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2D cobalt-based hexagonal nanosheets (HNs) with an adjustable structure formed by a melamine thermal reflow method were proposed and were then calcined in an inert gas atmosphere to obtain single-atom ruthenium modified cobalt oxide.

Advances in brain imaging have led to a higher incidence of brain metastases (BM) being diagnosed. Stereotactic radiotherapy (SRS), systemic immunotherapy, and targeted drug therapy are commonly used for treating BM. In this study, we summarized the differences in overall survival (OS) between several treatments alone and in combination. We carried out a systematic literature search on Pubmed, EMBASE, and Cochrane Library. Differences in OS associated with Immune checkpoint inhibitors (ICI) alone versus targeted therapy alone and SRS + ICI or ICI alone were evaluated. This analysis was conducted on 11 studies involving 4,154 patients. The comprehensive results of fixed effect model showed that the OS of SRS + ICI group was longer than that of the ICI group (hazard ratio, 1.72; 95% CI: 1.41–2.11; P = 0.22; I 2 = 30%). The combined fixed-effect model showed that the OS time of ICI was longer than that of targeted therapy (hazard ratio, 2.09; 95% CI: 1.37–3.20; P = 0.21; I 2 = 35%). The study had a low risk of bias. In conclusion, our analysis confirmed that immunotherapy alone showed a higher OS benefit in BM patients than targeted therapy alone. The total survival time of patients with SRS combined with ICI was higher than that of patients with single ICI.

In order to study whether jujube trees can grow normally under rain-fed conditions in loess hilly areas, we planted jujube trees (Ziziphus jujuba Mill.) 4 years after felling a 23-year-old apple orchard. The growth process of the jujube trees and the variation in soil water content (SWC) were monitored for three consecutive years following planting in order to study the effects of the water-saving pruning (WSP) technique. Results showed the following. (1) The soil at a depth of 0–1,000 cm had been desiccated when the area was an apple orchard. (2) Under rain-fed conditions, the jujube trees with the WSP technique were always able to maintain normal growth while the jujube trees with conventional pruning method had a normal growth stage of only 4 years. The water use efficiency of the jujube trees with the WSP technique was much higher than that of the jujube trees with conventional pruning. We recommend WSP in jujube orchard management, because the jujube trees with WSP could maintain normal growth in the deep dried soils of the loess hilly region, as WSP can reduce the water consumption of the jujube trees and may have a positive effect on soil moisture restoration. HIGHLIGHTS We proposed water-saving pruning for the growth of jujube trees planted in dry soil.; Water-saving pruning can significantly improve water use efficiency of jujube trees planted in dry soil.; Water-saving pruning may have a positive impact on the restoration of soil water in dry soil.

Under the influence of environmental change, disturbance and other external conditions, sediments release internal nutrients to the overlying water and become a contamination source in the lake. Complex habitat systems provide a unique opportunity for determining the influences of environmental changes in lakes. In this study, Baiyangdian Lake (BYDL) was divided into different habitat systems (connected water areas, river courses, reed fields, lotus ponds, fishponds, farmland, and thorps) based on the influence of natural and artificial activities. The physical and chemical properties of overlying water and sediment in different habitat systems were investigated. In addition, statistical analytical methods were used to analyze the relationship between sediment characteristics and overlying water parameters in different habitat systems. The results showed that nitrogen and phosphorus in the overlying water could accumulate in the sediments, while disturbance was one of the main factors affecting the release of nutrients from sediments. Disturbance promoted the suspension of sediments and increased the oxygen content, thereby facilitating the internal release of nutrients. However, there were also some differences in the process of internal release of nutrients between the habitat systems. Nitrogen in the overlying water was closely related to the source of organic matter (r0.950), especially in the ponds (including lotus ponds, reed fields, and fishponds), and phosphorus was mainly influenced by turbidity (r0.870). In the river course (p = 0.198, n = 26), the disturbance and increase in pH promoted the internal release of nutrients from the sediments (contributions of 35.2 % and 25.1 %, respectively). In the ponds, the aquatic macrophytes reduced the release of nitrogen and phosphorus in sediments. Overall, this study provides more information on the migration and transformation of nutrients between sediment and overlying water in lakes with multiple habitats.

