aids in understanding the dynamic mechanism of rill erosion under intermittent rainfall conditions in the field. [ABSTRACT FROM AUTHOR]

Background and aims: Global wheat production is under threat due to climate change, specifically heat and drought and their combination. This study aims to address the root trait responses of heat-tolerant wheat genotypes to drought.The variability in root traits of CIMMYT wheat lines, which were previously developed for heat stress tolerance (HTWL), was evaluated alongside 10 Pakistani-approved varieties under three cultivation conditions and soil moisture levels.Our findings revealed that the plasticity of the wheat root system is highly pronounced, with rhizosphere conditions exerting a more substantial influence (5–49%) than the genotypic response (1–14%). Furthermore, in the hydroponic and pot system, we noted higher maximum-root length (1.5–1.8 fold) and root-to-shoot ratio (3.4–10.6 fold) as compared to field condition, while the root biomass was substantially higher in the field trial (3-57 fold). Nonetheless, persistent drought conditions exerted contrasting impact with reduction in most of the traits except specific root length and harvest index which were increased under drought.The variation in root traits against drought indicates the potential for the development of improved genotypes that can withstand multiple stresses. Furthermore, it is crucial to consider rhizosphere conditions when selecting genotypes, as the plasticity of wheat roots may lead to misinterpretations if rhizosphere conditions are disregarded. Root dry weight and root-to-shoot ratio are more stable traits as compared to maximum root length and specific root length. It is recommended to evaluate a broader range of rhizosphere conditions to select tolerant genotypes.Methods: Global wheat production is under threat due to climate change, specifically heat and drought and their combination. This study aims to address the root trait responses of heat-tolerant wheat genotypes to drought.The variability in root traits of CIMMYT wheat lines, which were previously developed for heat stress tolerance (HTWL), was evaluated alongside 10 Pakistani-approved varieties under three cultivation conditions and soil moisture levels.Our findings revealed that the plasticity of the wheat root system is highly pronounced, with rhizosphere conditions exerting a more substantial influence (5–49%) than the genotypic response (1–14%). Furthermore, in the hydroponic and pot system, we noted higher maximum-root length (1.5–1.8 fold) and root-to-shoot ratio (3.4–10.6 fold) as compared to field condition, while the root biomass was substantially higher in the field trial (3-57 fold). Nonetheless, persistent drought conditions exerted contrasting impact with reduction in most of the traits except specific root length and harvest index which were increased under drought.The variation in root traits against drought indicates the potential for the development of improved genotypes that can withstand multiple stresses. Furthermore, it is crucial to consider rhizosphere conditions when selecting genotypes, as the plasticity of wheat roots may lead to misinterpretations if rhizosphere conditions are disregarded. Root dry weight and root-to-shoot ratio are more stable traits as compared to maximum root length and specific root length. It is recommended to evaluate a broader range of rhizosphere conditions to select tolerant genotypes.Results: Global wheat production is under threat due to climate change, specifically heat and drought and their combination. This study aims to address the root trait responses of heat-tolerant wheat genotypes to drought.The variability in root traits of CIMMYT wheat lines, which were previously developed for heat stress tolerance (HTWL), was evaluated alongside 10 Pakistani-approved varieties under three cultivation conditions and soil moisture levels.Our findings revealed that the plasticity of the wheat root system is highly pronounced, with rhizosphere conditions exerting a more substantial influence (5–49%) than the genotypic response (1–14%). Furthermore, in the hydroponic and pot system, we noted higher maximum-root length (1.5–1.8 fold) and root-to-shoot ratio (3.4–10.6 fold) as compared to field condition, while the root biomass was substantially higher in the field trial (3-57 fold). Nonetheless, persistent drought conditions exerted contrasting impact with reduction in most of the traits except specific root length and harvest index which were increased under drought.The variation in root traits against drought indicates the potential for the development of improved genotypes that can withstand multiple stresses. Furthermore, it is crucial to consider rhizosphere conditions when selecting genotypes, as the plasticity of wheat roots may lead to misinterpretations if rhizosphere conditions are disregarded. Root dry weight and root-to-shoot ratio are more stable traits as compared to maximum root length and specific root length. It is recommended to evaluate a broader range of rhizosphere conditions to select tolerant genotypes.Conclusions: Global wheat production is under threat due to climate change, specifically heat and drought and their combination. This study aims to address the root trait responses of heat-tolerant wheat genotypes to drought.The variability in root traits of CIMMYT wheat lines, which were previously developed for heat stress tolerance (HTWL), was evaluated alongside 10 Pakistani-approved varieties under three cultivation conditions and soil moisture levels.Our findings revealed that the plasticity of the wheat root system is highly pronounced, with rhizosphere conditions exerting a more substantial influence (5–49%) than the genotypic response (1–14%). Furthermore, in the hydroponic and pot system, we noted higher maximum-root length (1.5–1.8 fold) and root-to-shoot ratio (3.4–10.6 fold) as compared to field condition, while the root biomass was substantially higher in the field trial (3-57 fold). Nonetheless, persistent drought conditions exerted contrasting impact with reduction in most of the traits except specific root length and harvest index which were increased under drought.The variation in root traits against drought indicates the potential for the development of improved genotypes that can withstand multiple stresses. Furthermore, it is crucial to consider rhizosphere conditions when selecting genotypes, as the plasticity of wheat roots may lead to misinterpretations if rhizosphere conditions are disregarded. Root dry weight and root-to-shoot ratio are more stable traits as compared to maximum root length and specific root length. It is recommended to evaluate a broader range of rhizosphere conditions to select tolerant genotypes. [ABSTRACT FROM AUTHOR]

