Management of Biogate-Fert Technique Based on a Simulation Model

Biogate-fert technique ensures to optimization of fertilizer and water units yield of the potato crop. There were two field tests conducted in the growing seasons. 2019-2020 and 2020-2021, at the research farm of the National Research Centre in Nubaria region, Egypt to study the management of biogate-fert technique based on a developed SALTMED model on potato crop under drip irrigation system in sandy soil conditions. According to the findings, the SALTMED model demonstrated its capacity to forecast soil moisture availability, yield, total dry matter, and nitrogen (ppm) for two growing seasons when using mineral and biogte- fert approaches., In order to maximize crop production and nitrogen levels, the model can calculate how much irrigation supply will be needed to move the soil moisture profile from a given soil moisture to a target soil moisture. Furthermore, accurate estimation of the solute and nutrient status and uptake at the same time is contingent upon accurate simulation of nitrogen and soil moisture

Statistical and fourier analysis of cyclic changes of zooplankton abundance in the eastern harbor of Alexandria

279-290Time series data of monthly averages, over three stations, for counts of zooplankton groups and species, and some environmental factors (water temperature, salinity and chlorophyll a) were collected from the Eastern Harbor of Alexandria, during the period of 48 months, from October 1999 to November 2003. The spectral density graphics with frequency indicated that inspite of the presence of several peaks for different variables the only significant peak, at 95% confidence limit, was found in case of water temperature. The results of Fourier analysis show that the most common periods that are relatively important and affecting the movement of the time-series of environmental and the biological variables are 12, 9 and 6 months. The 12 months was corresponding to seasonal changes, while periods less than 12 months were due to local changes depending on the hydrological exchange between the Eastern Harbor and the open Mediterranean coastal waters in front of the study area. The time lags of the occurrence of the maxima of each two variables at the important cycles with periods 12, 9 and 6 months were calculated to express the response time of the different groups flourishing relative to the occurrence of the effecting environmental factors. The cluster and correlation analyses of the different variables have also been done to show most correlated ones. The results indicated that the annual cycle is the most important one in most cases. The multiple regression equations between the zooplankton counts and the environmental variables showed the important controlling factor in the different species and groups of zooplankton

Predicting soil moisture distribution, dry matter, water productivity and potato yield under a modified ‎gated pipe irrigation system: SALTMED model application using field experimental data

The use of gated pipes in surface irrigation helps to reduce water losses commonly associated with the use of the traditional furrows. This study focused on predicting soil moisture content‎, total dry matter, crop yield and water productivity of potato crop using traditional and modified, self-compensating gate outlet (SCGO) gated pipe using the SALTMED model to explore the model suitability to identify the optimum and economic gate spacings. The traditional gated pipes are known to exhibit a range of pressure head variations along the pipeline causing a non-uniform discharge from orifices while the modified gate pipe system, known as compensating gated pipes (SCGO) stabilizes the pressure heads and produce more uniform water discharge along the pipe line. The effect of three gate spacings (0.7, 1.0 and 1.5 m) was studied in a field experiment that has been conducted for two successive seasons, 2011–2012 and 2012–2013. The SALTMED model has been applied and showed excellent agreement between the simulated and observed soil moisture, dry matter, yield and water productivity. Similar to the field results, the simulated values indicated that the modified (SCGO), with the 1.5 m gate spacing, gave the highest yield and water productivity. The modified gated pipe received less water than the traditional gated pipe, due to its high application efficiency. In addition to water saving, there is an economic benefit for using 1.5 m gate spacings as its cost is low (14 gates per 21 m pipe length) in comparison with 1.0 m and 0.7 m spacings. The results confirmed SALTMED ability to simulate with high precision, soil moisture, dry matter, water productivity and yield for potato under gated pipe irrigation. Therefore, the model can be used for design purposes to identify the optimum and economic gate spacings without the need to conduct expensive, costly and labor intensive field trials

Management of Biogate-Fert Technique Based on a Simulation Model

Biogate-fert technique ensures to optimization of fertilizer and water units yield of the potato crop. There were two field tests conducted in the growing seasons. 2019-2020 and 2020-2021, at the research farm of the National Research Centre in Nubaria region, Egypt to study the management of biogate-fert technique based on a developed SALTMED model on potato crop under drip irrigation system in sandy soil conditions. According to the findings, the SALTMED model demonstrated its capacity to forecast soil moisture availability, yield, total dry matter, and nitrogen (ppm) for two growing seasons when using mineral and biogte- fert approaches., In order to maximize crop production and nitrogen levels, the model can calculate how much irrigation supply will be needed to move the soil moisture profile from a given soil moisture to a target soil moisture. Furthermore, accurate estimation of the solute and nutrient status and uptake at the same time is contingent upon accurate simulation of nitrogen and soil moisture