Jujube (Ziziphus jujube Mill.) is a traditional economic forest crop and is widely cultivated in hilly areas of the Loess Plateau, China. However, soil desiccation was discovered in jujube plantations. Pruning is recognized as a water-saving method that can reduces soil water consumption. In this study, we monitored the jujube plots with control (CK), light (C1), medium (C2) and high (C3) pruning intensities during the jujube growing period of 2012–2015 to explore the effect of pruning intensity on soil moisture and water use efficiency (WUE) of jujube plantations in the hilly Loess Plateau Region. The results showed that pruning is an effective method for soil water conservation in jujube plantations. Soil moisture increased with increasing pruning intensity during the jujube growing period of 2012–2015. C1, C2 and C3 pruning intensities increased soil water storage by 6.1–18.3, 14.4–40.0 and 24.3–63.3 mm, respectively, compared to CK pruning intensity. Pruning promoted soil moisture infiltration to deeper soil layer. Soil moisture infiltrated to soil depths of 240, 280 and >300 cm under C3 pruning intensity, 220, 260 and 260 cm under C2 pruning intensity, 200, 240 and 220 cm under C1 pruning intensity, and 180, 200 and 160 cm under CK pruning intensity in 2013, 2014 and 2015, respectively. Soil water deficit was alleviated by higher pruning intensity. In 2013–2015, soil water change was positive under C2 (6.4 mm) and C3 (26.8 mm) pruning intensities but negative under C1 (−20.5 mm) and CK (−40.6 mm) pruning intensities. Moreover, pruning significantly improved fresh fruit yield and WUE of jujube plants. Fresh fruit yields were highest under C1 pruning intensity with the values of 6897.1–13,059.3 kg/hm2, which were 2758.4–4712.8, 385.7–1432.1 and 802.8–2331.5 kg/hm2 higher than those under CK, C2, and C3 pruning intensities during the jujube growing period of 2012–2015, respectively. However, C3 pruning intensity had the highest WUE values of 2.92–3.13 kg/m3, which were 1.6–2.0, 1.1–1.2 and 1.0–1.1 times greater than those under CK, C1 and C2 pruning intensities, respectively. Therefore, C3 pruning intensity is recommended to jujube plantations for its economic and ecological benefits. These results provide an alternative strategy to mitigate soil desiccation in jujube plantations in the hilly Loess Plateau Region, which is critical for sustainable cultivation of economic forest trees in this region.

Activated sludge treated by ultrasound was tested as a source of exogenous electron donor to accelerate quinoline mono-oxygenation, which requires an intracellular electron donor (2H). The quinoline-removal rate was proportional to the amount of treated or untreated sludge added in flask experiments, but the best biodegradation kinetics was obtained with a mixture of 25% untreated sludge plus 75% treated sludge. The treated sludge primarily provided exogenous electron donor, while the untreated sludge provided active biomass. A biofilm system also showed the same beneficial effect of treated sludge, and the soluble fraction of the treated sludge had the greatest impact. Using treated sludge instead of a purchased electron donor provides an economic advantage for accelerating the biodegradation of contaminants whose biodegradation is initiated by an oxygenation reaction, such as quinoline.

Drought climate and human activity have led to serious soil desiccation in the loess hilly region. Mulching measures can effectively increase rainfall infiltration and reduce evaporation, thus improving soil moisture status. The objective of this study was to explore the characteristics of water restoration of deep desiccated soil under different mulching measures and determine a promising mulching measure. We built large-scale simulation desiccated soil columns in the field (soil columns with an 0.8-m diameter and 10-m depth). Six kinds of treatments were tested: film mulching, gravel mulching, branch mulching, planting of jujube tree (Ziziphus jujuba Mill.) and robinia (Robinia pseudoacacia L.), and bare land as the control. The results showed that different mulching measures can increase soil water storage and alleviate the soil drying phenomenon to different degrees. Compared with other treatments, film mulching is more effective, with larger increment of soil water storage, deeper restoration of soil dry layer, and simple to operate in loess hilly region. So, we recommend film mulching, which is a feasible method to improve the soil desiccation status in hilly loess areas.

Artemisinin and its derivatives are a family of anti-malarial drugs with known clinical safety and efficacy. Apart from its anti-malarial effect, artemisinin has also been reported to show anti-cancer, anti-viral, anti-parasitosis, anti-inflammatory properties in vitro and in vivo. An increasing number of studies report that artemisinin can impact the fibrotic process through various ways, such as TGF-β, MAPK, Wnt/β-catenin, PI3K/AKT/mTRO, FRX and Notch signaling pathways, as well as regulation of BMP-7 and cell autophagy. Moreover, the anti-inflammatory properties of artemisinin also contribute to the anti-fibrotic process. The present review summarizes the related studies on artemisinin treatment in fibrosis and elucidates the underlying mechanisms. We believe that this review can explain the potential anti-fibrotic value of artemisinin, outlining its potential use in the development of a safe and effective therapeutic method to alleviate fibrosis in the future.

