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The efficiency of irrigation, as well as optimization of nutrients, affect spinach yield in all growth stages. In this study, the sensitivity of spinach (early and mature yields) to shallow saline groundwater and the effect of fertigation treatments on mature yield were experimentally investigated. The sprinkler irrigation experiments were conducted on 0.47 ha of silty clay soil at the University of California Desert Research and Extension Center (DREC) in Imperial Valley, California. Twelve beds in the experimental field were chosen randomly to investigate the effect of three fertigation treatments on spinach yield. Three rates of urea ammonium nitrate (UAN-32) fertilizer; T1: 200 kg ha−1 (150%), T2: 133.3 kg ha−1 (100%), and T3: 66.7 kg ha−1 (50%) in four replicates were applied. Soil samples to depths of up to 120 cm were collected at baby leaves and mature harvesting dates (17th October and 19th November 2019, respectively) for salinity measurements. Additionally, soil matric potential through the 120 cm soil depth was measured and groundwater levels in five observation wells were recorded during the growing season. Results showed that average soil salinity at baby leaves harvesting stage through the top 60 cm active root zone depth ranged from 0.61 to 1.48 dS m−1, which is lower than the spinach salinity threshold limit (2 dS m−1), while the average groundwater depth was 1.90 m with salinity ranging from 6.35 to 10.60 dS m−1. Correlation analysis showed that the baby spinach leaves yield was weakly correlated (r = 0.40) to the average soil salinity in the top 60 cm soil depth. Although groundwater and top 60 cm soil salinity showed an increase at the mature yield harvesting stage, the mature yield was weakly correlated to soil salinity (p = 0.116). As the UAN-32 rate increased, the mature spinach yield increased. The mature spinach yields were 17.31, 14.00, and 12.54 ton ha−1 for T1, T2, and T3 fertigation treatments, respectively. However, only a 10% reduction in yield occurred in T3 treatment corresponding to a 50% reduction in UAN-32 rate by 66.7 kg ha−1. Based on the results of this study, shallow saline groundwater has little impact on spinach yield. In addition, the 50% increase in UAN-32 rate had a significant impact on mature spinach yield. The 150% UAN-32 rate resulted in an increase in spinach yield and could be used in arid and semiarid regions with similar conditions to the Imperial Valley but additional measures to minimize the leaching of nitrate from the root zone and to reduce the load of nitrogen in drainage water are needed to minimize the potential negative impact of over-fertigation on the environment.
Khaled M. Bali; Mohamed G. Eltarabily; Ronny Berndtsson; Tarek Selim. Nutrient and salinity management for spinach production under sprinkler irrigation in the low desert region of California. Irrigation Science 2021, 1 -15.
AMA StyleKhaled M. Bali, Mohamed G. Eltarabily, Ronny Berndtsson, Tarek Selim. Nutrient and salinity management for spinach production under sprinkler irrigation in the low desert region of California. Irrigation Science. 2021; ():1-15.
Chicago/Turabian StyleKhaled M. Bali; Mohamed G. Eltarabily; Ronny Berndtsson; Tarek Selim. 2021. "Nutrient and salinity management for spinach production under sprinkler irrigation in the low desert region of California." Irrigation Science , no. : 1-15.
Agricultural drainage plays an important role worldwide in food production and conservation of soil resources, while safeguarding investments in agricultural production and irrigation projects. It can improve crop yields and land productivity, especially on poorly drained soils and in cases of prolonged waterlogging. Both the subsurface drainage materials and the installation techniques used have a long history dating to prehistoric times. Over time, new subsurface drainage materials, installation techniques and modernized equipment were being developed continuously to take advantage of technological advances provided through research and development, while the planning and organization of the implementation process were improved. Today’s new materials and improved installation methods can offer solutions to problems still unsolved, while sometimes creating new ones. This paper considers the evolution of basic subsurface drainage materials and their installation techniques as they developed and adapted over time as well as possible future trends in drainage system design and application.
Stavros I. Yannopoulos; Mark E. Grismer; Khaled M. Bali; Andreas N. Angelakis. Evolution of the Materials and Methods Used for Subsurface Drainage of Agricultural Lands from Antiquity to the Present. Water 2020, 12, 1767 .
