Effect Of Irrigation Water Quality Research Articles

Effect of source of irrigation water on yield performance of Boro rice

Industrial wastewater is a major problem in Gazipur, Bangladesh which is very cheaply available in the surrounding area for crop production. An experiment was conducted at Farmer’s Field of Gazipur district to study the effect of irrigation water quality on yield of boro rice. The study comprised three varieties viz., BR14, BRRI dhan28 and BRRI dhan29 and three sources of irrigation water viz. fresh water irrigation, mixed water (fresh + industrial wastewater) irrigation, industrial wastewater irrigation. The experiment was laid out in a split-plot design with three replications where irrigation water was assigned in the main plot and rice varieties in the subplot. BRRI dhan29 produced the tallest plant (85.25 cm), the highest number of total tillers hill-1 (19.77), effective tillers hill-1 (17.64), grains panicle-1 (111.0), sterile spikelets panicle-1 (44.29), 1000-grain weight (22.43 g), grain yield (4.56 t ha-1) and straw yield (7.99 t ha-1). On the other hand, plant height (74.50 cm), total tillers hill-1 (19.82), effective tillers hill-1 (17.53), grains panicle-1 (131.7), sterile spikelets panicle-1 (35.50), 1000-grain weight (25.83 g), grain yield (5.05 t ha-1) were found highest when applied fresh water irrigation. The highest numbers of grains panicle-1 (119.14), 1000-grain weight (25.10 g), grain (5.54 t ha-1) and straw (7.93 t ha-1) yield were obtained in BRRI dhan29 with fresh water irrigation. Therefore, BRRI dhan29 with fresh water irrigation would be safe to use. However, if fresh water irrigation is not possible, conjunctive use of fresh and wastewater can be used as irrigation for BRRI dhan29.

Systematic review: Effect of Irrigation Water Quality and Deficit Irrigation on Crop Yield and Water Use efficiency

The main purpose of this paper is to review on the effect of irrigation water quality and deficit irrigation on crop yield and water use efficiency. Low quality water for irrigation can impose a major environmental constraint to crop productivity. If salts become excessive, losses in yield will result. To prevent yield loss, salts in the soil must be controlled at a concentration below that which might affect yield. Irrigation application below the full evapotranspiration requirement is termed as deficit irrigation. Deficit irrigation consists of deliberately applying irrigation water in amounts below the plant‘s water requirements. Deficit irrigation can be applied at certain periods during the crop‘s growing season or throughout its growing season. Yield reductions also occur in a number of crops when subjected to water stress. Yield reductions depend on the crop‘s sensitivity to water stress at its various growth stages. In order for deficit irrigation to be an economically viable practice, the revenue lost due to yield reduction should be lower than savings in total cost of production. The goal of deficit irrigation is to increase crop water use efficiency by reducing the amount of water that is applied or by reducing the number of irrigation events. The interaction effects of water quality and DI illustrated that when the two types of stresses; saline and DI were coupled together, a serious reduction occurred on total dry biomass and total yield. The interaction effects of water quality and deficit irrigation illustrated that when the two types of stresses; saline and deficit irrigation were coupled together, a serious reduction occurred on total dry biomass and total yields.

Effect of irrigation water quality on soil properties and infrared spectroscopic signatures

Aim of study: To study the effect of irrigation with medium-to-low-quality water on an olive farm that seems to be causing salinity and/or sodicity problems in soils, and the ability of infrared spectroscopy to detect this problem.Area of study: The study was conducted in an olive (Olea europaea L.) grove located in Guarromán (Jaen, Spain), on the boundary of the Sierra Morena Mountains and the Guadalquivir Depression.Material and methods: The olive farm is cultivated over two soil typologies, a calcareous area (carbonated) dominated by Regosols and a siliceous area with Leptosols. Typical soil physical and chemical parameters were determined, as well as near and mid infrared spectra were collected for analysis.Main results: Soil physical properties were affected by irrigation, with low infiltration rates and symptoms of structural degradation. Chemical properties were also altered, showing high pH, low amounts of organic carbon and N, and high sodium concentrations. These effects were stronger in the samples directly affected by the irrigation bulb, with the siliceous soils more affected than carbonated, probably due to the positive effect of the higher amounts of calcium in the latter. Using infrared spectroscopy, it was possible to discriminate the samples of this farm affected by sodicity from similar soil samples in Jaen province not affected.Research highlights: the use of medium-to-low quality irrigation water affected soil physical and chemical properties. Infrared spectroscopy could be useful for quick assessment of soil quality and soil degradation from salinity and sodicity.