Anthropogenic activities significantly influence the lake environment and are reflected by the element contents in sediments/soils. The lake fragmentation provides a unique opportunity for comparing the influences of natural/anthropogenic activities of different wetlands systems. In this study, a complex and fragmented lake was investigated, and sediment/soil samples were collected from different systems. The nutrient contents (C, N, and P), stable isotopic compositions (δ13C and δ15N), and trace metal contents (As, Cd, Cr, Cu, Ni, Pb, and Zn) in the sediments/soils were measured to determine the natural and anthropogenic influences and pollution sources. Lake fragmentation was caused by insufficient water input and long-term agricultural and aquacultural activities of local residents. Due to the effect of anthropogenic activities, the enrichment conditions of various elements differed significantly for different wetland systems. Industrial, agricultural, and biological sources significantly influenced the element enrichment in different systems. The results demonstrated that the anthropogenic activities significantly influenced the sediments/soils in wetland systems, and the lake fragmentation reduced the diffusion of the contaminants. These results provide accurate reference information for pollution control, lake management, and ecological restoration.

The development of a cost-effective and highly reusable visible-light responsive photocatalyst is necessary for reducing the costs of contaminant photodegradation. In this study, a novel visible-light driven waste-based loaded-geopolymer photocatalyst was prepared by a facile method. CdS nanoparticles were successfully loaded in the geopolymer slice by geopolymerization, and the optimal proportions of raw materials (CdS, Fe2O3, drinking water treatment residual, granulated blast furnace slag) were determined. The results indicated that the waste-based geopolymer loaded with 4 wt% CdS achieved the best photocatalytic performance of organic dye in aqueous solution. Geopolymer slice provided an easily recyclable and reusable carrier for CdS nanoparticles in the photocatalytic process that efficiently separated the photogenerated charges. In this sample, the recombination of photogenerated electron-hole pairs and photocorrosion of CdS were reduced, which effectively enhanced the reusability of loaded geopolymer. Overall, this work presents an effective and facile method for the rapid fabrication of visible-light driven loaded photocatalyst and provides a strategy by which the recyclability of photocatalyst could be enhanced.

Dew is an important water source for plants in arid and semi-arid regions. However, information on dew is scarce in such regions. In this study, we explored dew formation, amount, and duration of rain-fed jujube (Zizyphus jujube Mill) trees in a semi-arid loess hilly region of China (i.e., Mizhi County). The data included dew intensity and duration, relative humidity, temperature, and wind speed measured from 26 July to 23 October, 2012 and from 24 June to 17 October, 2013 using a micro-climate system (including dielectric leaf wetness sensors, VP-3 Relative Humidity/Temperature Sensor, High Resolution Rain Gauge, and Davis Cup Anemometer). The results show that atmospheric conditions of relative humidity of >78% and dew point temperature of 1°C–3°C are significantly favorable to dew formation. Compared with the rainfall, dew was characterized by high frequency, strong stability, and long duration. Furthermore, heavy dew accounted for a large proportion of the total amount. The empirical models (i.e., relative humidity model (RH model) and dew point depression model (DPD model)) for daily dew duration estimation performed well at 15-min intervals, with low errors ranging between 1.29 and 1.60 h, respectively. But it should be noted that the models should be calibrated firstly by determining the optimal thresholds of relatively humidity for RH model and dew point depression for DPD model. For rain-fed jujube trees in the semi-arid loess hilly regions of China, the optimal threshold of relative humidity was 78%, and the optimal upper and lower thresholds of dew point depression were 1°C and 5°C, respectively. The study further demonstrates that dew is an important water resource that cannot be ignored for rain-fed jujube trees and may affect water balance at regional scales.

International audience; Background and Aims: Depending on the species, water stress affects different growth and developmental processes, mainly due to changes in hydraulic properties and hormonal signalling. This study compared the impact of water stress on tree development and organ growth in three apple cultivars. Methods: Trees were differentially irrigated to induce water stress or to provide well-watered conditions in their second and third years of growth. Effects of water stress were evaluated at tree scale by shoot number and proportions of the different types of shoots, and at shoot scale by metamer appearance rate, growth duration and arrest time, as well as organ size. Key Results: Water stress promoted early growth cessation, prolonged summer arrests and decreased growth resumptions, thus modifying within-tree shoot demography in favour of short shoots. Growth cessations occurred in mild water stress conditions before any difference in stem water potential appeared. No major impact was observed on organ size. Consistently with tree ontogeny, the number of shoots that resumed growth after summer arrest decreased with years, but more in water-stressed than well-watered conditions. Conclusions: Even though the impact of water stress differed slightly among cultivars, the reduction in neoformation and increase in summer arrest played a common role in apple tree morphological responses and led to stress avoidance by early reduction of tree leaf area.

