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.

INFLUENCE OF SOLAR RADIATION AND SOIL MOISTURE ON GROWTH AND YIELD OF CHINOOK WHEAT

1969 ◽  
Vol 49 (6) ◽  
pp. 685-699 ◽  
Author(s):  
C. A. Campbell ◽  
W. L. Pelton ◽  
K. F. Nielsen
Keyword(s):  
Soil Moisture ◽  
Solar Radiation ◽  
Light Intensity ◽  
Crude Protein ◽  
Soluble Sugars ◽  
Moisture Stress ◽  
Growth And Yield ◽  
Regression Equations ◽  
Soil Moisture Stress ◽  
Net Assimilation

The influence of solar radiation on the growth and yield of Chinook wheat was determined in a 5-year field shading study, and a 1-year, 3 × 3 shading × soil moisture lysimeter experiment.In the field, shading with saran mesh reduced solar radiation and wind but had little effect on air or soil temperature. In moist years shade maintained soil moisture at a higher level than no shade. Generally, mean leaf area ratio decreased and mean net assimilation rate and relative growth rate increased linearly with increases in the log of light intensity. There were interactions between shading × years (weather) relative to dry matter yield. The efficiency with which solar energy was used for grain production increased with shading. The effect of shading on crude protein and soluble sugars in grain was variable.In the lysimeter shading study, regression equations were used to relate several plant characters to shading and soil moisture (in the available range). Plant height, stem diameter, days to head, number of tillers, weights of grain and of straw, and percent cellulose were negatively related to soil moisture stress; crude protein was positively related. Days to head and crude protein were negatively related to light intensity, but all the other characters were positively related. The partial regression coefficients indicated that the influence of soil moisture stress was much more important than solar radiation on the crude protein content of the grain.

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.

Control and Seedhead Suppression of Red Rice (Oryza sativa) in Soybeans (Glycine max)

1989 ◽  
Vol 3 (2) ◽  
pp. 238-243 ◽  
Author(s):  
Frederick P. Salzman ◽  
Roy J. Smith ◽  
Ronald E. Talbert
Keyword(s):  
Oryza Sativa ◽  
Soil Moisture ◽  
Glycine Max ◽  
Plant Growth ◽  
Growth Regulators ◽  
Moisture Stress ◽  
Growth Stages ◽  
Red Rice ◽  
Soil Moisture Stress ◽  
High Soil Moisture

Experiments were conducted in 1985 and 1986 at three locations in eastern Arkansas to evaluate red rice control in soybeans with postemergence grass herbicides and plant growth regulators applied singly or sequentially at early to late-tillering growth stages of red rice. Haloxyfop at 0.21 kg ai/ha and quizalofop at 0.14 kg ai/ha applied singly or sequentially and fluazifop at 0.21 kg ai/ha applied sequentially consistently controlled red rice and suppressed seedhead production in soybeans. Mid-season treatments were not beneficial when high soil moisture stress conditions existed. Mefluidide or sethoxydim applied singly or sequentially or amidochlor applied singly provided erratic control and seedhead suppression of red rice in soybeans.

INFLUENCE OF AIR TEMPERATURE, LIGHT INTENSITY AND SOIL MOISTURE ON THE GROWTH, YIELD AND SOME GROWTH ANALYSIS CHARACTERISTICS OF CHINOOK WHEAT GROWN IN THE GROWTH CHAMBER

1968 ◽  
Vol 48 (3) ◽  
pp. 299-311 ◽  
Author(s):  
C. A. Campbell ◽  
D. W. L. Read
Keyword(s):  
Growth Rate ◽  
Soil Moisture ◽  
Light Intensity ◽  
Leaf Area ◽  
Dry Matter ◽  
Moisture Stress ◽  
Assimilation Rate ◽  
Total Leaf Area ◽  
Relative Growth ◽  
Net Assimilation

The response of Chinook wheat to light intensity, air temperature and soil moisture stress was studied under controlled environmental conditions in a 3 × 3 × 2 factorial experiment.Increasing day temperature from 21 to 27 °C or night temperature from 13 to 21 °C did not affect tillering, but the plants had shorter, slimmer culms with smaller individual leaves, less total leaf area, and less vegetative and grain dry matter. Temperature changes had little effect on leaf area ratios and their influence on net assimilation rate and relative growth rate was inconsistent. Percent grain protein was increased by temperature.A reduction of light intensity from 17 to 6 cals cm−2hr−1 did not change individual leaf size, but did produce shorter plants with fewer tillers and weak culms. Vegetative, root and grain dry matter were reduced. Shading reduced the translocation of leaf assimilates and lowered the cellulose content of the straw, but increased percent grain protein.Plants developed more tillers at the lower moisture stress, but this difference disappeared by heading time. The lower stress resulted in taller, thicker-stemmed culms with a greater total leaf area, and greater yields of straw and root. The effect of moisture on leaf area ratio was small and its influence on net assimilation rate and relative growth rate was small and inconsistent. Its influence on grain yield varied with temperature; the latter interaction was traced specifically to the influence of moisture stress on seed set. The effect of moisture on percent protein and carbohydrates in grain and on percent cellulose in the straw was inconsistent.

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

scholarly journals Response of Native White Sorghum to Irrigation under Different Nitrogen-Fertility Levels and Seeding Rates in Lajas Valley, Puerto Rico

1969 ◽  
Vol 50 (2) ◽  
pp. 92-112
Author(s):  
R. Vázquez ◽  
A. Eschenwald-Hess ◽  
M. J. Martínez-Luciano
Keyword(s):  
Puerto Rico ◽  
Soil Moisture ◽  
Field Experiment ◽  
Dry Matter ◽  
Root Zone ◽  
High Moisture ◽  
Nitrogen Levels ◽  
Nitrogen Fertility ◽  
Native White ◽  
Active Root

A field experiment was conducted at Lajas Substation in order to study the effects of four irrigation and three nitrogen levels under three different seeding rates on dry-matter yields of White Native sorghum. The following irrigation treatments were tried: High moisture, plots irrigated when the average soil-moisture suction in the active root-zone reached 0.7 atm.; medium moisture, irrigated when the average soil-moisture suction reached 2.0 atm.; low moisture, irrigated when the average soil-moisture suction reached 5.0 atm., and nonirrigated plots were used as check. The nitrogen levels tested were 40, 80, and 120 pounds per acre per harvest. The seeding rates used were 10, 20, and 30 pounds per acre.

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