scholarly journals Soil-moisture and evapotranspiration simulations for irrigated wheat using Soil- Plant-Atmosphere- Water (SPAW ) model

MAUSAM ◽  
2022 ◽  
Vol 45 (1) ◽  
pp. 63-68
Author(s):  
L. S. RATHORE ◽  
G. SRINIVASAN ◽  
K. K. SINGH
Keyword(s):  
Soil Moisture ◽  
Final Stage ◽  
Wheat Crop ◽  
Irrigated Wheat

goil-Plant -Atmosph erc-Watcr (S PAW) model has been applied 10 sim ula te soil-moistureprofiles for .... hea l in Delhi. Prescr ibed Inrorrnation on wheat growt h characteristics and soils alongwit h dailymeteorological data on evaporation an d rainfall were used to estima te soil- moi sture 31 a locat ion in Delhi for I Iyear s. Soil moisture simulations from model runs of consecu tive f,."T"0P seasons from 1979-80 10 1989-90 were infa vourable agreement with the gravimetrically measured obse rved dat a. Comparisons were also made for themo del gene rat ed eva pot ra nspi rat ion values. Ccrrcla tionv between observed a nd simu la ted soil-moisture in tho:different layers ra nged from 0 .7 to 0.85 for the tl -year period . Similarl y. integrated co lumn moisture amountsduring d iffe rent stage; of the crop also sho wed sign ificant cor rela tio ns ra nging from 0 .4 to 0 .8 . The model exhibitsa tendency to syste-n nicall v over estimate soil-moist ure du ring the final stage s of crop. possibly due I,)im perfections in in put . model a rt ifacts an~ observationa l ina deq uaci es. H ONe..-er-. the overall ability of the modelto rep roduce obser ved changes m soil-moisture for activ ely growing wheat crop In Indian con ditions, underlinesito; uti lity.

A MOISTURE STRESS INDEX FOR WHEAT BY MEANS OF A MODULATED SOIL MOISTURE BUDGET

1968 ◽  
Vol 48 (5) ◽  
pp. 535-544 ◽  
Author(s):  
A. R. Mack ◽  
W. S. Ferguson
Keyword(s):  
Soil Moisture ◽  
Stress Function ◽  
Potential Evapotranspiration ◽  
Moisture Stress ◽  
Moisture Distribution ◽  
Stress Index ◽  
Wheat Crop ◽  
Moisture Budget ◽  
Dough Stage ◽  
Soil Moisture Budget

Actual evapotranspiration (AE), soil moisture distribution, and moisture stress for a wheat crop (PE-AE) were estimated by the modulated soil moisture budget of Holmes and Robertson. The estimated soil moisture was reasonably well correlated with soil moisture measured weekly by means of gypsum blocks. Wheat yields from experimental plots in the corresponding area were related more closely to the moisture stress function (PE-AE: r = − 0.83), than to the seasonal precipitation (r = 0.62), the potential evapotranspiration (PE) or the evapotranspiration ratio (AE/PE). Regression analyses showed that the grain yields were reduced by an average of 156 (±sb = 40) kg/ha per cm of moisture stress from emergence to harvest, or by 311 and 69 kg/ha per cm of stress, from the fifth-leaf to the soft-dough stage and from the soft-dough stage to maturity, respectively. The moisture stress function may be used to characterize the soil–plant–atmosphere environment for the growing season of a crop. Precipitation and evapotranspiration data are presented annually for three standardized growing periods at Brandon from 1921 to 1963.

scholarly journals The Influence of Some Phytotechnical Elements on Attaque of Diabrotica Virgifera Virgifera Le Conte (The Western Root Worm) in Maize from Crisurilor Plain

1970 ◽  
Vol 66 (1) ◽  
Author(s):  
Cornelia CIOBANU ◽  
Cornel DOMUŢA ◽  
Gheorghe CIOBANU ◽  
Maria ŞANDOR ◽  
Alina Dora SAMUEL ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Diabrotica Virgifera Virgifera ◽  
Crop Rotations ◽  
Wheat Crop ◽  
Diabrotica Virgifera ◽  
Term Trial ◽  
Lower Plant

