ESTIMATING YIELD COMPONENTS OF WHEAT FROM CALCULATED SOIL MOISTURE

1967 ◽  
Vol 47 (6) ◽  
pp. 617-630 ◽  
Author(s):  
W. Baier ◽  
Geo. W. Robertson
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Yield Components ◽  
Root Zone ◽  
Unit Area ◽  
Kernel Weight ◽  
Wheat Crop ◽  
Climatic Data ◽  
Grain Yields ◽  
Insight Into

Yield components of a wheat crop, namely number of heads per unit area, number of kernels per head and 1000-kernel weight, were related to soil moisture estimated from a meteorological budgeting procedure using only standard climatic data. Several soil-moisture variables, such as moisture content in the root zone from jointing to heading, significantly affected all three yield components and thereby final grain yields. The calculated yield components did not give better estimates of grain yields than those obtained directly from soil-moisture variables, but they did provide a better insight into the relationships between soil moisture, other climatic variables and grain yields at each of the eight stations across Canada. The practical use of a soil-moisture climatology based on the established relationships between estimated soil moisture and yield components is discussed.

Soil water relations and relative turgidity on leaves in the wheat crop

1966 ◽  
Vol 17 (3) ◽  
pp. 269 ◽  
Author(s):  
RA Fischer ◽  
GD Kohn
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Root Zone ◽  
Moisture Stress ◽  
Flowering Plant ◽  
Wheat Crop ◽  
Stage Of Development ◽  
South Wales ◽  
Plant Moisture

Trials were conducted in 1961 and 1962 at Wagga in southern New South Wales to investigate the yield physiology of the wheat crop. Various cultural treatments were applied to a single variety (Heron). The increases in evapotranspiration and associated reductions in total soil moisture content caused by early sowing, by heavier fertilizer applications, and to a lesser extent by a heavier rate of sowing were reflected in an increased plant moisture stress (reduced leaf relative turgidity) at a given time in the spring. At a given stage of development, however, relative turgidity was not much affected by time of sowing, and in fact post-flowering plant moisture stress increased with later sowing. There were only small treatment effects on the estimated depth and density of rooting. Relatively little water was extracted by crops from below 40 in.; dense crops reduced the soil moisture content throughout the root zone to less than the –15 bar value. Leaf relative turgidity at sunrise showed a consistent inverse relationship to soil moisture content in the root zone. Leaf turgidity (sunrise) was maintained at 100% until root zone moisture levels approached the –15 bar value.

Assessing soil moisture constraint on soil evaporation and plant transpiration fractioning

2020 ◽  
Author(s):  
Bouchra Ait Hssaine ◽  
Olivier Merlin ◽  
Jamal Ezzahar ◽  
Salah Er-raki ◽  
Saïd Khabba ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Land Surface ◽  
Water Resource Management ◽  
Root Zone ◽  
Temporal Variations ◽  
Soil Evaporation ◽  
Balance Model ◽  
Wheat Crop ◽  
Soil Resistance ◽  
Plant Transpiration

<p>Over semi-arid agricultural regions, detecting the crop water need at the onset of water stress is of paramount importance for optimizing the use of irrigation water. Evapotranspiration (ET) is a crucial component of the water cycle, it strongly impacts the water resource management, drought monitoring, and climate. Remote sensing observations provide very relevant information to feed ET models. In particular, the microwave-derived surface (0-5 cm) soil moisture (SM), which is the main controlling factor of soil evaporation, the visible/near-infratred-derived vegetation cover fraction (fc), which provides an essential structural constraint on the fractioning between vegetation transpiration and soil evaporation, and - thermal-derived land surface temperature (LST), which is a signature of both available energy and evapotranspiration (ET) rate. The aim of this work is to integrate those independent and complementary information on total ET within an energy balance model. As a state-of-the-art and commonly used model, we chose the TSEB modelling as a basis for developments. An innovative calibration procedure is proposed to retrieve the main parameters of soil evaporation (soil resistance, r<sub>ss</sub>) and plant transpiration (Priestly Taylor coefficient, α<sub>PT</sub>) based on a threshold on fc. The procedure is applied over an irrigated wheat field in the Tensift basin, central Morocco. Overall, the coupling of the soil resistance formulation with the TSEB formalism improves the estimation of soil evaporation, and consequently, improves the partitioning of ET. Analysis of the retrieved time series indicates that the daily α<sub>PT</sub> mainly follows the phenology of winter wheat crop with a maximum value coincident with the full development of green biomass and a minimum value reached at harvest. The temporal variations of α<sub>PT</sub> before senescence are attributed to the dynamics of both the root zone soil moisture and the amount of green biomass.</p>

