Search Results (995)

Dryland ecosystems are highly sensitive to climate change, making vegetation monitoring crucial for understanding ecological dynamics in these regions. In recent years, climate change, combined with large-scale ecological restoration efforts, has led significant greening in China’s arid areas. However, the mechanisms through which seasonal climate variations regulate vegetation growth are not yet fully understood. This study hypothesizes that seasonal climate change affects net primary productivity (NPP) of vegetation by influencing phenology. We focused on China’s Windbreak and Sand-Fixation Ecological Function Conservation Areas (WSEFCAs) as representative regions of dryland vegetation. The Carnegie–Ames–Stanford Approach (CASA) model was used to estimate vegetation NPP from 2000 to 2020. To extract phenological information, NDVI data were processed using Savitzky–Golay (S–G) filtering and threshold methods to determine the start of season (SOS) and end of season (EOS). The structural equation model (SEM) was constructed to quantitatively assess the contributions of climate change (temperature and precipitation) and phenology to variations in vegetation NPP, identifying the pathways of influence. The results indicate that the average annual NPP in WSEFCAs increased from 55.55 gC/(m²·a) to 75.01 gC/(m²·a), exhibiting uneven spatial distribution. The pathways through which seasonal climate affects vegetation NPP are more complex and uneven. Summer precipitation directly promoted NPP growth (direct effect = 0.243, p < 0.001) while also indirectly enhancing NPP by significantly advancing SOS (0.433, p < 0.001) and delaying EOS (−0.271, p < 0.001), with an indirect effect of 0.133. This finding highlights the critical role of phenology in vegetation growth, particularly in regions with substantial seasonal climate fluctuations. Although the overall ecological environment of WSEFCAs has improved, significant regional disparities remain, especially in northwestern China. This study introduces causal mediation analysis to systematically explore the mechanisms through which seasonal climate change impacts vegetation NPP in WSEFCAs, providing new insights into the broader implications of climate change and offering scientific support for ecological restoration and management strategies in arid regions. Full article

The growing impacts of climate change have adversely affected smallholder farmers across the world, leading to low output, decreased incomes, and high levels of food insecurity. As a result, farmers have been advised to find alternative ways of dealing with this phenomenon. The low adoption of climate-smart irrigation technology in Botswana warrants an investigation into the factors and the impact of adoption. This study used a semi-structured questionnaire to collect data from 271 smallholder maize farmers, who were selected through a multi-stage sampling approach. Descriptive statistics, probit regression, and propensity score matching technique (PSM) were employed to analyze the data. The results revealed that the majority of the respondents (55%) were male and 62% of farmers were above 50 years. The majority (62%) of the participants had a farm size of less than 5 ha and were heavily reliant on family labour for farm operations. Despite high (66%) awareness of climate-smart irrigation technology, many (52%) farmers did not adopt smart irrigation in Botswana. Age, gender, and access to credit had a statistical and negative influence on adoption. However, level of education and farming experience had a positive influence on adoption. The result of the propensity score matching model indicated that farmers using climate-smart irrigation techniques experienced positive and significant improvement in crop yield compared to dryland farmers. The study recommends that relevant institutions in Botswana should design a strategy that will be tailored to addressing issues of access to credit, facilitate training and education on advanced irrigation methods, and encourage more young farmers to engage in farming activities. Full article

Re-establishing native plants while controlling invasive species is a challenge for many dryland restoration efforts globally. Invasive plants often create highly competitive environments so controlling them is necessary for effective establishment of native species. In the sagebrush steppe of the United States, invasive annual grasses are commonly controlled with herbicide treatments. However, the same herbicides that control invasive annual grasses also impact the native species being planted. As such, carbon-based seed technologies to protect native seeds from herbicide applications are being trialed. In addition to controlling invasive species, ensuring good seed-to-soil contact is important for effective establishment of native species. In this grow room study, we explored the impact of different seed ameliorations when no herbicide was applied and when herbicide was applied. We selected two native species that are important to the sagebrush steppe for this study—the sub-shrub Krascheninnikovia lanata and the perennial bunchgrass Pseudoroegneria spicata—and used three different seed ameliorations—seed pelleting with local soil alone, local soil plus activated carbon and activated carbon alone—to ensure both greater seed-to-soil contact and protection against herbicides. Shoot and root biomass data were collected eight weeks after planting. We found that when herbicide was not applied, K. lanata had the strongest response to the soil alone amelioration, while P. spicata had the strongest response to the activated carbon alone amelioration. However, when herbicide was applied, K. lanata performed best with the soil plus activated carbon treatments, with an average 1500% increase in biomass, while P. spicata performed best with the activated carbon alone treatments, with an over 4000% increase in biomass, relative to bare seed. The results from our study indicate that there is a positive effect of local soils and activated carbon as seed ameliorations, and further testing in the field is needed to understand how these ameliorations might perform in actual restoration scenarios. Full article

