Table 6.9: Accumulation of secondary essential plant nutrients (nitrogen, phosphorus, potassium, calcium, magnesium and sulphur) in head, root and shoot portion of irrigated wheat. Table 6.10: Accumulation of secondary essential plant nutrients (sodium, iron, copper, manganese and zinc) in the head portion of wheat grown under irrigated wastewater samples using a field.
Introduction
Overview of the thesis
- Water scarcity in the UAE
- Wastewater
- Wastewater treatment
- Irrigation of wastewater
- Wastewater irrigation UAE
- Agriculture techniques
- Global wheat production
The adoption of efficient treatment methods and better management practices in wastewater reuse is expected to bring many benefits to crops (Balkhair et al., 2013). Another way, the existing approach, is that the quality of the treated wastewater determines the use of the wastewater.
Statement of the problem
Research objectives
Methods
Water
Water scarcity
Wastewater
In several parts of the world, the use of wastewater in agriculture has increased significantly over the past 120 years to counteract global water scarcity (Asano & Levine 1996; Jimenez & Asano, 2008). Therefore, microbiological vision and wastewater safety standards have been proposed in the specifications for irrigation.
Constituents of domestic wastewater
Wastewater treatment
- Types of wastewater treatment
- Sources of wastewater
It usually consists of highly pathogenic and toxic contaminated chemicals (Van Voorthuizen et al., 2008). Depending on the source, waste water is usually divided into household sewage and non-sewerage.
Wastewater management
- Primary treatment
- Secondary treatment
- Tertiary treatment methods
- Treated wastewater in agriculture
Algae remaining in the pond effluent can later be removed by filtration or by combining chemical treatment and settling (Butler et al., 2017). The complete tertiary treatment method should involve the suspension of a measured amount of antibiotic resistance genes in an available log10 reductions (log removal value of pathogenic microorganisms (LRV)) in the solids and aqueous waste (Quach-Cu et al., 2018 ).
Benefits of using wastewater reuse in agriculture
The study conducted by Wang et al. 2012) showed that sewage increased the soil's macro and micronutrient content. The increase in total carotenoid and chlorophyll content of maize treated with sewage water was recorded by Khan and Bano (2016).
Wastewater in UAE
In 2017, treated wastewater from Abu Dhabi and Dubai accounted for around 45% of the total treated wastewater, and Sharjah contributed 17%. These in turn affect the population's ability to use the water for beneficial purposes.
Treated wastewater in UAE
However, in recent years, agricultural use of wastewater for vegetation has been the last option because it can increase environmental and human health risks (Srinivasan & Reddy, 2009; Qadir et al., 2011). The purpose of a high degree of control for wastewater reuse is to provide recommendations that the water contains the appropriate high nutrients and is considered acceptable.
Irrigation in agriculture
- Drip irrigation
- Hydroponics
The hydroponic system or the soilless cultivation system is divided into two: An open system, where the nutrient solution is not recycled, and a closed system, where the excess flow of nutrients from the plants' roots is collected and recycled (Maucieri et al. ., 2019). The closed system is advantageous compared to the open system, as the nutrient is used in the open system rather than being collected or recycled.
Hydroponic technique in agriculture
Water stress faced by the soil based crops is not a problem in case of the soilless farming method as the crops grown in a controlled environment will have a 10-30 times less water requirement. Currently, one of the main challenges is promising food security to the low urban population in developing countries with rapid urbanization and population growth.
Agriculture sector in the UAE
As many groundwater sources are dried up, water resource consultants are determined to increase the reuse of treated wastewater for irrigation. Therefore, a general commitment to the conservation of groundwater resources has been of national importance to the UAE (Environmental Report, 2017).
Introduction to wheat cultivation
Propiconazole spreads at a rate of 2 mL/Ltr of water in high incidence cases (Tao et al., 2014). To manage the disease, carnal bunt resistant varieties are used, or propiconazole (Tilt 25 EC) 2 mL/Ltr water is sprayed (Zhang et al., 2015).
Irrigation based wheat cultivation
On the one hand, the demand for fresh water is increasing in the UAE and on the other hand, there has been a rapid loss of resources. Therefore, agriculture is the best option to reuse the treated wastewater as it has an alternative source of water for irrigation. it is called wheat and the main food grain in the world.