Oil spills have become a threat to the ecosystem by releasing the petroleum hydrocarbons and gained substantial public concern in the Chennai coast. This study assesses the effectiveness of bioremediation and its impact on the environment due to remedial operations in the site. Soil and water samples were collected from the bio remediation site at regular intervals of the pit from the topsoil and 20 cm below the ground level from June 2017 to Nov 2019. The average TPH concentration present in the bottom and top soil of bioremediation pit were vary in the range of 21,238.4–46,600 mg/kg and 17577–26910 mg/kg. Central Pollution Control Board (CPCB) allowable limit for TPH concentration present in the soil should be 5000 mg/kg. We have also observed that the mixing was not uniform in the pit and major amount of oil has been penetrated deep inside the soil. Results on gravimetric analysis showed that there was still a large amount of untreated long-chain hydrocarbons are there in the pit. From the results, we can conclude that nC30-nC40 and lower carbon range alkane intermediates have to be treated with additional treatment like thermal smoldering and pyrolysis. [Display omitted] [ABSTRACT FROM AUTHOR]

Coated urea can improve nitrogen use efficiency (NUE) for crops, while it is also identified as a potential source of microplastics (MPs). Organic fertilizer (OF) shows potential to promote MPs degradation. However, little is known about the influence of OF incorporated with coated urea on MPs accumulation, NUE, and gaseous N loss (NH 3 and N 2 O) in paddies. Therefore, a field experiment was conducted to address this gap, with five fertilization treatments, viz., urea (un-coated) with full rates (U), coated urea with full rates (CU), coated urea with reduced rates (RCU), 70 % coated urea blending 30 % urea with reduced rates (RBU), and RBU blending OF (ORBU). The results showed that, compared with U, the CU increased the number of MPs by 62.2–117.4 %. The ORBU significantly reduced the weight of MPs by 53.2 % through decreasing large-particle size. Additionally, the ORBU enhanced the effect of CU on increasing grain yield and NUE, mainly due to the improvement in the yield components and N uptake. The distribution of NH 4 + in water and soil was a major factor driving NH 3 and N 2 O emissions. The ORBU elevated activities of N-assimilation enzymes, decreased water NH 4 + and NH 3 emissions, and increased soil NH 4 + and ammonium-oxidation bacteria and (nirK + nirS)/ nosZ , ultimately increased soil N 2 O emissions compared with RBU. However, the reduction in NH 3 much outweighed the increase in N 2 O emissions. In conclusion, this study highlighted coated urea as a source of MPs pollution, emphasized OF amendment as a strategy to diminish MPs accumulation, and found that OF incorporated with coated urea could increase grain yield and N uptake of rice while mitigating gaseous N loss in paddies. [Display omitted] • Coated urea application increased microplastics (MPs) in a dose-dependent. • Organic fertilizer amendment reduced the MPs from coated urea. • Organic fertilizer amendment decreased water NH 4 + and NH 3 emissions. • Organic fertilizer amendment increased N 2 O emissions by enhancing N-cycling genes. • The reduction in NH 3 much outweighed the increase in N 2 O emissions. [ABSTRACT FROM AUTHOR]

