scholarly journals Crop Evapotranspiration and Irrigation Scheduling in Blueberry

10.5772/18311 ◽  
2011 ◽  
Author(s):  
David R.
Keyword(s):  
Irrigation Scheduling ◽  
Crop Evapotranspiration

scholarly journals Irrigation and fertigation scheduling under drip irrigation for maize crop in sandy soil

2016 ◽  
Vol 30 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Mahmoud M. Ibrahim ◽  
Ahmed A. El-Baroudy ◽  
Ahmed M. Taha
Keyword(s):  
Sandy Soil ◽  
Irrigation Water ◽  
Drip Irrigation ◽  
Water Productivity ◽  
Fertilizer Application ◽  
Irrigation Scheduling ◽  
Growth And Yield ◽  
Control Treatment ◽  
Crop Evapotranspiration ◽  
Irrigation Time

Abstract Field experiments was conducted to determine the best irrigation scheduling and the proper period for injecting fertilizers through drip irrigation water in a sandy soil to optimize maize yield and water productivity. Four irrigation levels (0.6, 0.8, 1.0 and 1.2) of the crop evapotranspiration and two fertigation periods (applying the recommended fertilizer dose in 60 and 80% of the irrigation time) were applied in a split-plot design, in addition to a control treatment which represented conventional irrigation and fertilization of maize in the studied area. The results showed that increasing the irrigation water amount and the fertilizer application period increased vegetative growth and yield. The highest grain yield and the lowest one were obtained under the treatment at 1.2 and of 0.6 crop evapotranspiration, respectively. The treatment at 0.8 crop evapotranspiration with fertilizer application in 80% of the irrigation time gave the highest water productivity (1.631 kg m−3) and saved 27% of the irrigation water compared to the control treatment. Therefore, this treatment is recommended to irrigate maize crops because of the water scarcity conditions of the studied area.

scholarly journals Crop water productivity and yield response of two greenhouse basil (Ocimum basilicum L.) cultivars to deficit irrigation

2021 ◽  
Author(s):  
Morteza Goldani ◽  
Mohammad Bannayan ◽  
Fatemeh Yaghoubi
Keyword(s):  
Deficit Irrigation ◽  
Water Productivity ◽  
Irrigation Scheduling ◽  
Yield Response ◽  
Relative Reduction ◽  
Crop Evapotranspiration ◽  
Crop Water ◽  
Crop Water Productivity ◽  
Significant Difference ◽  
Herb Yield

Abstract This two-year study aimed to determine the most appropriate irrigation scheduling and crop water productivity (CWP) of basil plant under controlled conditions in Ferdowsi University of Mashhad, Iran. The experimental layout was a split-plot design with three replications. Three deficit irrigation (DI) levels (DI0: 100%, DI30: 70% and DI60: 40% of the field capacity) and two basil cultivars (Green and Purple) were applied to main and subplots, respectively. The results showed that there was a decrease in yield and an increase in CWP for fresh leaves and fresh and dry herb by decreasing the irrigation water. However, a significant difference between fresh leaves and fresh and dry herb yield of DI0 and DI30 treatment was not observed. The Green basil had higher leaves and herb yield and CWP than other cultivar. A polynomial relationship was stablished between fresh leaves yield and crop evapotranspiration, however the yield response factor (Ky) indicated a linear relationship between the relative reduction in crop evapotranspiration vs. the relative reduction in yield. The Ky values were obtained as 0.70 and 0.76 for Green and Purple basil, respectively. The results revealed that the irrigation regime of 30% water saving could insure acceptable yield of basil plant and increase in CWP, especially for the Green basil cultivar.

scholarly journals Splitting and Length of Years for Improving Tree-Based Models to Predict Reference Crop Evapotranspiration in the Humid Regions of China

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3478
Author(s):  
Xiaoqiang Liu ◽  
Lifeng Wu ◽  
Fucang Zhang ◽  
Guomin Huang ◽  
Fulai Yan ◽  
...  
Keyword(s):  
Random Forest ◽  
Southern China ◽  
Irrigation Scheduling ◽  
Estimation Accuracy ◽  
Gradient Boosting ◽  
Crop Evapotranspiration ◽  
Data Splitting ◽  
Reference Crop Evapotranspiration ◽  
Extreme Gradient Boosting ◽  
Reference Crop