The “chañar” (Geoffroea decorticans) is a tree native to the drylands of South America, historically valued for its nutritional, medicinal, and energy-providing properties. The significance of this species lies in its adaptation to conditions of water and salt stress, as well as its tolerance to wide thermal fluctuations, making it a candidate for utilization in climate change adaptation strategies. This study aimed to quantify the nutritional and mineral contributions of G. decorticans fruits from the province of Mendoza, Argentina. Representative specimens were selected, and the fruits were manually harvested for an analysis. The moisture and energy contents were determined using official analytical techniques. The evaluation of the nutritional components was conducted on a dry weight basis, including the total mineral, protein, fat, and total carbohydrate contents. In the mineral fraction test, nitrogen, phosphorus, potassium, sodium, calcium, and magnesium were quantified. The results revealed an adequate protein content (5.27 ± 0.06%) and elevated levels of crude fiber (19.27 ± 0.46%) and total carbohydrates (85.53 ± 0.98%). A high fiber content contributes to satiety, and its consumption could significantly enhance the population’s dietary reference intake. Although the mineral profile appears satisfactory, further investigation is required to clarify the factors affecting the bioavailability of each element. Even though there are existing studies on the variation of nutritional properties across different geographic regions, no local studies were identified. This research provides valuable data for the revaluation of ancestral species with nutritional significance, especially considering the growing trend towards the use of native plants in gastronomy. Full article

The cultivation of Salvia lavandulifolia, Spanish sage, makes an important contribution to the economy of many rural areas in Southeastern Spain. This aromatic plant species is characterized by high intraspecific variability, which makes the selection process for the establishment of homogeneous crops difficult. Additionally, imminent climate change threatens to reduce its production, especially when cultivated in drylands. Therefore, to guarantee the continued production of this type of sage, it is essential to study its agronomic behavior and production quality. For this, clones from four ecotypes were cultivated for three years, assessing changes in their biomass production, essential oil yield and quality, and phenolic fraction, as well as the corresponding antioxidant activity. The results suggest that essential oil yield is genetically predetermined, greater biomass not being associated with higher quantities of essential oil. Weather conditions affected both essential oil and phenolic fraction secondary metabolism. Under very harsh conditions, Spanish sage produces higher concentrations of camphor and 1,-8-cineole along with luteolin-7-O-glucoside, and lithospermic, rosmarinic, and salvianolic A acids in its phenolic fraction. The synthesis of these components helps the species to withstand the hot and dry conditions typical of southeast Spain. Full article

Managing water supply systems is essential for developing countries to face climate variability in dryland settings. This is exacerbated by high energy costs for pumping, water losses due to aging infrastructures, and increasing demand driven by population growth. Therefore, optimizing the available resources using a water–energy nexus approach can increase the reliability of the water distribution network by saving energy for distributing the same water. This study proposes a methodology that optimizes the Water Distribution Network (WDN) and its management that can be replicated elsewhere, as it is developed in a data-scarce area. Indeed, this approach shows the gathering of WDN information and a model to save energy by optimizing pump schedules, which guarantee water distribution at minimal operational costs. The approach integrates a genetic algorithm to create pumping patterns and the EPANET hydraulic simulator to test their reliability. The methodology is applied for a water utility in the dryland urban setting of Lodwar, Turkana County, Kenya. The results indicate a potential reduction in energy costs by 50% to 57% without compromising the supply reliability. The findings highlight the potential of WEN-based solutions in enhancing the efficiency and sustainability of data-scarce water utilities in dryland ecosystems. Full article