The widely adopted practice of clean-cultivation in rainfed orchards in the Loess Plateau has led to serious soil erosion and degradation problems. Agroforestry is a promising management practice for solving these problems, but may reduce available soil water. Thus, reasonable soil and water management strategies should be developed for agroforestry systems in this region. The objective of this study was to determine whether adopting proper mowing management of the understory intercrop limited soil drying in a rainfed jujube (Ziziphus jujuba Mill.) orchard in this region. Various mowing intensities (3-, 6-, 9-cm stubble height and unmowed treatments) were imposed on three intercrop species: bluegrass (Poa pratensis L.), white clover (Trifolium repens L.), and hairy vetch (Vicia villosa Roth) to investigate and compare their root characteristics and soil moisture responses to mowing under greenhouse and field conditions. Based on the results, the most promising intercrop species and mowing intensity to be used in a jujube orchard were selected for field validation. The results showed that mowing effectively regulated intercrop root amount and distribution, as well as associated soil moisture conditions. However, the sensitivities of root characteristics and soil moisture to mowing and growth environment were species-specific. Bluegrass mowed to a 3-cm stubble height produced the minimum root amount, the shallowest root depth, and the greatest soil water content. When this treatment was applied to a rainfed jujube orchard during the 2015 and 2016 growing seasons, average soil moisture in the 0–300 cm soil layer was essentially unaffected, while fruit yield was increased. Consequently, bluegrass mowed to a stubble height of 3 cm when intercropped with jujube trees in the Loess plateau is a feasible practice to increase jujube yield and avoid extra soil drying.

As a drought tolerant plant, jujube (Ziziphus jujuba Mill.) is commonly planted in Chinese semiarid Loess Plateau Region under rain-fed conditions. To evaluated the effectiveness of branch removal to conserve water resources in rain-fed jujube plantations in the region, two degrees of branch removal treatments (T1–two main branches removed; T2–one main branch removed) were compared with control treatment (none of the three main branches removed) and the effects on water use in Jujube plantations were analyzed. Sap flow was monitored (using the Granier-type thermal dissipation probes) along with meteorological factors, soil water content, vessel diameter, crown projection area and leaf area index, with soil moisture condition divided into water stress and non-water stress. Results showed that branch removal was an efficient way of conserving water resources in jujube plantations. a) It improved soil water content by reducing water loss via total evapotranspiration (ET) during jujube growth period. Total ET values were 452, 463 and 478 mm respectively for T1, T2 and the control treatments during jujube growth period in 2012; 408, 426 and 451 mm respectively for T1, T2 and the control treatments during jujube growth period in 2013 and 374, 381 and 392 mm respectively for T1, T2 and the control treatments during jujube growth period in 2014. b) Branch removal not only decreased transpiration per unit ground area (stand transpiration: Tg), but also increased the sensitivity of Tg to environmental variables. In contrast, the removal of two (out of three) branches increased transpiration per unit leaf area (leaf transpiration: Tl), making it less sensitive to soil water content. c) Treatment T1 significantly increased the sensitivity of canopy conductance (Gc) to vapor pressure deficit (VPD), which effect was not significant under T2. Isohydric regulation of water loss through Gc response to VPD was the same for the three treatments, regardless of the different tree canopy sizes and soil water conditions, but reference canopy conductance (Gcref: canopy conductance at VPD = 1 kPa) was treatment-specific. d) Branch removal improved the tolerant of jujube tree to negative water potential and xylem cavitation by decreasing average vessel lumen diameters. Compared with the control, both branch removal treatments (T1 and T2) resulted in a significant decrease in average vessel lumen diameter at 15 mm below the cambium (40.74, 42.53 and 46.81 μm respectively for T1, T2 and the control treatments). Similarly, T1 and T2 reduced mean vessel lumen diameter at 5 mm below the cambium (43.20, 47.44 and 48.39 μm respectively for T1, T2 and the control treatments). e) Branch removal significantly decreased the fresh fruit yield and water use efficiency except in 2013, during which differences were not significant. Fresh fruit yield values were 8082, 8964 and 11293 kg ha−1 respectively for T1, T2 and the control treatments in 2012; 5691, 5426 and 6000 kg ha−1 respectively for T1, T2 and the control treatments in 2013; 6804, 8341 and 10589 kg ha−1 respectively for T1, T2 and the control treatments in 2014. WUE values were 1.79, 1.94 and 2.36 kg m−3 in 2012; 1.40, 1.28 and 1.33 kg m−3 in 2013; 1.82, 2.19 and 2.70 kg m−3 in 2014. T1 treatment was recommended in terms of improving soil water storage as well as maintaining a certain amount of productivity in jujube plantations in Chinese semiarid Loess Plateau Region. The result of the study is critical for the development of effective water management strategies in jujube plantations ensure that the fragile ecology of the Loess Plateau is sustained.