Drip irrigation is a worldwide water-saving irrigation technology and benefits crop production. Yet, the emitter clogging is still a crucial problem for application. Recently, ceramic emitter (CE) with porous flow path was proposed as an alternative to the plastic drip emitter for continuous irrigation. However, there is still a gap in the estimation of the CE clogging degree. To address this, we conducted the field experiment in Tongxin, Yinchuan and Qinghai with the aim of the determination of the suitable discharge ratio variation (Dra) threshold of CEs under different climate conditions by using the AquaCrop model and segmented linear regressions. The results showed that there was a determined Dra threshold for soil water content (SWC), wolfberry canopy cover, biomass and yield in three experimental sites by 53.55 % - 54.62 %, 57.11 % - 65.94 %, 55.58 % - 64.30 % and 51.76 % - 61.23 %, respectively. Moreover, the Dra thresholds decreased with the precipitation increased in different climate conditions. Furthermore, we determined the Dra threshold of CEs was 56.1±5.3 % for wolfberry production, which was remarkably lower than the international standard of emitter clogging level by 75 %. Our study provides scientific insight to determine the clogging thresholds of CEs and further generalizes this technique in the irrigation science area. • Discharge ratio variation (Dra) threshold for ceramic emitter (CE) was determined. • AquaCrop model and segmented linear regressions were used to assess Dra threshold. • Dra thresholds of CEs were changed under different climate conditions. • A determined Dra threshold of CEs by 56.1±5.3 % was defined for wolfberry. [ABSTRACT FROM AUTHOR]

• Soil moisture fluctuations invert saturated hydraulic conductivity (K s) • Multi-frequency fluctuations contain non-redundant information, benefiting K s inversion. • Inversion algorithm can accommodate nonlinear data based on VG model. Soils are heterogeneous at multiple scales. Estimates of spatially varying saturated hydraulic conductivity (K s) of soils dictate the resolution of modeling water flux based on the Richardson-Richards equation (RRE), but direct measurements of K s everywhere in a field are practically impossible. As a result, this study develops an inverse approach to estimate spatially varying K s utilizing soil moisture observations driven by periodic weather variability at different frequencies. Using a numerical solution to vertical, one-dimensional RRE based on Gardner-Kozeny (GK) model in a heterogeneous soil with periodic flux, we investigate the spatial cross-correlation between K s and observations (the amplitude or phase shift) of soil moisture fluctuation at different frequencies without high computational cost in the conventional time-domain model. These correlation patterns vary with the spatial location and frequency, suggesting that soil moisture fluctuations at different frequencies at one monitoring location carry non-redundant information about the heterogeneous distribution of K s. Guided by cross-correlation maps, several inverse experiments reveal the effectiveness of multi-frequency data of soil moisture fluctuation for mapping the heterogeneous distribution of K s. Monte Carlo simulations suggest that multi-frequency data can provide non-redundant and useful information about the estimation of heterogeneous K s. Synthetic data based on a commonly-applied nonlinear van Genuchten-Mualem (VG) model is then tested in our inversion algorithm. The results indicate that the spatial pattern of the inverted GK K s is very similar to that of the VG K s , although these two parameters are inherently not identical since they are used in two different models. In addition, the inverted GK K s can successfully predict the soil moisture fluctuation of frequencies that were not used in the inversion. Despite having no field experiments to validate this model, we believe this is the first attempt to conduct frequency-domain inverse modeling in vadose zone hydrology using soil moisture fluctuation. [ABSTRACT FROM AUTHOR]

• Development of reference curves to describe temporal variation in soil properties. • Two-step model is proposed to obtain soil hydraulic properties at any time step. • Reduce need for extensive field measurements and numerical computations. • The developed model is validated with numerical and experimental data. Accurate knowledge of temporal variability in soil hydraulic properties (SHPs) can improve the prediction capability of flow and transport models. Lab and field measurements for determining SHPs at multiple timescales are expensive and time-consuming. Further, the existing Fokker-Plank equation (FPE) based numerical and analytical models for describing temporal variation in SHPs require parameterization. In this study, a scaling model is proposed to describe temporal variation in SHPs of four different soils. As field studies related to temporal variation in SHPs are limited, first synthetic temporally varying SHPs, soil water characteristic curves and hydraulic conductivity curves are generated using the analytical solution of FPE. Functional normalization approach is then used to develop reference curves and to obtain scale factors at different time-steps. The time-varying scale factors and the initial SHPs are related by two-step regression equations. The reference curves and the regression equations together can be used to estimate SHPs at any time given the initial SHPs. The developed model is validated using a 5-fold cross validation method and with experimental data at two study sites. The average percentage error in predicted van Genuchten parameters (θ s , n and K sat) except for α are mostly less than 10 %. The performance of the proposed model is comparable to that of FPE analytical model for experimental data. The proposed method holds promise for describing temporal variation in SHPs using only the initial SHPs. [ABSTRACT FROM AUTHOR]

