Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 6

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  deficit irrigation
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
The inequality between available water supplies and growing water demand from diverse sectors, as well as the predicted climate changes are putting significant pressures on Egypt’s food security. There is a nation-wide demand for new scientifically proven on-farm practices to boost water productivity of major food crops. The objective of this study was to explore the use of various deficit irrigation schemes to improve water productivity (WP) of tomato cultivated in Egypt under distinct climate change scenarios, RCP4.5 and RCP8.5, in three time-steps of the reference period (2006-2016), 2030s, and 2050s. The AquaCrop model was used to simulate the influence of climate change on the tomato crop, as well as two deficit irrigation application schemes for the full growing season and the regulated application for the initial and maturity crop stages. With the same irrigation method, the predicted WP increased in a general pattern across all climate change scenarios. The combination of irrigation schedule with the 80% deficit irrigation can enhance WP near the optimum level (approximately 2.2 kg∙m-3), especially during early and mature stages of the crop, saving up to 16% of water. The results showed that the expected temperature rise by 2050s would reduce the crop growth cycle by 3-11 days for all irrigation treatments, resulting in a 1-6% decrease in crop evapotranspiration (ETc) and affecting the dry tomato yield with different patterns of increase and decrease due to climate change.
EN
Drought is regarded as one of the environmental constraints threatening agriculture worldwide. Melatonin is a pleiotropic molecule prevalent in plants capable of promoting plant endogenous resilience to many environmental challenges including drought. Banana is an important staple food consumed in developing countries especially in Africa. In this research, we studied the role of melatonin in the growth of bananas subjected to drought under the Egyptian semi-arid conditions. To achieve this objective, a field experiment on banana (Musa spp., cv. Williams) mother plants and first ratoon was conducted on a private farm for two seasons - 2019 and 2020. Three irrigation treatments, 100, 90 and 80% irrigation water requirements (IWR) were used in conjunction with four concentrations of melatonin as a foliar spray (0 μmol, 40 μmol, 60 μmol, and 80 μmol) to determine the effect of both treatments on banana plant performance under drought. The results showed that there was a substantial difference between treatments, with the foliar application of melatonin at 80 μmol concentration improving most of the yield attributes, relative water content, total chlorophyll and proline with water deficit. However, the foliar application of the molecule lowered the biochemical characteristics mostly at 80% IWR under the Egyptian semi-arid conditions. Overall, there was a concentration-dependent response with regards to IWR for the two seasons 2019 and 2020.
EN
In this research, estimation potential of Aquacrop model under deficit irrigation and salinity conditions were evaluated for winter wheat grown under arid and semi-arid climates. Five different irrigation strategies and irrigation water salinity levels (0.5, 5, 7.5, 10, 15 dS m-1 ) were taken with the model to estimate deficit irrigation and salinity scenarios. Wheat grain yield, biomass production and canopy cover were simulated under deficit and salinity stresses. According to estimation of the model; the deficit irrigation with water reduction of more than 75 % of full irrigation was applied at growth stages of wheat, revealed the significant reduction in grain yield, biomass and canopy cover as compared with full irrigation practice. The increase in irrigation water salinity caused a significant decrease in grain yield and biomass value. It was compared to the 0.5 dS m-1 salinity level, a low value of 3% was obtained for the 5 dS m-1 salinity level. Yield loss of 7.5, 10 and 15 dS m-1 salinity levels were found to be 18.97%, 42.5% and 85.6% respectively. Also, increasing irrigation water depth in saline treatments resulted in increased grain and biomass yield. For sustainable water management in agriculture area, using simulation model such as Aquacrop is useful tolls to estimate effect of applied water depth and quality of irrigation water on crop yield.
EN
The research was conducted to determine the effects of Sulfurfoliar applications on the fibre quality of cotton plants exposed to water stress at different growth stages in the Amik Plain (Hatay province, Turkey) in 2015 and 2016. Cotton plants were studied in three different developmental stages (vegetative growth period (VG); flowering and boll development period (FB) and boll opening period (BO)) and full irrigation was applied in some periods, while deficit irrigation was applied in the others. Sulfur fertiliser from foliar was applied in different doses (S0: 0 ml da-1, S1: 150 ml da-1, S2: 250 ml da-1, S3: 350 ml da-1). The study was carried out with three replications according to the split plot design. In the research, the effects of the water deficit and sulfur dose applications on gin turnout and fibre quality characteristics at different growth stages were investigated. Results showed that the average spinning consistency index (SCI) decreased by 11.75% due to the water deficit (compared to the treatment of TTT, irrigation in all three crop developmental stages). Similar effects were observed in the fibre length, micronaire, fibre strength and uniformity index values, which were decreased by 7.31%, 4.07%, 5.89% and 2.17%, respectively. The average gin turnout of the irrigated treatment (TTT), in which there is no deficit irrigation, decreased by 2.5% compared to the control treatment (OOO). Similar effects were observed in fibre elongation and short fibre content values which were decreased by 8.43% and 14.60%, respectively. The average S1 and S3 sulfur doses increased the gin turnout by 0.44% and 0.35%, respectively, and the S2 dose decreased it by 0.79%.
