PHYSIOLOGICAL AND BIOCHEMICAL STUDIES IN PLANT METABOLISM: V. THE EFFECT OF CHANGES IN SOIL WATER CONTENT ON THE PHYSIOLOGICAL HETEROGENEITY IN THE FIRST LEAF OF WHEAT

1952 ◽  
Vol 30 (1) ◽  
pp. 50-66 ◽  
Author(s):  
D. W. A. Roberts
Keyword(s):  
Nitrogen Content ◽  
Water Content ◽  
Soil Water ◽  
Sugar Content ◽  
Soluble Nitrogen ◽  
Protein Nitrogen ◽  
Dry Conditions ◽  
Nitrogenous Substances ◽  
Physiological And Biochemical

The respiratory rate, soluble nitrogen content, protein nitrogen content, water content, reducing sugar content, and sucrose content of each of the four quarters of the first leaf of Khapli Emmer wheat have been determined for plants grown with different soil water supplies. Under dry conditions the first leaf of wheat contains a higher concentration of nitrogenous substances than it does under moist conditions. The water content of the first leaf of wheat grown in dry soil or very wet soil is lower than it is for leaves grown in moderately moist soil. The significance of these two observations is discussed. Further support has been obtained for the view that the concentration of none of the substances determined is solely responsible for the respiratory rates and gradients observed in the leaves. The role of leaf anatomy in controlling and producing the observed respiratory gradients is discussed.

Physiological and biochemical studies in plant metabolism. IV. Effect of illumination and darkness on the physiological heterogeneity in the first leaf of wheat

1951 ◽  
Vol 29 (4) ◽  
pp. 451-466 ◽  
Author(s):  
D.W.A. Roberts
Keyword(s):  
Respiratory Rate ◽  
Nitrogen Content ◽  
Leaf Anatomy ◽  
Soluble Nitrogen ◽  
Plant Metabolism ◽  
Sucrose Content ◽  
Protein Nitrogen ◽  
Biochemical Studies ◽  
Physiological And Biochemical ◽  
Physiological Heterogeneity

The respiratory rate, soluble nitrogen content, protein nitrogen content, water content, reducing substance content, and sucrose content of each of the four quarters of the first leaf of Khapli wheat have been determined after different exposures to light under standardized conditions. The respiratory rate of the different quarters of the leaf as a whole is not determined by the distribution of any of the above mentioned constituents. Protein, water, and sucrose distribution appear to be correlated with the anatomy of the leaf. Leaf anatomy is apparently an important consideration in the physiological heterogeneity of the first leaf of wheat.

scholarly journals The effect of a prototype hydromulch on soil water evaporation under controlled laboratory conditions

2020 ◽  
Vol 68 (4) ◽  
pp. 404-410
Author(s):  
Antoni M.C. Verdú ◽  
M. Teresa Mas ◽  
Ramon Josa ◽  
Marta Ginovart
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Time Course ◽  
Linear Models ◽  
Water Evaporation ◽  
Mechanical Resistance ◽  
Evaporation Process ◽  
Soil Columns ◽  
Dry Conditions

AbstractOrganic hydromulches can be an interesting alternative for weed control in perennial crops, but can also reduce soil water evaporation. To examine the effect of a hydromulch layer on soil water content in dry conditions laboratory experiments were conducted at constant 25°C, 40% air RH. Both for small soil containers with a short time course and for larger soil columns (with two sensors at depths of 6 cm and 11 cm) with a longer time course, the presence and also the thickness of hydromulch were significant factors for the temporal evolution of soil water content. Two distinct stages of the evaporation process, the first or initial stage and the last or final stage, were identified, analysed and compared for these experiments. General linear models performed on the soil water content temporal evolutions showed significant differences for the first and last stages at the top and bottom of the soil columns with and without hydromulch. Hydromulch application delayed the evaporation process in comparison with the control. Moreover, the hydromulch layer, which was tested for mechanical resistance to punching, offered enough resistance to prevent its perforation by the sprouts of weed rhizomes.