Comparison study of two different varieties of pea (Pisumsativum) crop under different quality of water

Agricultural practices are highly dependent on irrigation while the sustainability of agriculture is directly related to the quality of irrigation water. Industrial wastewater effluents used for agricultural practices due to decrease of water supplies in agroecosystems but unpromising effects on plants physical and chemical properties have been reported. Experiment was carried out to study the effect of textile industry effluent via measuring its different physicochemical properties along with trace heavy metals and also in order to assess its quality to be used being an alternate source of irrigation. The experiment was comprised of three treatments (T1= Canal water, T2= Treated water, T3 = Untreated water). The effects of irrigation water quality on two pea (Pisumsativum) crop varieties (Mateur and Pea09) yield were also significant. T3 produced the highest yield on Pea09 variety followed by T2 and T1 which produced the lowest yield as compared to Mateur variety, respectively. As the evaluated results, it can be used to develop future scenarios for optimization of the industrial treated wastewater for agriculture.

Effect of Irrigation Water Quality and Spraying with Tocopherol on Na, K, K+/Na+ and Cl- and Chemical Components of Okra (Abelmoschus esculentus L. Moench)

The experiment was carried out in a private orchard at Shat-Al- Arab District, Basrah Province during the summer seasons of 2011and 2012 in order to study the effect of irrigation water quality and spraying with Tocopherol on growth and yield of okra plants tolerance to salinity resulted from irrigation by salinity water and its effect on the leaves of chemical parameters. Treatments included three sources of water (i.e. tap water, tap water + river water 1:1 and river water) and spraying plants with Tocopherol at four concentrations 0, 50, 100 and150mg. l-1). Treatments of this experiment were distributed in Split Plot Design with three replicates, which were the main Plots represented water sources, spraying with tocopherol represented sub-plots. Means were compared according to L.S.D. Test at significant level of 0.05. Result could be summarized as follows: Plants irrigated with tap water had a significantly higher parameters (N, K, K+/Na+ ratio), carbohydrate, leaves chlorophyll concentration, abscisic acid contents in leaves for both seasons,.Foliar application with Tocopherol at 150 mg.l-1 caused an increase in N,K, K+/Na+, total soluble carbohydrate and chlorophyll contents in leaves while resulted decrease in proline and abscisic acid contents in leaves.The interactions between the studied factors were significant in all studied parameters for both seasons.

EFFECT OF WATER IRRIGATION QUALITY ON POTASSIUM DESORPTION IN SOME CALCAREOUS SOILS IN NINEVH PROVINCE

A laboratory study was conducted to determine the effect of irrigation water quality on potassium desorption in some calcareous soils. It was constructed by miscible displacement technique using chlorine and sulfuric water via two different textured soils from Fadhlia and Hamdania locations in Nineveh province / northern Iraq for 240 minute with 10 minutes interval at a rate flow 1 ml.minute-1. Results showed higher values of desorbed potassium rate in sulfuric water which were 3.57, 2.128 c.mole.kg-1, while these rates referred to be much lower than that resulted by using chlorine water 2.25, 1.15 c.mole.kg-1 for both locations respectively. Also high correlation appeared between K+ desorption capacity and flow time (R2 = 0.96 , R2 = 0.79) for both water qualities in Fadhlia location , while these rates were (R2 = 0.98, R2 = 0.95) for Hamdania location respectively. Mathematical description for diffusion equation appeared to be of higher values of K+ desorption capacity rates for sulfuric water which were 0.26, 0.13 c.mole.kg-1.min.-½ for Fadhlia and Hamdania locations respectively, while these rates for chlorine water were 0.146, 0.048 c.mole.kg-1.min.-½ for both locations respectively.

