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The use of wood ash as a soil amendment remains restricted in many parts of Canada. To better understand belowground biogeochemical responses to wood ash, soil solution chemistry was measured over 3 years following the application of wood ash (0, 2.5, 5.0, and 7.5 Mg·ha−1) at a hardwood stand in Ontario, after which soil microbial response was assessed using 16S rRNA gene and internal transcribed spacer sequencing. Metal concentrations in the locally sourced wood ash were below provincial regulatory limits. Significant increases in soil solution pH were observed within the forest floor in the first year of the trial, and significant increases in calcium and magnesium were also observed in later years of the trial. Concentrations of most metals in soil water either decreased or exhibited no significant change in response to wood ash. There was an increase in diversity and richness of soil prokaryotic groups in the FH horizon at the highest wood ash treatment that is most likely linked to the large increase in pH. This study indicates that wood ash has a strong ameliorative effect on soil and soil water chemistry without major changes to soil microbial communities and is a viable amendment to forest soils at dosages below 5 Mg·ha−1. [ABSTRACT FROM AUTHOR]

The Richardson-Richards equation (RRE), despite known shortcomings especially in regard to preferential flow, provides the basis for the vast majority of unsaturated flow models in use today. L.F. Richardson published this equation in 1922, nine years before L.A. Richards. Whereas Richards approached this problem directly from the groundbreaking developments of Edgar Buckingham, Richardson, surprisingly, cited as his starting point only the earlier work of L.J. Briggs. Collectively, these four scientists’ published and unpublished work reveals that: (1) Briggs’ work, though qualitative, captured the essential physical principles needed for quantifying unsaturated flow; (2) Buckingham came very close to deriving the RRE and explained why he stopped short of doing so; (3) derivation of the RRE from the work of either Briggs or Buckingham required only modest developmental work; and (4) besides deriving the RRE, Richards carried through much of the experimental agenda that Buckingham considered a necessary precursor to mathematical treatment. [ABSTRACT FROM AUTHOR]

Xerophytic vegetation re-regulates and allocates water resources through canopy interception, root water uptake and transpiration, and changes the water budget among precipitation, runoff, interception and infiltration, thus having a significant impact on the processes of the hydrological cycle. In this study, we investigated the effect of xerophytic shrub-Salix on soil water redistribution and water budget through an in situ monitoring experiment combined with two-dimensional vegetation water consumption modeling. The results showed that, due to the interception effect of root water uptake, it was difficult for precipitation infiltration to recharge deep soil water and groundwater. The measured data of soil moisture content, hydraulic head and precipitation were used to verify and calibrate the performance of the soil water flow model in the vadose zone by HYDRUS-2D. The effect of roots system on soil water was simulated, and the appropriate spacing of Salix replanting was estimated. Combined with the relationship between the transverse roots system and the crown width obtained by the investigation, it was determined that the spacing between the Salix should be greater than five times the crown width, so that the balance between the water consumption of Salix and the water supply of deep soil by precipitation could be considered. The results of this study are important for estimating groundwater recharge in arid areas and provide practical vegetation replanting options for similar regions. [ABSTRACT FROM AUTHOR]

Background: Soil water and organic carbon (C) are key factors affecting the growth and development of apple seedlings. The objective of the study was to investigate the effects of different soil moisture and glucose supplies on apple seedling growth and soil enzyme activities. We hypothesized that the growth of apple seedlings was affected by soil water and C content through their effects on root structure, plant physiological properties and soil enzymatic activities. A pot experiment consisting of nine treatments was set up, including three water treatments with soil moisture contents at 75–85% (normal irrigation, CK), 65–75% (light water stress, LS), and 55–65% (mild water stress, MS) of the soil field capacity, in combination with three glucose treatments with carbon/nitrogen (C/N) ratio of 7.5 (C1, no adding glucose), 10 (C2) and 15 (C3), respectively. Results: Results showed that the LSC2 treatment significantly increased plant height by 7%, stem diameter by 5% and leaf area by 17%, as compared with LSC1. Also, LSC2 significantly increased root dry weight, root vitality and soil enzyme activities. Moreover, results of leaf photosynthetic, malondialdehyde (MDA), peroxidase (POD), superoxide dismutase (SOD) and proline contents also proved that adding glucose improved the drought resistance of plants. Conclusion: LSC2 treatment is more conducive to the growth of apple seedlings, and application of carbon has a good alleviation effect on plant water stress. The study demonstrated that addition of exogenous glucose alleviated light water deficiency, significantly affected root vitality, and promoted apple seedling growth. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The extensive implementation of the 'Grain for Green' project over the Loess Plateau has improved environmental quality. However, it has resulted in a greater consumption of soil water, and its overall hydrological effects remain highly controversial. Our study utilized a coupled land-atmosphere model to evaluate the effects of vegetation changes resulting from revegetation or reclamation on the hydrology of the Loess Plateau. Revegetation was found to stimulate an increase in precipitation, evapotranspiration, and atmospheric water content. However, the increase in precipitation was insufficient to compensate for soil water loss driven by intensified evapotranspiration, resulting in a decrease in both runoff and soil water content. In contrast to revegetation, reclamation would reduce precipitation, although the reduction was less than the decrease in evapotranspiration. This could lead to an increase in both runoff and soil water content. The results provide an important scientific basis for the hydrological effects of vegetation changes on the Loess Plateau, which is particularly important for guiding current and future revegetation activities toward sustainable ecosystem development and water resources management. [ABSTRACT FROM AUTHOR]

The complex relationships within desert ecosystems and their environmental conditions are reflected in patterns of plant water use. Thus, understanding the sources of water used by plants in these areas is crucial for effective resource management. In this study, we investigated the water use pattern of Haloxylon ammodendron in Semnan province, in the central plateau of Iran, using the stable isotope analysis. We employed a simple, homemade cryogenic vacuum distillation (CVD) system to directly extract water from soil samples and different plant components for subsequent analysis by mass spectrometer. The contribution of each possible water source to the plant xylem water was estimated using the IsoSource mixing model. The pattern of δ 18O values in the xylem water of H. ammodendron indicated its reliance on groundwater as a primary water resource during the wet season. Additionally, the correlation of sand particles with both δ2H and δ18O was found to be 0.32. Moreover, the δ 18O values of H. ammodendron xylem water were mainly similar to those of groundwater, suggesting the species' dominant use of groundwater. The findings of this study provide valuable insights for strategically planting H. ammodendron to mitigate impacts on groundwater resources and ensure long-term sustainability in arid and semi-arid regions. [ABSTRACT FROM AUTHOR]

A straw interlayer added to soil can effectively reduce soil salinity effects on plant growth, however, the effects of soil moisture, salt and microbial community composition on plant growth under a straw interlayer are unclear. A rhizobox study was conducted to investigate the role of straw interlayer thickness on soil moisture, salt migration, microbial community composition, as well as root growth in sunflower. The study included four treatments: Control (no straw interlayer); S3 (straw interlayer of 3.0 cm); S5 (straw interlayer of 5.0 cm); S7 (straw interlayer of 7.0 cm). Straw interlayer treatments increased soil moisture by 8.2–11.0% after irrigation and decreased soil salt content after the bud stage in 0–40 cm soil. Total root length, total root surface area, average root diameter, total root volume and the number of root tips of sunflower plants were higher under straw interlayer treatments than in the control, and were the highest under the S5 treatment. This stimulated root growth was ascribed to the higher abundance of Chloroflexi and Verrucomicrobia bacteria in soil with a straw interlayer, which was increased by 55.7 and 54.7%, respectively, in the S5 treatment. Addition of a straw interlayer of 5 cm thickness is a practical and environmentally feasible approach for improving sunflower root growth in saline-alkali soil.

