Analysis on Coupling Degree among Crop Evapotranspiration, Effective Precipitation and Water Requirement of Corn on Southern Kerqin Sandy Land in China

2013 ◽  
Vol 742 ◽  
pp. 331-336
Author(s):  
Ning Yang ◽  
Zhan Xiang Sun ◽  
Jia Ming Zheng ◽  
Dao Cai Chi
Keyword(s):  
Crop Coefficient ◽  
Growing Season ◽  
Water Requirement ◽  
Weather Data ◽  
Growth Stages ◽  
Sandy Land ◽  
Crop Evapotranspiration ◽  
Irrigation Frequency ◽  
Agricultural Water Management ◽  
Kerqin Sandy Land

Historical characteristics of crop evapotranspiration and irrigation requirement were the bases for determining the irrigation quota in local areas. Based on the trials of two years, crop evapotranspiration and crop coefficient of corn at monthly growth stages were determined and tested by soil water balance method in Fuxin of the southern kerqin sandy land. Using the weather data in Fuxin and Chaoyang from 1953 to 2009, estimated the coupling degree between crop water requirement of λ and apply irrigation water (ETaw) in growing season under three hydrologic years (P=25%,50%and75%).Under the humid year (25%),λ (0.756) in Fuxin was more suitable than Chaoyang (0.694),ETaw(95.5mm) in Fuxin was lower than Chaoyang (148.7mm);under the normal year (50%),λ(0.622) in Fuxin was close to Chaoyang (0.647),ETaw(180.4mm) in Fuxin was higher than Chaoyang (154mm); under droughty year (75%), λ (0.574) in Fuxin was also more suitable than Chaoyang (0.523),ETaw (204.8mm) in Fuxin was also lower than Chaoyang (245mm). The monthly change of λ and ETaw were sharping and influenced irrigation frequency in the growing season of humid and droughty year. The method and results can be further applied to agricultural water management study and guide irrigation in other same regions.

scholarly journals Temporal Downscaling of Crop Coefficient and Crop Water Requirement from Growing Stage to Substage Scales

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Songhao Shang
Keyword(s):  
Water Management ◽  
Reference Evapotranspiration ◽  
Crop Coefficient ◽  
Water Requirement ◽  
Crop Water Requirement ◽  
Crop Evapotranspiration ◽  
Agricultural Water ◽  
Crop Water ◽  
Agricultural Water Management

Crop water requirement is essential for agricultural water management, which is usually available for crop growing stages. However, crop water requirement values of monthly or weekly scales are more useful for water management. A method was proposed to downscale crop coefficient and water requirement from growing stage to substage scales, which is based on the interpolation of accumulated crop and reference evapotranspiration calculated from their values in growing stages. The proposed method was compared with two straightforward methods, that is, direct interpolation of crop evapotranspiration and crop coefficient by assuming that stage average values occurred in the middle of the stage. These methods were tested with a simulated daily crop evapotranspiration series. Results indicate that the proposed method is more reliable, showing that the downscaled crop evapotranspiration series is very close to the simulated ones.

scholarly journals Impact of Deficit Irrigation on Shallow Saline Groundwater Contribution and Sunflower Productivity in the Imperial Valley, California

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 571
Author(s):  
Mohamed Galal Eltarabily ◽  
John M. Burke ◽  
Khaled M. Bali
Keyword(s):  
Irrigation Water ◽  
Deficit Irrigation ◽  
Growing Season ◽  
Yield Reduction ◽  
Growth Stages ◽  
Crop Evapotranspiration ◽  
Imperial Valley ◽  
Saline Groundwater ◽  
Irrigation Treatments ◽  
Groundwater Contribution