Reinforced concrete is a commonly used material for constructing basements in low-rise buildings or residential houses in Canada, and as the use of cross-laminated timber (CLT) advances, the door to think of an alternative basement material to offset greenhouse gas emissions associated with reinforced concrete is open. However, the evaluation of CLT durability in below-grade environments, specifically concerning moisture and mould development, remains an unexplored field in research. Hence, this paper aims to analyze CLT's moisture response and mould growth risk in below-grade environments using field and laboratory experiments. A laboratory experiment was carried out to test a waterproofing membrane solution selected to compose the wall assembly in the field experiment. A large-scale experimental CLT basement was built at a cohesive soil site in Edmonton, Canada. The field experiment involved monitoring the relative humidity, temperature, and soil volumetric water content of the CLT panels, which measure 3 m by 6 m in plan and 2 m deep. Data was collected for an extended period from June 2022 to July 2023. The VVT model, developed by Hukka and Viitanen (1999) and updated by Viitanen et al., 2011 to estimate the mould growth level, was used to predict the risk of mould growth. The laboratory experiment showed that the waterproofing membrane is suitable for protection against moisture in a still-water setup. Field experiment results suggested that the primary moisture source was below the basement floor when the floor was finished inadequately. The moisture content of CLT walls was significantly increased by floor flooding and decreased by heating the basement interior. The acceptable mould index of three was surpassed during periods of abundant water below the basement floor due to flood events, showing that the CLT panels were at risk of mould growth development. • CLT use inbasements is in research stage. This paper contains insights for developing future research on this subject. • CLT in basement construction requires robust envelope with waterproofing membranes that perform well below grade. • Elevated moisture levels could pose structural and biological risks to the CLT basement and its occupants. • CLT basement walls take time to dry, and during this period, the walls may be exposed to risky levels of mould growth. [ABSTRACT FROM AUTHOR]

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Natural recovery of acidic soils following heavy traffic is assumed to take several decades. The aim of this study was to monitor the recovery of soil penetration resistance (PR) after soil compaction by heavy traffic at two forest sites. The sites, located in northeast France, have soils that differ slightly in pH and silt content. The impact on soil PR following heavy traffic was dependent on the soil water content (WC) at the time of measurement, and, therefore, the entire WC range and corresponding PR values were measured. For the most acidic and silty soil, no difference in PR among treatments was observed when the soils were near saturation; however, the difference in PR values was high when soils were close to wilting point. For the least acidic and silty soil, the impact of heavy traffic on PR could be detected whatever the soil moisture, with the magnitude of the effect dependent on the soil water content and depth considered. Standardized PR values with regard to WC allowed an analysis of the evolution of the effect of heavy traffic with time. Ten years after being subjected to heavy traffic, the PR values in the 0‐ to 40‐cm layer recovered to undisturbed values at the least acidic and silty site, but not WC dynamic. The most acidic and silty soil site did not show any recovery of PR or WC dynamic ten years following traffic, although liming at this site was able to increase the regeneration of PR to undisturbed levels. [ABSTRACT FROM AUTHOR]

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Accurate and efficient numerical simulations of soil water movement, as described by the highly nonlinear Richards' equation, often require local refinement near recharge or sink/source terms. In this paper, we present a novel numerical scheme for solving Richards' equation. Our approach is based on the vertex-centered finite volume method (VCFVM) and can be easily adapted to locally refined meshes. The proposed scheme offers some key features, including the definition of all unknowns over vertices of the primary mesh, expression of flux crossing dual edges as combinations of hydraulic heads at the vertices of the primary cell, and the capability to handle nonmatching meshes in the presence of local mesh refinement. For performance evaluation, soil water content and soil water potential simulated by the proposed scheme are benchmarked against results produced from HYDRUS (a widely used soil water numerical model) and the observed values in four test cases, including a convergence test case, a synthetic case, a laboratory experiment case and a field experiment case. The comparison results demonstrate the effectiveness and applicability of our scheme across a wide range of soil parameters and boundary conditions. [ABSTRACT FROM AUTHOR]

