Optimized spectral index models for accurately retrieving soil moisture (SM) of winter wheat under water stress

2022 ◽  
Vol 261 ◽  
pp. 107333
Author(s):  
Shoujia Ren ◽  
Bin Guo ◽  
Zhijun Wang ◽  
Juan Wang ◽  
Quanxiao Fang ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Winter Wheat ◽  
Spectral Index

Winter wheat and maize under varying soil moisture: from leaf to canopy

2021 ◽  
Author(s):  
Thuy Huu Nguyen ◽  
Matthias Langensiepen ◽  
Thomas Gaiser ◽  
Heidi Webber ◽  
Hella Ahrends ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Winter Wheat ◽  
Leaf Area ◽  
Dynamic Change ◽  
Crop Growth ◽  
Leaf Water ◽  
Area Index ◽  
Canopy Transpiration ◽  
Stomatal Responses

<p>Drought is one of the most detrimental factors limiting crop growth and production of important staple crops such as winter wheat and maize. For both crops, stomatal regulation and change of canopy structure responses to water stress can be observed. A substantial range of stomatal behavior in regulating water loss was recently reported while the crop growth and morphological responses to drought stress depend on the intensity and duration of the imposed stress. Insights into the responses from leaf to the canopy are important for crop modeling and soil-vegetation-atmosphere models (SVAT). Stomatal responses and effects of soil water deficit on the dynamic change of canopy photosynthesis and transpiration, and seasonal crop growth of winter wheat and maize are investigated based on data collected from field-grown conditions with varying soil moisture treatments (sheltered, rainfed, irrigated) in 2016, 2017, and 2018. A reduction of leaf net photosynthesis (An), stomatal conductance (Gs), transpiration (E), and leaf water potential (LWP) was observed in the sheltered plot as compared to the rainfed and irrigated plots in winter wheat in 2016, indicating anisohydric stomatal responses. Maize showed seasonal isohydric behaviour with the minimum LWP from -1.5 to -2 MPa in 2017 and -2 to -2.7 MPa in the extremely hot and dry year in 2018. Crop growth (biomass, leaf area index, and yield) was substantially reduced under drought conditions, particularly for maize in 2018. Leaf water use efficiency (An/E) and crop WUE (total dry biomass/canopy transpiration) were not significantly different among treatments in both crops. The reduction of tiller number (in winter wheat) and leaf-rolling and plant size (in maize) resulted in a reduction of canopy transpiration, assimilation rate, and thus biomass. The seasonal isohydry in maize and the seasonal variability of LWP in winter wheat suggest a possibility to use the same critical LWP thresholds for maize and wheat to simulate the stomatal control in process-based crop and SVAT models. The canopy response such as dynamically reducing leaf area under water stress adds complexity in simulating gas exchange and crop growth rate that needs adequate consideration in the current modeling approaches.</p>

Nested Validation of Aquacrop Model for Simulation of Winter Wheat Grain Yield, Soil Moisture and Salinity Profiles under Simultaneous Salinity and Water Stress

2016 ◽  
Vol 65 (1) ◽  
pp. 112-128 ◽  
Author(s):  
M. Mohammadi ◽  
B. Ghahraman ◽  
K. Davary ◽  
H. Ansari ◽  
A. Shahidi ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Winter Wheat ◽  
Grain Yield ◽  
Wheat Grain ◽  
Aquacrop Model

scholarly journals Estimation of Winter Wheat Yield in Arid and Semiarid Regions Based on Assimilated Multi-Source Sentinel Data and the CERES-Wheat Model

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1247
Author(s):  
Zhengchun Liu ◽  
Zhanjun Xu ◽  
Rutian Bi ◽  
Chao Wang ◽  
Peng He ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Data Assimilation ◽  
Winter Wheat ◽  
Soil Water ◽  
High Precision ◽  
Stress Conditions ◽  
Crop Modeling ◽  
Semiarid Regions ◽  
Arid And Semiarid

The farmland area in arid and semiarid regions accounts for about 40% of the total area of farmland in the world, and it continues to increase. It is critical for global food security to predict the crop yield in arid and semiarid regions. To improve the prediction of crop yields in arid and semiarid regions, we explored data assimilation-crop modeling strategies for estimating the yield of winter wheat under different water stress conditions across different growing areas. We incorporated leaf area index (LAI) and soil moisture derived from multi-source Sentinel data with the CERES-Wheat model using ensemble Kalman filter data assimilation. According to different water stress conditions, different data assimilation strategies were applied to estimate winter wheat yields in arid and semiarid areas. Sentinel data provided LAI and soil moisture data with higher frequency (<14 d) and higher precision, with root mean square errors (RMSE) of 0.9955 m2 m−2 and 0.0305 cm3 cm−3, respectively, for data assimilation-crop modeling. The temporal continuity of the CERES-Wheat model and the spatial continuity of the remote sensing images obtained from the Sentinel data were integrated using the assimilation method. The RMSE of LAI and soil water obtained by the assimilation method were lower than those simulated by the CERES-Wheat model, which were reduced by 0.4458 m2 m−2 and 0.0244 cm3 cm−3, respectively. Assimilation of LAI independently estimated yield with high precision and efficiency in irrigated areas for winter wheat, with RMSE and absolute relative error (ARE) of 427.57 kg ha−1 and 6.07%, respectively. However, in rain-fed areas of winter wheat under water stress, assimilating both LAI and soil moisture achieved the highest accuracy in estimating yield (RMSE = 424.75 kg ha−1, ARE = 9.55%) by modifying the growth and development of the canopy simultaneously and by promoting soil water balance. Sentinel data can provide high temporal and spatial resolution data for deriving LAI and soil moisture in the study area, thereby improving the estimation accuracy of the assimilation model at a regional scale. In the arid and semiarid region of the southeastern Loess Plateau, assimilation of LAI independently can obtain high-precision yield estimation of winter wheat in irrigated area, while it requires assimilating both LAI and soil moisture to achieve high-precision yield estimation in the rain-fed area.