Yield and production functions of sunflower (Helianthus annuus) were evaluated under full and deficit irrigation practices with the presence of shallow saline groundwater in a semi-arid region in the Imperial Valley of southern California, USA. A growing degree day (GDD) model was utilized to estimate the various growth stages and schedule irrigation events throughout the growing season. The crop was germinated and established using overhead irrigation prior to the use of a subsurface drip irrigation (SDI) system for the remainder of the growing season. Four irrigation treatments were implemented: full irrigation (100% full sunflower crop evapotranspiration, ETC), two reduced irrigation scenarios (95% ETC and 80% ETC), and a deficit irrigation scenario (65% ETC). The salinity of the irrigation water (EC) (Colorado River water) was nearly constant at 1.13 dS·m−1 during the growing season. The depth to groundwater and groundwater salinity (ECGW) were continuously monitored in five 3 m deep observation wells. Depth to groundwater fluctuated slightly under the full and reduced irrigation treatments, but drastically increased under deficit irrigation, particularly toward the end of the growing season. Estimates of ECGW ranged from 7.34 to 12.62 dS·m−1. The distribution of soil electrical conductivity (ECS) and soil matric potential were monitored within the active root zone (120 cm) at selected locations in each of the four treatments. By the end of the experiment, soil salinity (ECS) across soil depths ranged from 1.80 to 6.18 dS·m−1. The estimated groundwater contribution to crop evapotranspiration was 9.03 cm or approximately 16.3% of the ETC of the fully irrigated crop. The relative yields were 91.8%, 82.4%, and 83.5% for the reduced (95% and 80% ETC) and deficit (65% ETC) treatments, respectively, while the production function using applied irrigation water (IW) was: yield = 0.0188 × (IW)2 − 15.504 × IW + 4856.8. Yield reduction in response to water stress was attributed to a significant reduction in both seed weight and the number of seed produced resulting in overall average yields of 2048.9, 1879.9, 1688.1, and 1710.3 kg·ha−1 for the full, both reduced, and deficit treatments, respectively. The yield response factor, ky, was 0.63 with R2 = 0.745 and the irrigation water use efficiencies (IWUE) were 3.70, 3.57, 3.81, and 4.75 kg·ha−1·mm−1 for the full, reduced, and deficit treatments, respectively. Our results indicate that sunflowers can sustain the implemented 35% deficit irrigation with root water uptake from shallow groundwater in arid regions with a less than 20% reduction in yield.

scholarly journals Validation of Crop Coefficients and Water Requirement of Maize Crop in the Temperate Climatic Region of India

2020 ◽  
Vol 8 (5) ◽  
pp. 5132-5138
Keyword(s):  
Water Balance ◽  
Reference Evapotranspiration ◽  
Crop Coefficient ◽  
Growth Period ◽  
Water Requirement ◽  
Balance Method ◽  
Growth Stages ◽  
Maize Crop ◽  
Water Balance Method ◽  
Crop Coefficients

The field study was conducted on Lysimeter by employing the soil water balance method to compute the water requirement and Crop coefficient of Maize in the temperate climatic zone of India. Non-weighing type lysimeters (drainage type) of 2 × 1.5 × 2 m was installed to compute the irrigation requirement, actual crop evapotranspiration (ETc) and actual crop coefficient of maize by water balance method. The water requirement of maize was found 410.4 mm using lysimeter data. The mean daily reference evapotranspiration (ETo) of maize ranged from 0.91 mm/day in the starting growth period to 5.29 mm/day at midseason. The peak ETo of Maize was found 6.3mm/day. The computed crop coefficient (Kc) values of Maize for diffrent crop growth stages were 0.53 for intial, 0.93 for development , 1.05 for mid-season, and 0.78 for late season .A Correlation was also established between Penman-Monteith (P-M) and four other reference Evapotranspiration methods.

scholarly journals Crop coefficient and water requirement of prickly pear in the Agreste region of Alagoas state, Brazil

2019 ◽  
Vol 23 (12) ◽  
pp. 925-929
Author(s):  
Jesiele S. Divincula ◽  
Cinara B. da Silva ◽  
Marcio A. L. dos Santos ◽  
Daniella P. dos Santos ◽  
Luan W. dos Santos
Keyword(s):  
Crop Coefficient ◽  
Field Capacity ◽  
Experimental Period ◽  
Water Requirement ◽  
Prickly Pear ◽  
Climatic Data ◽  
Crop Evapotranspiration ◽  
Livestock Farming ◽  
Opposite Sequence ◽  
Total Crop

ABSTRACT Prickly pear cultivation has played an important role in the Brazilian livestock farming, being used as forage for animals in the Northeast region, especially during the drying season, because it is an excellent source of water. Thus, the objective of this study was to estimate the crop coefficient and water requirement of prickly pear in the Agreste region of Alagoas state, Brazil. Prickly pear crop evapotranspiration (ETc) was determined using five drainage lysimeters, made of polyethylene with dimensions of 0.35 x 0.40 m (side and depth). Four soil layers were separated and put into the lysimeters in the opposite sequence, in order to maintain it as close as possible to the initial soil structure. The reference evapotranspiration (ETo) was estimated by the Penman-Monteith, Hargreaves-Samani and FAO-Radiation methods, using climatic data from the meteorological station of the Instituto Nacional de Meteorologia (INMET) in the city of Arapiraca, AL, Brazil. Crop coefficient (kc) was calculated by the ratio between ETc and ETo. The average kc obtained was 0.72, 0.84 and 0.48 for the Penman-Monteith, Hargreaves-Samani and FAO-Radiation methods, respectively. Keeping the soil under field capacity during the experimental period, the total crop evapotranspiration was 637.84 mm, with daily value equal to 4.22 mm d-1.