Herbicide abuse has a significantly negative impact on soil microflora and further influences the ecological benefit. The regulating measures and corresponding mechanisms mitigating the decreased bacterial diversity due to herbicide use have rarely been studied. A field experiment containing the application gradient of an efficient maize herbicide thiencarbazone-methyl·isoxaflutole was performed. The relationship between soil bacterial community and thiencarbazone-methyl·isoxaflutole use was revealed. Modified attapulgite was added to explore its impacts on soil microflora under the thiencarbazone-methyl·isoxaflutole application. Based on the analytic network process–entropy weighting method–TOPSIS method model, the ecological benefit focusing on microbial responses was quantitatively estimated along with technical effectiveness and economic benefit. The results showed that the diversity indices of soil microflora, especially the Inv_Simpson index, were reduced at the recommended, 5 and 10 times the recommended dosages of thiencarbazone-methyl·isoxaflutole use. The Flavisolibacter bacteria was negatively correlated with the residues in soils based on the random forest model and correlation analysis, indicating a potential degrader of thiencarbazone-methyl·isoxaflutole residues. The structural equation model further confirmed that the high soil water content and soil pH promoted the function of Flavisolibacter bacteria, facilitated the dissipation of thiencarbazone-methyl·isoxaflutole residues and further improved the diversity of soil microflora. In addition, the presence of modified attapulgite was found to increase the soil pH, which may improve bacterial diversity through the regulating pathway. This explained the high ecological benefits of the treatment where the thiencarbazone-methyl·isoxaflutole was applied at the recommended dosage rates in conjunction with modified attapulgite addition. Therefore, the comprehensive benefits of thiencarbazone-methyl·isoxaflutole application with a focus on ecological benefits can be improved by regulating the soil pH with modified attapulgite. [Display omitted] • TMI use at the recommended, 5 and 10 times the recommended doses decreased diversity. • The coupling effect of soil water content and pH controlled the dissipation of TMI. • Increased pH improved the ecological benefit by adding modified attapulgite. [ABSTRACT FROM AUTHOR]

• Monitoring hydro-evolution of an artificial rainfall-induced loess landslide by tl-3D-ERT. • Slope experienced a movement process of initiation, acceleration, and deceleration. • Slope wetting showed substantial spatiotemporal heterogeneity. • Variability of 3D hydro-evolution is an essential indicator of slope movement trend. Rainfall can increase the moisture content of a slope, which changes its mechanical properties and thus acts as an important mechanism to trigger landslides. However, it is unclear how moisture contents vary in space and time during rainfall-induced slope movements, and which soil-wetting patterns precede landslide events. Here, we used point sensors and time-lapse 3D electrical resistivity tomography (tl-3D-ERT) technology to monitor the spatiotemporal evolution of the hydrology and movement within a rainfall-induced loess landslide. We observed that movement of the slope involved a semi-continuous process of initiation, acceleration, and deceleration to stabilization. The slope hydrology evolution suggested that initial saturation, dominant flow, and changes in slope recharge and drainage owing to internal seepage and erosion are important factors that affect moisture changes. The movement accelerated when the average saturation value and spatial variation in moisture distribution within the slope increased; however, the movement decelerated when both parameters did not change significantly with time. The accumulation and dissipation of pore water pressure within the slope owing to uneven humidification may be the underlying cause of changes in landslide movement. Our study demonstrates the potential of tl-3D-ERT for monitoring the spatiotemporal variability of moisture evolution within rainfall-induced landslides to determine landslide deformation trends and develop a landslide early warning system. [ABSTRACT FROM AUTHOR]

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• Spatiotemporal patterns of SWC and ST were altered in rocky soils compared to those in rock-free soils. • Rock fragment content (RFC) significantly reduced soil water content both in wet and dry season. • SWC showed a unimodal trend in 0% and 25% RFC, and monotonic increase in 50% and 75% RFC as soil profile deepened. • RFC exerted divergent impacts on soil temperature (ST), and the effects depended on season and soil layers. • RFC enhanced coupling correlation between SWC and ST. Soil water and temperature play a crucial role on hydrological and heat cycling in terrestrial ecosystems, yet rock fragment content in affecting soil water content, temperature, and their relationship is still poorly understood, particularly in dynamic water-heat environments in stony region. In this study, we conducted a field experiment with rock fragment content ranging from 0% to 75%, and investigated soil water content and soil temperature across soil profiles from 2018 to 2022. Soil water content and temperature showed apparent spatiotemporal dynamics under varying rock fragment content. Increased rock fragment content significantly decreased soil water content, but the effect in wet season was stronger than that in dry season. Soil water content increased first and then decreased with increasing soil depths in the conditions of 0% and 25% rock fragment content, but monotonically increased in soils with 50% and 75% rock fragment content. Presence of rock fragment raised annual mean soil temperature, and rock fragment content posed various impacts on soil temperature which depended on seasons and soil layers. Among the rock fragment content gradient, 25% rock fragment content posed a consecutive warming effect on soils in each season. Negative correlation between soil water content with soil temperature was observed both in 10 cm and 30 cm soil layers during wet season, while positive correlation in 30 cm soil layer during dry season. These results indicated that rock fragment content can drive the change in spatiotemporal patterns of soil water content and temperature, and presence of rock fragment strengthened coupling relationship between soil water content and temperature during the wet period. [ABSTRACT FROM AUTHOR]