The paper based on the researches carried out during 2005 – 2008 in the long term trial placed in 1990 on the preluvosoil from Oradea. The monoculture of maize, maize – wheat and maize – soybean – wheat crop rotations were studied in unirrigated and irrigated conditions. The crop rotatin of six years (oat + clover – clover – maize – wheat – maize - sunflower) was studied in unirrigated conditions. The researches emphasized that the monoculture is the most responsible for the pest multiplication. In maize monoculture the larvae number on the roots was ranged between 4.91-8.23 and root attack degree in IOWA scale (with marks from 1 to 6 in which maximum attack is 6), had values between 3.84 and 5.62 and the frequent of attacked plants with the symptom “goose neck” ranged between 16,4% and 31.2% and larval aggressiveness being higher in the case of favorable soil moisture in irrigated condition. The maize rotation with other plants interrupts the biologic pest cycle. The results obtained emphasize that later maize sowing alongside by the utilizing of lower plant thickness level contribute to prevention of pest multiplication, while earlier sowing at high thickness favor the larvae developing.

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>

The relationship between evapotranspiration and growth in the wheat crop

1966 ◽  
Vol 17 (3) ◽  
pp. 255 ◽  
Author(s):  
RA Fischer ◽  
GD Kohn
Keyword(s):  
Soil Moisture ◽  
Vegetative Growth ◽  
Dry Weight ◽  
Fertilizer Application ◽  
Wheat Crop ◽  
South Wales ◽  
Evapotranspiration Rate ◽  
Total Dry Weight ◽  
Delayed Flowering ◽  
The Relationship

In trials conducted in 1961 and 1962 at Wagga in southern New South Wales, to investigate the yield physiology of wheat, the variety Heron was grown under various cultural treatments. This paper deals with the relationship of evapotranspiration to crop growth. Vegetative growth at a given date in the spring was influenced markedly by time of sowing and fertilizer application, and to a lesser extent by sowing rate. Large differences in vegetative growth caused relatively small differences in evapotranspiration rate when soil moisture was adequate. An increase in total dry weight of 100 g/m² in early October was associated with an increase in cumulative evapotranspiration up to that time of about 0.50 in. It was concluded that although a reduced fertilizer application and reduced sowing rate (below 3b lb seed per acre) permitted higher soil moisture levels at flowering, this necessarily involved a considerable reduction in total dry weight at flowering. With delayed time of sowing, the post-flowering moisture status of the crop can be expected to deteriorate, primarily because of delayed flowering date.

scholarly journals The Diurnal Cycle of Land–Atmosphere Interactions across Oklahoma’s Winter Wheat Belt

2005 ◽  
Vol 133 (1) ◽  
pp. 120-130 ◽  
Author(s):  
Matthew J. Haugland ◽  
Kenneth C. Crawford
Keyword(s):  
Soil Moisture ◽  
Winter Wheat ◽  
Surface Pressure ◽  
Diurnal Cycle ◽  
Wheat Crop ◽  
Near Surface ◽  
Diurnal Cycles ◽  
Dewpoint Temperature ◽  
Before And After ◽  
The Impact

Abstract This manuscript documents the impact of Oklahoma’s winter wheat belt (WWB) on the near-surface atmosphere by comparing the diurnal cycle of meteorological conditions within the WWB relative to conditions in adjacent counties before and after the wheat harvest. To isolate the impact of the winter wheat belt on the atmosphere, data from several meteorological parameters were averaged to create a diurnal cycle before and after the wheat harvest. Observations from 17 Oklahoma Mesonet sites within the WWB (during a period of 9 yr) were compared with observations from 22 Mesonet sites in adjacent counties outside the winter wheat belt. The average diurnal cycles of dewpoint, temperature, and surface pressure exhibited patterns that revealed a distinct mesoscale impact of the wheat fields. The diurnal patterns were consistent with the status of the wheat crop and the grassland in adjacent counties. The impact of the WWB was shown to be more significant during a month when soil moisture was abundant, and minimal during a month when soil moisture was limited. Statistically significant, hydrostatically consistent afternoon surface pressure anomalies suggest that there is a strong possibility of weak mesoscale circulations induced by the WWB.

scholarly journals Validation of irrigation scheduling for cultivation of irrigated wheat in semi-arid climatic condition of Ethiopia