To improve the accuracy of estimating reference crop evapotranspiration for the efficient management of water resources and the optimal design of irrigation scheduling, the drawback of the traditional FAO-56 Penman–Monteith method requiring complete meteorological input variables needs to be overcome. This study evaluates the effects of using five data splitting strategies and three different time lengths of input datasets on predicting ET0. The random forest (RF) and extreme gradient boosting (XGB) models coupled with a K-fold cross-validation approach were applied to accomplish this objective. The results showed that the accuracy of the RF (R2 = 0.862, RMSE = 0.528, MAE = 0.383, NSE = 0.854) was overall better than that of XGB (R2 = 0.867, RMSE = 0.517, MAE = 0.377, NSE = 0.860) in different input parameters. Both the RF and XGB models with the combination of Tmax, Tmin, and Rs as inputs provided better accuracy on daily ET0 estimation than the corresponding models with other input combinations. Among all the data splitting strategies, S5 (with a 9:1 proportion) showed the optimal performance. Compared with the length of 30 years, the estimation accuracy of the 50-year length with limited data was reduced, while the length of meteorological data of 10 years improved the accuracy in southern China. Nevertheless, the performance of the 10-year data was the worst among the three time spans when considering the independent test. Therefore, to improve the daily ET0 predicting performance of the tree-based models in humid regions of China, the random forest model with datasets of 30 years and the 9:1 data splitting strategy is recommended.

scholarly journals Understanding the effect of canopy design on crop evapotranspiration for Scilate apple and Syrah grape in Hawke's Bay, New Zealand

2021 ◽  
Author(s):  
Michelle Schurmann
Keyword(s):  
New Zealand ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Fruit Quality ◽  
Irrigation Scheduling ◽  
Light Interception ◽  
Crop Evapotranspiration ◽  
Fresh Weight ◽  
Weight Yield

<p><b>Efficient and effective irrigation scheduling is strongly dependent upon accurate estimation of crop evapotranspiration (ETc), this requires understanding and incorporation of the effects that different soil conditions, orchard designs and trellis systems have on ETc. Orchard designs and trellis systems are designed to harness ≥ 85% light interception when fully grown, which is expected to lead to high yield and fruit quality. To investigate the effectiveness of such designs, an experiment in Hawke’s Bay, New Zealand, was carried out. Scilate apple trees of fifth-leaf vee and tall spindle, fourth-leaf planar, and Syrah grapes that were seven-years-old grown on silt-loam soil, and fourteen-years-old grown on stoney soil were used to investigate how light interception (LI), leaf area index (LAI), yield and fruit quality differed among these orchard designs, and ultimately affected evapotranspiration during the 2019/20 season. </b></p><p>Frequency domain reflectometers measuring soil water content (SWC), and tensiometers (matric potential) were used to continuously measure the soil water balance and estimate crop evapotranspiration. Light interception (LI-COR, Lincoln, Nebraska, USA) and manual LAI readings were taken over four periods from budburst to full canopy. Fresh weight yield was extrapolated from a sample per tree/vine (n=30), maturity was measured by starch pattern index in apples, and quality was estimated from dry matter content (DMC%), and soluble solids content. Hourly ETo was computed using the FAO standardised Penman-Monteith equation, and data collected by an automated on-site weather station. ETc was estimated for ‘well-watered’ conditions using extrapolated daily light interception measurements, and compared with measured changes in SWC. </p><p>The apple trellis systems showed variation in LI (vee: 56%, tall spindle: 50%, planar: 36%), and LAI (vee: 3.2, tall spindle: 1.6, planar: 1.3). The vee system had the largest fresh weight yield in tonnes per hectare (vee: 141, tall spindle: 108, planar: 54). The different aged vines and soil type also showed variability in LI (young Syrah: 36%, old Syrah: 22%) and LAI (young Syrah: 1.3, old Syrah: 0.7). This variability was particularly obvious in the SWC results, where tall spindle showed the highest ETc and change in SWC, whereas planar and vee the lowest which was attributed to an ‘over-irrigated’ environment causing waterlogging, and ultimately decreasing transpiration, despite vee having the highest LI and LAI. Differences in orchard design and trellis system caused changes in ETc and soil water content which can be illustrated by light interception and LAI. However, this thesis demonstrated that soil and groundwater heterogeneity can cause significant variability in results which needs to be accounted for when modelling, irrigating and growing. Future work suggestions are the inclusion of transpiration measurements using sap flow meters to differentiate drainage and groundwater effects from ETc, and to further clarify when the trees/vines are being over-watered.</p>

scholarly journals Understanding the effect of canopy design on crop evapotranspiration for Scilate apple and Syrah grape in Hawke's Bay, New Zealand