106. The Role of Rennet in the Ripening of Cheddar Cheese

1935 ◽  
Vol 6 (2) ◽  
pp. 204-217 ◽  
Author(s):  
I. R. Sherwood
Keyword(s):  
Normal Control ◽  
Strong Evidence ◽  
Volatile Acid ◽  
Soluble Nitrogen ◽  
Protein Nitrogen ◽  
Ripening Process ◽  
Bacterial Action ◽  
Proteolytic Action ◽  
Activity Of Enzymes

Attempts were made to eliminate the bacterial factor in Cheddar cheeseripening, through the agency of chloroform, and an assessment of the role of rennet was thus rendered possible.After investigating the effect of chloroform and toluene upon the proteolytic action of rennet and trypsin in milk, the results obtained were applied in studies upon the ripening of cheese in the presence of chloroform. Cheese of normal manufacture was chloroformed at the salting stage or one week or more after manufacture (when the curd had lost its rubbery nature and the germicide was more easily incorporated). Owing to the weakened activity of enzymes in the presence of germicides, it was necessary to employ larger proportions than usual of rennet, measured additions generally being made at the time when the chloroform was added. Under these conditions the general course of protein degradation, as measured by determinations of soluble nitrogen and non-protein nitrogen, was found to be identical with that occurring in normal control cheeses. Strong evidence was thus afforded that rennet is the only important agent attacking cheese protein during the ripening process.In the partition between the non-protein constituents of the normal and chloroformed cheeses, respectively, there were observed definite differences which tended to remain constant over the greater part of the ripening period. The relatively higher proportion of subpeptone nitrogen in the normal cheese was shown to be due, at least in some measure, to bacterial action.Cheese ripened in the presence of chloroform developed no volatile acid, and no cheese flavour could be detected.

How do spatial throughfall patterns reflect in soil moisture patterns?

2021 ◽  
Author(s):  
Christine Fischer ◽  
Murray Lark ◽  
Johanna C. Metzger ◽  
Thomas Wutzler ◽  
Anke Hildebrandt
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Temporal Stability ◽  
Water Storage ◽  
Rainfall Event ◽  
Content Increase ◽  
Water Content Increase ◽  
Air Capacity

<div> <p>This study investigates whether and how vegetation cover affects the spatial heterogeneity and vertical penetration of water through the Upper Critical Zone (UCZ). We assessed rainfall, throughfall and soil water contents on a 1‐ha temperate mixed beech forest plot in Germany. Throughfall and soil water content in two depths (7.5 cm and 27.5 cm) were measured on an event basis during the 2015 - 2016 growing season in independent high‐resolution stratified random designs. We calculated the increase of soil water content (Δθ) due to the rainfall by the difference between measurements at the beginning (pre-event) and the maximum soil water content after the end of rainfall event (post-event). Since throughfall and soil water content cannot be assessed at the same location, we used kriging to derive the throughfall values at the locations where soil water content was measured. We explore the spatial variation and temporal stability of throughfall and soil water content and evaluate the effects of throughfall, soil properties (field capacity and air capacity), and vegetation parameters (next tree distance) on soil water content variability.</p> <p>Throughfall patterns were related to canopy density although correlation length decreased with increasing event size. Temporal stability was high, leading to persistently high and lower input locations across rainfall events.</p> <p>A linear mixed effect model analysis confirmed that the soil water content increase due to precipitation depended on throughfall patterns, in that more water was stored in the soil where throughfall was enhanced. This was especially the case in large events and in both investigated soil depths. However, we also identified additional factors that enhanced or decreased water storage in the soil, and probably indicate fast drainage and runoff components. Locations with low topsoil water content tended to store less of the available water, indicating the role of preferential flow. In contrast in subsoil, locations with high water content, and probably poor drainage, stored less water, indicating lateral flow. Also, distance to the next tree and air capacity modified soil water storage.</p> <p>Spatial soil water content patterns shortly before a rainfall event (pre-event conditions) seem to be a key factor in soil water content increase, and also explained much of soil water content shortly after the rainfall event. Pre-event soil water content was mostly driven by random local effects, probably microtopography and root water uptake, which were not quantified in this study. The remaining spatial variation was explained by air capacity in both soil layers, indicating the role of macroporosity.</p> <p>Our findings show at the same time systematic patterns of times and locations where the soil capacity to store water is reduced and water probably conducted quickly to greater depth. Not only soil moisture patterns but also deeper percolation may depend on small scale spatial heterogeneity of canopy input patterns.</p> </div>

scholarly journals Soil water content drives spatiotemporal patterns of CO<sub>2</sub> and N<sub>2</sub>O emissions from a Mediterranean riparian forest soil