AMA StyleStavros I. Yannopoulos, Mark E. Grismer, Khaled M. Bali, Andreas N. Angelakis. Evolution of the Materials and Methods Used for Subsurface Drainage of Agricultural Lands from Antiquity to the Present. Water. 2020; 12 (6):1767.
Chicago/Turabian StyleStavros I. Yannopoulos; Mark E. Grismer; Khaled M. Bali; Andreas N. Angelakis. 2020. "Evolution of the Materials and Methods Used for Subsurface Drainage of Agricultural Lands from Antiquity to the Present." Water 12, no. 6: 1767.
Evapotranspiration is the transfer of water from the earth's surface to the atmosphere. It comprises the sum of water losses to atmosphere due to the processes of evaporation of moisture from soil, water bodies and wet plant canopies, and the transpiration of water from plants. Forecasts of this crucial component of the hydrologic cycle can be very valuable for growers, farm managers, irrigation practitioners, water resource planners and managers, and reservoir operators for their planning, allocation, delivery and scheduling decisions, as well as to hydrologic scientists for research purposes. Verifying the reliability of models’ forecasts is among the critical tasks for development and performance evaluation of physical models. In fact, the verification allows understanding the models’ behavior, and evaluating their applicability and dependability. The US National Weather Service (NWS) has released a product that provides forecasts of reference evapotranspiration (FRET) at 2.5-km grid resolution for the entire continental US. In this study, a comparison is made between ETo estimates from FRET and ETo values calculated by the California Irrigation Management Information System (CIMIS) for 68 days during summer 2019. Both the FRET forecasts and ETo values were obtained from NWS and CIMIS, respectively, on the basis of 15 CIMIS locations that are representative of different climatic conditions in California. In addition, air temperature, dew point temperature, relative humidity, wind speed, and vapor pressure deficit (VPD) data were also collected/calculated from the NWS and CIMIS websites to analyze the sensitivity of FRET forecasts to predictions of these parameters. All FRET forecasts were performed with timescales of 1, 3, 5 and 7 days. Statistical indices were calculated to assess the dependability of FRET values. They showed a good correlation of the FRET model outputs with CIMIS ETo data, with some differences depending on the climatic characteristics of selected weather stations’ locations, suggesting that FRET data could be valuable for anticipating near-future water demand and improve irrigation management in California.
Ghaieth Ben Hamouda; Francesca Ventura; Daniele Zaccaria; Khaled M. Bali; Richard L. Snyder. Comparison between forecasts of reference evapotranspiration and ETo values calculated using data from different climatic conditions. 2020, 1 .
AMA StyleGhaieth Ben Hamouda, Francesca Ventura, Daniele Zaccaria, Khaled M. Bali, Richard L. Snyder. Comparison between forecasts of reference evapotranspiration and ETo values calculated using data from different climatic conditions. . 2020; ():1.
Chicago/Turabian StyleGhaieth Ben Hamouda; Francesca Ventura; Daniele Zaccaria; Khaled M. Bali; Richard L. Snyder. 2020. "Comparison between forecasts of reference evapotranspiration and ETo values calculated using data from different climatic conditions." , no. : 1.
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.
Mohamed Galal Eltarabily; John M. Burke; Khaled M. Bali. Impact of Deficit Irrigation on Shallow Saline Groundwater Contribution and Sunflower Productivity in the Imperial Valley, California. Water 2020, 12, 571 .
AMA StyleMohamed Galal Eltarabily, John M. Burke, Khaled M. Bali. Impact of Deficit Irrigation on Shallow Saline Groundwater Contribution and Sunflower Productivity in the Imperial Valley, California. Water. 2020; 12 (2):571.
Chicago/Turabian StyleMohamed Galal Eltarabily; John M. Burke; Khaled M. Bali. 2020. "Impact of Deficit Irrigation on Shallow Saline Groundwater Contribution and Sunflower Productivity in the Imperial Valley, California." Water 12, no. 2: 571.