2021 ◽  
Author(s):  
Michelle Schurmann
Keyword(s):  
New Zealand ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Fruit Quality ◽  
Irrigation Scheduling ◽  
Light Interception ◽  
Crop Evapotranspiration ◽  
Fresh Weight ◽  
Weight Yield

<p><b>Efficient and effective irrigation scheduling is strongly dependent upon accurate estimation of crop evapotranspiration (ETc), this requires understanding and incorporation of the effects that different soil conditions, orchard designs and trellis systems have on ETc. Orchard designs and trellis systems are designed to harness ≥ 85% light interception when fully grown, which is expected to lead to high yield and fruit quality. To investigate the effectiveness of such designs, an experiment in Hawke’s Bay, New Zealand, was carried out. Scilate apple trees of fifth-leaf vee and tall spindle, fourth-leaf planar, and Syrah grapes that were seven-years-old grown on silt-loam soil, and fourteen-years-old grown on stoney soil were used to investigate how light interception (LI), leaf area index (LAI), yield and fruit quality differed among these orchard designs, and ultimately affected evapotranspiration during the 2019/20 season. </b></p><p>Frequency domain reflectometers measuring soil water content (SWC), and tensiometers (matric potential) were used to continuously measure the soil water balance and estimate crop evapotranspiration. Light interception (LI-COR, Lincoln, Nebraska, USA) and manual LAI readings were taken over four periods from budburst to full canopy. Fresh weight yield was extrapolated from a sample per tree/vine (n=30), maturity was measured by starch pattern index in apples, and quality was estimated from dry matter content (DMC%), and soluble solids content. Hourly ETo was computed using the FAO standardised Penman-Monteith equation, and data collected by an automated on-site weather station. ETc was estimated for ‘well-watered’ conditions using extrapolated daily light interception measurements, and compared with measured changes in SWC. </p><p>The apple trellis systems showed variation in LI (vee: 56%, tall spindle: 50%, planar: 36%), and LAI (vee: 3.2, tall spindle: 1.6, planar: 1.3). The vee system had the largest fresh weight yield in tonnes per hectare (vee: 141, tall spindle: 108, planar: 54). The different aged vines and soil type also showed variability in LI (young Syrah: 36%, old Syrah: 22%) and LAI (young Syrah: 1.3, old Syrah: 0.7). This variability was particularly obvious in the SWC results, where tall spindle showed the highest ETc and change in SWC, whereas planar and vee the lowest which was attributed to an ‘over-irrigated’ environment causing waterlogging, and ultimately decreasing transpiration, despite vee having the highest LI and LAI. Differences in orchard design and trellis system caused changes in ETc and soil water content which can be illustrated by light interception and LAI. However, this thesis demonstrated that soil and groundwater heterogeneity can cause significant variability in results which needs to be accounted for when modelling, irrigating and growing. Future work suggestions are the inclusion of transpiration measurements using sap flow meters to differentiate drainage and groundwater effects from ETc, and to further clarify when the trees/vines are being over-watered.</p>

scholarly journals Predicting Crop Evapotranspiration by Integrating Ground and Remote Sensors with Air Temperature Forecasts

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1740 ◽  
Author(s):  
Anna Pelosi ◽  
Paolo Villani ◽  
Salvatore Falanga Bolognesi ◽  
Giovanni Battista Chirico ◽  
Guido D’Urso
Keyword(s):  
Air Temperature ◽  
Irrigation Scheduling ◽  
Lead Times ◽  
Multispectral Images ◽  
Crop Evapotranspiration ◽  
Campania Region ◽  
Weather Forecasts ◽  
Advisory Systems ◽  
Crop Parameters ◽  
Main Component