Change in rainfall pattern with longer dry period depletes soil water content (SWC) and incorrect sowing time adversely affects rainfed sorghum production in Semi-Arid Tropics (SATs). The present study was conducted to develop agricultural water management strategies for improving SWC and to evaluate sowing time as climate change agro-adaptations for sorghum production in SATs. The field experiments on two land-water management (flatbed, broad bed furrows (BBF)) and four nutrient management (application of macro-and micronutrients through combination of chemical and organic fertilizers) were conducted in 2014 and 2015 at International Crops Research Institute for the Semi-Arid Tropics, India. The average SWC in 'BBF' was higher over 'flatbed' by 0.90 cm and 1.06 cm in 0–30 cm soil depth, 0.67 cm and 1.02 cm in 30–60 cm depth, 0.51 cm and 0.84 cm in 60–90 cm depth and, 0.34 cm and 0.67 cm in 90–120 cm during 2014 and 2015, respectively. The SWC in BBF was higher over flatbed by 7.28% throughout 0–120 cm soil depth during longest dry period of 26 days in the year 2014. The simulation analyses using DSSAT Version 4.6 for Coupled Model Intercomparison Project Phase 5 with RCP 4.5 stated that postponing the normal sowing time (30 June) to 10 July resulted in lower grain yield reduction i.e. 14.75% in 2030 and 19.37% in 2050 as compared to base period (1988–2007) yield with normal sowing in Parbhani location of India. The BBF combined with macro-and micronutrients application through chemical fertilizer and postponing sowing time was found the effective climate change agro-adaptation strategies for improving sorghum production in SATs. This study indicates the need for desired policy orientation by the government to promote integrated land-water-nutrient management as the effective agro-adaptations to climate change in SATs. • Broad bed furrows (BBF) recorded higher soil water content (SWC) than flatbed. • Average SWC in BBF was more over flatbed by 0.75 cm (7.28%) in 0–120 cm soil depth. • BBF increased rainwater use efficiency by 19.5% over flatbed in ICRISAT, India. • BBF found efficient land-water management technology during longest dry period. • Sowing postponement is an agro-adaptation strategy for sorghum production in SAT. [ABSTRACT FROM AUTHOR]

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There is a gap in our understanding of grain sorghum [ Sorghum bicolor (L.) Moench] crop production and soil resource (water and N) use in response to different crown root angles (CRA) in any pedoclimatic conditions. CRA is used as a proxy for different root system architectures in field conditions. Therefore, we selected grain sorghum genotypes previously classified to exhibit 'shallow' (∡ 40.5) and 'steep' (∡ 59.3) CRA from a diverse panel of 130 recombinant inbred lines to evaluate aboveground responses to CRA under different agronomic practices. These lines were planted as architectural monocultures and compared with a rooting architecture diversity treatment ('shallow', 'intermediate' (∡ 47.4), 'steep') at four N rates (0, 20, 100, and 200 kg N ha−1) for two years in Experiment I. Similarly, the monocultures 'shallow' and 'steep' were compared to two rooting architecture diversity treatments ('mix2′ and 'mix10′) under two water regimes (irrigated vs. rainfed) for two years in Experiment II. Yield, other aboveground plant traits, soil water and N dynamics were evaluated. In Experiment I, increasing N application rate positively influenced all the aboveground traits measured, while rooting architecture had minimal or no impact on crop N uptake and other parameters. There were no yield benefits or penalties associated with different CRA. The results of Experiment II indicated that, while root system architecture did influence a variety of soil response variables, including water drainage and NO 3 -N leaching below the rootzone, the trends across CRA treatments and years made the results largely inconclusive. Few studies have been conducted on this topic, some showing positive outcomes, but results of these studies showed limited benefit of diverse and contrasting CRA to sorghum productivity, N recovery, and water uptake when grown in coarse-textured soil. • Rooting architecture had minimal or no impact on crop N uptake and other aboveground parameters evaluated. • There were no yield benefits or penalties associated with different architectures. • These field studies provided early data comparing effects of contrasting rooting architectures in sorghum. • Rooting architecture influenced soil resources, but trends across treatments and years were inconclusive. [ABSTRACT FROM AUTHOR]

