Simulation of Energy Sorghum under Limited Irrigation Levels Using the EPIC Model

2018 ◽  
Vol 61 (1) ◽  
pp. 121-131 ◽  
Author(s):  
Jose C. Chavez ◽  
Juan Enciso ◽  
Manyowa N. Meki ◽  
Jaehak Jeong ◽  
Vijay P. Singh

Abstract. Energy sorghum is one of the most attractive alternatives for producing energy in many regions of the world because of the high biomass productivity obtained in a short period. However, it faces many challenges, particularly where water resources are limited. Crop simulation models are suitable decision support tools for the assessment of crop water use and biomass production under different spatial and climatic conditions. Calibration of simulation models to local conditions is a necessary procedure to improve model reliability. The objective of this study was to calibrate and evaluate the Environmental Policy Integrated Climate (EPIC) model for the production of energy sorghum under different irrigation levels. The model was then used to simulate crop biomass productivity and crop water use to identify appropriate irrigation strategies. This study was conducted at the Texas A&M AgriLife Research Center in Weslaco, Texas. Simulations were performed to determine the total dry biomass, crop water use, the relationship between crop productivity and crop evapotranspiration (ETc), and water use efficiency (WUE). Simulated ETc agreed well with estimates from a weather station, except for a few simulation events. The statistical parameters derived from measured versus simulated dry biomass in the calibrated model, which indicated that the model performed well, were R2 = 0.99 and PBIAS = -5.35%. The calibrated model showed great potential for simulating the total dry biomass. At full irrigation, the difference between measured and simulated total dry biomass was 4.3% in 2013 and 3.0% in 2015. This study showed that energy sorghum requires approximately 600 mm of water to obtain 23 Mg ha-1 of total dry biomass. It also demonstrated that the EPIC model could be used for assessment of crop water use and total biomass under limited irrigation levels, especially in semi-arid regions. Keywords: Crop model, Dry biomass, Energy sorghum, EPIC model, Irrigation, Model calibration, Water use efficiency.

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1344
Author(s):  
Juan Enciso ◽  
Jose C. Chavez ◽  
Girisha Ganjegunte ◽  
Samuel D. Zapata

Water availability and supply are critical factors in the production of bioenergy. Dry biomass productivity and water use efficiency (WUE) of two biomass sorghum cultivars (Sorghum bicolor (L.) Moench) were studied in two different climatic locations during 2014 and 2015. The objective of this field study was to evaluate the dry biomass productivity and water use efficiency of two energy sorghum cultivars grown in two different climatic environments: one at Pecos located in the Chihuahuan Desert and a second one located at Weslaco in the Lower Rio Grande bordering Mexico and with a semiarid environment. There were significant differences between locations in dry biomass and WUE. Dry biomass productivity ranged from 22.4 to 31.9 Mg ha−1 in Weslaco, while in Pecos it ranged from 7.4 to 17.6 Mg ha−1. Even though it was possible to produce energy sorghum biomass in an arid environment with saline-sodic soils and saline irrigation, the energy sorghum dry biomass yield was reduced more than 50% in the arid environment compared to production in a semiarid environment with good soil and water quality, and it required approximately twice as much water. Harsh production conditions combined with low energy prices resulted in negative net returns for all treatments. However, a moderate increase in ethanol price could make the semiarid cropland of Texas an economically feasible feedstock production location.


2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Alaa Salih Ati ◽  
Hadeel Amer Jabbar ◽  
Abd-alkareem hamad

"A field experiment was conducted during the agricultural season of 2017-2018 in the site is located at 82"" 10' 33ᵒ North, and longitude 51"" 32' 44ᵒ , East at an altitude of 33m above sea level. In order to evaluate the productivity of irrigation water by method of cultivation on irrigated furrows, when growing crops of wheat. Two factors were experienced in the cultivation of wheat, The first factor is the method of cultivation of five treatments were used included: Treatment of the cultivation of wheat in basins (B), treatment of the cultivation of wheat on bed with 50 cm width (S1), 60cm (S2), 70cm (S3) and 80cm (S4), The second factor is irrigation levels depletion included: 40, 60 and 80% of available water coded as W1, W2 and W3, respectively,. The results were as follows: Actual water consumption values for basin and bed treatments reached 389, 384, 365, 369.20, 367and 341mm for treatment BW1, BW2, BW3,SW1, SW2 and SW3 respectively. Treatment of wheat crops on bed with 80 cm width gave the highest average field water use efficiency reached 6.84 kg m-3 while BW3 treatment gave lowest average field water use efficiency reached 1.47 kg m-3. The highest average crop water use efficiency were found in S4W1ٚ S4W2 reached 2.06 and 2.07 kg m-3, respectively, It was lowest value for crop water use efficiency at BW3 reached 1.06 kg m-3. The percentage increase in the average efficiency of crop water using for bed treatments 40.37, 57.80, 73.39 and 85.32% for treatments S1, S2, S3 and S4 respectively Compared with basin treatment (B).The highest average total grains yield for Treatment of wheat crops on bed with 80 cm width was 7253kg ha-1 , Irrigation levels also affected the total grains yield, irrigation treatment of depletion 40% gave highest average 6300 kg ha-1 , That did not differ significantly from the irrigation treatments of depletion 60% In which the total grain yield was reached 6228 kg ha-1 ,In the interference factors between the cultivation method and the irrigation levels, the interference factors excelled S4W1, S3W2 and S4W2 Without significant differences in the total yield average 7600,7310 and 7600 kg ha-1, Respectively"