Eurasian dryland ecosystems consist mainly of cropland and grassland, and their changes are driven by both natural factors and human activities. This study utilized the normalized difference vegetation index (NDVI), gross primary productivity (GPP) and solar-induced chlorophyll fluorescence (SIF) to analyze the changing characteristics of vegetation activity in Eurasia over the past two decades. Additionally, we integrated the mean annual temperature (MAT), the mean annual precipitation (MAP), the soil moisture (SM), the vapor pressure deficit (VPD) and the terrestrial water storage (TWS) to analyze natural factors’ influence on the vegetation activity from 2003 to 2022. Through partial correlation and residual analysis, we quantitatively described the contributions of both natural and human factors to changes in vegetation activity. The results indicated an overall increasing trend in vegetation activity in Eurasia; the growth rates of vegetation greenness, productivity and photosynthetic capacity were 1.00 × 10⁻³ yr⁻¹ (p < 0.01), 1.30 g C m⁻² yr⁻² (p < 0.01) and 1.00 × 10⁻³ Wm⁻²μm⁻¹sr⁻¹yr⁻¹ (p < 0.01), respectively. Furthermore, we found that soil moisture was the most important natural factor influencing vegetation activity. Human activities were identified as the main driving factors of vegetation activity in the Eurasian drylands. The relative contributions of human-induced changes to NDVI, GPP and SIF were 52.45%, 55.81% and 74.18%, respectively. These findings can deepen our understanding of the impacts of current natural change and intensified human activities on dryland vegetation coverage change in Eurasia. Full article

Mulching could effectively improve the soil hydrothermal environment, improve changes in the soil structure, increase entropy, and conserve soil moisture to solve the problem of grain reduction caused by perennial drought in Northwest China. Thus, a two-growing-season field experiment (2020–2021) with five treatments (PM1, biodegradable plastic film mulching; PM2, plastic film mulching; SM1, straw strip mulching; SM2, crushed corn straw full mulching; and CK, no mulching as the control) was conducted to investigate the effects of different mulching materials on the soil hydrothermal environment, soil aggregate distribution, stability, and tuber yield of rainfed potato farmland in Northwest China. Over two growing seasons, mulching planting, on average, increased (p < 0.05) the soil moisture at the 0–200 cm depth by 9.0% relative to CK (SM2 (11.6%) > SM1 (10.3%) > PM2 (8.6%) > PM1 (7.0%)). The mulching treatments significantly regulated the soil temperature during the whole growth period, in which plastic mulching significantly increased the soil temperature of the 0–25 cm soil depth during the whole growth period by 2.1 °C (PM2 (2.1 °C) > PM1 (2.0 °C)); meanwhile, straw mulching significantly reduced the soil temperature by 1.4 °C (SM2 (0.9 °C) > SM1 (0.6 °C)). All mulching treatments improved the soil macroaggregate content and soil aggregate stability in all soil depths from 0 to 40 cm, with increases of 31.4% and 27.1% in the mean weight diameter (MWD) and 22.6% and 21.2% in the geometric mean diameter (GWD) compared with CK, respectively. Straw and plastic mulching significantly increased the fresh tuber yield by 12.5% and 12.6% compared with CK, respectively. The increases were greatest in SM2 and PM2. Crushed corn straw full mulching is difficult to sow and harvest; therefore, straw strip mulching could improve the soil hydrothermal environment, increase production, and provide an environmentally friendly technology for dryland potato production. Full article

Newly incorporated module into the WASH_2D model has enabled simulating a rainwater harvesting system (RWHS) using a tank. The incorporated module in WASH_2D was tested for two field experiments to determine the optimal tank capacity and cultivated area that give the highest net income for farmers. The first experiment was composed of treatments A, B, and C having the same cultivated and harvested areas (plastic sheets) of 24 m² and 12.5 m², respectively. The capacity of the tanks for treatments A, B, and C was set at 500, 300, and 200 L, corresponding to storability of 21, 13, and 8 mm, respectively, while in the second experiment we carried out three treatments: F, G, and H having the same tank capacity of 300 L and harvested area of 12.5 m² with variable cultivated areas as G and H were larger by two and three times than F (10.5 m²), respectively. Water was applied automatically through a drip irrigation system by monitoring soil water suction. Results of the first experiment showed that the optimal storability and seasonal net income simulated by WASH_2D were 17 mm and 5.82 USD yr⁻¹, which were fairly close to 18 mm and 5.75 USD yr⁻¹ observed from field data, respectively. Similarly, the results of the second experiment revealed that simulated net incomes for different cultivated areas agreed well with the observed data. We concluded that the use of the simulation model WASH_2D can be economically useful to promote small-scale irrigation in semi-arid regions and guide planning irrigation or rainwater harvesting investments. Full article