Soil salinization and water scarcity are main restrictive factors for irrigated agriculture development in arid regions. Knowing dynamics of soil water and salt content is an important antecedent in remediating salinized soils and optimizing irrigation management. Previous studies mostly used remote sensing technologies to individually monitor water or salt content dynamics in agricultural areas. Their ability to asses different levels of crop water and salt management has been less explored. Therefore, how to extract effective diagnostic features from remote sensing images derived spectral information is crucial for accurately estimating soil water and salt content. In this study, Linear spectral unmixing method (LSU) was used to obtain the contribution of soil water and salt to each band spectrum (abundance), and endmember spectra from Sentinel-2 images. Calculating spectral indices and selecting optimal spectal combination were individually based on soil water and salt endmember spectra. The estimation models were constructed using six machine learning algorithms: BP Neural Network (BPNN), Support Vector Regression (SVR), Partial Least Squares Regression (PLSR), Random Forest Regression (RFR), Gradient Boost Regression Tree (GBRT), and eXtreme Gradient Boosting tree (XGBoost). The results showed that the spectral indices calculated from endmember spectra were able to effectively characterize the response of crop spectral properties to soil water and salt, which circumvent spectral ambiguity induced by water-salt mixing. NDRE spectral index was a reliable indicator for estimating water and salt content, with determination coefficients (R2) being 0.55 and 0.57, respectively. Compared to other models, LSU-XGBoost model achieved the best performance. This model properly reflected the process of soil water-salt dynamics in farmland during crop growth period. This study provided new methods and ideas for soil water-salt estimation in dry irrigated agricultural areas, and provided decision support for governance of salinized land and optimal management of irrigation.

The water footprint is an increasingly demanded environmental sustainability indicator for certifications and labels in agricultural production. Processing tomatoes are highly water-intensive, and existing studies on water footprint have uncertainties and do not consider the impact of different irrigation configurations (e.g., surface drip irrigation (SDI) and subsurface drip irrigation (SSDI)) and irrigation strategies. This study presents a two-year experimental investigation to determine the water footprint of processing tomatoes grown in southern Spain (Andalusia) and the impact of SSDI and deficit irrigation. Five irrigation treatments were established: SDI1 (surface drip irrigation without water limitation), SDI2 (surface drip irrigation without water limitation adjusted by soil moisture readings), SSDI1 (subsurface drip irrigation without water limitation and a dripline depth of 15 cm), SSDI2 (similar to SSDI1 but with mild/moderate water deficit during the fruit ripening stage), and SSDI3 (subsurface drip irrigation without water limitation and a dripline depth of 35 cm (first year) and 25 cm (second year)). Measurements included crop vegetative growth, leaf water potential, leaf gas exchange, nitrate concentration in soil solution, and crop yield and quality. The soil water balance components (actual evaporation, actual transpiration, deep drainage), necessary for determining the total crop water footprint, were simulated on a daily scale using Hydrus 2D software. Results indicated that SSDI makes more efficient use of irrigation water than SDI. The water footprint of SSDI1 was 20–35% lower than that of SDI1. SSDI2 showed similar water footprint values to SDI1 under highly demanding environmental conditions and significantly lower values (≈40%) in a year with lower evaporative demand. The dripline depth in SSDI was critical to the water footprint. With a 35 cm installation depth, SSDI3 had a significantly higher water footprint than the other treatments, while the values were similar to SSDI1 when the depth was reduced to 25 cm. [ABSTRACT FROM AUTHOR]

Straw returning may be an efficient strategy to maintain agricultural sustainability. However, which straw returning strategy can effectively improve soil properties and crop yield remain unclear. A five-year (2011–2016) field experiment in sub-humid, drought-prone areas of northwestern China with uneven rainfall distribution and irrigation was conducted to evaluate the effects of nitrogen fertilizer without straw mulching (CK), with regular straw mulching (LSM), and with ammoniated straw plowing (ALSP) on soil water, soil aggregates, soil organic carbon (SOC), total nitrogen (TN), and water use efficiency (WUE) in an annual winter wheat (Triticum aestivum L.)–summer maize (Zea mays L.) rotation system. The results demonstrate that ALSP had a greater soil water content than CK in the 0–60 cm soil layer. ALSP also had substantially more soil water than LSM in the 0–100 cm layer during the wet year (2011–2012) and two dry years (2014–2015 and 2015–2016). In the normal years (2012–2013 and 2013–2014), the soil water content in ALSP was significantly lower than in LSM in the 0–20 cm soil layer. ALSP was better able to alleviate soil drought in dry years and excessive humidity in wet years. Compared to CK, SOC in the 0–20 cm soil layer in 2016 increased by 8.3% in LSM and 11.7% in ALSP, and TN in the upper soil increased by 6.6% in LSM and 10.1% in ALSP. The equivalent wheat yield and WUE increased in ALSP by 15.6% and 17.5%, respectively, relative to CK, and by 6.79% and 5.97%, respectively, relative to LSM. Thus, we concluded that plowing ammoniated straw with N fertilization is a promising strategy for improving soil fertility and crop productivity in winter wheat–summer maize rotation systems in the sub-humid, drought-prone areas of northwestern China. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office 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.)

The aim of this study was to analyse the physical quality of a Planosols in the semi-arid environment under integrated and conventional agricultural production systems after eight years of management and to observe if the physical properties of the soil under grazing respond differently to the production systems assessment. The experiment has been carried out since 2015 in Alagoinha, Paraíba, on a Planosols. The treatments were composed of: Urochloa decumbens + Ipê (BI); Ur. decumbens + Gliricídia (BG); Ur. decumbens + sabiá (BS); Ur. decumbens + milho (L) and Ur. decumbens (B). Soil samples were collected in 2022 in the 0-10, 10-20 and 20-30 cm depth layers to determine soil bulk density (Bd), total porosity (TP), macroporosity (Mac), microrosity (Mic) and saturated hydraulic conductivity (K0). The data was subjected to analysis of variance and principal component analysis (PCA) (p<0.05). The results showed that there was no difference (p<0.05) between the treatments evaluated, but BI and B showed considerable K0 on the surface 7.5 and 3.1 cm h-1, respectively. Mac was restrictive in all treatments in the 0-10 cm layer, with average values <0.10 m3 m-3. It can be concluded that the physical quality of the soil under grazing is the same between integrated and conventional (pasture) agricultural production systems after a period of eight years. [ABSTRACT FROM AUTHOR]

Forest trees greatly influence both the routing of water downward into the subsurface and the re‐routing of water upward through water uptake and transpiration. To reveal how the subsurface soil water pools used by trees change across seasons, we analysed 2 years of stable isotope ratios of precipitation, soil water from different depths (using both bulk sampling and suction‐cup lysimeters), and xylem in a mixed beech and spruce forest. Precipitation as well as mobile and bulk soil waters all showed a distinct seasonal signature; the seasonal amplitude decreased with depth, and mobile soil waters fluctuated less than bulk soil waters. Xylem water signatures in both tree species were similar to the bulk soil water signatures and rather different from the mobile soil water signatures. The beech and spruce trees had different isotope ratios, suggesting the use of different water sources, and these differences were larger under dry antecedent conditions than wet antecedent conditions. Despite these differences, both species predominantly transpired waters with a winter‐precipitation isotopic signature throughout the summer, including during wet conditions when more recent precipitation was available. Over most of the sampling dates, the fraction of recent precipitation (i.e. from the preceding 30 days) in xylem water was low, despite both species typically demonstrating the use of both shallow and deeper soil waters. These results provide evidence that the soil water storages used by these trees are largely filled in winter and bypassed by recent precipitation, implying long residence times. [ABSTRACT FROM AUTHOR]

