scholarly journals Modeling of Fertilizer Transport for Various Fertigation Scenarios under Drip Irrigation

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 893 ◽  
Author(s):  
Romysaa Elasbah ◽  
Tarek Selim ◽  
Ahmed Mirdan ◽  
Ronny Berndtsson

Frequent application of nitrogen fertilizers through irrigation is likely to increase the concentration of nitrate in groundwater. In this study, the HYDRUS-2D/3D model was used to simulate fertilizer movement through the soil under surface (DI) and subsurface drip irrigation (SDI) with 10 and 20 cm emitter depths for tomato growing in three different typical and representative Egyptian soil types, namely sand, loamy sand, and sandy loam. Ammonium, nitrate, phosphorus, and potassium fertilizers were considered during simulation. Laboratory experiments were conducted to estimate the soils’ adsorption behavior. The impact of soil hydraulic properties and fertigation strategies on fertilizer distribution and use efficiency were investigated. Results showed that for DI, the percentage of nitrogen accumulated below the zone of maximum root density was 33%, 28%, and 24% for sand, loamy sand, and sandy loam soil, respectively. For SDI with 10 and 20 cm emitter depths, it was 34%, 29%, and 26%, and 44%, 37%, and 35%, respectively. Results showed that shallow emitter depth produced maximum nitrogen use efficiency varying from 27 to 37%, regardless of fertigation strategy. Therefore, subsurface drip irrigation with a shallow emitter depth is recommended for medium-textured soils. Moreover, the study showed that to reduce potential fertilizer leaching, fertilizers should be added at the beginning of irrigation events for SDI and at the end of irrigation events for DI. As nitrate uptake rate and leaching are affected by soil’s adsorption, it is important to determine the adsorption coefficient for nitrate before planting, as it will help to precisely assign application rates. This will lead to improve nutrient uptake and minimize potential leaching.

2019 ◽  
Vol 25 (9) ◽  
pp. 41-53
Author(s):  
Heba Najem Abid ◽  
Maysoon Basheer Abid

Soil wetted pattern from a subsurface drip plays great importance in the design of subsurface drip irrigation (SDI) system for delivering the required water directly to the roots of the plant. An equation to estimate the dimensions of the wetted area in soil are taking into account water uptake by roots is simulated numerically using HYDRUS (2D/3D) software. In this paper, three soil textures namely loamy sand, sandy loam, and loam soil were used with three different types of crops tomato, pepper, and cucumber, respectively, and different values of drip discharge, drip depth, and initial soil moisture content were proposed. The soil wetting patterns were obtained at every thirty minutes for a total time of irrigation equal to three hours. Equations for wetted width and depth were predicted and evaluated by utilizing the statistical parameters (model efficiency (EF), and root mean square error (RMSE)). The model efficiency was more than 95%, and RMSE did not exceed 0.64 cm for three soils. This shows that evolved formula can be utilized to describe the soil wetting pattern from SDI system with good accuracy.      


2013 ◽  
Vol 726-731 ◽  
pp. 3035-3039 ◽  
Author(s):  
Xue Bin Qi ◽  
Zong Dong Huang ◽  
Dong Mei Qiao ◽  
Ping Li ◽  
Zhi Juan Zhao ◽  
...  

Agriculture is a big consumer of fresh water in competition with other sectors of the society. The agricultural sector continues to have a negative impact on the ecological status of the environment. The worlds interest in high quality food is increasing. Field experiments were conducted to investigate the effect of subsurface drip irrigation on physiological responses, yield and water use efficiency, Soil nitrogen, Root weight density of potato in the semi-humid region of middle China using subsurface drip irrigation. The experiment used second-stage treated wastewater with and without addition of chloride, and both subsurface drip and furrow irrigations were investigated. Results indicated that the alternate partial root-zone irrigation is a practicable water-saving strategy for potato. The drip with chlorinated and non-chlorinated water improved water use efficiency by 21.48% and 39.1%, respectively, and 44.1% in the furrow irrigation. Partial root zone drying irrigation stimulates potato root growth and enhances root density. The content of the heavy metal in the potato tubers is no more than the National Food Requirements, and it is consistent with National Food Hygiene Stands.


2016 ◽  
Vol 26 (4) ◽  
pp. 436-443 ◽  
Author(s):  
Timothy Coolong

Subsurface drip irrigation (SDI) has been increasingly used for the production of numerous agronomic crops and a limited number of vegetable crops. To determine the impact of SDI compared with surface drip irrigation (SUR), a study was conducted in 2011 and 2012 with ‘Table Queen’ acorn squash (Cucurbita pepo var. turbinata) with irrigation initiated at 75% and 50% plant available water (PAW). The study was arranged as a factorial randomized complete block design and plants were grown with two irrigation types (SUR or SDI) and two tensiometer-controlled irrigation regimes. Results from 2011 suggested that SDI used less water compared with SUR at each irrigation set point. However, in 2012, significantly more water was used in all treatments due to warmer temperatures and less rainfall. In 2012, SDI used more water than SUR treatments at the same irrigation set point. In 2012, yield was affected by irrigation treatment. Plants grown using SUR irrigating at 75% PAW had greater numbers of fruit compared with other treatments. Furthermore, the highest yielding treatment had more than twice the number of irrigation events than the other treatments though the average lengths of irrigation events were shorter. Although overall yields were greater in 2012, irrigation water use efficiency (iWUE) was lower than in 2011 due to increased water use. These results suggest that while SDI may have some advantages over traditional SUR, environmental factors during growth can significantly impact the efficiency and productivity of each system.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xuesong Cao ◽  
Yayang Feng ◽  
Heping Li ◽  
Hexiang Zheng ◽  
Jun Wang ◽  
...  

A field experiment was conducted for the purpose of examining the effects of different combinations of water and fertilizer applications on the water consumption and yields of alfalfa under subsurface drip irrigation (SDI). The results showed that the jointing and branching stages were the key stages for alfalfa water requirement. The water consumption had varied greatly (from 130 to 170 mm) during the growth period of each alfalfa crop. The water consumption during the whole growth period was approximately 500 mm, and the maximum water consumption intensity was 3.64 mm·d-1. The overall changes in water consumption and yields during the growth period of the alfalfa displayed trends of first increasing and then decreasing. The sensitivities of the yields to water changes were much higher than that of fertilizer. The water use efficiency (WUE) of the alfalfa was determined to range from 1.68 to 3.20 kg·m-3, and the rate of growth had ranged from 4.85% to 51.77%. The WUE and rate of growth of the alfalfa indicated the following trend: second crop > third crop > first crop. The results of frequency analysis based on the water-nitrogen-yield regression equation are the following: irrigation amounts of 142~165 mm and nitrogen application of 61~80 kg·hm-2 have a 95% probability of obtaining a hay yield of alfalfa of more than 11903 kg·hm-2. These results suggest that SDI is a promising irrigation method, which can increase the WUE and hay yield of alfalfa under the condition of SDI within an appropriate amount of water and nitrogen fertilizer, and too low or too high water and nitrogen fertilizer will adversely affect the WUE and hay yield of alfalfa.


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