scholarly journals Consideration of Latent Infections Improves the Prediction of Botrytis Bunch Rot Severity in Vineyards

Plant Disease ◽  
2020 ◽  
Vol 104 (5) ◽  
pp. 1291-1297 ◽  
Author(s):  
Giorgia Fedele ◽  
Elisa González-Domínguez ◽  
Laurent Delière ◽  
Ana M. Díez-Navajas ◽  
Vittorio Rossi
Keyword(s):  
Decision Making ◽  
Mechanistic Model ◽  
False Negative ◽  
Growing Season ◽  
Weather Data ◽  
Growth Stages ◽  
Latent Infections ◽  
Vine Growth ◽  
Model Predictions ◽  
Bunch Rot

The current study validated a mechanistic model for Botrytis cinerea on grapevine with data from 23 independent Botrytis bunch rot (BBR) epidemics (combinations of vineyards × year) that occurred between 1997 and 2018 in Italy, France, and Spain. The model was operated for each vineyard by using weather data and vine growth stages to anticipate, at any day of the vine-growing season, the disease severity (DS) at harvest (severe, DS ≥ 15%; intermediate, 5 < DS < 15%; and mild, DS ≤ 5%). To determine the ability of the model to account for latent infections, postharvest incubation assays were also conducted using mature berries without symptoms or signs of BBR. The model correctly classified the severity of 15 of 23 epidemics (65% of epidemics) when the classification was based on field assessments of BBR severity; when the model was operated to include BBR severity after incubation assays, its ability to correctly predict BBR severity increased from 65% to >87%. This result showed that the model correctly accounts for latent infections, which is important because latent infections can substantially increase DS. The model was sensitive and specific, with the false-positive and false-negative proportion of model predictions equal to 0.24 and 0, respectively. Therefore, the model may be considered a reliable tool for decision-making for BBR control in vineyards.

Effects of Subsurface Water Retention Technology on Crop Coefficient and Crop Evapotranspiration of Eggplant

2018 ◽  
Vol 24 (8) ◽  
pp. 96
Author(s):  
Sabah Anwer Almasraf ◽  
Ahmed Hatif Salim
Keyword(s):  
Water Retention ◽  
Sandy Loam ◽  
Crop Coefficient ◽  
Growing Season ◽  
Control Plot ◽  
Subsurface Water ◽  
Crop Evapotranspiration ◽  
Initial Development ◽  
Loam Soil ◽  
Crop Coefficients

In this paper, the effects of subsurface water retention technology (SWRT) on crop coefficient (kc) and crop evapotranspiration (ETc) of eggplant were investigated in sandy loam soil. For this purpose, two treatments plot (with SWRT and without using SWRT) were adopted during 93 days of cultivation. The study was conducted in open field within Al-Fahamah Township, Baghdad, Iraq during summer growing season 2017. The accumulated ETc of eggplant was 403.3 and 515.2 mm for SWRT treatment and control plot, respectively by reduction percentage 21.7 %. The average values of ETc during the growing season were 4.3 and 5.5 mm/day, respectively. The crop coefficients value during the growing stages for initial, development, mid-season and late season stages was 0.15, 0.41, 0.81 and 0.78 in SWRT treatment plot for the respective stages and for the control plot one 0.2, 0.46, 1.13 and 0.9, respectively.  

Analyzing Temperature and Precipitation Influences on Yield Distributions of Canola and Spring Wheat in Saskatchewan

2017 ◽  
Vol 56 (4) ◽  
pp. 897-913 ◽  
Author(s):  
Ting Meng ◽  
Richard Carew ◽  
Wojciech J. Florkowski ◽  
Anna M. Klepacka
Keyword(s):  
Crop Yield ◽  
Spring Wheat ◽  
Climate Model ◽  
Crop Yields ◽  
Wheat Yield ◽  
Growing Season ◽  
Weather Data ◽  
Growth Stages ◽  
Yield Distribution ◽  
The Impact