The hydrologic flows across the river–aquifer interface play an important role in groundwater dynamics and biogeochemical reactions within the subsurface; however, little is known about the effects of river–aquifer interactions on land surface processes. In this study, we developed a fully coupled three‐dimensional (3D) land surface and subsurface model at a high resolution (~1 km) that accounts for high‐frequency hydrologic exchange flow conditions to investigate how river–aquifer interactions modulate surface water budgets in the Upper Columbia‐Priest Rapids watershed, a typical semiarid watershed located in the northwestern United States where river stage fluctuates in response to reservoir releases changing. Our results show that the spatiotemporal dynamics of river–aquifer interactions are highly heterogeneous, driven mainly by river‐stage fluctuations. Adding 6.64 × 106 m3 year−1 of water over the watershed from the river to groundwater owing to the lateral flow, river–aquifer interactions led to an increase in soil evaporation and transpiration supplied by higher soil moisture content, particularly in deeper subsurface. In a hypothetic future scenarios where a 5‐m rise in river stage was assumed, the hydrologic flow exchange rates were intensified, resulting in higher surface water over the entire watershed. Overall, lateral flow induced by river–aquifer exchanges leads to an increase in evapotranspiration of ~75% in the historical period and of ~83% in the hypothetical future scenario. Our study demonstrates the potential of coupled model as an effective tool for understanding river–aquifer–land surface interactions, and indicates that river–aquifer interactions fundamentally alter the water balance of the riparian zone for the semiarid watershed and will likely become more frequent and intense in the future under the effects of climate change. [ABSTRACT FROM AUTHOR]

Saline soils limit plant growth due to high salinity. Straw returning has proven effective in enhancing soil adaptability and agricultural stability on saline lands. This study evaluates the effects of different straw-returning methods—straw mulching (SM), straw incorporation (SI), and straw biochar (BC)—on soil nutrients, water dynamics, and salinity in a barley–cotton rotation system using field box experiments. SM improved soil water retention during barley's jointing and heading stages, while SI was more effective in its filling and maturation stages. BC showed lesser water storage capacity. During cotton's growth, SI enhanced early-stage water retention, and SM benefited the flowering and boll opening stages. Grey relational analysis pinpointed significant water relationships at 10 cm and 20 cm soil depths, with SM regulating water across layers. SM and BC notably reduced soil conductivity, primarily within the top 20 cm, and their effectiveness decreased with depth. SI significantly lowered soil conductivity at barley's jointing stage. SM effectively reduced salinity at 10 cm and 20 cm soil depths, whereas BC decreased soil conductivity throughout barley's jointing, filling, and heading stages. For cotton, SI lowered soil conductivity at the seedling and boll opening stages. SM consistently reduced salinity across all stages, and BC decreased conductivity in the top 30 cm of soil during all growth stages. Both SM and BC significantly enhanced the total nutrient availability for barley and cotton, especially improving soil organic carbon and available potassium, with BC showing notable improvements. At barley's heading stage, SI maximized dry matter accumulation, while SM boosted accumulation in leaves, stems, and spikes during the filling and maturation stages. Straw returning increased barley yield, particularly with SM and BC, and improved water use efficiency by 11.60% and 5.74%, respectively. For cotton, straw returning significantly boosted yield and water use efficiency, especially with SI and SM treatments, enhancing the total bolls and yield. In conclusion, straw returning effectively improves saline soils, enhances fertility, boosts crop yields, and supports sustainable agriculture. These results provide a robust scientific foundation for adopting efficient soil improvement strategies on saline lands, with significant theoretical and practical implications for increasing agricultural productivity and crop resilience to salt stress. [ABSTRACT FROM AUTHOR]

One of the ways to reduce evaporation from the soil is to use modifiers. The aim of this research was to evaluate the effect of modifiers with two mixed and surface applications on the rate of evaporation from the soil. This research was carried out in the greenhouse of the Faculty of Agriculture of Lorestan University with treatments of wheat straw and cow manure at three levels (zero, 1 and 5% weight). The soil moisture was kept constant for 4 months at the agricultural capacity. The amount of evaporation in June and August 2021 in each pot was measured by weight in two periodes of 10 and 18 days. The results showed that there was a significant difference in the rate of evaporation between the treatments used with surface application and mixture. After the end of evaporation measurement and stopping it in June and August, wheat straw had the lowest evaporation. The use of wheat straw at the level of 5% by weight on the surface in June 4.7 and in August 1.7 times compared to the control treatment had the greatest reduction in evaporation. In addition, the use of modifiers improves the soil structure, which the results of this test show with the highest MWD with the use of a mixture of 5% by weight of wheat straw in the amount of 0.48 mm. Due to the significant difference in the application of modifiers, the surface application of modifiers is recommended to control the rate of evaporation. [ABSTRACT FROM AUTHOR]

Plants on the land surface play a vital role in the hydrological water cycle as they transport soil water to the atmosphere through transpiration. Root water uptake (RWU) is considered a crucial step in this process as it is the first stage of transpiration, directly determining the actual transpiration (Ta) of plants. However, accurately measuring RWU or Ta in situ poses significant challenges. Here, we establish an overall approach of combining mathematical models and machine learning algorithms to obtain high-precision (500 m×500 m) regional-scale daily Ta maps for various future climate patterns. The Hydrus-1D and AquaCrop models were employed to calculate the total RWU fluxes across the entire root zone, aiming to achieve Ta at a point scale. A machine learning model was developed using the CatBoost algorithm and environmental covariates extracted from the Google Earth Engine (GEE) platform to upscale these point-scale Ta to the regional scale. Furthermore, a total of 22 CMIP6 Earth System Models (ESMs) were evaluated, and among them, ACCESS-CM2 and ACCESS-ESM1–5 were selected for simulating future climate scenarios. Based on the established machine learning model and selected ESMs, regional-scale Ta maps were generated from 2020 to 2100 for the SSP245 and SSP585 (Shared Socioeconomic Pathways) scenarios. The results indicate that near-surface specific humidity, mean near-surface air temperature, latitude, and surface downwelling shortwave radiation are the critical factors influencing regional-scale Ta. As greenhouse gas emissions intensify and temperatures rise, regional-scale Ta is enhanced, leading to an accelerated transfer of soil water to atmospheric water. Under the SSP245 scenario, Ta increases on average by 0.55–1.16 % every 20 years, with its incremental value ranging from 7.14∙10−4 to 8.65∙10−4 cm day−1, while under the SSP585 scenario, Ta increases more significantly, achieving an average increase of 0.64–1.81 % every 20 years, with its incremental value ranging from 1.595∙10−3 to 2.821∙10−3 cm day−1. This study provides a robust integrated approach to assess the future regional-scale Ta providing valuable insights into the underlying water cycle mechanisms and regional water requirements for future climate scenarios.

Wine quality is affected by environmental factors in the location where the vines are cultivated, in particular the soil and the climate. Major soil-related factors influencing vine development, yield, and berry composition (and thus wine quality) include soil water availability, soil temperature, and soil nutrients, particularly nitrogen. These can be impacted by soil depth and soil compaction. Mapping these factors with classical field-based methods is constraining and expensive. Near surface geophysics (NSG) can be useful in increasing the resolution of data acquisition and, possibly, its cost. Among these techniques, many are already commercially available, but some of them, including Magnetic Resonance Sounding, Induced Polarization and Spectral Analysis of Surface Waves, require a high degree of expertise for acquisition and processing. These should be further developed in order to enlarge the application possibilities. This article reviews soil-related parameters relevant to terroir expression in vineyards and how these can be measured with NSG techniques.

