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PubMed1989

Effect of landfill leachate irrigation on red maple (Acer rubrum L.) and sugar maple (Acer saccharum Marsh.) seedling growth and on foliar nutrient concentrations.

Greenhouse experiments were conducted to investigate the nature and severity of stresses imposed on northern hardwood tree species (red maple (Acer rubrum L.) and sugar maple (Acer saccharum Marsh.)) by the application of municipal landfill leachate. Red maple seedlings received applications of untreated and pretreated (lime, activated carbon) leachate, to both leaves and soil, at irrigation rates consistent with evapotranspirational demands. Plant height measurements indicated no significant growth effects arising from leachate application over a 7-week period. Stem diameter, however, was positively affected by applications of both untreated and lime-treated leachate diluted to 75% with deionized water. Iron foliar concentrations were significantly higher in seedlings irrigated with untreated leachate applied to leaves and soil, but not in seedlings where leachate was applied to soil only. Nitrogen foliar concentrations were substantially higher in seedlings receiving undiluted and untreated leachate applied to the soil only. The Cu concentration of the red maple foliage decreased appreciably in plants receiving moderate applications of leachate. Foliar Ca concentrations decreased notably in seedlings irrigated with untreated leachate applied to the soil and with diluted, carbon-treated leachate. The Cu concentration of the red maple foliage decreased appreciably in plants receiving applications of undiluted and 50% water-diluted lime-treated leachate while Mn levels were consistently high across all treatments. Leachate application did not cause any discernable changes in foliar concentrations of P, K, Mg, B or Zn. In an ancillary experiment, sugar maple seedlings were subjected to saturation/ drainage treatment cycles with undiluted and untreated leachate. Severe visible symptoms of vegetative stress were apparent within 24 h and 100% seedling mortality occurred after five such waterlogging cycles. Fe assimilation was apparent in both leachate treatments relative to the 24 h water treatment. Despite the short-term nature of the experiments, the results indicate how quickly forest vegetation may respond to altered chemical environments. This underscores the need for correct installation and control of leachate irrigation systems.

Journal Article↗
PubMed2005

A multivariate analysis of the accumulation and fractionation of major and trace elements in agricultural soils in Hidalgo State, Mexico irrigated with raw wastewater.

We evaluated the accumulation and distribution of major and trace elements in agricultural soils of District 03 (DR03) in the State of Hidalgo, Mexico, irrigated with raw wastewaters for an average of 20 years. Samples of topsoils (0-30 cm depth) were extracted using a modified Tessier method. Total concentrations of the species tested were in the ranges of 675-1176 mg K kg(-1), 277.9-1001 mg Na kg(-1), 6,708-81,854 mg Ca kg(-1), 23,800-106,974 mg Mg kg(-1), 9.2-123.8 mg B kg(-1), 0.6-1.9 mg Cd kg(-1), 11.6-27.4 mg Cr kg(-1), 3.9-47.0 mg Pb kg(-1). Concentrations of As and Hg were very low. Concentrations of total Cd, Cr and Pb were generally below the maximum permissible levels set by the regulations of the European Union except for cadmium, which was in the middle of the maximum European range allowed for two soils. Regarding lead, one soil (S5) could reach the maximum permissible level of the EU in 6 more years of continued irrigation. On the other hand, contents of Pb in the most mobile fractions ("e" in this work) were significant (range: 3-28%). This distribution translated into concentrations of soluble plus exchangeable lead of approximately 2 mg Pb kg(-1) in three of six soils, significantly higher than the Swiss tolerance limit of 1.0 mg Pb kg(-1) for mobile fractions of lead in soils. Multivariate analysis of the data (Pearson correlation and principal component analysis) quantitatively confirmed that: (i) there is a strong covariance between boron contents and several variables representing the salinity of soils (electrolytic conductivity, a variety of alkaline and alkaline-earth total and fraction concentrations). It appears that there is a problem with high boron content in soils, although the salinity is high only for one of the soils (S3); (ii) a significant correlation among irrigation time, lead content (total, fraction easily exchangeable and bound to organic matter and sulfides) and organic carbon in soils was found; (iii) another association among irrigation time, total contents of cadmium, chromium and boron, and organic carbon was observed.

Agriculture↗
PubMed2006

Phytotoxicity data safeguard the performance of the recipient plants in leachate irrigation.

Leachates from an operating and a closed landfill were examined for their phytotoxicity by seed germination/root elongation tests using seeds of Brassica chinensis and Lolium perenne. Their EC50s ranged from 3% to 46% v/v, which varied remarkably with the operating status of the landfills. Seedlings of twelve tree species were grown in pots, which were irrigated with landfill leachate at the EC50 levels, with tap water as control. No tree mortality or growth inhibition was observed after 90 days of leachate application. Chlorophyll fluorescence measurement also showed that plants receiving leachate did not suffer from a decline in photosynthetic efficiency. Litsea glutinosa and Hibiscus tiliaceus had remarkable growth, and other non-N-fixers were not inferior to the N-fixing Acacia auriculiformis. Leachate irrigation improved soil N content, though P deficiency is still a problem. The seed bioassay provided a conservative estimate of the phytotoxicity of landfill leachate. Plants irrigated can be protected from growth inhibition when the leachate irrigation plan is designed with reference to phytotoxicity data.