Irrigation water quality and mulching effects on tuber yield and soil properties in potato (Solanum tuberosum L.) under semi-arid conditions of Indian Punjab

A field experiment was conducted for 5 years from 2009 to 2015 at Punjab Agricultural University Regional Research Station, Bathinda, Punjab, India to observe the effect of irrigation water quality on tuber yield, soil characteristics and water productivity of potato under mulched conditions in light textured soil under semi arid climate of Indian Punjab. The experiment was conducted in split plot design with three mulch treatments viz. no mulch (M0), rice straw mulch @ 6 t ha−1 (Ms) and polyethylene mulch, black 50 μm (Mp) in main plots and three irrigation water qualities viz. canal water alone (CW), poor quality saline-sodic ground water alone (GW) and cyclic use of CW and GW (CW-GW) in sub plots. The experimental soil was alkaline in reaction, low in organic carbon, medium in available phosphorus and high in available potassium. The electrical conductivity (EC) and residual sodium carbonate (RSC) of canal water and ground water was 0.45 dS m−1, -0.6 mmolc L−1; and 2.2 dS m−1, 6.44 mmolc L−1, respectively. The results revealed that under unmulched conditions (M0), CW and CW- GW gave significantly higher tuber yield than GW. Mulching, in general, resulted in significantly higher marketable tuber yield than in non mulched conditions. The tuber yield was statistically at par with Ms and Mp, irrespective of the irrigation water quality. Similar trends were observed in case of yield attributing parameters viz. plant height, number of haulms per plant and number of marketable tubers per plant. The water use efficiency was higher under Ms and Mp than under M0. The highest water use efficiency was recorded in Ms under CW irrigation. Among the quality parameters, dry matter and total sugars increased with application of saline-sodic GW as compared to CW-GW and CW irrigation due to higher abiotic stress due to salts.

How Water Quality and Quantity Affect Pepper Yield and Postharvest Quality

There are gaps in our knowledge of the effects of irrigation water quality and amount on yield and postharvest quality of pepper fruit (Capsicum annuum L.). We studied the effects of water quality and quantity treatments on pepper fruits during subsequent simulated storage and shelf-life. Total yield decreased with increasing water salinity, but export-quality yield was not significantly different in fruits irrigated with water of either 1.6 or 2.8 dS/m, but there was a 30–35% reduction in export-quality yield following use of water at 4.5 dS/m. Water quantity hardly affected either total or export-quality yield. Water quality but not quantity significantly affected fruit weight loss after 14 days at 7 °C plus three days at 20 °C; irrigation with water at 2.8 dS/m gave the least weight loss. Fruits were significantly firmer after irrigation with good-quality water than with salty water. The saltier the water, the higher was the sugar content. Vitamin C content was not affected by water quality or quantity, but water quality significantly affected antioxidant (AOX) content. The highest AOX activity was found with commercial quality water, the lowest with salty water. Pepper yield benefited by irrigation with fresh water (1.6 dS/m) and was not affected by water quantity, but post-storage fruit quality was maintained better after use of moderately-saline water (2.8 dS/m). Thus, irrigation water with salinity not exceeding 2.8 dS/m will not impair postharvest quality, although the yield will be reduced at this salinity level.

Impact of drought and salinity on olive water status and physiological performance in an arid climate

Effects of drought and salinity on water status, growth and physiological activity of olive can be temporary or permanent and may impact olive production sustainability, especially in southern Mediterranean areas. Tunisia has a Mediterranean climate with high temperatures and low summer rainfall. Thus water stress problems are likely to be more severe for cultivated olive trees. In addition, the reduction in the availability of good quality irrigation water will increase the use of saline water. Olive trees are able to tolerate low soil water availability and quality and develop physiological adaptations to cope with water and salt stress. However, these adaptation strategies are limited and permanent damages can be observed. The permanent effects caused to olive leaves due to drought, and the capacity of irrigation with saline water to avoid these impacts is not well known. The aim of this work was to compare olive leaves performance after a severe drought with, and without, irrigation and to assess recovering capacities after a rainy period. Moreover, irrigation water quality effects were also evaluated. The results showed that, photosynthetic rate was very low for rainfed plants, during drought, as compared to irrigated ones. After re-watering, rainfed trees photosynthetic rate was only 55% of that of trees irrigated with fresh water. Irrigation with saline water (EC = 7.5 dS m−1) reduced drought impact by increasing photosynthesis by 55% but remained lower than that of fresh water by 23%. Thus olive leaves were unable to recover their whole photosynthetic capacity after being exposed to severe water or salt stress. Furthermore, young leaves had the same photosynthetic capacity at the beginning. This indicated that olive leaves lost permanently half of their photosynthetic activity during to drought without irrigation. The use of saline water reduced this gap to 23% as compared to fresh water.

