Search results for "Water content"
showing 10 items of 380 documents
Response of transgenic mannitol-producing tobacco plants to water deficit
2008
Transgenic mannitol-producing (+mtlD) and wild type (-mtlD) tobacco plants were exposed to water deficit to test whether mannitol is involved in drought stress protection. Rooted cuttings of -mtlD and +mtlD plants were fully irrigated (100% ET) or received 25% ET for 40 days, followed by 20 days of re-watering. Water deficit reduced RWC of both plant types starting on the 22nd day, total stem length of -mtlD 25% ET already after 11 days, whereas that of +mtlD 25% ET only after 34 days. After 30 days of deficit, a greater percentage of mature foliage was retained by +mtlD 25% ET compared to -mtlD 25% ET. Mannitol-1-phosphate dehydrogenase activity of +mtlD plants was not affected by water de…
On the use of unmanned aerial systems for environmental monitoring
2018
[EN] Environmental monitoring plays a central role in diagnosing climate and management impacts on natural and agricultural systems; enhancing the understanding of hydrological processes; optimizing the allocation and distribution of water resources; and assessing, forecasting, and even preventing natural disasters. Nowadays, most monitoring and data collection systems are based upon a combination of ground-based measurements, manned airborne sensors, and satellite observations. These data are utilized in describing both small-and large-scale processes, but have spatiotemporal constraints inherent to each respective collection system. Bridging the unique spatial and temporal divides that li…
SMOS-IC: An Alternative SMOS Soil Moisture and Vegetation Optical Depth Product
2017
© 2017 by the authors. The main goal of the Soil Moisture and Ocean Salinity (SMOS) mission over land surfaces is the production of global maps of soil moisture (SM) and vegetation optical depth (τ) based on multi-angular brightness temperature (TB) measurements at L-band. The operational SMOS Level 2 and Level 3 soil moisture algorithms account for different surface effects, such as vegetation opacity and soil roughness at 4 km resolution, in order to produce global retrievals of SM and τ. In this study, we present an alternative SMOS product that was developed by INRA (Institut National de la Recherche Agronomique) and CESBIO (Centre d'Etudes Spatiales de la BIOsphère). One of the main go…
Biomass Assessment of Agricultural Crops Using Multi-temporal Dual-Polarimetric TerraSAR-X Data
2019
The biomass of three agricultural crops, winter wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and canola (Brassica napus L.), was studied using multi-temporal dual-polarimetric TerraSAR-X data. The radar backscattering coefficient sigma nought of the two polarization channels HH and VV was extracted from the satellite images. Subsequently, combinations of HH and VV polarizations were calculated (e.g. HH/VV, HH + VV, HH × VV) to establish relationships between SAR data and the fresh and dry biomass of each crop type using multiple stepwise regression. Additionally, the semi-empirical water cloud model (WCM) was used to account for the effect of crop biomass on radar backscatter …
Pellets based on polyuronates: Relationship between gelation and release properties
2017
International audience; Three polyuronates: amidated low methoxyl pectin (ALMP), low methoxyl pectin (LMP) and polygalacturonic acid (PGA) were used to encapsulate rutin in pellets, and they were characterized by different techniques (macroscopic properties, Calcium and rutin release). The ability of the three polyuronates to bind calcium ions and the viscoelastic properties of gels were performed to relate the properties of the pellets to the gel structures. The pellets size, the water content, the water uptake, the release of calcium and rutin varied depending on the polyuronate used. The pellets size of ALMP were smaller than LMP and PGA with a lower water content, but this matrix was mo…
Chemical Characteristics and Viability of Starter Cultures of Freeze–Dried Sweet Potato Extract–Supplemented Synbiotic Yogurt
2021
The research aimed to determine the sucrose concentration as a cryoprotectant to obtain the chemical properties and the viability of Lactic Acid Bacteria (LAB) and Lactobasillus plantarum in the synbiotic yogurt. It adopted a one–factor Completely Randomized Design (CRD) by including sucrose in concentrations from 0 %, 2.5 %, 5 % to 7.5 %, three replications. The results showed various sucrose concentrations significantly affected the yields of the purple sweet potato extract– supplemented synbiotic yogurt, reduction–sugar level, the total of LAB, and the total of L. plantarum before and after the freeze–drying process, no significant impact on the moisture content and total quantity of LAB…
The adsorption of water vapor on super absorbent product at low temperatures and low mass.
2006
The adsorption isotherms of water vapor on super absorbent product have the same form of type III isotherm at ambient temperature with the hysteresis phenomena. For temperatures lower than ambient, the isotherms become deformed because of the chains effect. The polymer is characterized by a multilayer adsorption, which occurs before a full-course is complete. During adsorption reactions, the polymer undergoes rearrangement polymeric network, which results from a cooperative diffusion of the water molecules and from a chain spacing followed by an expansion of the polymeric network. Three types of water molecules adsorbed on polymer were identified: strongly dependent water, adsorbed water, a…
The effects of post-pasture woody plant colonization on soil and aboveground litter carbon and nitrogen along a bioclimatic transect.
2013
Abstract: We investigated the effects of woody plant colonization of abandoned pastures on soil and litter organic carbon (C) stocks and nitrogen (N) content along a bioclimatic transect in a semi-arid environment (Sicily, Italy). Soil samples were taken in three successional stages (grazed pasture, shrubland, forest) within each of three bioclimates (supramediterranean - “supra”, mesomediterranean - “meso”, thermomediterranean - “thermo”). Organic C and N in litter and soil (0-10 cm and 10-30 cm depth) were determined, as well as soil bulk density. Especially at 0-10 cm depth, changes in C and N contents along successional stages differed among bioclimates. Soil organic carbon (SOC) stock …
Variation characteristics of soil respiration fluxes in four types of grassland communities under different precipitation intensity
2005
A two consecutive years’ field experiment was carried out on four types of semiarid grassland along precipitation gradient in Xilin River Basin of Inner Mongolia during 2001–2003 using a static enclosed black chamber technique. The variation characteristics of soil respiration fluxes from four different types of grassland along precipitation gradient were compared. The possible effect of water-heat factors on characteristics of grassland soil respiration was statistically analyzed and the numerical relational model between soil respiration and water-heat factors was established. Meanwhile the soil CO2 annual emissions of different types of grassland were estimated based on the consecutive a…
Evaluation Of The Soil Moisture Agricultural Drought Index (SMADI) And Precipitation-Based Drought Indices In Argentina
2020
Abstract. Agricultural drought is one of the most critical hazards with regard to intensity, severity, frequency, spatial extension and impact on livelihoods. This is especially true for Argentina, where agricultural exports can represent up to 10% of gross domestic product (GDP), and where drought events for 2018 led to a decrease of nearly 0.5% of GDP. In this work, we investigate the applicability of the Soil Moisture Agricultural Drought Index (SMADI) for detection of droughts in Argentina, and compare its performance with the use of two well-known precipitation-based indices: the Standardized Precipitation Index (SPI) and the Standardized Precipitation- Evaporation Index (SPEI). SMADI …