Nitrogen (N) accounts for more than 80% of the total mineral nutrients absorbed by plants and it is the most widely limiting element for crop production, particularly under water deficit conditions. For a comprehensive understanding of sunflower Helianthus annuus N uptake under deficit irrigation conditions, experimental and numerical simulation studies were conducted for full (100% ETC) and deficit (65% ETC) irrigation practices under the semi-arid conditions of the Imperial Valley, California, USA. Plants were established with overhead sprinkler irrigation before transitioning to subsurface drip irrigation (SDI). Based on pre-plant soil N testing, 39 kg ha−1 of N and 78 kg ha−1 of P were applied as a pre-plant dry fertilizer in the form of monoammonium phosphate (MAP) and an additional application of 33 kg ha−1 of N from urea ammonium nitrate (UAN-32) liquid fertilizer was made during the growing season. Soil samples at 15-cm depth increments to 1.2 m (8 layers, 15 cm each) were collected prior to planting and at three additional time points from two locations each in the full and deficit irrigation treatments. We used HYDRUS/2D for the simulation in this study and the model was calibrated for the soil moisture parameters (θs and θr), the rate constant factors of nitrification (the sensitive parameter) in the liquid and solid states (μw,3, and μs,3). The HYDRUS model predicted cumulative root water uptake fluxes of 533 mm and 337 mm for the 100% ETC and 65% ETC, respectively. The simulated cumulative drainage depths were 23.7 mm and 20.4 mm for the 100% ETC and 65% ETC which represented only 4% and 5% of the applied irrigation water, respectively. The soil wetting profile after SDI irrigation was mostly around emitters for the last four SDI irrigation events, while the maximum values of soil moisture in the top 30 cm of the soil profile were 0.262 cm3 cm−3 and 0.129 cm3 cm−3 for 100% ETC and 65% ETC, respectively. The 16.5 kg ha−1 (NH2)2CO (50% of the total N) that was applied during the growing season was completely hydrolyzed to NH4+ within 7 days of application, while 4.36 mg cm−1 cumulative decay was achieved by the end of the 98-day growing season. We found that 86% of NH4+ (74.25 mg cm−1) was nitrified to NO3− while 14% remained in the top 50 cm of the soil profile. The denitrification and free drainage of NO3− were similar for 100% ETC and 65% ETC, and the maximum nitrate was drained during the sprinkler irrigation period. By the end of the growing season, 30.8 mg cm−1 of nitrate was denitrified to N2 and the reduction of nitrate plant uptake was 17.1% for the deficit irrigation section as compared to the fully irrigated side (19.44 mg cm−1 vs. 16.12 mg cm−1). This reduction in N uptake due to deficit irrigation on sunflower could help farmers conserve resources by reducing the amount of fertilizer required if deficit irrigation practices are implemented due to the limited availability of irrigation water.
Mohamed Galal Eltarabily; John M. Burke; Khaled M. Bali. Effect of Deficit Irrigation on Nitrogen Uptake of Sunflower in the Low Desert Region of California. Water 2019, 11, 2340 .
AMA StyleMohamed Galal Eltarabily, John M. Burke, Khaled M. Bali. Effect of Deficit Irrigation on Nitrogen Uptake of Sunflower in the Low Desert Region of California. Water. 2019; 11 (11):2340.
Chicago/Turabian StyleMohamed Galal Eltarabily; John M. Burke; Khaled M. Bali. 2019. "Effect of Deficit Irrigation on Nitrogen Uptake of Sunflower in the Low Desert Region of California." Water 11, no. 11: 2340.