Effects of Plastic Mulching Modes on Soil Moisture and Grain Yield in Dryland Winter Wheat

2015 ◽  
Vol 41 (5) ◽  
pp. 787 ◽  
Author(s):  
Shou-Xi CHAI ◽  
Chang-Gang YANG ◽  
Shu-Fang ZHANG ◽  
Heng-Hong CHEN ◽  
Lei CHANG
Keyword(s):  
Soil Moisture ◽  
Winter Wheat ◽  
Grain Yield ◽  
Plastic Mulching

EFFECT OF DEFICIT IRRIGATION ON YIELD, RELATIVE LEAF WATER CONTENT, LEAF PROLINE ACCUMULATION AND CHLOROPHYLL STABILITY INDEX OF COTTON–MAIZE CROPPING SEQUENCE

2013 ◽  
Vol 50 (3) ◽  
pp. 407-425 ◽  
Author(s):  
T. SAMPATHKUMAR ◽  
B. J. PANDIAN ◽  
P. JEYAKUMAR ◽  
P. MANICKASUNDARAM
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Water Content ◽  
Deficit Irrigation ◽  
Stability Index ◽  
Moisture Gradient ◽  
Proline Content ◽  
Leaf Water Content ◽  
Chlorophyll Stability Index ◽  
Soil Moisture Gradient

SUMMARYWater stress induces some physiological changes in plants and has cumulative effects on crop growth and yield. Field experiments were conducted to study the effect of deficit irrigation (DI) on yield and some physiological parameters in cotton and maize in a sequential cropping system. Creation of soil moisture gradient is indispensable to explore the beneficial effects of partial root zone drying (PRD) irrigation and it could be possible only through alternate deficit irrigation (ADI) practice in paired row system of drip layout that is commonly practiced in India. In the present study, PRD and DI concepts (creation of soil moisture gradient) were implemented through ADI at two levels of irrigation using drip system. Maize was sown after cotton under no till condition without disturbing the raised bed and drip layout. Relative leaf water content (RLWC) and chlorophyll stability index (CSI) of cotton and maize were reduced under water stress. A higher level of leaf proline content was observed under severe water-stressed treatments in cotton and maize. RLWC and CSI were highest and leaf proline content was lowest in mild water deficit (ADI at 100% crop evapotranspiration once in three days) irrigation in cotton and maize. The same treatments registered higher values for crop yields, net income and benefit cost ratio for both the crops.

Estimation water status of the vineyard by calculating multispectral index from satellite images

2021 ◽  
Author(s):  
Marta Rodríguez-Fernández ◽  
María Fandiño ◽  
Xesús Pablo González ◽  
Javier J. Cancela
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Spectral Index ◽  
Satellite Images ◽  
Irrigation System ◽  
Water Status ◽  
Stress Index ◽  
Stem Water Potential ◽  
Stem Water ◽  
Water Potential Measurements

&lt;p&gt;The estimation of the water status in the vineyard, is a very important factor, in which every day the winegrowers show more interest since it directly affects the quality and production in the vineyards. The situation generated by COVID-19 in viticulture, adds importance to tools that provide information of the hydric status of vineyard plants in a telematic way.&lt;/p&gt;&lt;p&gt;In the present study, the stem water potential in the 2018 and 2019 seasons, is analysed in a vineyard belonging to the Rias Baixas wine-growing area (Vilagarcia de Arousa, Spain), with 32 sampling points distributed throughout the plot, which allows the contrast and validation with the remote sensing methodology to estimate the water status of the vineyard using satellite images.&lt;/p&gt;&lt;p&gt;The satellite images have been downloaded from the Sentinel-2 satellite, on the closets available dates regarding the stem water potential measurements, carried out in the months of June to September, because this dates are considered the months in which vine plants have higher water requirements.&lt;/p&gt;&lt;p&gt;With satellite images, two spectral index related to the detection of water stress have been calculated: NDWI (Normalized Difference Water Index) and MSI (Moisture Stress Index). Stem water potential measurements, have allowed a linear regression with both index, to validate the use of these multispectral index to determine water stress in the vineyard.&lt;/p&gt;&lt;p&gt;Determination coefficients of r&lt;sup&gt;2&lt;/sup&gt;=0.62 and 0.67, have been obtained in July and August 2018 and 0.54 in June of 2019 for the NDWI index, as well as values of 0.53 and 0.63 in July 2018 and June 2019 respectively, when it has been analysed the MSI index.&lt;/p&gt;&lt;p&gt;Between both seasons, the difference observed, that implies slightly greater water stress in 2019, is reflected in the climate conditions during the summer months, with an average accumulated rainfall that doesn&amp;#8217;t exceed 46 mm of water. Although, the NDWI index has allowed to establish better relationships in the 2018 season respect to the MSI index and the 2019 season, (r&lt;sup&gt;2&lt;/sup&gt;=0.60 NDWI in 2018), as well as greater differences in terms of water stress presented in the vineyard.&lt;/p&gt;&lt;p&gt;With the spectral index calculated, it has been possible to validate the use of these index for the determination of the water stress of the vineyard plants, as an efficient, fast and less expensive method, which allows the application of an efficient irrigation system in the vineyard.&lt;/p&gt;