Environmental stress
Due to its high fertility value, untreated wastewater irrigation has been used in Pakistan as a traditional method (Matsuno et al., 2001). High temperature stress does not allow the plant to maintain its water status by increasing leaf temperature, causing dehydration in plant tissues, which affects photosynthesis (Farooq et al., 2009).
Impacts of climate change on plant growth
The four dimensions of food security would be seriously affected by these changes: food supply, food availability, food consumption and food system stability. When it comes to crop productivity, the link between climate change and food security is often raised (Walker et al., 1999).
Climate change impact on food security
Several studies have identified climate change as a potential hazard affecting water and food availability (Pinstrup-Andersen &. The UNDP proposed in 2006 that climate change would lead to water scarcity and food insecurity by 2080 (UNDP, 2006).
Phenology and yield
Phenophase is the plant's time for its normal development, hindered by the rising temperature (Singh et al., 2017). The accumulation and separation of dry matter in dissimilar parts of the crop, as well as crop response to ecological and peripheral factors, is calculated by the length of each phenophase (Sankaranarayanan et al., 2010).
Climate change effects on UAE crop production
According to the FAO, dates are the most cultivated agricultural crop, representing 345 thousand metric tons in 2018. Tomatoes, eggplant, cabbage, squash and cauliflower are the most important crops and supply almost all the country's needs during the season (Azzam & Rettab, 2012).
Plant responses to drought under climate change
Change in the metabolic pathway that allows the plant to survive by being drought resistant. Plants make changes to physiological structure, such as shedding older leaves to overcome drought.
Impacts of increased CO 2 concentration on plant growth and
However, any further increase in CO2 concentration in the future may not have the same most significant effect on plant carbon uptake due to the saturation response of the plants or crops (Long et al., 2006). All the plants do not sufficiently absorb the accumulation of excess sugars in the roots.
Effect of UV-B on plants
Starch is also known to increase in the case of plants growing in e[CO2], which contributes to the high sucrose content by converting starch into invert sugar overnight. But in e[CO2]-grown plants, the increased starch production is not completely exhausted at night.
Since the temperature inside the OTC is often 4-5 degrees higher than the ambient temperature due to the PVC sheet (Heyneke et al., 2012).
CO 2 supply to OTC and air sampling
CO 2 control and monitoring system
PLC and SCADA are the automatic software developed to continuously monitor and control the desired CO2 level within each OTC. Sensors deployed in the OTC help in measuring the prevailing weather and humidity in the OTC (Pal, 2015; Dwivedi et al., 2015).
Modelling climate change
A set of four desiccant glass columns made of coarse silica gel is fitted (Hazarika et al., 2009). Solenoid valve receives the signal by the computer either to close or open for the supply of CO2 to maintain the desired or practical set level of CO2.
Open Top Chamber (OTC) facility for climate studies in the
CO2 treatment for 8 h showed an increase in carotenoid content in LuLu plants. Plants treated with UV-B and UV-B + CO2 showed an increase in proline oxidase activity.
Mitigation and adaptation
Due to the location and the type of climate change the region is facing, there will be different adaptations in the agricultural sectors. Methane emission is associated with the production of improved livestock feed, the restoration of biogas production.
Materials and Methods
Experiment site
Selection of crop
The utilization of wheat grain as the seed of the experiment lays a foundation for sustainability of food sources worldwide, which also justifies the use of treated waste water. The program at CIMMYT uses a unique classification system established in 1988 to target global regions and their environmental requirements.
Treated wastewater
21,600 gallons of treated wastewater from the Abu Dhabi Pumping Station and 24,000 gallons from the Al Ain Pumping Station. After each run, a 1-liter sample of various sources of treated wastewater and well water was collected for chemical and microbiological analysis.
Modes of cultivation
- Field experiment
- Hydroponics system experiment
- Open Top Chambers (OTC) experimental site and
The following equation was then used to calculate the nitrogen content in g/kg of the sample. Plant height was measured in centimeters from soil level to the tip of the shoot.
Physiochemical, Elemental, and Bacteriological Analysis
- pH, electrical conductivity, and elemental analysis
- The level of potassium content
- The level of calcium (Ca) and boron (B) content
- Bacteriological standards
The concentration of bicarbonates in AD(T1), AA(T2) and control samples used for irrigation in the present study are shown in Table 4.2 and are considered less than the limits established by FAO (1992). 117 Table 4.1: pH, Electrical conductivity, total dissolved solids, SAR, total nitrogen and other elemental analyzes of water content in control and.