Shallow groundwater contamination by nitrate is frequent in agricultural lands in Egypt because of the use of urea fertilizers. The urea transformation process in the vadose zone was simulated using a HYDRUS-2D model, Software package for simulations of 2D movement of water, heat, and multiple solutes in variably saturated media, for subsurface drip irrigation. The root water and nutrient uptake were assessed for three soil types (sandy loam, loam, and silty loam) with three emitter discharge levels (1.0 L h−1, 1.50 L h−1, and 2.0 L h−1), for a comparison of three fertigation strategies (A) at the beginning, (B) at the end, and (C) at the middle of the irrigation cycle. The extension of the wetted area mainly depends on soil hydraulic conductivity. The high emitter discharge with a short irrigation time is suitable for shallow-rooted crops. The cumulative flux was highest for silty loam soil and the lowest was for the sandy loam soil (1891, and 1824 cm3) for the 2 L h−1 emitter discharge within the 35 days simulation. The cumulative drainage significantly differs among soil types with little effect of emitter discharge. It recorded 1213, 295, 11.9 cm3 for sandy loam, loam, silty loam, respectively. Urea transformation is controlled by hydrolysis and nitrification as well as the adsorption coefficient of ammonium. Nitrate distribution is mainly governed by soil type rather than the emitter discharge where the sandy loam soil is more highly susceptible to nitrate leaching than to silty loam. Nitrate concentration has recorded the minimum possible level when applying the urea fertilizer at the beginning of the irrigation event for sandy loam and loam soil while for the silty loam soil, urea application at the middle of the irrigation event is more effective. Urea application at the end of the irrigation event gives the highest accumulated leached nitrate concentration below the root zone and should be avoided (the worst strategy).
Mohamed Galal Eltarabily; Khaled M. Bali; AbdelAzim M. Negm; Chihiro Yoshimura. Evaluation of Root Water Uptake and Urea Fertigation Distribution under Subsurface Drip Irrigation. Water 2019, 11, 1487 .
AMA StyleMohamed Galal Eltarabily, Khaled M. Bali, AbdelAzim M. Negm, Chihiro Yoshimura. Evaluation of Root Water Uptake and Urea Fertigation Distribution under Subsurface Drip Irrigation. Water. 2019; 11 (7):1487.
Chicago/Turabian StyleMohamed Galal Eltarabily; Khaled M. Bali; AbdelAzim M. Negm; Chihiro Yoshimura. 2019. "Evaluation of Root Water Uptake and Urea Fertigation Distribution under Subsurface Drip Irrigation." Water 11, no. 7: 1487.
California is a global leader in the agricultural sector and produces more than 400 types of commodities. The state produces over a third of the country’s vegetables and two-thirds of its fruits and nuts. Despite being highly productive, current and future climate change poses many challenges to the agricultural sector. This paper provides a summary of the current state of knowledge on historical and future trends in climate and their impacts on California agriculture. We present a synthesis of climate change impacts on California agriculture in the context of: (1) historic trends and projected changes in temperature, precipitation, snowpack, heat waves, drought, and flood events; and (2) consequent impacts on crop yields, chill hours, pests and diseases, and agricultural vulnerability to climate risks. Finally, we highlight important findings and directions for future research and implementation. The detailed review presented in this paper provides sufficient evidence that the climate in California has changed significantly and is expected to continue changing in the future, and justifies the urgency and importance of enhancing the adaptive capacity of agriculture and reducing vulnerability to climate change. Since agriculture in California is very diverse and each crop responds to climate differently, climate adaptation research should be locally focused along with effective stakeholder engagement and systematic outreach efforts for effective adoption and implementation. The expected readership of this paper includes local stakeholders, researchers, state and national agencies, and international communities interested in learning about climate change and California’s agriculture.
Tapan B. Pathak; Mahesh L. Maskey; Jeffery A. Dahlberg; Faith Kearns; Khaled M. Bali; Daniele Zaccaria. Climate Change Trends and Impacts on California Agriculture: A Detailed Review. Agronomy 2018, 8, 25 .
AMA StyleTapan B. Pathak, Mahesh L. Maskey, Jeffery A. Dahlberg, Faith Kearns, Khaled M. Bali, Daniele Zaccaria. Climate Change Trends and Impacts on California Agriculture: A Detailed Review. Agronomy. 2018; 8 (3):25.
Chicago/Turabian StyleTapan B. Pathak; Mahesh L. Maskey; Jeffery A. Dahlberg; Faith Kearns; Khaled M. Bali; Daniele Zaccaria. 2018. "Climate Change Trends and Impacts on California Agriculture: A Detailed Review." Agronomy 8, no. 3: 25.