Root microbiome response to treated wastewater irrigation

With increasing fresh water (FW) scarcity, the use of treated wastewater (TWW) for crop irrigation is expanding globally. Besides clear benefits, some undesired long-term effects of irrigation with this low quality water on plant performance have been reported. As the rhizosphere microbiome can mediate plant-soil interactions, an examination of the response of these organisms to TWW is necessary to understand the full effects of water quality. In the current study, the effects of irrigation water quality on the microbial community structure of soil and roots as well as edaphic properties and plant performance were evaluated. We compared soil and roots microbiomes of two different plant species (tomato and lettuce), each grown in two distinct soils, and irrigated with either FW or TWW. Irrigation with TWW significantly increase soil pH, EC, K, Na and DOC, and decrease plant fruit and shoot weight, relatively to samples irrigated with FW. We calculated the effect size of plant species, soil type, and irrigation water quality on microbial community structure in soil and root. In the roots, plant species and irrigation water were the dominant factors in shaping both total (DNA based) and active (RNA based) microbial communities, with both factors contributing similarly to the observed microbial population. Soil type and irrigation water were the dominant factors shaping the total microbial community in the soil and were of similar magnitude. Irrigation water quality is demonstrated to be a major force in shaping root-associated microbiome, leading to altered microbial community structure in the critical juncture between plant and soil.

Effect of Irrigation Water Quality on the Microbial Contamination of Fresh Vegetables in the Bekaa Valley, Lebanon

Irrigation water is probably the leading source of contamination of fresh vegetables in the world. In agricultural intensive areas, surface and groundwater resources are more likely to be exposed to be contaminated with zoonotic bacteria, given their close proximity to sources of faeces from livestock, dairy farms and wildlife. The aim of this study was to determine the role of irrigation water as a vehicle for the transmission of zoonotic bacteria of faecal origin and its contribution to the bacterial contamination of fresh vegetables to conclude with a need of risk management in rural areas. First, to determine the magnitude and the frequency of faecal contamination and the pathogens in the water source, the microbiological quality of the water resources used in irrigation in the studied area, including the upper Litani and the private wells located near its basin was investigated. In a second step, an assessment of the microbiological quality of the fresh vegetables irrigated from these water resources was done. A total of twelve different vegetables comprising spinach, parsley, cabbage and lettuce and 38 water samples were collected from both the well waters and the Litani River from the 5 studied sites and analyzed for a period of 5 months, to assess the microbial contamination level. Samples were analyzed for aerobic bacteria, total coliforms, faecal coliforms, E.coli and S.aureus . All vegetables sampled during the study period recorded high level of coliforms, E.coli and S.aureus. The microbial load recorded in the water samples was generally higher than that recorded in the vegetables. Since most of these vegetables are eaten fresh or slightly cooked, there is a concern on the public health that will be affected. Education of farmers and consumers on food safety has to be intensified to avert a possible outbreak.

Effect of Irrigation Water Quality on Soil Structure Along Asa River Bank, Ilorin Kwara State

Effect of Irrigation Water Quality on Soil Structure Along Asa River Bank, Ilorin Kwara State

Effect of irrigation water quality on some physiological processes and the concentrationof heavy elements in five types of cultivated plants in Nineveh province

This study was carryout at the department of Biology ,College of Education ,Mosul University .Five Plants species Eggplant (Solanum melongena ) ,Green bean (Viana radiate ) ,Green pepper (Capsicum grossum),Squash (Cucurbita moschata ), Okra (Abeiomoschus esculentus ). was taken from six different farms sites in around the left riverbank of Nineveh province .These sites are Al-Jmasa,Vally of Al-hamedea ,Uarmga , Al-mazara, Al-entesar,and Al-whda The Plants in these sites are irrigated by different sources of water like artisan wells, domestic influent and combined domestic influent and industrial wastes water. The results of current revealed that there was a significant decrease in the relative water content and the degree of stability of cytoplasmic membrane and significant increase in proline in the plants leaf tissues. As well an increase in the concentrations of heavy metals (cu, zn) in the different parts of plants at the farms of Uarmga , Al-mazara, Al-entesar,and Al-whda, Which were irrigated by the domestic, or domestic and industrial wastes water. where significant increase in the relative water content and the degree of stability of cytoplasmic membrane and significant decrease in proline in the plants leaf tissues and in the concentrations of (cu, zn) in the 2 parts in plants of the Al-Jmasa and Vally Al-hamedea farms that were irrigated by the wall water in comparison with other areas irrigated by other water sources.