Effects of Patterns and Methods of Sowing on Sorghum/Striga Relations

1981 ◽  
Vol 17 (3) ◽  
pp. 337-341 ◽  
Author(s):  
F. F. Bebawi ◽  
A. F. Farah
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Yield Components ◽  
Soil Moisture Content ◽  
Plant Competition ◽  
Traditional Pattern

SUMMARYChanging the geometry of planting under irrigated conditions from the traditional pattern of regular rows (with plants equidistant from each other) into double rows (with plants arranged in row pairs) promoted plant competition. This resulted in a significant reduction in overall yield components of sorghum but a marked increase in shoot yields of striga. A better yield of sorghum was obtained in ridged plots than in flat plots, associated with less striga infestation and a slightly higher soil moisture content under the ridged plots.

scholarly journals Comparing soil moisture anomalies from multiple independent sources over different regions across the globe

2017 ◽  
Author(s):  
Carmelo Cammalleri ◽  
Jürgen V. Vogt ◽  
Bernard Bisselink ◽  
Ad de Roo
Keyword(s):  
Soil Moisture ◽  
North America ◽  
Southern Africa ◽  
Land Surface ◽  
Root Zone ◽  
Agricultural Drought ◽  
Drought Monitoring ◽  
Distributed Hydrological Model ◽  
Ground Station ◽  
Insight Into

Abstract. Agricultural drought events can affect large regions across the World, implying the urge for a suitable global tool for an accurate monitoring of this phenomenon. Soil moisture anomalies are considered a good metric to capture the occurrence of agricultural drought events, and they have become an important component of several operational drought monitoring systems. In the framework of the JRC Global Drought Observatory (GDO, http://edo.jrc.ec.europa.eu/gdo/) the suitability of modelled and/or satellite-derived proxy of soil moisture anomalies was investigated. In this study, three datasets have been evaluated as possible proxies of root zone soil moisture anomalies: (1) soil moisture from the Lisflood distributed hydrological model (LIS), (2) remotely sensed land surface temperature data from the MODIS satellite (LST), and (3) the combined passive/active microwave skin soil moisture dataset developed by ESA (CCI). Due to the independency of these three datasets, the Triple Collocation (TC) technique has been applied, aiming at quantifying the likely error associated to each dataset in comparison to the unknown true status of the system. TC analysis was performed on five macro-regions (namely North America, Europe, India, Southern Africa and Australia) detected as suitable for the experiment, providing insight into the mutual relationship between these datasets as well as assessment of the accuracy of each method. A clear outcome of the TC analysis is the good performance of remote sensing datasets, especially CCI, over dry regions such as Australia and Southern Africa, whereas the outputs of LIS seem to be more reliable over areas that are well monitored through meteorological ground station networks, such as North America and Europe. In a global drought monitoring system, these results can be used to design an ensemble system that exploits the advantages of each dataset.

scholarly journals The effect of soil conservation tillage on soil moisture dynamics under single cropping and crop rotation

2011 ◽  
Vol 51 (No. 3) ◽  
pp. 124-130 ◽  
Author(s):  
K. Kováč ◽  
M. Macák ◽  
M. Švančárková
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Crop Rotation ◽  
Spring Barley ◽  
Soil Layer ◽  
Conventional Tillage ◽  
Wheat Crop ◽  
Soil Moisture Dynamics ◽  
No Till ◽  
Moisture Dynamics

During 1993–1995 the effect of conventional tillage, reduced till, mulch till and no-till technology on soil moisture dynamics has been studied in field experiment on Haplic chernozems near Piešťany. The tillage treatments were evaluated under a single cropping of maize and spring barley – common peas – winter wheat crop rotation. Soil samples for gravimetric determination of moisture content were collected from six layers up to 0.8 m, three times per year (April–July). The soil moisture was highly significantly influenced in order of importance by date of sampling, year, growing crops, tillage treatments, soil layer and by interactions year × crops, year × date of sampling, crops × date of sampling, tillage × date of sampling, year × tillage, date of sampling × layer and significant influences by interactions, tillage × crops. The soil under conventional tillage had significantly higher moisture content than tested reduced till, mulch till and no-till treatments. The significant influence of maize stand on better soil humidity condition (16.35%) in comparison to crops grown in a crop rotation (in average 14.10%) has been ascertained.