EN
CropSyst (Cropping Systems Simulation) is used as an analytic tool for studying irrigation water management to increase wheat productivity. Therefore, two field experiments were conducted to 1) calibrate CropSyst model for wheat grown under sprinkler and drip irrigation systems, 2) to use the simulation results to analyse the relationship between applied irrigation amount and the resulted yield and 3) to simulate the effect of saving irrigation water on wheat yield. Drip irrigation system in three treatments (100%, 75% and 50% of crop evapotranspiration – ETc) and under sprinkler irrigation system in five treatments (100%, 80%, 60%, 40%, and 20% of ETc) were imposed on these experiments. Results using CropSyst calibration revealed that results of using CropSyst calibration revealed that the model was able to predict wheat grain and biological yield, with high degree of accuracy. Using 100% ETc under drip system resulted in very low water stress index (WSI = 0.008), whereas using 100% ETc sprinkler system resulted in WSI = 0.1, which proved that application of 100% ETc enough to ensure high yield. The rest of deficit irrigation treatments resulted in high yield losses. Simulation of application of 90% ETc not only reduced yield losses to either irrigation system, but also increased land and water productivity. Thus, it can be recommended to apply irrigation water to wheat equal to 90% ETc to save on the applied water and increase water productivity.
PL
CrosSyst (ang. Cropping Systems Simulation) wykorzystano jako narzędzie analityczne do zarządzania wodą do nawodnień w celu zwiększenia produktywności pszenicy. Przeprowadzono dwa eksperymenty terenowe w celu: 1) kalibracji modelu CropSyst w odniesieniu do pszenicy uprawianej w warunkach nawodnień deszczownianych i kroplowych, 2) zastosowania wyników symulacji do analizy zależności między wielkością nawodnień a plonem i 3) symulacji wpływu oszczędności wody użytej do nawodnień na plon pszenicy. W eksperymentach zastosowano trzy warianty nawodnień kroplowych (100%, 75% i 50% ewapotranspiracji – ETc) i pięć wariantów nawadniania deszczownianego (100%, 80%, 60%, 40% i 20% ETc). Wyniki kalibracji wykazały, że wartość RMSE wynosiła 0,03 i 0,14 t·ha–1 odpowiednio dla ziarna i biomasy. Model umożliwiał symulację dobowego stresu wodnego w ciągu całego sezonu wegetacyjnego. W wariancie 90% ETc nie tylko stwierdzono zmniejszenie strat plonu w każdym z systemów nawodnień, ale także zwiększenie produktywności wody. Dlatego można zalecić stosowanie dawki 90% ETc w celu oszczędności wody i zwiększenia jej produktywności.
EN
CropSyst model can be used as irrigation water management tool to increase wheat productivity with poor quality water. The objective of this study was to calibrate CropSyst model for wheat irrigated with fresh and agricultural drainage water. To do so, three field experiments were conducted during three successive seasons in Nubaria Agricultural Research Station, Egypt representing the newly reclaimed calcareous soils. In the first season the treatments were 100% crop evapotranspiration (ETc) of fresh water (FW) and 100% ETc of agricultural drainage water (DW), while in the second and the third seasons, the treatments were 100% ETc of FW, 100% ETc of DW, 120% ETc of DW and 130% ETc of DW. From these results one can concluded that deducting 5% of the applied water to all treatments reduced yield by 3, 5 and 7% in the first, second and third growing season, respectively as a result of heat stress existed in the 2nd and 3rd seasons during reproductive phase. Furthermore, deducting 5% of the applied water from all treatments in the vegetative phase only resulted in lower yield losses. Thus, using CropSyst model could guide us to when we could reduce the applied irrigation water to wheat to avoid high yield losses.
PL
Model CropSyst może znaleźć zastosowanie jako narzędzie w zarządzaniu systemem nawodnień wodą niskiej jakości w celu zwiększenia produkcji pszenicy. Przedmiotem przedstawionych badań było skalibrowanie modelu CropSyst do nawodnień pszenicy wodą naturalną i wodą z rolniczych systemów drenarskich. W tym celu przeprowadzono trzy eksperymenty polowe w trzech kolejnych sezonach realizowane w Nubaria Agricultural Research Station w Egipcie na ostatnio zmeliorowanych glebach wapiennych. W pierwszym sezonie warianty eksperymentalne obejmowały: 100% ewapotranspiracji (ETc) wody naturalnej (FW) i 100% ETc wody z systemów drenarskich (DW); w drugim i trzecim sezonie wariantami eksperymentalnymi były: 100% ETc z użyciem FW, 100% ETc z użyciem DW oraz 120% i 130% ETc z zastosowaniem DW. Uzyskane wyniki dają podstawy do wnioskowania, że zmniejszenie ilości wody zastosowanej do nawodnień o 5% we wszystkich wariantach zmniejszyło plony o 3, 5 i 7% odpowiednio w pierwszym, drugim i trzecim sezonie wskutek stresu termicznego, jaki wystąpił w drugim i trzecim sezonie w fazie reprodukcji. Ponadto, zmniejszenie ilości stosowanej wody o 5% jedynie w trakcie fazy wegetatywnej skutkowało mniejszymi stratami plonu. Podsumowując, zastosowanie modelu CropSyst umożliwia nam stwierdzenie, kiedy można ograniczyć ilość wody do nawodnień i uniknąć znaczących strat w plonie pszenicy.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.