THE ACTIVITY OF ANTIOXIDANTS ENZYMES AND NPK CONTENTS AS AFFECTED BY WATER QAULITY, KINETIN, BIO AND ORGANIC FERTILIZATION IN LETTUCE (Lactuca sativa L.)

A field experiment was conducted using split – split block design to study the effect of irrigation water quality ,organic composts ,kinetin and Bio- health application on N.P.K contents and anti-oxidant enzymes activity in lettuce, The experiment included three factors ,quality of irrigation water (W) at two levels (1.2, 6.1 dS m-1 ), kind of organic composts Plam fronds and Rice wastes(20) ton /hectare , kinetin application (50 mg.L-1) and bio-health fertilizers (5 kg/ hectare). The results indicated that elevation of water salinity levels led to elevation in activity of Peroxidase POX , Catalase CAT, Malondialdehyde MDA, Superoxide dismutase SOD enzymes and proline contents in leaves, while it decrease leaves contents of ( N.P.K), Organic composts , kinetin and bio-health applications alleviated from the negative effects of saline water by increasing the (NPK) contents in leaves ,reduced POX ,CAT, MDA,SOD and proline , That possible to mitigation the negative affect of salt stress in lettuce the application of plant growth regulators , bio fertilizers and decomposed organic matter.

Effect of soil and water characteristics on yield and properties of ‘Spunta’ potatoes

Soil texture and its characteristics besides water characteristics can play an eminent role in potato (Solanum tuberosum L.) production. Therefore, a soil and water quality index (SWQI, %) was derived to investigate the effect of combination of soil and water characteristics (sodium adsorption ratio for water and soil, electric conductivity of water and soil, pH for water and soil, organic matter in the soil, and soil texture index) on yield and properties of ‘Spunta’ potatoes produced under center pivot irrigation system. This index was formed studying separately the effect of irrigation water quality and soil texture on yield, water use efficiency, tuber modulus of elasticity, and tuber shape index of ‘Spunta’ potatoes. Field results demonstrated that the lowest potato yield was approximately 34.12 t ha-1 at SWQI 79.63%, and the highest potato yield was 37.79 t ha-1 at SWQI of 30.93%. The lowest water use efficiency was approximately 6.09 kg m-3 at SWQI 30.93%, and the highest water use efficiency was 6.83 kg m-3 at SWQI 79.63%. The lowest tuber modulus of elasticity was approximately 3.98 N mm-1 at SWQI 21.7%, and the highest tuber modulus of elasticity was 4.74 N mm-1 at SWQI 79.63%. Finally, the tuber shape index was approximately 342% at SWQI 79.63%, 418% at SWQI 21.72%, and 403% at SWQI 30.93%, which belongs to long and very long shapes. The soil and water quality index could be a useful tool to get relationships among water and soil characteristics, yield, and other properties of the potato crop.

EFFECT OF USING IRRIGATION WATER IN DEFFIRENT QUALITIES AND BIO-FERTILIZER IN SOME CHEMICAL PROPERTIES OF CALCAREOUS SOIL

A pots experiment was conducted at the canopy wood of Agriculture - University of Baghdad (Abu-Ghraib) during summer season of 2014 to study the effect of irrigation water quality and biofertilizer and their interactions on some soil chemical properties and growth of corn. Treatments included three water qualities river water (1.5 ds.m-1 ''Q1''), well water (4.4 ds.m-1 ''Q3'') and mixed water (3.0 ds.m-1 ''Q2'') and two levels of biofertilizer (without inoculation ''B0'' and inoculation with Azotobacter chroococcum, Bacillus megaterium and Pseudomonas fluorescens ''B1'') applied to clay loam soil, using complete randomization design (CRD) in three replicates. The results of study Soil EC values increased with increasing water salinity giving 5.18, 6.03 and 6.70 ds.m-1 for Q1, Q2 and Q3, respectively. And significantly increased exchange capacity of the cation ions CEC reached 22.20, 23.01 and 24.31 c mole c kg-1 soil for Q1, Q2 and Q3, respectively. Irrigation water salinity also led to a significant increase in soil organic matter content reached 11.06, 12.55 and 13.90 gm.kg-1 soil for Q1, Q2 and Q3, respectively. Biofertilization led to decrease in rates a significant values electrical conductivity (EC) increase exchange capacity of the cation ions CEC and organic matter soil.