Effect of Spray Components on Glyphosate Toxicity to Annual Grasses

Weed Science ◽  
1983 ◽  
Vol 31 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Douglas D. Buhler ◽  
Orvin C. Burnside
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Plant Growth ◽  
Surfactant Concentration ◽  
Growth Stage ◽  
Annual Grass ◽  
Spray Solution ◽  
Annual Grasses ◽  
Small Grains ◽  
Carrier Volume

Field and greenhouse research was conducted during 1980 and 1981 to evaluate the effects of carrier volume, surfactant concentration, and treatment date on glyphosate [N- (phosphonomethyl)glycine] toxicity to annual-grass weeds and volunteer small grains. Glyphosate phytotoxicity increased as carrier volume was decreased from 190 to 24 L/ha. The presence of a surfactant in the spray solution did not influence grass control when glyphosate was applied in a carrier volume of 24 L/ha. When glyphosate was applied in 48 or 95 L/ha, the presence of surfactant resulted in better grass control than glyphosate without surfactant. When applied in 190 L/ha, glyphosate with 0.5% (v/v) surfactant gave better grass control than glyphosate alone or commercially formulated glyphosate. When glyphosate was applied to plants under water stress, little control was achieved regardless of plant growth stage. Glyphosate application to grass after head initiation also resulted in reduced control. Maximum weed control with glyphosate was attained when applications were made to seedlings growing actively because of adequate soil moisture and favorable temperatures.

scholarly journals Weather Factors and Their Influence on the Adaptive Properties of Winter Wheat Varieties in the Western Forest-Steppe of Ukraine

2021 ◽  
Vol 24 (6) ◽  
pp. 34-40
Author(s):  
Maria Zapisotska ◽  
Olexandra Voloshchuk ◽  
Ihor Voloshchuk ◽  
Valentyna Hlyva
Keyword(s):  
Soil Moisture ◽  
Winter Wheat ◽  
Seed Quality ◽  
Phenotypic Variability ◽  
Yield Potential ◽  
Winter Period ◽  
Forest Steppe ◽  
Weather Factors ◽  
Field Germination ◽  
Soft Winter Wheat

The yield potential of winter wheat (Triticum aestivum L.) is formed in changing weather conditions and depends on the proposed agro-technological measures, to which the response of a particular variety is different. The purpose of this study was to determine the influence of weather factors on the field germination of soft winter wheat seeds, the growth and development of plants in the autumn and wintering in the zone of the Western Forest-Steppe of Ukraine, by sowing high-quality basic seed, careful soil preparation and the presence of optimum environmental factors. A sufficient level of productive soil moisture, which protects young shoots from possible deficiency after germination and is a long-term source of moisture at the next stages of organogenesis, has a great influence on obtaining friendly and timely shoots. Often overwintering conditions, when plants suffer from low negative temperatures at the beginning and at the end of the winter period, ground ice crust, resumption of vegetation in winter are the causes of freezing, loss, and ultimately a decrease in yield and seed quality. It has been confirmed that an increase in the temperature regime in 244-247°C in the autumn-winter period and the optimal amount of precipitation contribute to sufficient (31.6-34.6 mm) productive soil moisture (0-20 cm), which positively influences the process of germination of soft winter wheat, provides a high percentage of field germination of seeds of varieties (93.8-94.5%), lengthens the autumn development of plants by 3-12 days, which causes 3.5-5.7% higher accumulation of sugar content in the tillering nodes and a high percentage of overwintering (up to 95.5-96.4%). Varieties of the forest-steppe ecological type of soft winter wheat have insignificant phenotypic variability of adaptive traits, therefore, in the production of grain and seed products, it is recommended to give preference to the plant varieties listed in the Register, suitable for distribution in Ukraine for the Forest-Steppe zone, Polissya. The recommendations set out in this scientific work will help agricultural producers of the studied soil and climatic zone to carry out an effective, more ecologically plastic, highly productive variety replacement

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