2018 ◽  
Vol 6 (2) ◽  
pp. 139-147
Author(s):  
Elias Kebede ◽  
Yonas Derese ◽  
Nigussie Abebe ◽  
Fikadu Robi ◽  
Kebede Nanesa
Keyword(s):  
Soil Moisture ◽  
Grain Yield ◽  
Irrigation Water ◽  
Field Trial ◽  
Short Interval ◽  
Field Capacity ◽  
Irrigation Scheduling ◽  
Irrigation Regime ◽  
Irrigation Application ◽  
Irrigated Wheat

ABSTRACTThis study was conducted for three years (2014-2016) to validate irrigation scheduling of irrigated wheat cultivation to determine appropriate irrigation regime.  The experiments were irrigation scheduling based on CROPWAT Model 8.0 and validation on field trial. The treatments were arranged in randomized complete block design with three replications. The field trial was involving three irrigation regime treatments were used for comparison. The treatments were Treatment 1 (T1): Optimal irrigation regime as determined by Cowpat for windows that provides irrigation water of D1=50mm at an interval of I1=7 days, Treatment 2(T2): Optimal irrigation regime as determined by Cowpat for windows that provides irrigation water of D2=67mm at an interval of I2=10 days. Treatment 3(T3): Optimal irrigation regime as determined by Cowpat for windows that provides irrigation water of D3=108.3mm at an interval of I3=15 days. Treatment 4(T4): An irrigation regime that provides irrigation water at critical soil moisture depletion and an amount that would refill the soil moisture depletion to field capacity. Result indicated that grain yield was significantly affected by irrigation levels. Irrigation regime of Treatment 4 produced higher grain yield 2400 kg/ha and 20.0q/ha in 2015 and 2016 cropping season. The highest mean yield of wheat (2200 kg/ha) was obtained from critical moisture refill field capacity irrigation application. Whereas, the lowest mean yield (1778 kg/ha) was obtained from T3, 7 days irrigation interval and 50mm irrigation application. This indicates that yield of wheat decrease with decreasing water amount and short interval frequency. Irrigation scheduling based on cowpat model with irrigation regime that provides irrigation water at critical soil moisture depletion and an amount that would refill the soil moisture depletion to field capacity found promising optimum wheat scheduling under Werer and similar areas.

scholarly journals Assimilation of Wheat and Soil States into the APSIM-Wheat Crop Model: A Case Study

2021 ◽  
Vol 14 (1) ◽  
pp. 65
Author(s):  
Yuxi Zhang ◽  
Jeffrey P. Walker ◽  
Valentijn R. N. Pauwels ◽  
Yuval Sadeh
Keyword(s):  
Soil Moisture ◽  
Remotely Sensed ◽  
Crop Productivity ◽  
Open Loop ◽  
Wheat Crop ◽  
Spatial And Temporal Variability ◽  
Baseline Scenario ◽  
State Variables ◽  
Yield Estimation ◽  
Area Index

Optimised farm crop productivity requires careful management in response to the spatial and temporal variability of yield. Accordingly, combination of crop simulation models and remote sensing data provides a pathway for providing the spatially variable information needed on current crop status and the expected yield. An ensemble Kalman filter (EnKF) data assimilation framework was developed to assimilate plant and soil observations into a prediction model to improve crop development and yield forecasting. Specifically, this study explored the performance of assimilating state observations into the APSIM-Wheat model using a dataset collected during the 2018/19 wheat season at a farm near Cora Lynn in Victoria, Australia. The assimilated state variables include (1) ground-based measurements of Leaf Area Index (LAI), soil moisture throughout the profile, biomass, and soil nitrate-nitrogen; and (2) remotely sensed observations of LAI and surface soil moisture. In a baseline scenario, an unconstrained (open-loop) simulation greatly underestimated the wheat grain with a relative difference (RD) of −38.3%, while the assimilation constrained simulations using ground-based LAI, ground-based biomass, and remotely sensed LAI were all found to improve the RD, reducing it to −32.7%, −9.4%, and −7.6%, respectively. Further improvements in yield estimation were found when: (1) wheat states were assimilated in phenological stages 4 and 5 (end of juvenile to flowering), (2) plot-specific remotely sensed LAI was used instead of the field average, and (3) wheat phenology was constrained by ground observations. Even when using parameters that were not accurately calibrated or measured, the assimilation of LAI and biomass still provided improved yield estimation over that from an open-loop simulation.

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