The Jarvis canopy resistance sub-model is commonly used in transpiration modelling, although its optimal structure is rarely studied. It is still not fully clear that to what extent transpiration modeling may differ if using different constraint function forms for key environmental variable in Jarvis sub-model. In this study, various Jarvis canopy resistance sub-model configurations were embedded in the Penman-Monteith model to compare their ability to model daily transpiration of rain-fed jujube (Ziziphus jujuba Mill.) plantations where soil moisture is a key factor of tree water use. Parameters were calibrated using the Bayesian Markov Chain Monte Carlo (MCMC) simulation technique and model comparison was quantified using Deviance Information Criterion (DIC). The results showed significant differences in model performance between the constraint function forms of soil water content. The difference in DIC between the model with the best constraint function form and the other two forms reached 37.66–50.94, much higher than the evaluation criteria for significance (larger than 7). When the best constraint function form was used, the performance of the transpiration model improved. The model performance worsened when the other constraint function forms were used, even worse than those without consideration for soil water content. However, only slight differences in model performance were detected for the constraint function forms of temperature, vapor pressure deficit and photosynthetically active radiation. Using the best configuration of Jarvis canopy resistance sub-model, daily transpiration of jujube plantation was well estimated with overall good accuracy and acceptable uncertainty. The predictions and observations were highly correlated (R2 = 0.87 for calibration and R2 = 0.80 for validation). The results suggested that different constraint function forms of an environmental factor contributed differently to transpiration model performance, and the situation was different for different environmental factors. Including the key environmental factor in the Jarvis canopy resistance sub-model will not always improve the performance of transpiration models.

Non-rainfall water inputs (NRWIs) provide crucial water resources for dryland ecosystems in arid and semi-arid regions. However, little is known about the quantitative characteristics and formation of NRWIs, and the relative importance of NRWIs as water sources in a dryland jujube (Ziziphus jujuba Mill.) plantation in the Hilly Loess Region of China. The objectives of this study were to determine the characteristics of NRWIs during the jujube growing season with regard to amount, duration, and contributions to transpiration, evaporation, and evapotranspiration. Dew intensity and duration were monitored using dielectric leaf wetness sensors, Also sap flow, soil water content, soil temperature, and meteorological variables were measured during the 2017 and 2018 growing seasons. NRWIs were found to be composed of canopy dew (CD) and water vapor adsorption (WVAS) in the 0–5 cm soil layer, amounting to 75.218 mm in 2017 and 75.309 mm in 2018 (CD accounted for about 81% of NRWI). Daily average CD was significantly greater than WVAS (P

This study aimed to analyze the spatial correlation between soil water and root distribution in dense-dwarf jujube plantations in the Hilly Loess Region (HLR) of China. The soil coring method was used to sample roots at different depths within the 0–1,000 cm soil profile. The results showed that increase in average annual root depth decreased with increasing jujube stand age. The maximum root depth of the 12-year-old jujube was 520 cm. The difference between the maximum and minimum root depths in the 12-year-old jujube trees was 180 cm. Lateral roots started developing intersection networks 3 years after planting. Soil water fluctuation was not induced by vertical root systems of dense-dwarf jujube plants. With increasing jujube stand age, root depth, dry soil layer depth (below 240 cm) and annual soil water variance within the top 0–200 cm soil layer increased. However, root-zone soil water content decreased with increasing stand age while dry soil layer depth was slightly larger than root depth. The results of this study have important significance to provide vital technical support for jujube cultivation especially under semiarid conditions and were expected to find application in water management for plantations in the HLR.