2018 ◽  
Vol 10 (11) ◽  
pp. 1682 ◽  
Author(s):  
Kelly Thorp ◽  
Alison Thompson ◽  
Sara Harders ◽  
Andrew French ◽  
Richard Ward

Improvement of crop water use efficiency (CWUE), defined as crop yield per volume of water used, is an important goal for both crop management and breeding. While many technologies have been developed for measuring crop water use in crop management studies, rarely have these techniques been applied at the scale of breeding plots. The objective was to develop a high-throughput methodology for quantifying water use in a cotton breeding trial at Maricopa, AZ, USA in 2016 and 2017, using evapotranspiration (ET) measurements from a co-located irrigation management trial to evaluate the approach. Approximately weekly overflights with an unmanned aerial system provided multispectral imagery from which plot-level fractional vegetation cover ( f c ) was computed. The f c data were used to drive a daily ET-based soil water balance model for seasonal crop water use quantification. A mixed model statistical analysis demonstrated that differences in ET and CWUE could be discriminated among eight cotton varieties ( p < 0 . 05 ), which were sown at two planting dates and managed with four irrigation levels. The results permitted breeders to identify cotton varieties with more favorable water use characteristics and higher CWUE, indicating that the methodology could become a useful tool for breeding selection.


2020 ◽  
Vol 249 ◽  
pp. 107763 ◽  
Author(s):  
Yang Gao ◽  
Guangcheng Shao ◽  
Jia Lu ◽  
Kun Zhang ◽  
Shiqing Wu ◽  
...  

2019 ◽  
Author(s):  
Jannis Groh ◽  
Jan Vanderborght ◽  
Thomas Pütz ◽  
Hans-Jörg Vogel ◽  
Ralf Gründling ◽  
...  

Abstract. Future crop production will be affected by climatic changes. In several regions, the projected changes in total rainfall and seasonal rainfall patterns will lead to lower soil water storage (SWS) which in turn affects crop water uptake, crop yield, water use efficiency, grain quality and groundwater recharge. Effects of climate change on those variables depend on the soil properties and were often estimated based on model simulations. The objective of this study was to investigate the response of key variables in four different soils and for two different climates in Germany with different aridity index: 1.09 for the wetter (range: 0.82 to 1.29) and 1.57 for the drier climate (range: 1.19 to 1.77), by using high-precision weighable lysimeters. According to a “space-for-time” concept, intact soil monoliths that were moved to sites with contrasting climatic conditions have been monitored from April 2011 until December 2018. Evapotranspiration was lower for the same soil under the relatively drier climate whereas crop yield was significantly higher, without affecting grain quality. Especially non-productive water losses (evapotranspiration out of the main growing period) were lower which led to a more efficient crop water use in the drier climate. A characteristic decrease of the SWS for soils with a finer texture was observed after a longer drought period under a drier climate. The reduced SWS after the drought remained until the end of the observation period which demonstrates carry-over of drought from one growing season to another and the overall long term effects of single drought events. In the relatively drier climate, water flow at the soil profile bottom showed a small net upward flux over the entire monitoring period as compared to downward fluxes (ground water recharge) or drainage in the relatively wetter climate and larger recharge rates in the coarser- as compared to finer-textured soils. The large variability of recharge from year to year and the long lasting effects of drought periods on SWS imply that long term monitoring of soil water balance components is necessary to obtain representative estimates. Results confirmed a more efficient crop water use under less optimal soil moisture conditions. Long-term effects of changing climatic conditions on the SWS and ecosystem productivity should be considered when trying to develop adaptation strategies in the agricultural sector.


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