Effects of Dairy Farm’s Wastewater Irrigation on Wheat Production and Soil Health

An experiment was conducted at the experimental field of the Bangladesh Agricultural University (BAU) to investigate the effects of dairy farm’s wastewater irrigation on wheat (Triticum aestivum cv. BARI "Shatabdi") production and soil health during 30 November 2013 through 22 March 2014. Three irrigation and three fertilizer treatments were involved in the experiment. The experiment was laid down in a split-plot design with three replications of the treatments. Various growth and yield data of the crop were recorded. For the effect of irrigation water quality, the highest and the lowest grain yield (2.88 t ha-1 and 2.71 t ha-1) were obtained under I3 and I2, respectively. For the effect of fertilizer, the highest and the lowest grain yield (4.42 t ha-1and 1.59 t ha-1) were obtained under F2 and F0, respectively. The interaction effect between irrigation and fertilizer exerted a significant impact on the grain yield of wheat. Irrigation by wastewater did not significantly alter the quality parameters of the irrigated soils. The raw wastewater supplied more nutrients to the soil of the wheat field. Therefore, it may be used as a source of irrigation and fertilizer for wheat production without any hazard of the soil health.J. Environ. Sci. & Natural Resources, 8(2): 157-162 2015

Effect of Irrigation Water Quality and Fertilizer Applications on Pre- and Post-Storage Bacterial Infection of Lettuce

Effect of Irrigation Water Quality and Fertilizer Applications on Pre- and Post-Storage Bacterial Infection of Lettuce

Effects of Reclaimed Water on the Growth and Fruit Quality of Cucumber

AbstractThe purpose of this study was to evaluate the feasibility of using reclaimed water for cucumber irrigation. The experiment was conducted using raw canal water, and water reclaimed from treated wastewater using a natural recycling treatment system. The raw water quality met the Irrigation Water Quality Standards of Taiwan. The water quality of reclaimed water was treated within the ranges of DO: 3.9–8.4 (mg l−1); pH: 6.5–7.8; EC: 206–587 (µs cm−1, 25 °C); SS: 0.1–11.8 (mg l−1); NH4‐N: 0–18.16 (mg l−1) and BOD: 0.1–1.8 (mg l−1). The experimental period for cucumber growth was 75 days. Rg was defined as the different multiple of plant growth and used to estimate the effects of irrigation water quality. Furthermore, yield, weight, length, and diameter of cucumbers were used to quantify the influence of irrigation water quality on cucumber quality. Result shows that Rg was within the range (1.003–1.311). The heights of cucumbers grown using reclaimed water were longer than those grown using raw water. Comparing the yield, weight, length, and diameter of cucumbers irrigated by reclaimed water (RW) and by raw water (IW), the percentages of RW/IW were respectively 154, 96, 95.5 and 101%. Based on the results, this study concludes that using reclaimed water for cucumber irrigation is feasible. Copyright © 2015 John Wiley & Sons, Ltd.

Effects of irrigation water quality on vegetables Part 2: Chemical and nutritional content

The internal qualities of edible vegetable crops have not been widely researched in South Africa. The aim of this study was to determine possible accumulation of nutrients and heavy metals within these crops after being irrigated with greywater (generated from bathing and dishwashing activities), potable water (from a tap stand) and diluted greywater (1:1 ratio). Trials were conducted at the Umtata Dam Research Station, in a completely randomised design testing combinations of cabbage and onion, Swiss chard (here referred to as spinach) and beetroot, and carrot and lettuce across four sequential planting seasons. Greywater for gravity-fed drip irrigation was collected at a central point from a nearby small informal settlement. Chemical and nutritional content analysis on edible portions of vegetables was carried out. Crude protein (CP) was significantly elevated by 20% (4.5 mg kg−1) and 25% (57 mg kg−1) on cabbage (during the first season) and lettuce, respectively, when irrigated with diluted greywater compared with the control, whereas the CP of onion (during first season) and carrot was significantly higher by 40% (2.4 mg kg−1) and 31% (36.4 mg kg−1), respectively, due to greywater irrigation compared with potable water. Significant increases in nutritional elements, such as iron (Fe) and zinc (Zn), were observed on cabbage (in both seasons), onion (first season) and spinach when irrigated with diluted greywater, whereas in lettuce the Fe content was significantly elevated by greywater irrigation. There were no significant differences in cadmium (Cd) in spinach and lettuce due to greywater irrigation. The study concluded that the insignificant content of heavy metals observed posed no obvious human health risk from consumption of vegetables irrigated with greywater.