The use of biochar (BC) is discussed as a strategy to sequester carbon in soils, to reduce GHG emissions and improve soil fertility. However, the responses of crop yields to biochar amendments in agricultural ecosystems, specifically under temperate field conditions, are still uncertain. Furthermore, results obtained under field conditions are often differing from laboratory studies. Therefore, the establishment of long-term studies under field conditions is mandatory to provide the base for recommendations. We carried out a two-factorial split-plot field experiment over four years (2012–2015, still in progress ) to compare the effects of BC on crop yields, mineral nitrogen (NO 3 − and NH 4 + ) dynamics, soil moisture and initial soil CO 2 efflux. A temperate sandy soil was amended with BC (0, 15 and 30 Mg ha −1 ) with the second factor being watering regime (irrigated or rainfed). The soil CO 2 efflux was increased only for a short time following BC amendments. Freshly incorporated BC (30 Mg ha −1 ) initially induced manganese (Mn) deficiency at the vegetative stage of the first crop maize ( Zea maize L.). Biochar amendments significantly reduced NO 3 − leaching, as indicated by greater NO 3 − stocks in the topsoil and reduced stocks in the subsoil (0–15, BC amendment zone and 60–90 cm respectively). In BC treatments a higher soil moisture and higher NO 3 − amount was observed, however, this did not translate into higher yields. Rather, grain yields of maize (year I) and summer barley ( Hordeum vulgare L., year III, no nitrogen (N) fertilization) were significantly reduced (1–11 and 5–26% respectively) due to N deficiency with BC amendment or (non-alleviated) drought stress. A prolonged drought spell in 2015 (year IV) drastically reduced the grain yield of maize (5 and 0.7 Mg ha −1 ) and N uptake (96 and 11 kg ha −1 ) in the irrigated and rainfed treatments respectively, without any alleviating effects of biochar amendment. We conclude that application of large amounts of pure, non-nutrient-loaded biochar to temperate sandy soils may provide environmental benefits, such as carbon sequestration and reduction of nitrate leaching, but without an economic incentive for implementing biochar use, at least for the initial few years of application. [ABSTRACT FROM AUTHOR]

[Display omitted] • Use HYDRUS to simulate transport of in-situ leaching agent in a hilly rare earth mine. • Spatiotemporal distribution of soil NH 4 -N and NO 3 -N is highly heterogeneous across the hill. • Five years of rainwater leaching could remove <10% of soil NH 4 -N from the hill. • Nitrification and lateral flow led to buildup of NO 3 -N near surface at the bottom of the hill. The large amount of residual soil ammonium nitrogen (NH 4 -N) after in-situ leaching is a legacy environmental issue for ionic rare earth mines. Understanding and mitigating the associated risk to the aquatic ecosystems of the mining as well as its downstream areas would benefit from a quantitative description and prediction of NH 4 -N transformation and transport during and after in-situ leaching. Up to date, studies related to the transport and leaching characteristics of residual soil NH 4 -N have been mostly limited to laboratory experiments. Few field process-based studies of the transport behaviors of residual leaching agents in rare earth mines have been conducted partially because of their remote locations, restricted accessibility, and scarce background data. Based on field investigations at a remote hilly rare earth mine in Ganzhou City, Southern China, we established a HYDRUS-2D model to simulate the transport and transformation of soil NH 4 -N in the mine throughout in-situ leaching, flushing, and subsequent rainwater leaching. Though subjected to conceptual generalization and limited background data, the established HYDRUS-2D model was able to satisfactorily simulate the observed distinctively different vertical soil NH 4 -N and nitrate nitrogen (NO 3 -N) profiles at the top, middle, and bottom of the hill in March 2021, with R2 ranging from 0.71 to 0.89 for soil NH 4 -N and 0.69 to 0.86 for soil NO 3 -N. Further analysis of the HYDRUS simulation results revealed a much different spatiotemporal distribution pattern between soil NH 4 -N and NO 3 -N throughout the simulation period. For soil NH 4 -N, the shape and spatial extent of its distribution was largely determined by in-situ leaching, whereas flushing and rainwater leaching slowly pushed its spatial extent further downward, and to a less extent downslope to the right. Flushing and five years of rainwater leaching could merely remove around 10% of residual soil NH 4 -N from the hill. Unlike NH 4 -N, the spatial distribution pattern of soil NO 3 -N varied considerably among various phases of in-situ leaching, flushing, and rainwater leaching. Soil water movement affected the spatial distribution of soil NO 3 -N considerably, which was especially evident from its significant buildup near surface at the bottom of the hill. Overall, our study results have revealed the critical role of continuous water movement and solute transport in shaping the distribution patterns of residual leaching agents in rare earth mining regions. The proposed HYDRUS model may serve as a promising framework for investigating the transport and spatiotemporal distribution of in-situ leaching agent in rare earth mining regions with scarce background data. It also has great potentials in facilitating the development of more effective in-situ leaching programs and the design of suitable water pollution control and ecological remediation measures. [ABSTRACT FROM AUTHOR]