Soil respiration (SR) emits a vast amount of atmospheric carbon dioxide (CO2) and contributes largely to the global greenhouse gas budget. The study assessed the dynamics of SR rates in the Vea catchment in northeastern Ghana, a sparsely gauged semi-arid savannah ecosystem characterized by distinct patterns of soil CO2 efflux. Through field measurements using soil chambers, the study quantified soil CO2 efflux rates in different land use types (woodland, cropland and grazeland), and assessed the influence of soil moisture, temperature, and soil organic carbon stocks on SR variability. The highest soil CO2 fluxes (12.97 ± 0.89 Mg CO2C ha−1 yr−1) were recorded in woodland, followed by grazeland (9.10 ± 0.42 Mg CO2C ha−1 yr−1) with cropland having the lowest rate (5.61 ± 0.29 Mg CO2C ha−1 yr−1). We recorded mean annual soil CO2 flux of 9.23 ± 0.53 Mg CO2C ha−1 yr−1 across the land use types and also observed significant seasonal and spatial variations in SR rates. The highest SR rate (220 mg CO2C m−2 h−1) was recorded in the wet months (Jul-Sept and Mar-May) and the lowest rate (30 mg CO2C m−2 h−1) in the dry months (Nov-Jan). For the wet season, the mean weekly soil CO2 fluxes ranged between 140 and 160 mg CO2C m−2 hr−1 as opposed to 60–75 mg CO2C m−2 hr−1 for the dry season. Seasonal and spatial variations in SR rates were largely driven by land use type, soil moisture and the interaction of soil temperature and moisture. The results underscore the importance of understanding the emission patterns from various land uses in West African savanna ecosystems to harnessing their potential for climate change mitigation.

Effects of different management measures of afforestation on SWC (a) and the Pearson correlation coefficient between different impact factors of afforestation and the R (b) in northern China. [Display omitted] • We collected data comprising 1226 observations at 98 sites in northern China to assess the variation in soil water content (SWC) by afforestation. • The SWC has been decreased at rates of 0.6 mm decade–1 and 3.2 mm decade–1 by coniferous forest and broadleaf forest, respectively. • The effects of afforestation on soil water depend on prior land use types, tree taxa and the mean annual precipitation regime. • Afforestation might lead to a soil water deficit crisis in northern China in the long term at the regional scale. Trading water for carbon has cautioned large-scale afforestation in global drylands. However, model simulations suggested that the consumption of soil water could be partially offset by increasing precipitation due to vegetation feedback. A systematic meta-analysis of long-term and large-scale field observations is urgently required to address the abovementioned limitations, and the implementation of large-scale afforestation since 1978 in northern China provides an ideal example. This study collected data comprising 1226 observations from 98 sites in northern China to assess the variation in soil water content (SWC) with stand age after afforestation and discuss the effects of tree species, precipitation and conversions of land use types on SWC. We found that the SWC has been decreased by coniferous forest and broadleaf forest at rates of 0.6 and 3.2 mm decade–1, respectively, since 1978. There is a significant declining trend of SWC with the stand age of plantations, and the optimum growth stage for plantation forest is 0–20 a in northern China. However, we found increases in SWC for the conversion from grassland to forest and in the low-precipitation region, both are corresponding to the increased SWC in coniferous forest. Our study implies that afforestation might lead to a soil water deficit crisis in northern China in the long term at the regional scale but depends on prior land use types, tree taxa and the mean annual precipitation regime, which sheds light on decision-making regarding ecological restoration policies and water resource management in drylands. [ABSTRACT FROM AUTHOR]

Soil moisture (SM) is essential for sustaining services from Earth's critical zone, a thin-living skin spanning from the canopy to groundwater. In the Anthropocene epoch, intensive afforestation has remarkably contributed to global greening and certain service improvements, often at the cost of reduced SM. However, attributing the response of SM in deep soil to such human activities is a great challenge because of the scarcity of long-term observations. Here, we present a 37 y (1985 to 2021) analysis of SM dynamics at two scales across China's monsoon loess critical zone. Site-scale data indicate that land-use conversion from arable cropland to forest/grassland caused an 18% increase in SM deficit over 0 to 18 m depth (P < 0.01). Importantly, this SM deficit intensified over time, despite limited climate change influence. Across the Loess Plateau, SM storage in 0 to 10 m layer exhibited a significant decreasing trend from 1985 to 2021, with a turning point in 1999 when starting afforestation. Compared with SM storage before 1999, the relative contributions of climate change and afforestation to SM decline after 1999 were -8% and 108%, respectively. This emphasizes the pronounced impacts of intensifying land-use conversions as the principal catalyst of SM decline. Such a decline shifts 18% of total area into an at-risk status, mainly in the semiarid region, thereby threatening SM security. To mitigate this risk, future land management policies should acknowledge the crucial role of intensifying land-use conversions and their interplay with climate change. This is imperative to ensure SM security and sustain critical zone services. [ABSTRACT FROM AUTHOR]

[Objective]To determine the effect of degradable mulching film on spring maize yield in dryland farmland. [Method] Four treatments were set up: ordinary polyethylene mulching film with thickness 0. 010 mm (T1), PPC degradable mulching film with thickness of 0. 008 mm (T2), PPC degradable mulching film with thickness of 0. 007 mm (T3), and naked cultivation (CK). The effects of different film mulching treatments on soil moisture, temperature and yield of spring maize in dry land in northern Shaanxi were observed. [Result] In the 0- 25 cm soil layer, the soil temperature of the mulching treatment was 1. 9-5. 0 ℃ higher than that of the CK treatment, and the soil temperature of the T1 treatment was the highest. In the 0-100 cm soil layer, the soil water content of different treatments showed T1 >T2 >T3 >CK, The soil water content of the mulching treatment was 10. 7%-19. 3% higher than that of the CK. The 1 000-grain weight of T1 and T2 treatments was significantly increased by 14. 3% and 7. 4% compared with CK (P<0. 05), and the yield was significantly increased by 19. 1% and 14. 1% compared with CK (P<0. 05), and the bald tip rate of spring maize in T2 treatment was the lowest. There were no significant differences in water use efficiency among different treatments (P>0. 05). [Conclusion]T2 treatment is helpful to improve soil hydrothermal condition, increase spring maize yield and improve spring maize quality, and can be used as a suitable film mulching material for green and high-yield cultivation of spring maize in northern Shaanxi Province. [ABSTRACT FROM AUTHOR]

The application of nitrogen (N) improves the winter wheat yield. Excessive N application affects winter wheat yields, leading to low net incomes and negative environmental impacts, therefore, optimizing N application is essential. In this study, the effects of N rates on crop growth yield, net income (NI), water use efficiency (WUE), and nitrogen use efficiency (NUE) in the irrigated districts of the eastern loess plateau, China, were investigated using seven N application rates (N0, N90, N180, N210, N240, N270, and N300 kg ha−1) during the 2016–2017 and 2017–2018 seasons. N application significantly increased the total water consumption at 0–200 cm during the growth period, the aboveground dry matter at maturity, the grain nitrogen accumulation, yield, NI, and WUE. However, N exceeding 240 kg ha−1 did not favor dry matter and nitrogen accumulation or translocation from the anthesis stage to the maturity stage, thus leading to reduced yield, NI, and WUE. The transpiration rate and stomatal conductance N240 was highest 21–28 day after anthesis, at 187–276 kg ha−1, which can achieve a high yield and profitability with relatively low environmental costs. [ABSTRACT FROM AUTHOR]

