Crop water use efficiency (WUE, or yield per unit of water used), also known as crop water productivity, can be improved through irrigation management and methods, including deficit irrigation (irrigating less than is required for maximum yields) and supplemental irrigation (irrigating to supplement precipitation so as to avoid crop failure or severe yield decline). Thus, WUE is key for agricultural production with limited water resources.
Policymakers and water resource managers working at all scales need to evaluate the many ways in which cropping systems and the amounts, timing, and methods of both irrigation and fertilizer applications may be changed to improve WUE while meeting yield and harvest quality goals. Field experiments are too costly to address all scenarios, but computer models of crop growth and yield may fill in the gaps if the models are shown to be accurate predictors of WUE.
An international team of experts led by the Food and Agriculture Organization of the United Nations developed an agronomic model called AquaCrop to address the need for modeling of WUE under widely varying conditions around the world and with limited data.
To look at the ability of this and other agronomic models to estimate WUE, a team member with the USDA Agricultural Research Service, Bushland, TX, organized a symposium, “Yield Response to Water: Examination of the Role of Crop Models in Predicting Water Use Efficiency,” at the 2007 Annual International meeting of the Agronomy Society of America. Results using several agronomic models were discussed.
Nine papers arising from the symposium are published in a special section of the May–June 2009 issue of Agronomy Journal. The papers explore how four of the simulation models were used to simulate yield, water use, and WUE of cotton, maize (corn), quinoa, and sunflower in North and South America, Europe, and the Middle East. All the models simulated WUE adequately under well-watered conditions, but tended to overestimate or underestimate WUE under conditions of water stress. This limits their usefulness for exploration of deficit irrigation scenarios or rain-fed or dryland situations with less than adequate water.
According to symposium organizer Steve Evett, “Future studies exploring WUE simulation should include evaporation or transpiration measurements in addition to total crop water use measurements. In doing so, management methods that reduce evaporation in favor of transpiration can be studied and models of WUE can be tested and improved.”
This examination of WUE estimation by multiple models helps close the gap that exists between what can be done using crop simulation models and what policymakers and managers need from these models in order to develop useful management alternatives for crop selection and timing, tillage systems, and irrigation and fertilization practices. Development of AquaCrop and several other models is continuing and will be guided by the findings of these studies.
The full article is available for no charge for 30 days following the date of this summary. View the abstract at http://agron.scijournals.org/cgi/content/abstract/101/3/423.
A peer-reviewed international journal of agriculture and natural resource sciences, Agronomy Journal is published six times a year by the American Society of Agronomy, with articles relating to original research in soil science, crop science, agroclimatology and agronomic modeling, production agriculture, and software. For more information visit: http://agron.scijournals.org.
The American Society of Agronomy (ASA) www.agronomy.org, is a scientific society helping its 8,000+ members advance the disciplines and practices of agronomy by supporting professional growth and science policy initiatives, and by providing quality, research-based publications and a variety of member services.
Sara Uttech | Newswise Science News
“How trees coexist” – new findings from biodiversity research published in Nature Communications
21.03.2018 | Technische Universität Dresden
Earlier flowering of modern winter wheat cultivars
20.03.2018 | Georg-August-Universität Göttingen
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
21.03.2018 | Life Sciences
21.03.2018 | Life Sciences
21.03.2018 | Physics and Astronomy