In California, alfalfa is grown on a large area ranging between 325,000 and 410,000 hectares and ranks among the thirstiest crops. While the hay production industry is often scrutinized for the large usage of the state’s agricultural water, alfalfa is a crucial feed-supplier for the livestock and dairy sectors, which rank among the most profitable commodity groups in the state. Sub-surface drip irrigation (SDI), although only practiced on approximately 2% of the alfalfa production area in California, is claimed to have the potential to significantly increase hay yield (HY) and water productivity (WP) compared with surface irrigation (SI). In 2014–2016 we interviewed a number of growers pioneering SDI for alfalfa production in Central and Southern California who reported that yield improvements in the order of 10–30% and water saving of about 20–30% are achievable in SDI-irrigated fields compared with SI, according to their records and perceptions collected over few years of experience. Results from our research on SDI at the University of California, Davis, revealed significantly smaller yield gain (~5%) and a slight increase of water use (~2–3%) that are similar to findings from earlier research studies. We found that most of the interviewed alfalfa producers are generally satisfied with their SDI systems, yet face some challenges that call for additional research and educational efforts. Key limitations of SDI include high investment costs, use of energy to pressurize water, the need for more advanced irrigation management skills, and better understanding of soil-water dynamics by farm personnel. SDI-irrigated fields also need accurate water monitoring and control, attentive prevention and repair of rodent damages, and careful salinity management in the root zone. In this paper we attempt to evaluate the viability of the SDI technology for alfalfa production on the basis of preliminary results of our research and extension activities, with focus on its water and energy footprints within the context of resource efficiency.
Daniele Zaccaria; Maria Teresa Carrillo-Cobo; Aliasghar Montazar; Daniel H. Putnam; Khaled Bali. Assessing the Viability of Sub-Surface Drip Irrigation for Resource-Efficient Alfalfa Production in Central and Southern California. Water 2017, 9, 837 .
AMA StyleDaniele Zaccaria, Maria Teresa Carrillo-Cobo, Aliasghar Montazar, Daniel H. Putnam, Khaled Bali. Assessing the Viability of Sub-Surface Drip Irrigation for Resource-Efficient Alfalfa Production in Central and Southern California. Water. 2017; 9 (11):837.
Chicago/Turabian StyleDaniele Zaccaria; Maria Teresa Carrillo-Cobo; Aliasghar Montazar; Daniel H. Putnam; Khaled Bali. 2017. "Assessing the Viability of Sub-Surface Drip Irrigation for Resource-Efficient Alfalfa Production in Central and Southern California." Water 9, no. 11: 837.
Khaled M. Bali; Isabel Escabosa. Management Practices for Phosphorus and Sediment Reduction in the Salton Sea Watershed. International Journal of Environmental Science and Development 2014, 5, 251 -259.
AMA StyleKhaled M. Bali, Isabel Escabosa. Management Practices for Phosphorus and Sediment Reduction in the Salton Sea Watershed. International Journal of Environmental Science and Development. 2014; 5 (3):251-259.
Chicago/Turabian StyleKhaled M. Bali; Isabel Escabosa. 2014. "Management Practices for Phosphorus and Sediment Reduction in the Salton Sea Watershed." International Journal of Environmental Science and Development 5, no. 3: 251-259.
Evapotranspiration (ET) of fully-irrigated and deficit-irrigated (no irrigation in July, August, and September) was measured in five alfalfa fields at various locations throughout California. Seasonal ET ranged from 838 to 1,651 mm, which differed from historical seasonal ET. Deficit irrigation reduced ET, but the ET difference between fully-irrigated and deficit-irrigated alfalfa was site specific. Yields were reduced by deficit irrigation.
B. R. Hanson; K. M. Bali; S. B. Orloff; B. L. Sanden; D. Putnam. Mid-Summer Deficit Irrigation of Alfalfa as a Strategy for Saving Water. World Environmental and Water Resources Congress 2009 2009, 1 -7.
AMA StyleB. R. Hanson, K. M. Bali, S. B. Orloff, B. L. Sanden, D. Putnam. Mid-Summer Deficit Irrigation of Alfalfa as a Strategy for Saving Water. World Environmental and Water Resources Congress 2009. 2009; ():1-7.