Aimes: Vegetation restoration in post-mining land is one of the most important remediation strategies for rebuilding the soil carbon (C) pool and improving soil quality. We aimed to provide a global perspective on the effects of vegetation restoration on soil properties. Methods: By analyzing a database of 2799 observations extracted from 160 publications, we quantitatively assessed the effects of vegetation restoration on soil C, water holding capacity, electronic conductivity (EC), cation exchange capacity (CEC), and soil structure in post-mining land across the globe. Results: The results showed that (1) vegetation restoration significantly increased soil organic C (SOC) stock (averagely + 112%), dissolved organic C (DOC) concentration (+ 141%), water content (SWC, + 40%), saturated water content (SSWC, + 40%), hairy tube holding water (HTHW, + 29%), CEC (+ 19%), and the concentrations of sand (+ 17%) and silt (+ 11%), while decreased the EC (-22%) and pH (-7.1%); (2) vegetation type could mediate the effects of vegetation restoration on HTHW, CEC, and sand and silt concentrations, while mineral type of metal mine influenced the effects of vegetation restoration on pH, CEC, bulk density, and sand and silt concentrations; and (3) plant diversity positively affected the effects of vegetation restoration on soil DOC concentration and pH, whilst the effects of soil depth, climate, and restoration year varied for different variables of soil properties. Conclusions: These results suggested a critical role of vegetation restoration in the remediation of post-mining land. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office 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.)

Soil moisture is a critical variable in the hydrological cycle and the climate system, significantly impacting water resources, ecosystem functioning, and the occurrence of extreme events. However, soil moisture data are often scarce, and soil water dynamics are not fully understood in mountainous regions such as the tropical Andes of Ecuador. This study aims to model and predict soil moisture dynamics using in situ-collected hydrometeorological data for training and data-driven machine-learning techniques. Our results highlight the fundamental role of vegetation in controlling soil moisture dynamics and significant differences in soil water balance related to vegetation types and topography. A baseline model was developed to predict soil moisture dynamics using neural network techniques. Subsequently, by employing transfer-learning techniques, this model was effectively applied to different soil horizons and profiles, demonstrating its generalization capacity and adaptability. The use of neural network schemes and knowledge transfer techniques allowed us to develop predictive models for soil moisture trained on in situ-collected hydrometeorological data. The transfer-learning technique, which leveraged the knowledge from a pre-trained model to a model with a similar domain, yielded results with errors on the order of 1 × 10 − 6 < ϵ < 1 × 10 − 3 . For the training data, the forecast of the base network demonstrated excellent results, with the lowest magnitude error metric RMSE equal to 4.77 × 10 − 6 , and NSE and KGE both equal to 0.97. These models show promising potential to accurately predict short-term soil moisture dynamics with potential applications for natural hazard monitoring in mountainous regions. [ABSTRACT FROM AUTHOR]

To compare the disparities between free water evaporation and soil water evaporation, and unveil the temporal impact of soil water evaporation in diverse environments, a series of experiments were conducted to observe the soil water content in different temperature and humidity environments. Meanwhile, the soil water characteristic curve (SWCC) and the evaporation process of free water in air were determined, and the sensitivities of temperature, humidity and density on the soil water evaporation process were analysed. The results demonstrated that both external temperature and humidity can serve as variables for controlling the evaporation rate of soil water. These factors exerted a dynamic influence on the evaporation process, with the impact of each factor tending to stabilize as soil water content decreased. The evaporation rate of soil water was higher than that of free water at the initial stage and was lower than that of free water after the soil reached the residual water content; soil water tended to exist in a state with higher entropy than that of free water. This study provides valuable insights for the establishment of a soil water evaporation model. [ABSTRACT FROM AUTHOR]

Plastic film mulching is widely used in water and temperature-limited regions to enhance crop yields. Phosphorus (P) fertilization can address deficiencies in soil P availability. In this four-year field experiment conducted in an alpine agricultural area, we explored the effects of nitrogen (N) and P supply imbalance on faba bean cultivation, particularly examining intensified N competition between soil microbes and plants. The randomized block design comprised three film mulching treatments—no film mulching with flat planting (NMF), double ridges and furrows mulched with one plastic film (DRM), and three ridges and furrows mulched with one plastic film (TRM)—and three P levels—P0 (0 kg P ha−1), P1 (9.10 kg P ha−1), and P2 (18.2 kg P ha−1). The results indicated that NMF enhanced soil available N and microbial biomass N (MBN) during early growth stages, consequently improving faba bean yield, nodule weight, total N, and microbial biomass carbon (MBC) compared to DRM and TRM. DRM and TRM exhibited higher soil available N and MBN during later growth stages and higher soil temperature and water content, soil water storage (SWS), soil organic C (SOC), and soil C/N ratio than NMF. In NMF and DRM, P fertilization increased grain yield, nodule weight, SOC, total N, soil C/N ratio, soil available N, and MBC but decreased MBN during early growth stages, and decreased soil water content and SWS. TRM exhibited the opposite trend. P fertilization increased soil total P and available P. Overall, NMF combined with P fertilization (~18.2 kg P ha−1) significantly improved faba bean yield. However, it may also accelerate SOC decomposition, highlighting the need to consider N fertilizer application in this alpine agricultural region. [ABSTRACT FROM AUTHOR]

Much of the research on irrigation scheduling sensors, especially soil water sensors, assesses and refines the accuracy of sensor calibrations. However, a sensor with an accurate calibration but high variability among replicates may require a larger-than-acceptable number of replicates for informing recommendations of optimal irrigation timing. To compare the interreplicate variability of sensors across types and calibration accuracy levels, this study presented eight metrics: (1) absolute spread-to-change ratio, (2) shifted spread-to-change ratio, (3) coefficient of change variation, (4) standard deviation of relative value, (5) standard deviation of relative change, (6) standard deviation of absolute triggering date, (7) standard deviation of shifted triggering date, and (8) standard deviation of relative triggering date. These metrics enabled comparisons either by nondimensionalizing sensor measurements or by expressing interreplicate variability in terms of time. For demonstrating their usage and their particularities, the metrics were applied to two datasets that included soil water sensor types such as neutron probe (503DR), dielectric sensor (TDR-315, CS616, CS655, HydraProbe II, 5TE, TEROS 12, Drill & Drop), and granular matrix sensor (Watermark 200SS). The neutron probe in the single-depth dataset and the granular matrix sensor in the multi-depth dataset generally displayed less interreplicate variability than other evaluated sensor types over multiple drying cycles. Future research is suggested to calculate and improve the eight metrics for identifying combinations of sensor types, deployment methods, and data interpretation techniques that minimize interreplicate variability and maximize irrigation scheduling precision. [ABSTRACT FROM AUTHOR]

In tropical and subtropical island regions, alterations in precipitation patterns due to climate change have led to an escala- tion in extreme weather conditions. Owing to the limited availability of irrigation infrastructure, agricultural practices in these areas predominantly rely on rainwater and groundwater. The Optimized Subsurface Irrigation System (OPSIS), a water-efficient subsurface irrigation technology developed in Japan, was engineered to irrigate upland crops by harnessing soil capillarity. This study aimed to investigate soil water dynamics under OPSIS in a subtropical island located in Japan. The water supply from OPSIS in a field devoid of vegetation exhibited considerable variability contingent upon rainfall events. This observation implies that the infiltration of wa- ter captured by the waterproof sheet prompted the cessation of water supply in the OPSIS. Following the initiation of irrigation, soil water content increased at depths of 35 and 55 cm, proximal to the 60 cm depth from the OPSIS installation point, and soil moisture levels remained elevated, except at depths of 5 and 15 cm. Therefore, the implementation of OPSIS at a depth of 60 cm can effective- ly irrigate sugarcane with substantial water-saving benefits, except in the period immediately following planting. Irrigation and deep drainage were higher at 60 cm than at 30 cm depth of PVC sheet installation. To operate OPSIS with optimal water savings in areas with more severe water use restrictions, such as arid and semi-arid lands, controlling the irrigation of perforated pipes according to the soil moisture conditions in the effective root zone is essential. [ABSTRACT FROM AUTHOR]

