The hydrologic sciences and water resources management have long depended on a combination of in situ measurements and remotely sensed data for research and regulatory purposes. In situ measurements are constrained in their spatial distribution by both logistics and costs. Satellite‐ and manned aircraft‐based remote sensing provide spatially broad data, but often of a coarse resolution. Furthermore, all these data collection methods are often limited in their ability to respond to specific short‐term events when the data and imagery could inform real‐time assessment and decision‐making, especially during and immediately after natural disasters. Researchers and regulators are increasingly using unmanned aerial vehicles (UAVs) to fill these gaps in both spatial and temporal data resolution. UAVs are often more cost‐effective than traditional remote sensing or in situ data collection methodologies and the availability of new advancements in UAV design, power supply, payload capacity, and sensors has been driving rapid innovations in their use in the hydrological sciences. This in‐depth review explores these UAV technologies and how they are being employed for on‐demand and cost‐effective characterization, monitoring, assessment, and modeling of soil and water resources. Our discussion addresses both key opportunities and challenges in surface water and groundwater studies, land‐atmosphere interaction studies, water management in agriculture and forestry, ecosystem monitoring, and hydrological modeling.

Amidst intensifying global agricultural water demand, optimizing management practices and understanding the role of soil amendments, particularly biochar (BC), in modulating soil water dynamics are critical. Here, we review the potential impacts of BC on soil water dynamics, elucidate mechanistic underpinnings, and identify critical research gaps and prospective avenues. In general, BC modifies soil structure, hydraulic properties, surface albedo, and heat fluxes, which influence soil water storage, energy balance, and irrigation paradigms. Depending on soil texture and BC properties, BC demonstrates a greater reduction in bulk density and saturated hydraulic conductivity in coarse-textured soils compared to fine-textured soils. BC application generally increases water holding capacity (WHC) while exhibiting no consistent impact on soil water infiltration. Increased WHC of soils results from increased porosity, surface area, and soil aggregation. Increased porosity arises from a confluence of factors, encompassing new pores formation, reorganization of pores, increased soil aggregation, dilution effects of BC, reduced soil compaction, and biotic interactions, including increased population of burrowing invertebrates. BC tends to increase plant-available water in coarser soils, attributed to its hydrophilic nature, augmented specific surface area, and enhanced overall porosity. However, BC may induce soil water repellency, contingent upon variables such as feedstock composition, pyrolysis temperature, and specific soil attributes. While BC exhibits transformative potential in enhancing soil hydraulic properties, scalability concerns and economic viability pose challenges to its widespread agricultural application. Overall, BC offers promising avenues for sustainable water management. However, it is imperative to explore large-scale applications and conduct long-term field studies across different management, climate, and soil types to fully understand how different types of BC impact soil water dynamics. Graphical Abstract

Woody plant encroachment has profound impacts on the sustainable management of water resources in water-limited ecosystems. However, our understanding of the effects of this global phenomenon on groundwater recharge at local and regional scales is limited. Here, we reviewed studies related to (i) recharge estimation methods; (ii) mechanisms by which woody plants impact groundwater recharge; (iii) impacts of woody plant on recharge across different soil and geology; (iv) hydrological repercussions of woody plant removal; and (v) research gaps and needs for groundwater studies. We identified six different methods: water balance, water table, isotopes, chloride mass balance, electrical geophysical imaging, and modeling were used to study the impact of woody encroachment on groundwater. Woody plant encroachment could alter soil infiltration rates, soil water storage, transpiration, interception, and subsurface pathways to affect groundwater recharge. The impact is highly variable, with the extent and the magnitude varying across the soil, substrate, plant cover, and topographic locations. Our review revealed mixed effects of woody plant removal on groundwater recharge. Studies of litter interception, root water uptake, soil moisture dynamics, and deep percolation along with the progression of woody plant encroachment are still limited, warranting further experimental studies focusing on groundwater recharge. Overall, information about woody plant encroachment impacts on groundwater resources across a range of scales is essential for long-range planning of water resources.

Many land-grant institutions with agriculture and natural resource programs in the United States offer online courses to meet student demand. The goal of this study was to understand how major educational stakeholders, including instructors and students, perceive the benefits and limitations of online teaching and learning in agriculture and natural resource sciences. This study utilized a mixed mode data collection method, which involved informal meetings as well as online survey administration. The data were analyzed through strengths, weaknesses, opportunities, and threats (SWOT)-Analytic Hierarchical Process (AHP) framework. The study results offer novel perspectives on the perceived utility and challenges of several attributes of online learning including work-home balance, lack of social interactions, virtual classroom opportunities for working professionals, and academic integrity and cyber scam issues among others. Our findings may be beneficial to academic administrators, instructors, and institutions in identifying opportunities, challenges, and adopting programmatic strategies to improve effectiveness of online learning.