INFLUENCE OF SOIL MOISTURE STRESS APPLIED AT VARIOUS STAGES OF GROWTH ON THE YIELD COMPONENTS OF CHINOOK WHEAT

1968 ◽  
Vol 48 (3) ◽  
pp. 313-320 ◽  
Author(s):  
C. A. Campbell
Keyword(s):  
Soil Moisture ◽  
Grain Yield ◽  
Seed Set ◽  
Moisture Stress ◽  
Kernel Weight ◽  
Growth Stages ◽  
Soil Moisture Stress ◽  
Grain Yields ◽  
Dry Conditions ◽  
Main Components

Two series of moisture treatments were used to determine if there was a specific growth stage at which low soil moisture stress caused poor seed set in Chinook wheat, and also to determine whether grain yield could be maximized by manipulating time of increasing or decreasing moisture stress.Maintaining soil moisture at 25 to 10% (dry) until the shot-blade stage produced 80% seed set, compared with only 30% seed set when moisture was maintained at 25% to 16% (wet) during the same period. Increasing or decreasing the soil moisture stress at different growth stages had little effect on the number of florets per head or the mean kernel weight. Under the conditions of this experiment, the number of heads and percent seed set were the main components influencing grain yield. The highest grain yields were obtained when plants were grown under dry conditions until late shot-blade and under wet conditions thereafter. Conversely, minimum grain yields were realized where plants were grown under wet conditions until late shot-blade and under dry conditions thereafter. Straw yield was closely related to the total moisture used.

Changes in the yield components of durum wheat (Triticum durum Desf.) during irrigation controlled by soil sensors

2012 ◽  
Vol 60 (4) ◽  
pp. 309-317 ◽  
Author(s):  
J. Bányai ◽  
É. Láng ◽  
Z. Bognár ◽  
C. Kuti ◽  
T. SpitkÓ ◽  
...  
Keyword(s):  
Moisture Content ◽  
Durum Wheat ◽  
Irrigation Water ◽  
Yield Components ◽  
Kernel Weight ◽  
Weather Data ◽  
Wheat Varieties ◽  
Soil Sensors ◽  
Significant Difference ◽  
Triticum Durum Desf

The effect of irrigation water on the yield and on individual yield components was examined for 19 durum wheat varieties by continually recording weather data and carrying out measurements on the moisture content, temperature, electrical conductivity and tension of the soil. Dry (rain-fed) and irrigated treatments were included in the experiment, which was carried out in the framework of the EU FP7-244374 DROPS project.During the rainless spring of 2011 the soil moisture content of the non-irrigated area dropped to 21–22 vol% and the effect of drought stress was still felt at harvest. The quantity of irrigation water applied during the growing season ensured normal conditions for generative development and a significant difference could be detected between the yield components in the two treatments. The thousand-kernel weight of the varieties was identical in the dry and irrigated plots, but in response to irrigation there was an increase in the number of grains per ear and the grain weight, and an improvement in fertilisation, resulting in higher yields.

scholarly journals Laboratory Measurements of Subsurface Spatial Moisture Content by Ground-Penetrating Radar (GPR) Diffraction and Reflection Imaging of Agricultural Soils

2018 ◽  
Vol 10 (10) ◽  
pp. 1667 ◽  
Author(s):  
Omer Shamir ◽  
Naftaly Goldshleger ◽  
Uri Basson ◽  
Moshe Reshef
Keyword(s):  
Dielectric Constant ◽  
Soil Moisture ◽  
Moisture Content ◽  
Ground Penetrating Radar ◽  
Soil Type ◽  
Soil Moisture Content ◽  
Root Zone ◽  
Effective Dielectric Constant ◽  
Agricultural Practice ◽  
Ground Penetrating

Soil moisture content (SMC) down to the root zone is a major factor for the efficient cultivation of agricultural crops, especially in arid and semi-arid regions. Precise SMC can maximize crop yields (both quality and quantity), prevent crop damage, and decrease irrigation expenses and water waste, among other benefits. This study focuses on the subsurface spatial electromagnetic mapping of physical properties, mainly moisture content, using a ground-penetrating radar (GPR). In the laboratory, GPR measurements were carried out using an 800 MHz central-frequency antenna and conducted in soil boxes with loess soil type (calcic haploxeralf) from the northern Negev, hamra soil type (typic rhodoxeralf) from the Sharon coastal plain, and grumusol soil type (typic chromoxerets) from the Jezreel valley, Israel. These measurements enabled highly accurate, close-to-real-time evaluations of physical soil qualities (i.e., wave velocity and dielectric constant) connected to SMC. A mixture model based mainly on soil texture, porosity, and effective dielectric constant (permittivity) was developed to measure the subsurface spatial volumetric soil moisture content (VSMC) for a wide range of moisture contents. The analysis of the travel times for GPR reflection and diffraction waves enabled calculating electromagnetic velocities, effective dielectric constants, and spatial SMC under laboratory conditions, where the required penetration depth is low (root zone). The average VSMC was determined with an average accuracy of ±1.5% and was correlated to a standard oven-drying method, making this spatial method useful for agricultural practice and for the design of irrigation plans for different interfaces.

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