scholarly journals Lysimeter-based Crop Coefficients for Young Highbush Blueberries

HortScience ◽  
1996 ◽  
Vol 31 (5) ◽  
pp. 819-822 ◽  
Author(s):  
Craig A. Storlie ◽  
Paul Eck
Keyword(s):  
Water Use ◽  
Canopy Cover ◽  
Crop Coefficient ◽  
Average Diameter ◽  
Vaccinium Corymbosum ◽  
Average Height ◽  
Design Characteristics ◽  
Highbush Blueberries ◽  
June July ◽  
Crop Coefficients

Inexpensive weighing lysimeters ($1475/unit) were constructed for measuring evapotranspiration of young highbush blueberries (Vaccinium corymbosum L.). The use of a single load cell and other design characteristics decreased lysimeter measurement accuracy but minimized lysimeter construction costs. Measurement error was within ±3%. Crop coefficient (CC) curves for 5- and 6-year-old `Bluecrop' highbush blueberry plants in their third and fourth year of production were generated using reference evapotranspiration and crop water use data from the 1991 and 1992 growing seasons. The CC increased during leaf expansion and flowering in the spring to its maximum value of about 0.19 in 1991 and 0.27 in 1992 and remained near these values until leaves began senescing in the fall. Water use on sunny days during June, July, and August ranged from (liters/bush each day) 3.5 to 4.0 in 1991 and 4.0 to 4.5 in 1992. During the second year of the study, plants had an average height of 0.9 m, an average diameter of 0.9 m, and covered 18% of the total cultivated area. The maximum calculated CC was equal to 1.5 times the measured canopy cover percentage.

scholarly journals Determining Water Use and Crop Coefficients of Five Woody Landscape Plants

2006 ◽  
Vol 24 (3) ◽  
pp. 160-165 ◽  
Author(s):  
G. Niu ◽  
D.S. Rodriguez ◽  
R. Cabrera ◽  
C. McKenney ◽  
W. Mackay
Keyword(s):  
Leaf Area ◽  
Water Use ◽  
Culture System ◽  
Growth Parameters ◽  
Growth Index ◽  
Crop Coefficient ◽  
Nerium Oleander ◽  
Culture Systems ◽  
Unit Leaf ◽  
Crop Coefficients

Abstract The water use and crop coefficient of five woody landscape species were determined by growing the shrubs both in 56-liter (15 gal) drainage lysimeters and in above-ground 10-liter containers (#3). Water use per plant, crop coefficient and overall growth parameters differed by species and culture system. Of the five species tested, Buddleia davidii ‘Burgundy’ and Nerium oleander ‘Hardy Pink’ had higher water use per plant in the lysimeters than in the containers. Water use per plant for Abelia grandiflora ‘Edward Goucher’, Euonymus japonica and Ilex vomitoria ‘Pride of Houston’ was the same for the two culture systems. Crop coefficient and growth index of A. grandiflora, E. japonica, and I. vomitoria was similar between the two systems. The growth index of B. davidii and N. oleander was much higher in the lysimeters than in the containers. Abelia grandiflora and E. japonica had more growth in the containers than in the lysimeters while I. vomitoria had slightly larger leaf area in the lysimeters than in the containers. The culture system did not affect the water use per unit leaf area of all species. Therefore, our results indicated that by quantifying the leaf area, the plant water use in the two culture systems is exchangeable.

scholarly journals Simplified Water Requirement Calculators for Fruits and Vegetables

2016 ◽  
Vol 26 (4) ◽  
pp. 530-541 ◽  
Author(s):  
Brent Rowell ◽  
Mar Lar Soe
Keyword(s):  
Drip Irrigation ◽  
Fruits And Vegetables ◽  
Canopy Cover ◽  
Crop Coefficient ◽  
Climatic Data ◽  
Vegetable Crops ◽  
Rotating Disc ◽  
Water Requirements ◽  
Water Wheel ◽  
Crop Coefficients

New users of drip irrigation in Myanmar had no idea how much water to apply to their crops with drip and could not afford tensiometers or other soil moisture monitoring tools. The concept of a simple paper calculator was born out of their need for an easy-to-use yet inexpensive tool to estimate horticultural crop water requirements. We used a generalized crop coefficient and growth stage approach together with average evapotranspiration (ET) for the vegetable crops “Water Wheel” calculator and a canopy cover approach for the tree fruit calculator. Differences among published crop coefficients are relatively small for a large number of vegetables and single coefficients were used for groups of crops without putting farmers’ crops at risk. Vegetable crops were divided into two groups based on whether water requirements during harvest remained the same as for the flowering and fruiting stage or were reduced for the harvest period. A simplified canopy cover approach was used to determine water requirements for perennial fruit, tree, and vine crops. Our faith in the ability of farmers to make their own adjustments gave us confidence to simplify ET-based water requirements and make them available in the form of simple rotating disc calculators printed in color on laminated card stock. The calculators were welcomed by our staff and enabled them to provide reasonably reliable recommendations for new users of drip irrigation. When surveyed, field staff responded that 74% of farmers they advised followed Water Wheel recommendations. Rough estimates of fruit and vegetable water requirements reached a large number of new drip users in a form they could easily understand, thereby lowering adoption barriers for an unfamiliar technology. This paper describes the Water Wheel concept and design so nonspecialists might develop their own calculators using local climatic data.