AbstractThe IPCC indicates that global mean temperature increases of 2°C or more above preindustrial levels negatively affect such crops as wheat. Canadian climate model projections show warmer temperatures and variable rainfall will likely affect Saskatchewan’s canola and spring wheat production. Drier weather will have the greatest impact. The major climate change challenges will be summer water availability, greater drought frequencies, and crop adaptation. This study investigates the impact of precipitation and temperature changes on canola and spring wheat yield distributions using Environment Canada weather data and Statistics Canada crop yield and planted area for 20 crop districts over the 1987–2010 period. The moment-based methods (full- and partial-moment-based approaches) are employed to characterize and estimate asymmetric relationships between climate variables and the higher-order moments of crop yields. A stochastic production function and the focus on crop yield’s elasticity imply choosing the natural logarithm function as the mean function transformation prior to higher-moment function estimation. Results show that average crop yields are positively associated with the growing season degree-days and pregrowing season precipitation, while they are negatively affected by extremely high temperatures in the growing season. The climate measures have asymmetric effects on the higher moments of crop yield distribution along with stronger effects of changing temperatures than precipitation on yield distribution. Higher temperatures tend to decrease wheat yields, confirming earlier Saskatchewan studies. This study finds pregrowing season precipitation and precipitation in the early plant growth stages particularly relevant in providing opportunities to develop new crop varieties and agronomic practices to mitigate climate changes.

scholarly journals Crop coefficient of a popular potato variety in Bangladesh

2017 ◽  
Vol 42 (1) ◽  
pp. 67-76
Author(s):  
AR Akanda ◽  
MS Rahman ◽  
MS Islam ◽  
AJ Mila
Keyword(s):  
Potato Variety ◽  
Tuber Yield ◽  
Agricultural Research ◽  
Crop Coefficient ◽  
Climatic Conditions ◽  
Growth Stages ◽  
Crop Evapotranspiration ◽  
Agricultural Research Institute ◽  
Initial Development ◽  
Different Growth Stages

Crop evapotranspiration (ETc) and crop coefficient (Kc) values of potato (variety: BARI Alu -7, Diamant) at different growth stages were determined through lysimeter method at Irrigation and Water Management Division of Bangladesh Agricultural Research Institute (BARI), Gazipur during 2008 - 2009. The study was conducted by applying irrigation at 25 and 40 days after planting (DAP) allowing drainage (AD) (T1), at 25, 40, and 55 DAP AD (T2), at 25, 40, and 60 DAP AD (T3), and at 25, 40, 55, and 60 DAP AD (T4) within and adjacent of four lysimeter tanks. Irrigation at 25, 40, and 55 DAP produced the highest tuber yield and was considered to be suitable for estimating seasonal ETc, and Kc values. The seasonal highest ETc was found to be 162 mm. The Kc values of 0.25, 0.62, 0.70 and 0.18 were determined at initial, development, midseason and late season stages of potato. These values differed slightly from the FAO recommended values. As the lysimeter provides control environment, the Kc values determined by this method are most dependable and recommended for estimating ETc of potato in semi-arid climatic conditions of Bangladesh.Bangladesh J. Agril. Res. 42(1): 67-76, March 2017

scholarly journals Estimation of crop water requirement for rice- wheat and rice- maize cropping system using CROPWAT model for Pusa, Samastipur district, Bihar

2021 ◽  
Vol 8 (2) ◽  
pp. 143-148
Author(s):  
RAVISH CHANDRA ◽  
SHABANAM KUMARI
Keyword(s):  
Meteorological Data ◽  
Cropping System ◽  
Crop Coefficient ◽  
Water Requirement ◽  
Crop Water Requirement ◽  
Growth Stages ◽  
Effective Rainfall ◽  
Crop Water ◽  
Crop Growth Stages ◽  
Reference Crop

This study is about estimation of crop water requirement for rice-wheat and rice-rabi maize cropping system for Pusa Region of Samastipur district of Bihar using CROPWAT model for year 2017-18.The effective rainfall was calculated using USDA S.C. Method. Reference crop evaporation was calculated using meteorological data viz temperature, relative humidity, wind speed and Sunshine using Penman Monteith equation. The meteorological data were collected from university observatory of R.P.C.A.U Pusa. Crop coefficient (Kc) value was taken according to crop growth stages. Effective rainfall and crop water requirement was used for determining net irrigation requirement. The annual crop water requirement of Rice- Wheat cropping system was found to be 904.1 mm whereas the crop-water requirement of Rice- Rabi Maize cropping system was 991.7 mm.

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