Your search found 6 records
1 Campos, A. A.; Fabião, M. S.; Gonçalves, J. M.; Pereira, L. S.; Paredes, P.. 2003. Improved surface irrigation and scheduling for upland crops in the Huinong Irrigation District: Water saving and salinity control issues. In Pereira, L. S.; Cai, L. G.; Musy, A.; Minhas, P. S. (Eds.), Water savings in the Yellow River Basin: Issues and decision support tools in irrigation. Beijing, China: China Agriculture Press. pp.107-130.
Simulation models ; Surface irrigation ; Irrigation scheduling ; Crop production ; Water conservation ; Salinity control / China / Yellow River Basin / Huinong Irrigation District
(Location: IWMI-HQ Call no: 631.7 G592 PER Record No: H040064)
2 Campos, A. A.; Fabião, M. S.; Gonçalves, J. M.; Pereira, L. S.; Paredes, P.. 2003. Improving surface irrigation and scheduling in Bojili Irrigation District. In Pereira, L. S.; Cai, L. G.; Musy, A.; Minhas, P. S. (Eds.), Water savings in the Yellow River Basin: Issues and decision support tools in irrigation. Beijing, China: China Agriculture Press. pp.153-164.
Surface irrigation ; Irrigation scheduling ; Simulation models ; Water scarcity ; Groundwater / China / Yellow River Basin / Bojili Irrigation District
(Location: IWMI-HQ Call no: 631.7 G592 PER Record No: H040066)
3 Pereira, L. S.; Gonc alves, J. M.; Campos, A. A.; Fabiao, M. S.; Paredes, P.; Mao, Z.; Dong, B.; Liu, Y.; Li, Y. N.; Fang, S. X. 2003. Irrigation water saving issues in the Yellow River Basin: a case study in Huinong Irrigation District. In Yellow River Conservancy Commission. Proceedings, 1st International Yellow River Forum on River Basin Management – Volume III. Zhengzhou, China: The Yellow River Conservancy Publishing House. pp.17-36.
River basins ; Irrigation scheduling ; Basin irrigation ; Simulation models ; Irrigation canals ; Water conservation ; Wheat ; Maize ; Evapotranspiration / China / Yellow River / Huinong / Ningxia / Bojili / Shandong
(Location: IWMI-HQ Call no: 333.91 G592 YEL Record No: H034654)
4 Jovanovic, N.; Pereira, L. S.; Paredes, P.; Pocas, I.; Cantore, V.; Todorovic, M. 2020. A review of strategies, methods and technologies to reduce non-beneficial consumptive water use on farms considering the FAO56 methods. Agricultural Water Management, 239:106267. (Online first) [doi: https://doi.org/10.1016/j.agwat.2020.106267]
Water use efficiency ; Irrigation management ; Irrigation methods ; Remote sensing ; Soil management ; Water scarcity ; Water stress ; Water conservation ; Crop water use ; Water requirements ; Evapotranspiration ; Water productivity ; Deficit irrigation ; Irrigation systems ; Sprinkler irrigation ; Drip irrigation ; Irrigation scheduling ; Mulching ; Models
(Location: IWMI HQ Call no: e-copy only Record No: H049833)
(0.97 MB)
In the past few decades, research has developed a multitude of strategies, methods and technologies to reduce consumptive water use on farms for adaptation to the increasing incidence of water scarcity, agricultural droughts and multi-sectoral competition for water. The adoption of these water-saving practices implies accurate quantification of crop water requirements with the FAO56 crop coefficient approach, under diverse water availability and management practices. This paper critically reviews notions and means for maintaining high levels of water consumed through transpiration, land and water productivity, and for minimizing non-beneficial water consumption at farm level. Literature published on sound and quantified experimentation was used to evaluate water-saving practices related to irrigation methods, irrigation management and scheduling, crop management, remote sensing, plant conditioners, mulching, soil management and micro-climate regulation. Summary tables were developed on the benefits of these practices, their effects on non-beneficial water consumption, crop yields and crop water productivity, and the directions for adjustment of FAO56 crop coefficients when they are adopted. The main message is that on-farm application of these practices can result in water savings to a limited extent (usually <20%) compared to sound conventional practices, however this may translate into large volumes of water at catchment scale. The need to streamline data collection internationally was identified due to the insufficient number of sound field experiments and modelling work on the FAO56 crop water requirements that would allow an improved use of crop coefficients for different field conditions and practices. Optimization is required for the application of some practices that involve a large number of possible combinations (e.g. wetted area in micro-irrigation, row spacing and orientation, plant density, different types of mulching, in-field water harvesting) and for strategies such as deficit irrigation that aim at balancing water productivity, the economics of production, infrastructural and irrigation system requirements. Further research is required on promising technologies such as plant and soil conditioners, and remote sensing applications.