Agronomical and Morphological Analysis in Control and
Composition of hydroponic solution
Agronomical and morphological analysis
Values that do not share a common superscript letter in the figures differ significantly at P < 0.05 (DMRT). However, this does not apply to the less salty Al Ain H2 water, so the lower salt content has a positive effect on the yield and growth of the wheat crop.
Estimation of chlorophyll and carotene content
V1 crops treated with H2 showed significantly higher levels of carotenoid content and total chlorophyll in the hydroponic system. Depending on the environment; carotenoid must play a vital role in crops that can thrive under stressful conditions.
Analysis of nitrogen (N), phosphorous (P), and potassium (K)
Figures 5.5 to 5.7 show the analysis of nitrogen (N), phosphorus (P) and potassium (K) content in root, head and stem parts of wheat crops treated with irrigated wastewater. However, water treatment H2 (Al Ain city) was sufficient to increase the content of N, P and K in wheat variety V2 of root, head and shoot parts.
Analysis of micronutrients
135 Table 5.1: Composition of trace elements (%) in the root part of wheat grown under irrigated wastewater samples. 137 Table 5.3: Composition of trace elements (%) in the head part of wheat grown under irrigated wastewater samples.
Analysis of micro, secure and trace elements
H2 output is best for growth and productivity of wheat crops in a hydroponic system. Similarly, the accumulation of sodium, zinc and boron in plant tissues indicates a lack of nitrogen and sulfur in the medium.
Heavy metal accumulation in the wheat plant
Therefore, the accumulation of cadmium in the crop treated with HV1, H1V1, H1V2, HV2, H2V2 wastewater was apparent, yet high WHO/FAO (2007) standard limits. Such effluents may increase the hazardous effect of cadmium accumulation in the environment with long-term use.
Effect of irrigated wastewater in yield parameters of wheat
Therefore, the use of wheat treated with these HV1, H1V1, H1V2, HV2 and H2V2 effluents may reduce the potential danger of heavy metal accumulation in animals. Therefore, the accumulation of cadmium in the head of crops treated with HV1, H1V2 and H2V1 effluent was high compared to WHO/FAO (2007) standard limits.
Effect of irrigated wastewater in fiber and crude protein
The HV2-treated crop had the highest percentage of crude protein in the root system at 8.01±0.76%. The results of fiber and protein content in this study are closer to the effects of other related works.
Heavy metal accumulation before and after the treatment
Still, the application of H1 effluent is unsatisfactory, affecting photosystem B and decreasing carotenoid content, reducing leaf number and reducing nutrient uptake. Due to the high salinity, osmotic pressure and EC and H2 treated V1, the variety was sufficient and proved to produce a higher number of heads in the hydroponic system. Based on the observations, the H2V1 variety was also observed to show excellent results in terms of morphological traits in terms of branch and root weight and height of the plant and also yield and growth traits related to the length of the branch, a number of branches, 1000 seeds. weight, grain yield and number of grains per piece.
Agronomical and Morphological Analysis in Control and
- Electrical conductivity (EC)
- Sodium absorption ratio
- Nitrogen phosphorous and potassium
- Secondary plant essential nutrients accumulation
- Heavy metal accumulation
- Analysis of agronomical parameters
- Root length
- Head length
- No. of Head
- Flag leaf length
- Flag leaf area
- Chlorophyll and carotenoid content
- Analysis of harvest parameters
- No. of grains/head
- Grains yield
- Weight of 1000 grains
The highest value was observed in the irrigated control CV2 and the treated test sample T2V1 of the surface layer. The highest value was observed in the subsurface irrigated control CV2 and the treated test sample T2V1 of the surface layer.
Agronomical and Morphological Analysis in Control and
Effect of UV-B and CO 2 on morphology and physiology
Chlorophyll and carotenoid levels in UV-B and CO 2 treated
Protein content
Amino acid content
Phenol content
SOD levels in UV-B and CO 2 treated wheat plant
Peroxides levels in UV-B and CO 2 treated wheat plant
Proline oxidase activity in UV-B and CO 2 treated wheat plant
Glutathione reductase activity in UV-B and CO 2 treated wheat
Catalase activity in UV-B and CO 2 treated wheat plant
Conclusions and Future Directions