The present study endeavored to tackle the challenges posed by limited diversity in oat varieties and suboptimal nitrogen fertilizer utilization in the arid landscapes of the Loess Plateau. We selected three oat varieties, including early-maturing oats (E), medium-maturing oats (M), and late-maturing oats (L). In 2022, four nitrogen applications were set up as CK (0 kg N ha⁻¹), N1 (60 kg N ha⁻¹), N2 (90 kg N ha⁻¹), and N3 (120 kg N ha⁻¹). We introduced two additional nitrogen applications, N4 (180 kg N ha⁻¹) and N5 (240 kg N ha⁻¹), in 2023. The two-year study results demonstrated a significant increase in oat yield due to nitrogen application (p < 0.05). The highest grain yield was observed for E oats at 2216.63 kg·ha⁻¹ under the N3 treatment, while M and L oats had the highest grain yields at 2505.43 kg·ha⁻¹ and 2946.30 kg·ha⁻¹ under N4, respectively. The protein content of L oats reached a peak of 14.15% under N4, and the order of protein contents in oat protein components was globulin > gliadin> glutenin > albumin. The β-glucan content of L oats reached a peak of 4.92% under N3. The nitrogen fertilizer utilization efficiency (NFUE) of the three oats was highest under N2. L oats exhibited enhanced NFUE owing to an elevated pre-flowering nitrogen translocation amount (PrNTA), with a 42.94% and 29.51% increase relative to E and M oats, respectively. The pre-flowering nitrogen translocation contribution (PrNTC) in oats surpassed the post-flowering nitrogen accumulation contribution (PoNAC). Therefore, nitrogen application positively impacted oat growth, yet excessive application had an inhibitory effect. There is a significant positive correlation among oat yield, quality, nitrogen accumulation, and utilization efficiency. In summary, oat crops exhibited optimal performance in terms of yield, quality, and nitrogen use efficiency when nitrogen application rates ranged between 90 and 180 kg·ha⁻¹. Late-maturing oats coincide with the rainy and hot season in the northern dryland regions, making them more suitable for planting in the dryland areas of the Loess Plateau. Full article

Enhancing flood resilience has become crucial for watershed flood prevention. However, current methods for quantifying resilience often exhibit coarse spatiotemporal granularity, leading to insufficient precision in watershed resilience assessments and hindering the accurate implementation of resilience enhancement measures. This study proposes a watershed flood resilience assessment method based on a system performance curve that considers thresholds of inundation depth and duration. A nested one- and two-dimensional coupled hydrodynamic model, spanning two spatial scales, was utilized to simulate flood processes in plain river network areas with detailed and complex hydraulic connections. The proposed framework was applied to the Hangjiahu area (Taihu Basin, China). The results indicated that the overall trend of resilience curves across different underlying surfaces initially decreased and then increase, with a significant decline observed within 20–50 h. The resilience of paddy fields and forests was the highest, while that of drylands and grasslands was the lowest, but the former had less recovery ability than the latter. The resilience of urban systems sharply declined within the first 40 h and showed no signs of recovery, with the curve remaining at a low level. In some regions, the flood tolerance depth and duration for all land use types exceeded the upper threshold. The resilience of the western part of the Hangjiahu area was higher than that of other regions, whereas the resilience of the southern region was lower compared to the northern region. The terrain and tolerance thresholds of inundation depth were the main factors affecting watershed flood resilience. The findings of this study provide a basis for a deeper understanding of the spatiotemporal evolution patterns of flood resilience and for precisely guiding the implementation and management of flood resilience enhancement projects in the watershed. Full article

This on-farm study was conducted to assess the impact of six prevalent crop management practices adopted by growers in West Texas on various indicators of soil health. This study is a part of a citizen science project, where we collaborated with cotton growers who helped with standardized sample and data collection from 2017 to 2022. This project aimed to identify soil management practices that increase carbon sequestration, enhance biological activities, and improve overall soil health. We monitored soil moisture, soil organic matter (SOM), inorganic nitrogen (NH₄⁺-N and NO₃⁻-N) and other exchangeable nutrients, and soil microbial abundances as obtained via fatty acid methyl ester (FAME) in 85 fields, incorporating different management practices during the cotton growing season. In our study, volumetric moisture content (VWC) was increased by no-till, irrigation, and crop rotation, but the addition of residue decreased VWC. No-till, irrigation, and crop rotation increased SOM, but a cover crop decreased SOM. No-till and residue retention also increased microbial biomass carbon (MBC). Tillage, irrigation, and crop rotation influenced the abundance of the main microbial groups, including bacterial, fungi, and arbuscular mycorrhizal fungi (AMF). Additionally, water content, SOM, and microbial abundances are correlated with clay percentage. Our results indicate that no-till and crop rotation are the two most crucial soil management approaches for sustainable soil health. As such, implementing both no-till and crop rotation in the cropping systems has the most promising potential to increase the soil resilience in dryland cotton production in semiarid regions, thereby helping growers to maintain cotton production. Full article