scholarly journals Comparison of Lysimeter-Derived Crop Coefficients for Legacy and Modern Drought-Tolerant Maize Hybrids in the Texas High Plains

2020 ◽  
Vol 63 (5) ◽  
pp. 1243-1257
Author(s):  
Gary W. Marek ◽  
Thomas H. Marek ◽  
Steven R. Evett ◽  
Jourdan M. Bell ◽  
Paul D. Colaizzi ◽  
...  
Keyword(s):  
Water Use ◽  
Crop Coefficient ◽  
Irrigation Scheduling ◽  
High Plains ◽  
List Type ◽  
Season Length ◽  
Planting Dates ◽  
Corn Hybrids ◽  
Drought Tolerant ◽  
Crop Coefficients

HighlightsDaily maximum crop coefficient (Kc) values were similar for legacy hybrids and a modern drought-tolerant (DT) hybrid.Later planting dates for a DT hybrid resulted in average season lengths ~25 days shorter than those of legacy hybrids.Results illustrated the effects of environment, planting date, interannual variation in temperature, and the importance of climate-specific Kc functions.DT hybrids may be more effective at reproductive growth during periods of heat stress in semi-arid environments, although additional data are needed to support this conclusion.Abstract. Corn (Zea mays L.) is a major irrigated crop grown in the Southern High Plains including the Texas Panhandle. Irrigation from the Ogallala Aquifer is required to sustain profitable corn production in the region by supplementing inadequate and erratic rainfall. Effective irrigation scheduling works to extend limited groundwater resources by avoiding water losses associated with runoff and/or percolation below the root zone. The use of crop coefficient (Kc) and reference evapotranspiration (ETo) values to estimate daily crop water use (ETc) remains an effective scheduling tool that can complement other irrigation scheduling approaches. Both Food and Agriculture Organization (FAO-56) piecewise and curvilinear Kc values for corn are found in the literature. However, advances in corn genetics have led to questions about the applicability of Kc values developed using legacy corn hybrids to irrigation of modern drought-tolerant (DT) hybrids. Lysimeter-derived Kc values for legacy corn hybrids grown in large weighing lysimeter fields at the USDA-ARS Conservation and Production Research Laboratory at Bushland, Texas, were compared with those derived from a modern DT corn hybrid recently grown in the same fields. Results indicated that although midseason daily Kc values were similar for all hybrids, average season length was ~25 days shorter for the modern DT hybrid, characterized by a shortened initial growth period followed by more rapid increase of Kc during the development period. However, plots of Kc over thermal time illustrated that the differences in season length were likely attributable to later planting dates associated with the DT corn hybrids. Average seasonal water use was 730 and 811 mm for the legacy and modern DT hybrids, respectively (three years each), with corresponding average yields of 1.2 and 1.4 kg ha-1. Results suggest that published Kc and Kcb values developed with legacy corn hybrids remain largely applicable to modern DT corn hybrids when used with accurate estimates of effective canopy-based growth stages and climate-specific Kc functions. Keywords: Crop coefficients, Drought-tolerant, Evapotranspiration, Maize, Weighing lysimeters.

scholarly journals Evapotranspiration, crop coefficient and water use efficiency of onion cultivated under different irrigation depths

2022 ◽  
Vol 26 (3) ◽  
pp. 219-225
Author(s):  
Wendy K. Matsunaga ◽  
Vicente de P. R. da Silva ◽  
Victória P. Amorim ◽  
Eliton S. G. Sales ◽  
Sílvia M. Dantas ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Field Experiments ◽  
Crop Coefficient ◽  
Northeastern Brazil ◽  
Semiarid Region ◽  
Crop Evapotranspiration ◽  
Maturation Stages ◽  
Use Efficiency ◽  
Crop Coefficients