Jujube is widely cultivated in the semi-arid region of the Loess Plateau in Northwest China due to its high water deficit tolerance. In such an ecologically vulnerable area, it is critical to explore the water consumption processes of key tree species and their responses to driving factors. Sap flow data gathered during a two-year field study in a jujube plantation were analyzed as a surrogate for transpiration measurements. The measured sap flows were related to changes in the soil water content, meteorological factors (the vapor pressure deficit and the level of photosynthetically active radiation), and plant physiological factors (the sap wood area, leaf area and leaf area index). The factors that govern sap flow were found to vary depending on the growing season, and on hourly and daily timescales. The plants' drought tolerance could be predicted based on their peak sap flows and the variation in their sap flow rates at different soil water levels. The sap flow was most strongly affected by the water content of the topmost (0-20 cm) soil layer. Of the studied meteorological factors, the photosynthetically active radiation had a greater effect on sap flow than the vapor pressure deficit. The correlation we found could be applied to predict jujube tree water consumption and assist the design of irrigation scheme.

As a drought tolerant plant, jujube (Ziziphus jujuba Mill.) is commonly planted in semiarid Northwest China under rainfed conditions. To clarify the response of water use to climatic conditions, sap flow (SF) in 8 non-irrigated jujube trees was monitored using thermal dissipation probes. Also meteorological variables, soil water content, crown projection area and leaf area index were measured during the 2012 growth season. Based on relative extractable water (θe), soil moisture conditions were classified into water stress (θe 0.4) conditions. Since leaf area (LA) significantly influences SF, relative sap flow (defined as SFR = SF/LA) was used to analyze its relationships with selected meteorological factors. Obvious differences were noted between responses of SFR and its sensitivity to meteorological factors under the two different soil moisture conditions. Daily SFR was linearly related with solar radiation (Rs) but logarithmically related with vapor pressure deficit (VPD), variable of transpiration (VT) and reference crop evapotranspiration under both soil moisture conditions. Hourly SFR was linearly related with Rs, VPD and VT at θe > 0.4, while, at θe

Finding low-cost electron donors to drive denitrification is an important target for many municipal wastewater treatment plants (MWTPs). Excess sludge (biomass) potentially is a low-cost electron donor generated internally to the MWTP, but it has to be made more bioavailable. Aerobic and anoxic biomasses were treated with ultrasound, and their supernatants were used as electron donors for stimulating denitrification. The supernatant from ultrasound-treated anoxic biomass achieved 54% faster nitrate-N removal than did supernatant from the treated aerobic biomass, and the supernatant of untreated biomass was ineffective as an electron donor. UV illumination of the supernatants further enhanced the rates, with increments of 19% and 14%, respectively for the aerobic and anoxic supernatants. Sodium acetate at a range of initial concentrations was compared as a readily bioavailable electron donor to gauge the acceleration impact of the supernatants as equivalent bioavailable chemical oxygen demand (COD). The total chemical oxygen demand (TCOD) of the supernatant harvested from anoxic biomass without UV illumination was 76% bioavailable, while its bioavailable TCOD was 78% after UV illumination. For the supernatant from the aerobic biomass, the bioavailable fractions were, respectively, 56% and 58% without and with UV illumination. The greatest impact for converting excess biomass into a source of bioavailable electron donor to drive denitrification came from ultrasound treatment of the biomass, which disrupted the biomass to form particulate chemical oxygen demand (PCOD) that was bioavailable. PCOD was at least 51% bioavailable, and it contributed no less than 82% of the bioavailable COD.

Aimed to understand how soil water was depleted by deep roots, the effects of drip irrigation and stand age on the deep root distribution, rooting depth, and soil water profile dynamics were investigated in a jujube (Ziziphus jujube Mill. CV. Lizao) plantation. A soil coring method with a LuoYang shovel was used for sampling until no more roots were found. It showed that the maximum fine rooting depth (

