scholarly journals EFFECT OF SOIL MOISTURE STRESS ON UPTAKE AND RECOVERY OF TAGGED NITROGEN BY WHEAT

1971 ◽  
Vol 51 (1) ◽  
pp. 37-43 ◽  
Author(s):  
E. A. PAUL ◽  
R. J. K. MYERS
Keyword(s):  
Soil Moisture ◽  
Moisture Stress ◽  
Organic Soil ◽  
Soil Mineral ◽  
High Moisture ◽  
Soil Moisture Stress ◽  
Mineral N ◽  
Growing Period ◽  
Stress Effects ◽  
N Utilization

Labelled 15NH4NO3 was used in a growth chamber to study the effect of moisture stress on the utilization of nitrogen by wheat. This made it possible to determine the recovery of nitrogen (N) in the soil-plant system of two Chernozemic soils. Moisture stress effects were less evident in a clay soil than in a loam. Approximately 55% of the N utilized by the growing plants came from organic soil-N mineralized during the growing period. From 59 to 71% of the initial fertilizer plus soil mineral-N was utilized by the plants. Twenty to 36% remained in the soil, and 1 to 17% was lost. Losses were greatest in soils exposed to high moisture stress and were related to the residual NO3-N levels in the soil. They were attributed to denitrification. Immobilization of N was highest at low moisture stress where plant growth was the greatest, but mineralization was unaffected by the moisture stress applied. It was estimated that 5.0 to 6.2 kg N were required to produce 100 kg of wheat, the highest efficiency of N utilization being obtained at low soil moisture stress.

INFLUENCE OF AIR TEMPERATURE, LIGHT INTENSITY, SOIL MOISTURE STRESS AND SOIL AERATION ON MOISTURE USE BY WHEAT

1969 ◽  
Vol 49 (2) ◽  
pp. 129-137 ◽  
Author(s):  
C. A. Campbell ◽  
W. S. Ferguson
Keyword(s):  
Soil Moisture ◽  
Light Intensity ◽  
Dry Matter ◽  
Moisture Stress ◽  
High Moisture ◽  
Soil Moisture Stress ◽  
Stem Extension ◽  
High Soil Moisture ◽  
Poor Seed ◽  
Reduced Rate

In growth chamber experiments, it was found that total and rate of moisture use by wheat were directly proportional to light intensity, except under conditions which restricted growth.Increasing the day temperature from 21° to 27 °C reduced the total moisture use. This was attributed to the greater vegetative dry matter produced at 21 °C. Under high soil moisture stress, (0.2 to 15 atm), plants used less water at a slower rate than at the lower stress (0.2 to 1.4 atm), but the moisture treatment had little effect on moisture use per gram of dry matter Apparently, under the conditions of this experiment the most important cause of reduced transpiration at high moisture stress was reduced plant growth.At about the late tillering to stem-extension stage, wheat was surprisingly insensitive to changes in moisture stress. An increase in soil moisture stress during this period did not result in the usual reduced rate of moisture consumption.Irrespective of the growth stage at which the stress was changed (increased or decreased), stress had little influence on moisture use per unit of straw dry matter. If the soil was "wet" (0.2 to 1.4 atm) at about the stem-extension stage, poor seed set occurred and thus moisture use per gram of seed was increased. When plants were provided with adequate aeration, moisture use per gram of seed was one-third that of plants grown under poor aeration.

scholarly journals Effect of soil moisture stress on growth light azimuth and yield of dryland sorghum

MAUSAM ◽  
2022 ◽  
Vol 44 (3) ◽  
pp. 261-264
Author(s):  
H. P. DAS ◽  
A. N. KALE ◽  
A. S. PONKSHE
Keyword(s):  
Soil Moisture ◽  
Root Zone ◽  
Potential Evapotranspiration ◽  
Moisture Stress ◽  
Growth Cycle ◽  
Yield Reduction ◽  
Soil Moisture Stress ◽  
Growing Period ◽  
Moisture Balance ◽  
Soil Moisture Balance

Based on weekly data for 4 years (1986-1989) at Bellary, soil moisture balance for rabi sorghum has been worked out for both irrigated and non-irrigated conditions. These soil moisture values have been used to identify periods of water stress which the crop experienced. during the growth cycle. The extent of yield reduction due to the stress was then evaluated from the actual soil water content and total available water extent and discussed. The ratio of evapotranspiration to potential evapotranspiration and water requirement of the crop has also been worked out to assess the stress situation of the crop during its growing period. This ratio has been found to be related to moisture availability at the root zone.

scholarly journals Improved understanding of drought controls on seasonal variation in Mediterranean forest canopy CO<sub>2</sub> and water fluxes through combined in situ measurements and ecosystem modelling

2009 ◽  
Vol 6 (8) ◽  
pp. 1423-1444 ◽  
Author(s):  
T. Keenan ◽  
R. García ◽  
A. D. Friend ◽  
S. Zaehle ◽  
C. Gracia ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Forest Canopy ◽  
Moisture Stress ◽  
Mediterranean Ecosystems ◽  
Forest Growth ◽  
Water Fluxes ◽  
Soil Moisture Stress ◽  
Dynamic Global Vegetation Model ◽  
Forest Growth Model

Abstract. Water stress is a defining characteristic of Mediterranean ecosystems, and is likely to become more severe in the coming decades. Simulation models are key tools for making predictions, but our current understanding of how soil moisture controls ecosystem functioning is not sufficient to adequately constrain parameterisations. Canopy-scale flux data from four forest ecosystems with Mediterranean-type climates were used in order to analyse the physiological controls on carbon and water flues through the year. Significant non-stomatal limitations on photosynthesis were detected, along with lesser changes in the conductance-assimilation relationship. New model parameterisations were derived and implemented in two contrasting modelling approaches. The effectiveness of two models, one a dynamic global vegetation model ("ORCHIDEE"), and the other a forest growth model particularly developed for Mediterranean simulations ("GOTILWA+"), was assessed and modelled canopy responses to seasonal changes in soil moisture were analysed in comparison with in situ flux measurements. In contrast to commonly held assumptions, we find that changing the ratio of conductance to assimilation under natural, seasonally-developing, soil moisture stress is not sufficient to reproduce forest canopy CO2 and water fluxes. However, accurate predictions of both CO2 and water fluxes under all soil moisture levels encountered in the field are obtained if photosynthetic capacity is assumed to vary with soil moisture. This new parameterisation has important consequences for simulated responses of carbon and water fluxes to seasonal soil moisture stress, and should greatly improve our ability to anticipate future impacts of climate changes on the functioning of ecosystems in Mediterranean-type climates.

scholarly journals Erratum: Effect of soil moisture stress from flowering to grain maturity on functional properties of Sri Lankan rice flour

2011 ◽  
Vol 63 (6) ◽  
pp. 392-392 ◽  
Author(s):  
Anil Gunaratne ◽  
Upul Kumari Ratnayaka ◽  
Nihal Sirisena ◽  
Jennet Ratnayaka ◽  
Xiangli Kong ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Functional Properties ◽  
Rice Flour ◽  
Moisture Stress ◽  
Sri Lankan ◽  
Soil Moisture Stress
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