Ninety-four percent of U.S. soybeans are produced under rainfed conditions with potential for intermittent late season droughts during reproductive stages. Therefore, the ability of a crop to recover effectively from drought is important for yield stability. In 2019 and 2020, two controlled environment and two field studies were conducted to screen nine soybean genotypes for transpiration rate (TR) recovery following water-deficit stress. In experiment 1, under a controlled environment, soybeans were grown in pots sealed to prevent evaporation. Soybeans gradually transpired until the endpoint of transpirable soil water before being re-watered. In experiment 2, soybeans were exposed to varying vapor pressure deficit (VPD) levels. In both experiments, TR was measured gravimetrically. In field studies, portable rainout shelters were used to exclude precipitation. In experiment 1 and the field studies, recovery irrigation was applied after a period of extreme water-deficit. Then, leaf wilting score (WS) was rated visually on a scale of zero to five. Stomatal conductance (g s), pre- and post-recovery canopy temperature (CT), and stomatal density (SD) were measured under field conditions. Genotypic differences in soybean contributed to differentiated recovery from water-deficit in experiment 1 and field studies. In experiment 1, genotypes TN09–029, TN16–520R1, and Ellis had superior recovery from water-deficit based on WS while USG Allen and TN09–008 had the most rapid TR recovery; RIL #1360 and USG 7496XTS showed the least recovery. In experiment 2, seven genotypes expressed a limited-TR trait under high VPD. In the field studies, Ellis, USG Allen, and TN09–029 exhibited a more robust recovery based on WS and Ellis exhibited the highest post-recovery g s. TN09–029 and Ellis had the largest reduction in CT after recovery. The top five yielding genotypes all expressed desirable responses in several of the individual drought recovery traits, confirming the utility of these phenotypes. Ellis produced the highest yield at 3517 kg ha−1, consistently expressed the early decrease in TR with delayed wilting when soil water-deficit developed, and had the highest g s post-recovery. Response and recovery to drought and high yield relative to other genotypes under the water-deficit conditions make Ellis and related lines good candidates in future efforts to breed for drought tolerance traits. • The ability of a crop to recover effectively from drought is important for yield stability. • Identifying variation in mid-south genotypes transpiration and leaf maintenance recovery from severe water-deficit stress. • Field studies confirmed the results found and reported in the controlled environment experiments. • The top yielding genotypes had early stomatal closure, lower stomatal density, and lower thermal rate following recovery. [ABSTRACT FROM AUTHOR]

Highlights: [•] Electromagnetic induction (EMI) method is commonly used to distinguish soils. [•] Apparent electrical conductivity (ECa) derived with EMI method relates well with soil water. [•] Local calibration of EMI equipment is necessary to measure soil water at field scale. [•] ECa maps are useful to measure spatial distribution of soil water in irrigated crop fields. [ABSTRACT FROM AUTHOR]

Highlights: [•] Characterizing soil moisture variability is key to understand soil water fluxes at the field scale. [•] Novel measurement technologies provide unique possibilities to characterize soil moisture. [•] Network monitoring design requires should better involve soil cover studies. [•] Progress is needed in measurement quality at the extremes of the soil moisture range. [•] Modeling is key to identify local and non-local on soil water dynamics. [ABSTRACT FROM AUTHOR]