Knowledge of the spatial variability and forecast of soil water in the ultra‐deep (>21 m) loess profile are important for understanding the chemical, physical, and biological processes in the CZ. In this study, we regularly monitor soil water content (SWC) in deep soil profile along regional transect on the Loess Plateau. Descriptive statistical analysis found that the coefficient of variation (CV) of mean SWC in Ansai and Shenmu were 16.036% and 13.606%, respectively, indicating moderate variability. The CV of mean SWC in Yangling, Changwu, and Fuxian were 4.111%, 7.951%, and 6.117%, respectively, showing low variability. Geo‐statistical analysis indicated that mean SWC showed strong spatial dependence. Wavelet analysis showed that the approximative trend of mean SWC in five sampling sites showed an increased trend along depth series. In addition, a good fit line equation (R2 = 0.329) was established by using observed values and ANN‐forecast of three sites (Yangling, Fuxian, and Shenmu). And the RMSE values of five sample sites, respectively, were 1.302, 4.546, 2.662, 6.231, and 4.293. This study fills the gap in research' ultra‐deep (>21 m) soil water changes and forecast, evidence from soil borehole data. At the same time, our research provides valuable information for the vegetation restoration and modelling of deep soil water. [ABSTRACT FROM AUTHOR]

Understanding soil moisture dynamics is crucial for crop growth. The digital mapping of field soil moisture distribution provides valuable information for agricultural water management. The optical satellite data provides fine scale soil moisture information for a region. However, these data are greatly limited due to cloud contamination and revisit period. Despite the reported beneficial effects of spatiotemporal fusion methods, the accurate estimates of high-resolution soil moisture through spatiotemporal fusion data are still unclear, particularly when using Sentinel-2/3 fusion images. This study introduces a new soil moisture estimation framework integrating spatio-temporal spectral information from Sentinel-2/3 fusion images and machine learning algorithm,and thus provide spatiotemporally continuous soil moisture estimation. The framework includes four fusion methods (ESTARRFM, Fit-FC, FSDAF and STFMF) and four machine learning models (PLSR, SVM, RF and GBRT). The feasibility of the framework was validated in the Hetao Irrigation Area of Inner Mongolia, China. The results showed that the Sentinel-2/3 fused image generated by Fit-FC was visually the closest to the true image, followed by ESTARFM, FSDAF, and STFMF. The spatiotemporal fusion-machine learning estimation framework provided reliable estimation for multi-layer (0 ∼ 20, 20 ∼ 40 and 40 ∼ 60 cm) soil water in the irrigation area. The dense time series of soil water generated by the framework facilitated the detection of irrigation events in the irrigated farmland. Our findings highlighted the effectiveness of Sentinel-2/3 fused images in providing high-resolution continuous daily monitoring of farmland soil water on a large scale. These high spatial–temporal resolution time series are valuable for monitoring crop growth and water resource management, contributing to further expanding the application of satellite remote sensing in precision agriculture.

A 3-year rainfed field experiment was carried out to determine the effects of combined tied ridges and cattle manure application rates on maize productivity. The experiment was laid as a 2 × 4 factorial in a completely randomized block design (CRBD) with three replicates. Treatment combinations were tied ridges + 7.5 t ha−1 low cattle manure (TLM), tied ridges + 15 t ha−1 standard cattle manure (TSM), and tied ridges + 22.5 t ha−1 high cattle manure (THM) application rates. No-tied ridges + low, medium, and high quantities of cattle manure were used as positive controls. Early maturing maize variety (SC537) was then planted at 52,000 plants ha−1 in each plot. Soil water storage, soil bulk density, rainfall, dry matter accumulation (DMA), and grain yield were measured. Rainfall use efficiency (RUE) was then calculated. Analysis of variance was carried out to determine the effects of tied ridging and cattle manure on soil moisture content, RUE, and grain yield. The addition of cattle manure in tied ridges increased the soil moisture content, RUE, DMA, and grain yield. The measured parameters were significantly (p < 0.05) increasing with an increase in the quantity of cattle manure applied. The THM had 40% higher soil moisture content, 20% more RUE, and > 50% DMA compared to TLM. Grain yields significantly (p < 0.05) increased with an increase in application rates of cattle manure with the highest (3.2 t ha−1) recorded in the 2022 season under the THM treatment. The THM had significantly (p < 0.05) higher grain yield compared to no-tied ridges combined with corresponding cattle manure application rates. Farmers can practice tied ridges and 22.5 t ha−1 cattle manure to improve RUE and maize grain yields in the semi-arid areas of Zimbabwe.

[Objective] Part of the newly cultivated farmland formed by the “Gully Control and Land Reclamation” project is facing the risk of soil salinization in the loess hilly region. The spatial distribution characteristics of soil water and salt and their influencing factors were studied for preventing and controlling soil salinization, and promoting sustainable utilization of newly cultivated land. [Methods] A typical area of newly cultivated land was selected, and six experimental plots were established along a gully head to the gully mouth, with sampling points numbered sequentially from 1 to 6. The grid method was used to obtain soil samples from the 0—20 and 20—40 cm layers in each plot. The multifractal method was used to analyze the spatial distribution characteristics of soil water and salt. [Results] Soil water content and salt content gradually decreased from the gully head to the gully mouth. The mean soil water contents and salt contents at sampling points 1, 2, and 3 were 17.6% and 0.81 g/kg, respectively, which were 23.0% and 14.1% higher than the respective values at sampling points 4, 5, and 6. Meanwhile, the multifractal parameters D1 of soil water and salt at sampling points 1, 2, and 3 were less than the respective values at sampling points 4, 5, and 6. ΔD values showed the opposite result, indicating that the spatial variability of soil water and salt at sampling points 1, 2, and 3 were higher. The depth of groundwater influence was the main reason for increased accumulation of salt in the surface soil at sampling points 1, 2, and 3 (p

Xerophytic vegetation re-regulates and allocates water resources through canopy interception, root water uptake and transpiration, and changes the water budget among precipitation, runoff, interception and infiltration, thus having a significant impact on the processes of the hydrological cycle. In this study, we investigated the effect of xerophytic shrub-Salix on soil water redistribution and water budget through an in situ monitoring experiment combined with two-dimensional vegetation water consumption modeling. The results showed that, due to the interception effect of root water uptake, it was difficult for precipitation infiltration to recharge deep soil water and groundwater. The measured data of soil moisture content, hydraulic head and precipitation were used to verify and calibrate the performance of the soil water flow model in the vadose zone by HYDRUS-2D. The effect of roots system on soil water was simulated, and the appropriate spacing of Salix replanting was estimated. Combined with the relationship between the transverse roots system and the crown width obtained by the investigation, it was determined that the spacing between the Salix should be greater than five times the crown width, so that the balance between the water consumption of Salix and the water supply of deep soil by precipitation could be considered. The results of this study are important for estimating groundwater recharge in arid areas and provide practical vegetation replanting options for similar regions.