ABSTRACT This study aimed to determine crop evapotranspiration through the soil water balance, the crop coefficient and water use efficiency of the onion (Allium cepa L.) in a system with four irrigation regimes, cultivated in the semiarid region of northeastern Brazil. Two field experiments were carried out during the rainy and dry periods of the region in 2018, using the treatments of 100% (T1), 75% (T2), 50% (T3) and 25% (T4) of the reference evapotranspiration for daily water replacement and five replicates for each treatment. It was verified that crop evapotranspiration varies according to the water availability in the soil; however, the highest water use efficiency occurred for the T3 treatment. The T1 treatment obtained the highest estimated yield, 43.86 tons ha-1, while T4 obtained 13.47 tons ha-1, the lowest estimated yield among the treatments, and this difference was statistically significant (p ≤ 0.05) by F test. The crop coefficients obtained were 0.68, 0.89, 0.99 and 0.73 for the initial, vegetative, bulbing and maturation stages, respectively.

scholarly journals ESTIMATING WATER REQUIREMENTS OF LANDSCAPE PLANTINGS

HortScience ◽  
1992 ◽  
Vol 27 (12) ◽  
pp. 1263f-1263
Author(s):  
L.R. Costello ◽  
N.P. Matheny ◽  
J.R. Clark
Keyword(s):  
Water Use ◽  
Water Loss ◽  
Reference Evapotranspiration ◽  
Crop Coefficient ◽  
Vegetation Density ◽  
Water Requirements ◽  
Landscape Water ◽  
Crop Coefficients

Since it is unlikely that crop coefficients will be established for landscape plantings, a method to estimate landscape water requirements is proposed. By evaluating three factors that significantly influence water use-species planted, vegetation density, and site microclimate-and assigning numerical values to each, an estimate of a landscape crop coefficient (or landscape coefficient, KL) can be calculated. An estimate of evapotranspirational water loss for landscapes is then the product of the landscape coefficient multiplied by the reference evapotranspiration. This paper presents values for the above three factors and discusses the rationale for each. Examples using the landscape coefficient formula are included, as well as a discussion of special considerations relative to its use.

scholarly journals Effects of Cultivar and Plant Spacing on the Seasonal Water Requirements of Highbush Blueberry

2007 ◽  
Vol 132 (2) ◽  
pp. 270-277 ◽  
Author(s):  
David R. Bryla ◽  
Bernadine C. Strik
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Canopy Cover ◽  
Dry Weight ◽  
Vaccinium Corymbosum ◽  
High Density ◽  
Highbush Blueberry ◽  
Plant Water ◽  
Water Requirements ◽  
Total Dry Weight

Plant water requirements were investigated in three northern highbush blueberry (Vaccinium corymbosum L.) cultivars, Duke, Bluecrop, and Elliott, grown either at a high-density spacing of 0.45 m apart within rows or a more traditional spacing of 1.2 m. Spacing between rows was 3.0 m. As is typical for the species, each cultivar was shallow-rooted with most roots located less than 0.4 m deep, and each was sensitive to soil water deficits with plant water potentials declining as low as −1.6 MPa within 5 to 7 days without rain or irrigation. Compared with traditional spacing, planting at high density significantly reduced dry weight and yield of individual plants but significantly increased total dry weight and yield per hectare. High-density planting also significantly increased total canopy cover and water use per hectare. However, although canopy cover (often considered a factor in water use) increased up to 246%, water use never increased more than 10%. Because of more canopy cover at high density, less water penetrated the canopy during rain or irrigation (by overhead sprinklers), reducing both soil water availability and plant water potential in each cultivar and potentially reducing water use. Among cultivars, water use was highest in ‘Duke’, which used 5 to 10 mm·d−1, and lowest in ‘Elliott’, which used 3 to 5 mm·d−1. Peak water use in each cultivar was during fruit development, but water use after harvest declined sharply. Longer irrigation sets (i.e., longer run times) or alternative irrigation methods (e.g., drip) may be required when growing blueberry at high density, especially in cultivars with dense canopies such as ‘Elliott’.

scholarly journals ESTIMATION OF CROP WATER REQUIREMENT AND CROP COEFFICIENT OF TOMATO CROP USING METEOROLOGICAL DATA IN PAMPAIDA MILLENNIUM VILLAGE, KADUNA STATE, NIGERIA

2020 ◽  
Vol 4 (3) ◽  
pp. 538-546
Author(s):  
A. Ahmed ◽  
M. A. Oyebode ◽  
H. E. Igbadun ◽  
Ezekiel Oiganji
Keyword(s):  
Soil Moisture ◽  
Water Use ◽  
Crop Coefficient ◽  
Water Requirement ◽  
Crop Water Requirement ◽  
Growth Stages ◽  
Crop Water ◽  
Tomato Crop ◽  
Crop Water Use ◽  
Crop Coefficients

