While various studies have attempted to investigate the efficacy of biochars in enhancing plant seedlings, research on the application of biochar specifically for Coffea arabica L. seedlings in drought conditions remains restricted. To reveal the mitigation of biochar in the Coffee. seedlings under drought stress, the impacts of different biochar doses on soil physicochemical, biological, and hydrological parameters, as well as the growth of Coffee seedlings were evaluated. To mimic the effect of drought stress, utilizing three different levels of water holding capacity (20 %, 40 %, and 60 % of WHC) was performed with three different corncob biochar application rates of 1 %, 2.5 %, and 5 % w/w of soil. The results revealed that corncob biochar application increased pH, cation exchange capacity and organic matter. While soil microbial respiration, microbial biomass carbon, and dissolved organic carbon had increased in application biochar 1 and 5 % under both drought and no drought conditions. Corncob biochar at 1 % application rate enhanced the growth and chlorophyll content under drought condition significantly (p < 0.05). However, no statistically significant differences were observed between biochar application and water holding capacity on membrane damage and total soluble sugar content under drought conditions. The relative water and proline content had increased in biochar application at 1 %. Based on these findings, the application of biochar into coffee seedling production systems may help mitigate the adverse effects of water scarcity while promoting long-term soil health and agricultural resilience, particularly in tropical and subtropical highland regions where climate change-induced drought events are becoming more frequent.

Rubble deposits with a high concentration of rock debris were created after the powerful earthquakes in Jiuzhaigou. Because of the restricted soil resources, water leaks, and nutrient deficits, these deposits pose serious obstacles for vegetation regeneration. The purpose of this study was to investigate the main mechanisms controlling soil water retention and evaluate the effects of different amendments on the hydraulic characteristics and water-holding capacity of collapsed rubble soils. Fine-grained soil, forest humus, crushed straw, and organic components that retain water were added to the altered soils to study the pore structure images and soil-water characteristic curves. Comparing understory humus to other supplements, the results showed a considerable increase in the soil's saturated and wilting water content. The saturated water content and wilting water content rose by 17.9% and 4.3%, respectively, when the percentage of understory soil reached 30%. Additionally, the enhanced soil's microporosity and total pore volume increased by 45.33% and 11.27%, respectively, according to nuclear magnetic imaging. It was shown that while clay particles and organic matter improved the soil's ability to adsorb water, they also increased the soil's total capacity to store water. Fine particulate matter did this by decreasing macropores and increasing capillary pores. These results offer an essential starting point for creating strategies for soil repair that would encourage the restoration of plants on slopes that have been damaged.

To explore the effects of mattic epipedon (ME) on soil moisture and hydraulic properties in the alpine meadow of three-river source region, the soil moisture, water infiltration, evapotranspiration, soil bulk density and soil water holding capacity of original vegetation (OV), light degradation (LD), moderate degradation (MD) and severe degradation (SD) was conducted in this study, respectively. The results showed that: (1) the alpine meadow degradation reduced the soil moisture in the shallow layer (0-10 cm) and had no significant effects on the soil moisture in the deep layer (20-30 cm). (2) The effects of alpine meadow degradation on infiltration was depend on the presence of ME or not, when the ME existed on the land surface (from OV treatment to MD treatment), the alpine meadow degradation had no significant effects on infiltration. Once the ME disappeared on the land surface (from MD treatment to SD treatment), the alpine meadow degradation mainly increased the infiltration. (3) With the aggravation of alpine meadow degradation, the daily evapotranspiration first decreased and then significantly increased when the gravimetric soil water content at 0-5 cm in SD treatment (GWC5) was exceeded 19.5%, the daily evapotranspiration gradually decreased when GWC5 ranged from 9.3% to 19.5%, and had no significant changes on the evapotranspiration when GWC5 was less than 9.3%. Considering the characteristics of precipitation in alpine meadow, it was concluded that the alpine meadow degradation accelerated the evapotranspiration during the plant-growing season. (4) The effect of alpine meadow degradation on soil bulk density and saturated water capacity was concentrated at 0-10 cm. With the aggravation of alpine meadow degradation, the bulk density at 0-10 cm was first stable and then significantly increased and the saturated water capacity at 0-10 cm was first gradually increased and then significantly decreased. Our results suggested that the ME is vital for water conservation of alpine meadow and the protection of ME should be emphasized to promote the sustainable development of the ecosystem and the water supply of water towers in China.

Floodplains are one of the most dynamic and youngest areas of the Earth's Quaternary surface. They are located in transitional conditions (land-ocean) of the permafrost zone of present and of particular interest for ongoing geochemical processes and soil/water balance. The soil thermal and water regimes of polar soils are crucial for the development of vegetation cover as well as production, accumulation and redistribution of organic matter. This work characterizes the hydrological properties of soils formed in Russian Arctic. The data showed differences in water holding capacity between soils formed in conditions of seasonal flooding (soil stratification, redistribution of organic and mineral matter through the soil profile) and those not influenced by flooding in Lena River Delta (gradual decreasing of water holding capacity as a function of depth). Both of the soil profiles from the Yamal Peninsula are characterized by a gradually decreasing water-holding capacity with depth. The hydrological regime characteristics were strongly related to the depth of the active layer. The intensity and rate of the thawing/freezing processes depends on the features of the hydrological regime. In this study, significant differences were noted in the soil characteristics of the two study areas. That is why the profile values of water-holding capacity differed among the study sites. The predicted global climate change and high sensitivity of Arctic ecosystems may lead to significant changes in permafrost-affected landscapes and may alter their water regime in a very prominent way, as permafrost degrades and lateral and vertical water flow in the basins of large arctic rivers changes.