The extensive implementation of the ‘Grain for Green’ project over the Loess Plateau has improved environmental quality. However, it has resulted in a greater consumption of soil water, and its overall hydrological effects remain highly controversial. Our study utilized a coupled land-atmosphere model to evaluate the effects of vegetation changes resulting from revegetation or reclamation on the hydrology of the Loess Plateau. Revegetation was found to stimulate an increase in precipitation, evapotranspiration, and atmospheric water content. However, the increase in precipitation was insufficient to compensate for soil water loss driven by intensified evapotranspiration, resulting in a decrease in both runoff and soil water content. In contrast to revegetation, reclamation would reduce precipitation, although the reduction was less than the decrease in evapotranspiration. This could lead to an increase in both runoff and soil water content. The results provide an important scientific basis for the hydrological effects of vegetation changes on the Loess Plateau, which is particularly important for guiding current and future revegetation activities toward sustainable ecosystem development and water resources management.

To deeply understand the characteristics of soil freeze–thaw water–heat change in the alpine grassland in the Duogerong Basin of the Yellow River source, the soil water–heat profile change monitoring was carried out based on the field monitoring station in the Duogerong Basin of the Yellow River source. By analyzing the comprehensive monitoring data from September 2022 to September 2023, the characteristics of the soil temperature and water content changes in the freeze–thaw cycle of the alpine grassland in the Duogerong Basin at the source of the Yellow River were explored. The results showed that the temperature and water content of each layer of the soil profile changed periodically, and the range of change was negatively correlated with the depth. The annual freeze–thaw process at the observation site is divided into five stages: 31 October to 3 November is the short initial freezing period, 4 November to 18 April is the stable freezing period, 19 April to 26 April is the early ablation period, 27 April to 30 April is the late ablation period, and 1 May to 30 October is the complete ablation period. The maximum soil freezing depth during the observation period was about 250 cm. Soil temperature and moisture content change affect each other; soil water is essential in heat transfer, and the two correlate well. The research results provide theoretical support for further understanding the characteristics of soil hydrothermal changes during the freeze–thaw process in the alpine grassland permafrost area at the source of the Yellow River. [ABSTRACT FROM AUTHOR]

Soil health encompasses the effects the uppermost part of the land have on human wellbeing in a broad sense, because soil is where most food ultimately comes from, and because it more inconspicuously fulfils other ecological functions, as important as feeding, for our planet's welfare, which is ours. Viticulture exploits the soil's resources from which wine, its most valuable produce, boasts to obtain some of its unique quality traits, which are wrapped within the terroir concept. However, using conventional methods, viticulture also has harsh impacts on the soil, thus jeopardizing its sustainability. How long will the terroir expression remain unchanged as vineyard soil degradation goes on? While this question is difficult to answer because of the complex nature of terroirs, it is undeniable that conventional soil management practices in viticulture leave, in general, ample room for improvement, in their impact on vineyards as much as on the environment. In response, viticulture must adopt practices that enable the long-lasting preservation of its grounds for both on-farm and off-farm benefits. In this regard, the increase in the soil's organic matter alongside the enhancement of the soil's biological community are key because they benefit many other soil properties of a physical, chemical, and biological nature, thus determining the soil's healthy functioning, where the vines may thrive for a long time, whereas its surroundings remain minimally disturbed. In the present review, the importance of soil health as it relates to vineyards is discussed, the soil degradation factors and processes that threaten winegrowing areas are presented, successful soil-health enhancement practices are shown, and future research trends are identified for the benefit of researchers and stakeholders in this special agricultural industry. [ABSTRACT FROM AUTHOR]

In the context of the heterogeneity in the unsaturated or vadose zone, accurately representing the analytical mechanisms and in‐situ water content within the soil layer poses a significant challenge. Particularly in shallow layers, thermal conditions exhibit rapid changes in response to evolving surface temperatures. This study proposes a hypothesis suggesting that the in situ heat mechanism may notably impact the soil water layer. The research introduces an innovative approach to theoretically uncover thermal conditions, including soil temperature, soil temperature gradients, and heat flux, within the shallow Quaternary gravel layer at various depths through spectral analysis of temporal observations. The study presents a stochastic inverse solution to estimate thermal conductivity by leveraging spectral analysis of soil heat flux and temperature gradients. The findings reveal that thermal conditions exhibit the most prominent periodic fluctuations during the diurnal process over a 24‐hour cycle. The soil temperature gradients and heat flux measurements at depths of 0.1, 0.3, 0.6, and 1.2 m demonstrate their ability to capture changes in soil temperature and air temperature to a certain extent within the frequency domain. Furthermore, the analysis highlights the intrinsic uncertainty and sensitivity of estimating thermal conductivity in heterogeneous soil environments. The wide variability observed in thermal conductivity values, coupled with their dependence on soil type and environmental conditions, underscores the need for careful consideration of these factors in future studies and modeling efforts. Applying the derived inverse spectral solution allows for determining thermal conductivity throughout the soil‐water system across depths ranging from 0.1 to 1.2 m. As a result, this research demonstrates the feasibility and practicality of assessing the thermal conductivity of the soil layer in conjunction with heat flux and temperature gradients through spectral analysis. [ABSTRACT FROM AUTHOR]

Changes in seasonality and form of precipitation alter the structure and function of grassland and steppe ecosystems and pose challenges for land management and crop production in regions like the Northern Great Plains, North America. This research uses isotopic composition of water (δ18O and δ2H) to explore the sources and fate of soil water in lower‐elevation agricultural areas of the Judith River watershed, in the headwaters of the Missouri River, USA. Extensive non‐irrigated cereal crop production in this area occurs on well‐drained soils and depends on careful water management. Our observations indicate that colder precipitation contributes isotopically distinct water to cultivated terrace soils relative to downgradient groundwaters and streams. Riparian waters also exhibit a higher fraction of contributions from colder precipitation relative to terrace groundwaters and streams. Apparent contributions from colder precipitation in terrace and riparian soil waters suggest that snowmelt is a key component of the water supply to these systems. Riparian waters also show evidence of evaporation suggesting that water spends sufficient time in some ponds and open channels in the riparian corridor to reflect fractionation by evaporation. The evolution of water isotopic composition from soils to shallow aquifers to stream corridors indicates source water partitioning as precipitation moves through this semi‐arid agricultural landscape. The apparent mixing processes evident in this evolution reveal source water dynamics that are necessary to understand plant transpiration, solute processing, and contaminant leaching processes. [ABSTRACT FROM AUTHOR]

Plantations in dry and semi-arid areas significantly affect the soil’s ability to store carbon and maintain a stable water balance. It is yet unclear, though, how planted trees in these regions might impact the soil’s carbon and water levels. As a forest ages, it is unknown how soil water and soil carbon interact with one another. In order to conduct this study, four Saxaul plantations in the Alxa Plateau were chosen, with the neighboring mobile sandy (MS) ground serving as a control. The ages of the plantations ranged from 5 to 46 years. The major topics of the study included the relationship between soil water and soil carbon, changes in the 0- 300 cm soil layer’s soil water content (SWC), soil organic carbon (SOC), and soil inorganic carbon (SIC) following afforestation. The findings demonstrated that, in comparison to MS, afforestation considerably increased SOC and SIC stocks. In comparison to MS, the SIC grew by 4.02 kg m-2, 4.12 kg m-2, 5.12 kg m-2, and 6.52 kg m-2 throughout periods of 5 years, 11 years, 22 years, and 46 years, respectively. SOC increased relative to MS by 2.55 kg m-2, 2.91 kg m-2, 3.53 kg m-2, and 4.05 kg m-2. Afforestation, however, also contributed to a considerable decline in deep SWC and an increase in the soil water deficit (SWD). In comparison to MS, the mean SWC values were lower at 5 years, 11 years, 22 years, and 46 years, respectively, by 0.48%, 1.37%, 1.56%, and 4.00%. The increase in soil carbon pool caused by sand afforestation actually came at the expense of a reduction in soil water due to a large negative association between deep SWC, SOC, and SIC. To limit SWC losses and encourage sustainable forest land development, we advocate suitable harvest management practices on forest land. [ABSTRACT FROM AUTHOR]