This report presents a study of crop water requirement and crop coefficient (Kc) for Tomato crop cultivated under irrigation in Pampaida Millennium Village Cluster, Ikara Local Government Area of Kaduna State, Nigeria, during the 2009/2010 dry season. A total of 7 tomato farmers were selected out of 45 farmers for the assessment exercise. Water applied per irrigation and soil moisture contents before and after irrigation was monitored throughout the seasons, while Tomato bulbs were harvested at the end of season and weighed. Average  crop water use were estimated from the soil moisture content using the gypsum block, while daily reference Evapotranspiration (ETo) were computed from weather data using method Hargreaves equation. Crop coefficient values (Kc) were computed as the ratio of crop water use to ETo. The values of crop coefficients and seasonal crop water requirement per irrigation for different growth stages were determined, the computed *Kc values for different growth stage for the tomato crop grown in the study area was found to be between 0.77-1.15, the initial stage (*Kc =0.81; 20 mm/irrigation), crop development stage (*Kc = 1.09; 28 mm/irrigation), mid-season (*Kc = 1.15; 29 mm/ irrigation) and Late stage (*Kc = 0.77; 19 mm/irrigation), hence the mid-season gave the highest Kc value. However, the crop seasonal water requirement was found to be 386mm, which was within the recommended range. The crop coefficients and seasonal water requirement estimated in this study are reliable and could be used in irrigation design and scheduling for Tomato in the study area.

scholarly journals High-Resolution Spatiotemporal Water Use Mapping of Surface and Direct-Root-Zone Drip-Irrigated Grapevines Using UAS-Based Thermal and Multispectral Remote Sensing

2021 ◽  
Vol 13 (5) ◽  
pp. 954
Author(s):  
Abhilash K. Chandel ◽  
Lav R. Khot ◽  
Behnaz Molaei ◽  
R. Troy Peters ◽  
Claudio O. Stöckle ◽  
...  
Keyword(s):  
High Resolution ◽  
Water Use ◽  
Root Zone ◽  
Lateral Roots ◽  
Irrigation Treatment ◽  
Crop Coefficient ◽  
Spatiotemporal Resolution ◽  
Site Specific ◽  
Canopy Transpiration ◽  
Irrigation Treatments

Site-specific irrigation management for perennial crops such as grape requires water use assessments at high spatiotemporal resolution. In this study, small unmanned-aerial-system (UAS)-based imaging was used with a modified mapping evapotranspiration at high resolution with internalized calibration (METRIC) energy balance model to map water use (UASM-ET approach) of a commercial, surface, and direct-root-zone (DRZ) drip-irrigated vineyard. Four irrigation treatments, 100%, 80%, 60%, and 40%, of commercial rate (CR) were also applied, with the CR estimated using soil moisture data and a non-stressed average crop coefficient of 0.5. Fourteen campaigns were conducted in the 2018 and 2019 seasons to collect multispectral (ground sampling distance (GSD): 7 cm/pixel) and thermal imaging (GSD: 13 cm/pixel) data. Six of those campaigns were near Landsat 7/8 satellite overpass of the field site. Weather inputs were obtained from a nearby WSU-AgWeatherNet station (1 km). First, UASM-ET estimates were compared to those derived from soil water balance (SWB) and conventional Landsat-METRIC (LM) approaches. Overall, UASM-ET (2.70 ± 1.03 mm day−1 [mean ± std. dev.]) was higher than SWB-ET (1.80 ± 0.98 mm day−1). However, both estimates had a significant linear correlation (r = 0.64–0.81, p < 0.01). For the days of satellite overpass, UASM-ET was statistically similar to LM-ET, with mean absolute normalized ET departures (ETd,MAN) of 4.30% and a mean r of 0.83 (p < 0.01). The study also extracted spatial canopy transpiration (UASM-T) maps by segmenting the soil background from the UASM-ET, which had strong correlation with the estimates derived by the standard basal crop coefficient approach (Td,MAN = 14%, r = 0.95, p < 0.01). The UASM-T maps were then used to quantify water use differences in the DRZ-irrigated grapevines. Canopy transpiration (T) was statistically significant among the irrigation treatments and was highest for grapevines irrigated at 100% or 80% of the CR, followed by 60% and 40% of the CR (p < 0.01). Reference T fraction (TrF) curves established from the UASM-T maps showed a notable effect of irrigation treatment rates. The total water use of grapevines estimated using interpolated TrF curves was highest for treatments of 100% (425 and 320 mm for the 2018 and 2019 seasons, respectively), followed by 80% (420 and 317 mm), 60% (391 and 318 mm), and 40% (370 and 304 mm) of the CR. Such estimates were within 5% to 11% of the SWB-based water use calculations. The UASM-T-estimated water use was not the same as the actual amount of water applied in the two seasons, probably because DRZ-irrigated vines might have developed deeper or lateral roots to fulfill water requirements outside the irrigated soil volume. Overall, results highlight the usefulness of high-resolution imagery toward site-specific water use management of grapevines.

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