Chicago/Turabian StyleB. R. Hanson; K. M. Bali; S. B. Orloff; B. L. Sanden; D. Putnam. 2009. "Mid-Summer Deficit Irrigation of Alfalfa as a Strategy for Saving Water." World Environmental and Water Resources Congress 2009 , no. : 1-7.
A method is presented that uses continuous soil moisture measurements and hourly reference evapotranspiration data to estimate a soil hydraulic factor (β) for modeling soil evaporation. The β factor is used to assess the end of the energy limited soil evaporation phase (Stage 1) and the evaporation rate during the soil hydraulic limited phase (Stage 2) of a two-stage soil evaporation model. A previously developed and tested method to determine β uses an energy balance approach with sensible heat flux density estimated using the surface renewal method to obtain the continuous soil evaporation. A new method is presented, which uses a hydroprobe soil moisture measuring device to estimate the continuous soil evaporation. The estimation of evaporation with soil moisture sensors was simpler and less expensive when compared to the energy balance technique. The methods, evaluated in two field experiments, showed good agreement with evaporation data. Using the evaporation model and β derived from either method provided a good estimate of measured soil evaporation. Modeled daily soil evaporation, using either energy balance or soil measurements to obtain β , gave a root-mean-square error of 0.6 mmday−1 when compared with soil evaporation measured using the energy balance method. When daily soil evaporation from soil moisture measurements was compared with soil evaporation estimated from energy balance measurements, the root-mean-square error was 1.3 mmday−1 . Direct soil monitoring method had bigger error, but the method is less costly.
Francesca Ventura; Richard L. Snyder; Khaled M. Bali. Estimating Evaporation from Bare Soil Using Soil Moisture Data. Journal of Irrigation and Drainage Engineering 2006, 132, 153 -158.
AMA StyleFrancesca Ventura, Richard L. Snyder, Khaled M. Bali. Estimating Evaporation from Bare Soil Using Soil Moisture Data. Journal of Irrigation and Drainage Engineering. 2006; 132 (2):153-158.
Chicago/Turabian StyleFrancesca Ventura; Richard L. Snyder; Khaled M. Bali. 2006. "Estimating Evaporation from Bare Soil Using Soil Moisture Data." Journal of Irrigation and Drainage Engineering 132, no. 2: 153-158.
Accurate estimates of crop evapotranspiration ETc, that quantify the total water used by a crop, are needed to optimize irrigation scheduling for horticultural crops and to minimize water degradation. During early growth, accurate assessments of ETc are difficult in vegetable crops because of high soil evaporation due to frequent irrigation. A model to estimate ETc for vegetable crops, using only daily reference evapotranspiration data as an input parameter, was developed. It calculates crop transpiration and soil evaporation based on ground cover and daily radiation intercepted by the canopy. The model uses a two-stage soil evaporation method adapted to conditions of variable reference evapotranspiration. The model was evaluated against data using measurements from two seasons of lettuce crop, two tomato fields in the same season, and one season of broccoli crop production. Using all of the crop data, the root-mean-square error for measured versus modeled daily ETc was 0.72 mm day−1, indicating that the model works well.
Francesca Ventura; Ben A. Faber; Khaled M. Bali; Richard L. Snyder; Donatella Spano; Pierpaolo Duce; Kurt F. Schulbach. Model for Estimating Evaporation and Transpiration from Row Crops. Journal of Irrigation and Drainage Engineering 2001, 127, 339 -345.
AMA StyleFrancesca Ventura, Ben A. Faber, Khaled M. Bali, Richard L. Snyder, Donatella Spano, Pierpaolo Duce, Kurt F. Schulbach. Model for Estimating Evaporation and Transpiration from Row Crops. Journal of Irrigation and Drainage Engineering. 2001; 127 (6):339-345.
Chicago/Turabian StyleFrancesca Ventura; Ben A. Faber; Khaled M. Bali; Richard L. Snyder; Donatella Spano; Pierpaolo Duce; Kurt F. Schulbach. 2001. "Model for Estimating Evaporation and Transpiration from Row Crops." Journal of Irrigation and Drainage Engineering 127, no. 6: 339-345.