Planting density is a major factor during the conversion of cropland to woodland in the semiarid hilly region of the Chinese Loess Plateau. Jujube (cv. Lizao on Ziziphus rootstock) tree plantations have been planted densely to increase income, with a spacing of 3 m between tree rows and 2 m between trees in rows. This practice could lead to soil water depletion. To estimate these risks, water budgets should be calculated accurately, based on a realistic characterization of root distribution. The objective of this study was to determine the spatial root distribution (vertical and horizontal) in a dense jujube plantation under different water management practices in the hilly region of the Chinese Loess Plateau. Spatial root distribution in densely planted 8-year-old jujube trees was investigated using a trench-profile method down to 1 m. Four treatments were tested: sloping land (W1), mini-catchment (W2), drip-irrigation (W3), and drip-irrigation plus mini-catchment (W4). Furthermore, mechanical excavation combined with a water spraying method was used to determine the maximum rooting depth. Spatial root distribution was most affected by drip-irrigation. Horizontally, fine roots were concentrated in the area soaked by irrigation in treatments W3 (69.8%) and W4 (73.8%). Similarly, in the vertical direction, there were significantly more fine roots within the 0–1 m profile in the W4 and W3 treatments compared with the W2 and W1 treatments. Fine root intersects were even more abundant in top 0.4 m of W4 treatments compared with the whole soil profile (0–1 m depth) in the W2 and W1 treatments. The W2 and W4 treatments with mini-catchments did not result in a significantly higher number of fine root intersects relative to the treatments without catchments (W1 and W3, respectively). The correlation between fine root intersects and maximum rooting depth was analyzed and the results indicated that drip-irrigation and mini-catchment treatments increased fine root intersects, but decreased the maximum rooting depth. This study found that root distribution was most affected by the drip-irrigation treatment, which led to higher root densities close to water emitters on the surface, down to a depth of 0.6 m in the soil. Thus, drip-irrigation could have a significant impact on the root development of densely planted jujube trees in semiarid regions and it might potentially avoid the formation of dry soil layers. These findings provide significant support for the dense planting of jujube trees in the semiarid region.

An understanding of spatial variability for soil chemical properties is essential in optimizing fertilization and sustaining yield. The objective of this study was to investigate the spatial variability of soil chemical properties in a 10-year-old jujube trees hillslope (2,725 m2) on the Loe

Soil desiccation and water shortage are major challenges of rain-fed crop production in the semi-arid areas of the Loess Plateau of China. Mulching and pruning were considered effective strategies to improve harvest by reducing soil water evaporation and plant transpiration rates. In the present study, the possible synergistic effects of the combination of mulching and pruning on soil water status, growth, yield, and water use efficiency were explored in the jujube plant. Field experiments were conducted in a typical hilly semi-arid region over three growing seasons and two dormancy seasons in 2015–2017. The three treatments applied to mountain jujube plantations throughout the year were grassland (CK), regular pruning (PR), and pruning and mulching (PM). Soil water storage (0–200 cm) was higher in the PM than the PR treatment but lower than that of the CK in all three growing seasons. Relative to PR and CK, PM significantly decreased soil water loss during the dormancy season. The soil moisture infiltration depths were 300 cm, 160 cm, and 420 cm in 2016 and 420 cm, 280 cm, and 460 cm in 2017 for PM, PR, and CK, respectively. Soil desiccation was substantially reduced under the PM treatment in the deep soil layer but was less effectively mitigated under the PR treatment. In the CK treatment, soil desiccation appeared at 0–200 cm but was alleviated by heavy rainfall. Fresh fruit yield ranged from 6643–11,056 kg ha−1 for the PM treatment in 2015–2017. This range was 1221–2628 kg ha−1 higher than that for the PR treatment. Water use efficiency was 2.28 kg m−3, 2.05 kg m−3, and 2.22 kg m−3 under the PM treatment in 2015, 2016, and 2017, respectively. These rates were 1.27 × , 1.26 × , and 1.39 × higher, respectively, than those for the PR treatment. These results suggest that the combination of mulching and pruning is an alternative strategy for mitigating soil desiccation in the hilly regions of the Loess Plateau of China. This alternative land management system may be critical for the sustainable cultivation of economically important forest trees in the Loess Plateau region and elsewhere. Keywords: Soil desiccation, Soil water storage, Pruning, Crop yield, Water use efficiency

The authors studied the effects using three different levels of irrigation on the growth and biomass allocation in H. ammodendron and T. ramosissima seedlings in the shelterbelt along the Tarim Desert Highway. The three irrigation amounts were 35 (CK), 24.5 (treatment 1), and 14 (treatment 2) kg·ind. plant−1·once−1, respectively. The results show that (1) the vertical depth of the two seedlings’ root increased with lower levels of irrigation showing that the two species adapted to decreased irrigation by root elongation in the hinterland of the Taklimakan Desert, and the vertical root depth of H. ammodendron under treatment 2 was notably higher than CK. (2) Compared with CK, the belowground biomass of treatment 1 and 2 both showed a significant increase as follows: H. ammodendron seedlings increased by 14.51% and 37.03% under treatment 1 and 2, respectively, while T. ramosissima seedlings increased by 68.19% and 25.78% under treatment 1 and 2, respectively. This means that H. ammodendron seedlings were more adapted to the conditions in treatment 2 while T. ramosissima seedlings were better adapted to treatment 1 conditions. (3) When compared with CK, the fine root bomass of these two species all exhibited some increase under both treatments, and ANOVA analysis showed that the biomass of deep layer root of the two species under treatment 2 was notably higher than CK and treatment 1. This should help seedlings to more effectively absorb soil water from deep layers during dry conditions. (4) The root-shoot ratio was different for these two species. For H. ammodendron seedlings, the root-shoot ratio was less than 1, while for T. ramosissim seedlings it was larger than 1. The root-shoot ratio of H. ammodendron seedlings increased with decreasing levels of irrigation, and that of T. ramosissim seedlings also increased under treatment 2. (5) With decreasing levels of irrigation, due to the difference of species, the growth variation of aboveground indexes was also different, while compared with CK, it was not significant.