2017 ◽  
Vol 14 (18) ◽  
pp. 4195-4208 ◽  
Author(s):  
Sílvia Poblador ◽  
Anna Lupon ◽  
Santiago Sabaté ◽  
Francesc Sabater
Keyword(s):  
Climate Change ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Riparian Forest ◽  
Ghg Emissions ◽  
Microbial Processes ◽  
N2o Emissions ◽  
Nitrification And Denitrification

Abstract. Riparian zones play a fundamental role in regulating the amount of carbon (C) and nitrogen (N) that is exported from catchments. However, C and N removal via soil gaseous pathways can influence local budgets of greenhouse gas (GHG) emissions and contribute to climate change. Over a year, we quantified soil effluxes of carbon dioxide (CO2) and nitrous oxide (N2O) from a Mediterranean riparian forest in order to understand the role of these ecosystems on catchment GHG emissions. In addition, we evaluated the main soil microbial processes that produce GHG (mineralization, nitrification, and denitrification) and how changes in soil properties can modify the GHG production over time and space. Riparian soils emitted larger amounts of CO2 (1.2–10 g C m−2 d−1) than N2O (0.001–0.2 mg N m−2 d−1) to the atmosphere attributed to high respiration and low denitrification rates. Both CO2 and N2O emissions showed a marked (but antagonistic) spatial gradient as a result of variations in soil water content across the riparian zone. Deep groundwater tables fueled large soil CO2 effluxes near the hillslope, while N2O emissions were higher in the wet zones adjacent to the stream channel. However, both CO2 and N2O emissions peaked after spring rewetting events, when optimal conditions of soil water content, temperature, and N availability favor microbial respiration, nitrification, and denitrification. Overall, our results highlight the role of water availability on riparian soil biogeochemistry and GHG emissions and suggest that climate change alterations in hydrologic regimes can affect the microbial processes that produce GHG as well as the contribution of these systems to regional and global biogeochemical cycles.

Physiological and biochemical responses of Festuca sinensis seedlings to temperature and soil moisture stress

2017 ◽  
Vol 44 (10) ◽  
pp. 1007
Author(s):  
Jian-Jun Wang ◽  
Wei-Hu Lin ◽  
Yan-Ting Zhao ◽  
Cheng Meng ◽  
An-Wei Ma ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Moisture Content ◽  
Soluble Sugar ◽  
Free Proline ◽  
Relative Water ◽  
Physiological And Biochemical

The interaction effects between temperature and soil moisture on Festuca sinensis Keng ex E.B.Alexeev were analysed to determine how F. sinensis responds to these environmental conditions. A pot experiment was conducted in a greenhouse under simulated growth conditions with four soil moisture contents (80, 65, 50 and 35% relative saturation moisture content) and three temperature conditions (15, 20 and 25°C). Physiological (relative water content and root activity) and biochemical parameters (chlorophyll, peroxidase (POD), malondialdehyde (MDA), soluble protein, soluble sugar and free proline) were evaluated at the seedling stage. Results showed that with a decrease in soil water content, the POD activities, MDA content, soluble protein content, soluble sugar content and free proline content of plants under the 15°C and 20°C treatments initially decreased and then increased, whereas they increased with a decrease of soil water content at 25°C. The relative water contents of plants under the three temperature treatments decreased with a decreasing soil moisture content, but then increased temperature significantly reduced the relative water content of the seedlings under low soil water content. The chlorophyll contents of plants under the 25°C treatment decreased with a decrease of soil moisture content, but those of plants under the 15°C and 20°C treatments initially increased and then decreased. The root activities of plants under the 15°C and 20°C treatments increased with a decreasing soil moisture content; however, those of plants under the 25°C treatment initially increased and then decreased. Thus, results indicated that changes of temperature and soil moisture content had significant and complicated effects on the physiological-biochemical characteristics of F. sinensis; the conditions of 20°C and 65% RSMC had positive effects on F. sinensis seedling growth and the appropriate drought stress could promote the growth of seedling roots under the three different temperature conditions. In conclusion, F. sinensis seedlings could adapt to certain changes in the ecological environment by regulating their physiological and biochemical reactions.

Sign in / Sign up

Export Citation Format

Share Document