Stand density is an important index of forest structure, which strongly affects local environments and functions in the forest. Many black locust (Robinia pseudoacacia) plantations with low quality in the Loess hilly region are assumed to be caused by inappropriate stand density. In this study, the growth status, spatio-temporal variations in soil water and nutrient conditions were investigated in the nearly middle-aged plantations with three density classes. The proportion of stunted trees increased with the increase in density class. The stands of <2500 stems ha−1 not only had the distribution peak of diameter at breast height (DBH) being at a larger diameter class, but also showed relatively rapid growths in diameter and biomass per tree. However, stand density did not show a significant effect on the growth rate of both mean tree height and biomass density. The maximum biomass density and relatively high soil NH4+-N content appeared in the density class of 2500–3500 stems ha−1. The temporal stability of soil water content (SWC) on a seasonal scale increased with the deepening of the soil layer, and spatio-temporal variations in the SWC remained relatively stable in the deep layer (200–300 cm). While the infiltration depth after rainfall was rainfall-amount-dependent, the depth of effective replenishment reduced with the density class increasing. The average SWC and its temporal stability in 0–300 cm of soil layer are the best in a stand density of less than 2500 stems ha−1. No significant differences were observed among the stand density classes in the contents of total nitrogen, total phosphorus, NO3−-N, and available phosphorus in soils of these nearly middle-aged plantations that have experienced similar management history since the afforestation of abandoned cropland. Overall, the stand condition of density class I is superior at present. But thinning of stand density may be needed to maintain the best stand conditions in the future, with the stand age increasing. The results contribute to further understanding of the relations between density gradient and multiple variables in the plantations, which offer a reference for the forest management and sustainable development of ecosystems in the semiarid region of the Loess Plateau. [ABSTRACT FROM AUTHOR]

Climate change and water resource shortages have become important problems limiting winter wheat production in the North China Plain (NCP). Understanding the physiological characteristics of different wheat varieties and their relationship with crop growth and yield is of great importance for addressing climate change through a scientific approach, adopting reliable wheat varieties, and ensuring food production. This study was conducted throughout three winter wheat seasons from 2018 to 2021. The crop growth, physiological indicators, crop yields, and water productivity (WP) of 12 wheat varieties widely cultivated in the NCP were measured to investigate the relationships between physiological characteristics and crop yield. The results showed that among the three wheat seasons, the maximum plant height of each wheat variety was relatively stable, while the changes in maximum plant density (PDm), maximum leaf area index (LAIm), and maximum dry matter (DMm) were highly variable. The gas exchange parameters and fluorescence parameters of wheat flag leaves varied with growth stage, and certain varieties were sensitive to water stress. The wheat grain yield, seasonal crop evapotranspiration (ETa), and WP of the 12 varieties were similar in the 2019–2020 and 2020–2011 seasons and were approximately 25%, 7%, and 19% higher than those in the 2018–2019 season, respectively, in which there were consecutive cool events in the winter and spring. Generally, the grain yields were positively correlated with PDm, LAIm, DMm, ETa, the harvest index, and WP, at a significance level of 0.01. The high-yield wheat varieties had higher photosynthetic rates in the middle and late grain-filling stages. Based on these relationships, high-yield wheat varieties may be selected to address climate change in the NCP as well as other regions in the world. Considering the variations in yield and WP in the three different climatic conditions, we recommend Yingbo700, Lunxuan103, Shimai26, Shinong086, Han6172, and Hanong1412 as high-yield and drought-resistant wheat varieties to be used in the NCP. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Soil & Water Conservation is the property of Bulletin of Soil & Water Conservation Editorial Office 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.)

Agricultural production is the practice that uses the most water on the planet, especially the irrigated agriculture, which represents a large part of this demand. As well as the quantitative issue, adequate quality is essential to meet the demands of the crop and its return to the water sources, in a way that does not cause damage to the environment. To measure this consumption, the expression "water footprint" emerged. The water footprint seeks to quantify the demand for water incorporated into products. This paper aims to determine the amount of water used to produce irrigated rice in six rice growing regions in the state of Rio Grande do Sul (RS), in the 2019/2020 crop. The mentioned regions are represented the municipalities of Uruguaiana (West Border), Dom Pedrito (Campanha), Santa Maria (Central Region), Camaquã (Internal Coastal Plain), Porto Alegre (External Coastal Plain), and Rio Grande (South Zone). Climate data from the analyzed regions, during the plant cycle, and productivity values in the crop in question were used. Values of 1187 m3 t−1 were found for WB, 1347 m3 t−1 for CA, 1058 m3 t−1 for CR, 783 m3 t−1 for ICP, 1115 m3 t−1 for ECP, and 1066 m3 t−1 for SZ. For the state of Rio Grande do Sul, an average water footprint was obtained in the 2019/2020 crop of 1093 m3 t−1. [ABSTRACT FROM AUTHOR]

Study region: From 2017 to 2019, xylem and leaf samples of Cinnamomum camphora were sampled and soil water samples at 0–100 cm depth were sampled 65 times simultaneously in a typical East Asian monsoon region. Study focus: The seasonal origin of plant and soil water from precipitation was inferred based on the stable isotope techniques, including the evaporation line slope (SEL) estimations and the seasonal origin index (SOI) calculation. New hydrological insights for the region: The regression SEL of leaf water was close to the theoretical SELs estimated based on the Craig–Gordon model, but xylem water and soil water showed higher regression SELs than the theoretical SELs, this may be due to the seasonality of the precipitation isotopes and evaporative fractionation. The fractionation-compensated isotopic values calculated based on the theoretical SELs of different water types were close, with the differences within 2.4‰ for δ18O and 20.0‰ for δ2H of each other, and the uncertainty of the fractionation-compensated isotopic values was low enough in the calculation of SOI. The SOI results showed that summer precipitation was more prevalent in plant and soil water, and more winter precipitation may recharge runoff when evapotranspiration demand is weak. Overall, the leaf sampling and the theoretical method have the potential to infer the seasonal water origin over a relatively long period.

The supra-permafrost water is a vital water source to support the ecosystem and an important link in maintaining the hydrothermal cycle in the permafrost area. Under the intensification of climate change, scientific understanding of the effect of permafrost degradation on the supra-permafrost water is of great significance to water resources and ecological protection. Focusing on the hydrological effects of permafrost degradation in the source areas of the Yellow River, this study analyzed the degradation characteristics of permafrost, and revealed the response of the depth of groundwater level and recharge process of the supra-permafrost water to the permafrost degradation, on the basis of the temperature and moisture content of frozen soil at typical monitoring points and the runoff change at the Huangheyan Hydrologic Station. The results show that the average temperature increased 0.42 °C at the 0−2.4 m profile of the monitoring point from 2010 to 2020. The depth of the upper interface of the permafrost reduced from 2.1m to 2.5 m, with an average decrease rate of 4cm/a. After 2018, the depth of supra-permafrost water level reduced from less than 0.9 m to 0.9−1.8 m. The permafros degradation led to the runoff process in the melting period of active layer (May−October) being advanced, the ratio of extreme value being reduced，and the runoff hydrograph in January being more prominent. Ground temperature is the dominant factor in controlling the changes of depth of the supra-permafrost water. Under the condition of warm and humid climate change, Permafrost degradation would change the dynamic characteristics of the water above the frozen layer and its hydraulic relationship with surface water, affecting the hydrological and ecological processes in the source area of the Yellow River.