Water use efficiency in agriculture can be improved by implementing advisory systems that support on-farm irrigation scheduling, with reliable forecasts of the actual crop water requirements, where crop evapotranspiration (ETc) is the main component. The development of such advisory systems is highly dependent upon the availability of timely updated crop canopy parameters and weather forecasts several days in advance, at low operational costs. This study presents a methodology for forecasting ETc, based on crop parameters retrieved from multispectral images, data from ground weather sensors, and air temperature forecasts. Crop multispectral images are freely provided by recent satellite missions, with high spatial and temporal resolutions. Meteorological services broadcast air temperature forecasts with lead times of several days, at no subscription costs, and with high accuracy. The performance of the proposed methodology was applied at 18 sites of the Campania region in Italy, by exploiting the data of intensive field campaigns in the years 2014–2015. ETc measurements were forecast with a median bias of 0.2 mm, and a median root mean square error (RMSE) of 0.75 mm at the first day of forecast. At the 5th day of accumulated forecast, the median bias and RMSE become 1 mm and 2.75 mm, respectively. The forecast performances were proved to be as accurate and as precise as those provided with a complete set of forecasted weather variables.

scholarly journals APPLICATION OF SIMPLIFIED SURFACE ENERGY BALANCE INDEX (S-SEBI) FOR CROP EVAPOTRANSPIRATION USING LANDSAT 8

2018 ◽  
Vol XLII-1 ◽  
pp. 33-37 ◽  
Author(s):  
A. Basit ◽  
R. Z. Khalil ◽  
S. Haque
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
Surface Energy Balance ◽  
Irrigation Scheduling ◽  
Water Requirement ◽  
Crop Water Requirement ◽  
Landsat 8 ◽  
Crop Evapotranspiration ◽  
Crop Water ◽  
Balance Index

<p><strong>Abstract.</strong> Assessment and monitoring of crop water requirement (CWR) or crop evapotranspiration (ETc) over a large spatial scale is the critical component for irrigation and drought management. Due to growing competition and increasing shortage of water, careful utilization of water in irrigation is essential. The usage of water for irrigation/agriculture is a top priority for countries like Pakistan, where the GDP mostly based on agriculture, and its scarcity may affect the crop production. Remote sensing techniques can be used to estimate crop water requirement or crop evapotranspiration which can help in efficient irrigation. Simplified-surface energy balance index (SSEBI) model is used to estimate evapotranspiration (ET) of wheat during 2015&amp;ndash;16 growing period in Tando Adam, Sindh. Landsat-8 satellite data for the corresponding years were used. With the help of National Agromet Centre report chart of Crop coefficient (Kc) the CWR, ETc of all phonological stages were estimated. Results indicated that maximum ET and maximum CWR were found in the third leaf to tillering stage with a value of 0.75 and 0.89 respectively. This study will help in managing and monitoring of ET spatial distribution over irrigated crops which results in better irrigation scheduling and water consumption.</p>

scholarly journals Efficient Irrigation for Optimum Fruit Quality and Yield in Apples

HortScience ◽  
2010 ◽  
Vol 45 (11) ◽  
pp. 1616-1625 ◽  
Author(s):  
Esmaeil Fallahi ◽  
Denise Neilsen ◽  
Gerry H. Neilsen ◽  
Bahar Fallahi ◽  
Bahman Shafii
Keyword(s):  
Root Zone ◽  
Fruit Size ◽  
Crop Coefficient ◽  
Sprinkler System ◽  
Irrigation Scheduling ◽  
Tree Canopy ◽  
Crop Evapotranspiration ◽  
Water Deficiency ◽  
System A

Use of crop evapotranspiration (ETc), when a precise crop coefficient value (Kc) is used, provides a reliable tool (irrigation scheduling) for determination of water requirement. In this process, Kc should be modified by percentage of ground shade (GS) and tree canopy maturity (M). In an experiment in Idaho with ET-based irrigation scheduling, each tree with a full microjet sprinkler system received an average of 6461.7 L (994 mm), whereas each one with a full drip system used 3996 L (614.1 mm) of irrigation water. In general, deficit drip irrigation was shown to initially increase yield as a result of induction of stress and the production of a higher number of fruit spurs. However, production declined if the extreme water deficiency was repeatedly applied to the trees over several years. Using a microjet sprinkler system, a partial root zone drying regime reduced fruit size but slightly improved fruit color. Application of water at 65% full drip rate, applied on both sides of the tree row (DD), reduced fruit size. However, when the 65% of full drip rate was applied to only one of the alternating sides of the tree every other week (PRD), fruit size was larger than those with DD treatment.

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