Potassium (K) deficiency is common in cotton (Gossypium hirsutum L.)-growing areas. This study aims to investigate the effects of different rates of foliar K fertilizer application on three cotton varieties: NG 5711 B3XF (V1), PHY 480 W3FE (V2), and FM 1953GLTP (V3). Potassium fertilizer was dissolved in water and was foliar-applied at 34, 50, and 67 kg ha⁻¹. Cotton plant height (CH) and canopy width (CW) were monitored throughout the growing season. The results showed that foliar K fertilizer application significantly impacted the CH and CW in dry years. Although insignificant, the cotton lint yield increased by 15% and 20% with 34 and 50 kg ha⁻¹ in 2020 and by 9% and 7% with 50 and 67 kg ha⁻¹ in 2021, indicating the potential for improved lint yield with foliar K application in rainfed production systems. Similarly, variety V3 had significantly greater lint and seed yields than V1 in 2020. The average lint yield among the varieties was 32%, and the seed yield was 27% greater in 2020 than in 2021. The cotton fiber color grade was significantly greater at 50 kg ha⁻¹ in 2020 and 67 kg ha⁻¹ in 2021. Cotton variety significantly affected color grade, uniformity, staple length, Col, RD, and Col-b contents in 2020 and 2021. The results suggest that foliar K application can enhance cotton production in rainfed production systems. However, more research is required to quantify varietal and foliar K application rates for improved lint yield and quality. Full article

Ceratitis capitata (Wiedemann) (medfly) strongly affects Argentinean fruit production and export. Augmentative biological control using the exotic parasitoid Diachasmimorpha longicaudata (Ashmead) is currently applied to this problem. The ability to find and parasitize medfly larvae on a wide diversity of fruit host species is a key issue that needs to be analyzed. This research assessed the effect of the physical features of fruit on the preference of foraging D. longicaudata females and the influence of varying release density on parasitoid performance as a pest mortality factor in three fruit species. Trials were performed inside field cages under semi-arid environmental conditions in Argentina’s central-western fruit-growing region. Sweet orange, peach, and fig were tested. The fruits were inoculated with third-instar larvae of the Vienna-8 temperature-sensitive lethal medfly strain. Naïve, 5 d-old mated D. longicaudata females were released in cages at 20, 40, 80, and 160 parasitoid densities. The highest levels of medfly mortality and parasitoid emergence were recorded in fig and peach, although D. longicaudata also induced mortality in orange, a fruit with few physical features favorable to parasitism. The medfly mortality in all fruit host species significantly increased with an increased number of parasitoid females released into the field cages. Diachsmimorpha longicaudata has high potential as a medfly biocontrol agent. Full article

Dryland lakes are indispensable to regional water resource systems. Ebinur Lake, the largest saline lake in Xinjiang Uygur Autonomous Region, is vital for regional biodiversity and environmental stability but has been facing the predicament of gradual shrinkage in recent decades. In this study, we proposed a new dual-index method for Landsat (-5, -7, -8, and -9) data to extract water with the combinations of the normalized difference water index (NDWI) and the modified NDWI for turbid waters (NDWI_turbid). The dual-index method showed a high overall accuracy of 96.36% for Ebinur Lake. Landsat series images from 1992 to 2023 were employed to acquire the water areas of Ebinur Lake. The results showed that, over the past three decades, the area of Ebinur Lake exhibited a fluctuating decreasing trend, with an average lake area of 568.74 ± 152.43 km². The northwest intermittent water areas showed significant changes, and there was a close connection between the northwest and core water areas. Seasonally, the lake area decreased from spring to autumn. River inflow, driven by rainfall and human activities, was the primary factor affecting the inter/inner annual changes in Ebinur Lake. Furthermore, due to the valley effects, wind was found to be a critical factor in the diurnal changes in the water areas. This study should deepen the understanding of the variations of Ebinur Lake and benefit local water resource management. Full article