- WETTED ZONE BEHAVIOR UNDER MICRO IRRIGATED CROPS

Keyword(s):  
2014 ◽  
Author(s):  
International Food Policy Research Institute (IFPRI)

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2120
Author(s):  
Clifford B. Fedler

Water reuse via land application is old technology; but the water balance only design approach and practice has not worked well. There are many benefits of water reuse by irrigating crops; however, there are some risks if not designed properly. When the design approach uses a combined water-nutrient-salt balance, the most effective and sustainable, long-term system is achieved. This approach provides a design based on land area requirements, on-site water storage, and economic return from the irrigated crops. The single, most often overlooked step in the water balance is accounting for the water stored in the soil. When spread over large areas, this quantity of water results in considerably less required surface water storage, which saves capital costs. This design approach has been used successfully on multiple sites for over 30 years without failure.


2021 ◽  
Author(s):  
Daniel Kurtzman ◽  
Beeri Kanner ◽  
Yehuda Levy ◽  
Ido Nitsan ◽  
Asher Bar-Tal

<p>Reducing nitrate leaching from agricultural land to aquifers is a high priority concern for more than a half a century. Theory and observations of a threshold concentration of nitrate in the root-zone (Cmax), from which the leachate concentration increases at higher rates with increasing root-zone nitrate concentration, are presented. Cmax is derived both by direct results from container experiments with varying nitrogen (N) fertigation, and as calibration parameter in N-transport models beneath commercial agricultural plots. For five different crops, Cmax ranged between 20-45 mg/l of NO<sub>3</sub>-N derived from experiments and models. However, for lettuce, which was irrigated with a large leaching fraction, a Cmax could not be defined. For the crops irrigated and fertilized in the warm/dry season (corn and citrus) experiments show a dramatic change in leachate concentrations and simulations reveal a wide range of sensitivity of leachate NO<sub>3</sub>-N concentration to Cmax. Annual crops that are irrigated and fertilized in the cool/wet season (e.g. potato in Mediterranean climate) showed a distinct Cmax yet less dramatic than the summer-irrigated crops in the container experiment, and smaller impact of Cmax in models. Simulations showed that for summer-irrigated crops maintaining fertigation at C<Cmax has a significant effect on deep leachate concentrations, whereas for the winter annual crops the simulations revealed no threshold. It is suggested that for summer-irrigated crops fertigation below Cmax robustly serves the co-sustainability of intensive agriculture and aquifer water quality, for the winter crops it is suggested but benefits are not robust. For short season, small root-system crops (lettuce) efforts should be made to detach the crop from the soil.</p>


2014 ◽  
Vol 44 (4) ◽  
pp. 175 ◽  
Author(s):  
Daniele Duca ◽  
Giuseppe Toscano ◽  
Ester Foppa Pedretti ◽  
Giovanni Riva

The use of renewable energies as alternative to fossil fuels has value from different points of view and has effects at environmental, social and economic level. These aspects are often connected to each other and together define the overall sustainability of bioenergy. At European level, the Directive 2009/28/EC gives the basic criteria for the estimation of sustainability of biofuels and indicates a minimum threshold of 35% of greenhouse gas saving for a biofuel in order to be considered sustainable. The Directive gives the possibility to identify standard regional values for the cultivation steps that could be utilized for the certification. This paper aims to give a contribution to the definition of these values considering the RED methodology applied to the sunflower cropped in central Italy which is characterized by a hilly landscape and not-irrigated crops. To determine input and output of sunflower cultivation in the central Italy, the results of PROBIO project, carried out by the Authors, were used. The sustainability of biodiesel produced from sunflower grown in central Italy is variable and depends on the nitrogen input and seasonal climatic conditions that affect the yields. The greenhouse gases savings of the Italian chain is 40% in average, greater than the required 35% and would be possible to assign this value as standard to the biofuel chain <em>biodiesel from sunflower cultivated in central Italy</em>. Using an averaged regional standard value guards against the possibility of considering unsustainable harvesting in unfavourable years and seeing it overestimated in the favourable ones.


2021 ◽  
pp. 86-89
Author(s):  
Dmitry Aleksandrovich Solovyev ◽  
Viktor Vladislavovich Korsak ◽  
Galina Nikolaevna Kamyshova ◽  
Olga Nikolaevna Mityureva ◽  
Pavel Olegovich Terekhov

The article presents the results of the development of a digital technology for optimizing the parameters of moisture in the calculated soil layer. The introduction of precision irrigation technologies requires the development of new approaches to the development of decision support systems for their technical implementation in modern high-level programming languages. The developed computer program for determining the optimal moisture parameters of the calculated soil layer for the main irrigated crops of the Saratov region is easy to use and easily integrated into digital automated irrigation control systems.


Author(s):  
Donato Zingaro ◽  
Ivan Portoghese ◽  
Giacomo Giannoccaro

Agriculture and farming worldwide are responsible for numerous environmental threats, including degradation of land and water resources depletion. Underlining the dynamic interaction between bio-physical and socio-economic drivers is the key towards a more sustainable land and water management. With regard to a highly developed agricultural area in southern Italy, multi-regression models were developed to interpret the observed inter-annual variability of cropped land. Main drivers related to Common Agricultural Policy support, product market prices, crop yield and irrigation water availability were investigated. The adopted models revealed the different weighs of each driver. The findings reported the role that direct payments played in supporting the extension of irrigated crops, such as processing tomato. Likewise, the models pointed to decoupled payment scheme as the most important driver of change in the crop pattern over the last years.


Author(s):  
Melek Yiğen ◽  
Murat Tekiner

The “Action Plan for the Water Use in Agriculture Activation Program” in the Tenth Five-Year Development Plan, prepared by The Ministry of Development for the period 2014-2018, is one of the most important indicators of the increasing importance of water resources and irrigation. It’s published according to Blaney-Criddle method with the data of the Crop Evapotranspiration Guideline in 1982, for a guide to be updated by General Directorate of Agricultural Research And Policies (TAGEM) and General Directorate of State Hydraulic Works (DSI) in 2013, using the Food and Agriculture Organization (FAO) Penman Monteith method. While DSİ undertakes the calculation of reference plant water consumption (ET0), effective precipitation and irrigation water requirement of this update, TAGEM is responsible for the compilation of information obtained from irrigation researches, calculation of plant coefficient (kc) values, publication of guides in written and electronic media realized. In this study, five guides (Balıkesir, Çanakkale, Edirne, Kocaeli and Tekirdağ) in three different climatic regions (Akdeniz Ardı, Marmara and İç Geçit-Marmara) were used in this guide, which the two institutions jointly organize and update with intensive effort, TUIK 2012-2016 considering the data, the county made on the basis of agriculture and untreated plants, guide place whether to get cases examined, the importance and aspects to be developed contacts have tried to reveal.


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