5 Pereira, L. S.; Paredes, P.; Melton, F.; Johnson, L.; Wang, T.; Lopez-Urrea, R.; Cancela, J. J.; Allen, R. G. 2020. Prediction of crop coefficients from fraction of ground cover and height. Background and validation using ground and remote sensing data. Agricultural Water Management, 241:106197. (Online first) [doi: https://doi.org/10.1016/j.agwat.2020.106197]
Crops ; Forecasting ; Remote sensing ; Satellites ; Evapotranspiration ; Vegetation ; Irrigation management ; Water stress ; Water management ; Energy balance ; Indicators ; Vegetable crops ; Field crops ; Soil water balance
(Location: IWMI HQ Call no: e-copy only Record No: H049857)
(2.32 MB)
The current study aims at reviewing and providing advances on methods for estimating and applying crop coefficients from observations of ground cover and vegetation height. The review first focuses on the relationships between single Kc and basal Kcb and various parameters including the fraction of ground covered by the canopy (fc), the leaf area index (LAI), the fraction of ground shaded by the canopy (fshad), the fraction of intercepted light (flight) and intercepted photosynthetic active radiation (fIPAR). These relationships were first studied in the 1970’s, for annual crops, and later, in the last decennia, for tree and vine perennials. Research has now provided a variety of methods to observe and measure fc and height (h) using both ground and remote sensing tools, which has favored the further development of Kc related functions. In the past, these relationships were not used predictively but to support the understanding of dynamics of Kc and Kcb in relation to the processes of evapotranspiration or transpiration, inclusive of the role of soil evaporation. Later, the approach proposed by Allen and Pereira (2009), the A&P approach, used fc and height (h) or LAI data to define a crop density coefficient that was used to directly estimate Kc and Kcb values for a variety of annual and perennial crops in both research and practice. It is opportune to review the A&P method in the context of a variety of studies that have derived Kc and Kcb values from field measured data with simultaneously observed ground cover fc and height. Applications used to test the approach include various tree and vine crops (olive, pear, and lemon orchards and vineyards), vegetable crops (pea, onion and tomato crops), field crops (barley, wheat, maize, sunflower, canola, cotton and soybean crops), as well as a grassland and a Bermudagrass pasture. Comparisons of Kcb values computed with the A&P method produced regression coefficients close to 1.0 and coefficients of determination = 0.90, except for orchards. Results indicate that the A&P approach can produce estimates of potential Kcb, using vegetation characteristics alone, within reasonable or acceptable error, and are useful for refining Kcb for conditions of plant spacing, size and density that differ from standard values. The comparisons provide parameters appropriate to applications for the tested crops. In addition, the A&P approach was applied with remotely sensed fc data for a variety of crops in California using the Satellite Irrigation Management Support (SIMS) framework. Daily SIMS crop ET (ETc-SIMS) produced Kcb values using the FAO56 and A&P approaches. Combination of satellite derived fc and Kcb values with ETo data from Spatial CIMIS (California Irrigation Management Information System) produced ET estimates that were compared with daily actual crop ET derived from energy balance calculations from micrometeorological instrumentation (ETc EB).Results produced coefficients of regression of 1.05 for field crops and 1.08 for woody crops, and R2 values of 0.81 and 0.91, respectively. These values suggest that daily ETc-SIMS -based ET can be accurately estimated within reasonable error and that the A&P approach is appropriate to support that estimation. It is likely that accuracy can be improved via progress in remote sensing determination of fc. Tabulated Kcb results and calculation parameters are presented in a companion paper in this Special Issue.
6 Serra, J.; Paredes, P.; Cordovil, C.; Cruz, S.; Hutchings, N.; Cameira, M. 2023. Is irrigation water an overlooked source of nitrogen in agriculture? Agricultural Water Management, 278:108147. (Online first) [doi: https://doi.org/10.1016/j.agwat.2023.108147]
Irrigation water ; Nitrogen ; Nutrient management ; Water management ; Fertilizers ; Surface water ; Water storage ; Evapotranspiration ; Irrigation systems ; Water requirements ; Soil water ; Crop yield ; Biomass ; Precipitation ; Crop modelling ; Wheat ; Maize ; Potatoes ; Tomatoes ; Rice ; Policies ; Irrigation requirements ; Sprinklers ; Groundwater table ; Indicators ; Water quality ; Water productivity
(Location: IWMI HQ Call no: e-copy only Record No: H051602)
https://www.sciencedirect.com/science/article/pii/S0378377423000124/pdfft?md5=3eead5852e7b50db297647ba3cd26036&pid=1-s2.0-S0378377423000124-main.pdf
https://vlibrary.iwmi.org/pdf/H051602.pdf
https://vlibrary.iwmi.org/pdf/H051602.pdf
(15.60 MB) (15.6 MB)
The increase of agricultural nitrogen (N) inputs since the 1960s is a key driver in surface- and groundwater nitrate pollution. The water abstracted from these sources can input substantial amounts of reactive nitrogen (NIrrig) if used for crop irrigation. This input is often not included in N related agricultural policies and studies, which are likely underestimating the magnitude of N pollution hotspots and overestimating the N use efficiency. In this study, we provided prima facie evidence that NIrrig is a neglected source of N in irrigated systems. The NIrrig was computed for 278 municipalities in mainland Portugal along the period 1995–2019 based on the gross irrigation requirements and nitrate concentration in ground- and surface water sources. The former was derived using two complementary approaches, using the AquaCrop and GlobWat models, while the latter were computed following spatially explicit approaches. NIrrig showed annual large fluctuations (6–11 Gg N yr-1), of which 91% was from groundwater sources. Results show that NIrrig averaged 14 ( ± 11) kg N ha-1 yr-1, which is equivalent to 3 ( ± 4) % of the N in synthetic fertilisers. This input was higher in the municipalities that simultaneously present high irrigation demand and the nitrate-contaminated groundwater as an irrigation source. In these cases, located in Nitrate Vulnerable Zones, NIrrig reached up to 95 kg N ha-1 yr-1 and more than 80% of the N in synthetic fertilizers. This study highlights the importance of linking water and nutrient policies to better gain insight on NIrrig, for which the current study provided for a simple modelling framework.
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