International audience; In order to select suitable evapotranspiration (ET) models for rainfed and sparsely cultivated jujube (Ziziphus jujuba Mill.) plantations in the Loess Plateau, this study used Bayesian analysis to compare the performances (accuracies and uncertainties) of the Shuttleworth-Wallace (SW) model, the Penman-Monteith (PM) model and the Penman-Monteith equation with a variable surface canopy resistance (PMv) model in terms of daily and hourly ET. To determine seasonal variations and soil water dependence, probabilistic analyses were independently used to calibrate the SW and PM model parameters at every growth stages and the PMv model parameters for different soil water conditions in the growth season of rainfed jujube plantations in 2013. Finally, data for the growth season in 2012 were used to validate the calibrated models. The results showed that the posterior distributions of the parameters of the three models narrowed down at both daily and hourly scales, suggesting decreasing uncertainties in the parameters. Some model parameters varied with season (increasing for the last two growth seasons) or soil water condition (decreasing with increasing soil moisture). The performances of the ET models also varied with time scale, generally less precise at hourly than at daily time scale. Irrespectively, the three ET models met the evaluation criteria (mean relative error (MAE) < 20% and coefficient of determination (R-2) > 0.8 and Willmott index of agreement (D) > 0.8) with acceptable accuracy and uncertainty at the daily time scale in both calibration (with R-2, MAE and D values of 0.94, 6.78% and 0.94 for the SW model; 0.94, 7.52% and 0.94 for the PM model; and 0.89, 8.49% and 0.83 for the PMV model, respectively) and validation periods (with R-2, MAE and D values of 0.94, 5.77% and 0.92 for the SW model; 0.93, 5.15% and 0.91 for the PM model; and 0.89, 10.26% and 0.86 for the PMV model, respectively). Where only climate data were available, the PMV model was recommended for estimation of daily ET in the study area due to less complexity, low data requirements, and high accuracy. Where sufficient monitoring data were available, the PM model was preferred for estimation of the daily ET in the study area due to less complexity and small differences in performance with the SW model. All three models met the evaluation criteria for calibration period(with R-2, MAE and D values of 0.92, 16.04% and 0.92 for the SW model; 0.96,14.37% and 0.94 for the PM model; and 0.89, 18.56% and 0.91 for the PMV model, respectively) while only the SW model met the evaluation criteria for validation period (with R-2, MAE and D values of 0.87, 16.33% and 0.88 for the SW model; 0.85, 20.70% and 0.85 for the PM model; and 0.85, 23.95% and 0.83 for the PMV model, respectively) at the hourly time scale. Based on model accuracy and uncertainty at the hourly time scale, the SW model was recommended for use in estimating ET in jujube plantations in the Loess Plateau

In order to ease soil desiccation and prevent ecological deterioration in the Loess Plateau, where jujube (Zizyphus jujube MIll) is widely cultivated as a drought tolerant plant, four pruning intensities (PI), from PI-1 (light) to PI-4 (heavy) were set up based on total length of secondary branches to study the effects of pruning on transpiration and soil moisture in jujube plantations. Furthermore, growth indexes were regularly monitored to estimate jujubes biomass. Sap flow, meteorological and soil moisture conditions were monitored using thermal dissipation probes (TDP), weather station (RR-9100) and the combination of time domain transmission (TDT) technology and neutron moisture gauges (CNC503B), respectively. The results showed that daily actual transpiration of jujube was positively correlated with leaf biomass. Compared with PI-1, jujube transpiration during growth period under PI-2, PI-3, and PI-4 dropped by 11.1%, 29.2%, and 47.9%, respectively. On the contrary, annual water storage under PI-2, PI-3, and PI-4 increased by 6.29 mm, 25.78 mm and 34.74 mm while water use efficiency increased by 5.1%, 15.7% and 24.2%, respectively. Overall, increase in pruning intensity could significantly reduce water consumption of jujube and improve soil moisture in jujube plantations.