Acacia↗
PubMed2006

Effects of soil compaction and irrigation on the concentrations of selenium and arsenic in wheat grains.

Arsenic is a known human carcinogen, whereas Se is essential to human health and human Se intake in some European countries has decreased in recent decades. There have been few reports on the potential effect of soil physical conditions on the uptake of Se and As by food crops. Field experiments were conducted to evaluate the effects of soil compaction and irrigation on Se and As concentrations in wheat grains in two seasons. Grain Se concentration varied from 10 to 115 microg kg(-1), whereas the concentration of As in grain was low (<20 microg kg(-1)). Irrigation significantly decreased grain Se concentration by 30-75%, and the effect was likely due to a dilution as a result of increased grain yield, a competition of sulfate added in the irrigation water on Se uptake and increased leaching losses. Soil compaction significantly decreased grain Se concentration in one season. In contrast, soil compaction increased grain As concentration significantly when the crop was irrigated. The contrasting effects of soil compaction on As and Se uptake are explained by the difference in their mobility in soil and the pathway of ion transport to roots. The observed effect on grain Se is significant for human and animal nutrition, because the concentration varied from sufficient to very low levels in response to the alternation of soil physical conditions in the field. Soil physical conditions have to be taken into account when assessing the bioavailability of the contaminant As or the essential nutrient Se.

Agriculture↗
PubMed2005

Malarial vectors in an irrigated rice cultivation area in southern Sri Lanka.

Entomological surveys were carried out from March 1998 to December 1999 to study the prevalence, distribution and abundance of malarial vectors in relation to selected environmental factors and potential mosquito breeding sites in irrigation channels in 15 villages in the Lunugamvehera Irrigation and Settlement Project, a malaria-endemic area of southern Sri Lanka. Mosquito collections were made at monthly intervals using four sampling methods. Thirteen anopheline species were collected. Following monsoonal rains, anopheline breeding took place primarily in rainwater accumulations. During the inter-monsoonal period, pools formed in the irrigation system, semi-permanent pools formed as a result of rainfall and permanent ground pools were the major breeding sites of anophelines. Very little anopheline breeding took place within the irrigation channels. Amongst the seven anopheline species collected from human dwellings, Anopheles subpictus was the most prevalent, followed by A. culicifacies; together these two species comprised more than 99% of the indoor resting population. The number of days of rain was an important macro-epidemiological factor influencing the density of malarial vectors. There was no consistent trend between the amount of water released or the number of days of water release from the reservoir and the outdoor or indoor resting densities of anophelines.

Agriculture↗
PubMed2005

Formation of nitrosodimethylamine (NDMA) during chlorine disinfection of wastewater effluents prior to use in irrigation systems.

The probable human carcinogen nitrosodimethylamine (NDMA) is produced when wastewater effluent is disinfected with chlorine. In systems where wastewater effluent is used for landscape or crop irrigation, relatively high chlorine doses (i.e., up to 2,000,mg-min/L) are often used to ensure adequate disinfection and to minimize biofouling in the irrigation system. To assess the formation of NDMA in such systems, samples were collected from several locations in full-scale wastewater treatment systems and their associated irrigation systems. Up to 460 ng/L of NDMA was produced in full-scale systems in which chloramines were formed when wastewater effluent was disinfected with chlorine in the presence of ammonia. Less than 20 ng/L of NDMA was produced in systems that used free chlorine (i.e., HOCl/OCl(-)) for disinfection in the absence of ammonia. The production of NDMA in ammonia-containing systems was correlated with the concentration of NDMA precursors in the wastewater effluent and the overall dose of chlorine applied. Much of the NDMA formation occurred in chlorine contact basins or in storage basins where water that contained chloramines was held after disinfection. When landscape or crop irrigation is practiced with ammonia-containing wastewater effluent, NDMA production can be controlled by use of lower chlorine doses or by application of alternative disinfectants.

Agriculture↗
PubMed2003

The phenology of malaria mosquitoes in irrigated rice fields in Mali.

A field study was carried out in the large-scale rice irrigation scheme of the Office du Niger in Mali to investigate the relation between anopheline mosquito larval development and small-scale differences in irrigation practices, such as water level, irrigation application and irrigation frequency. The objective of the study was to find out if water management can be used as a tool for vector control to reduce the malaria transmission risk. Larvae of Anopheles gambiae s.s.,; the main malaria vector in the study area, developed mostly in the first 6 weeks after transplanting the rice. During rice development, a succession of anopheline species was observed. This was associated with a marked decrease in light intensity reaching the water surface as plant height increased. Minor differences in water management resulted in noticeable variations in larval densities and species composition. A. gambiae s.s. larvae were most abundant during the early growing stages and almost absent in a closed rice crop. Due to improper drainage after harvest, A. gambiae s.s. breeding was soon re-established in fields where small pools of water were retained. The results suggest that larval mosquito habitats in the Office du Niger can be significantly reduced by water management, simultaneous planting and harvesting and proper drainage of fallow fields.

Agriculture↗
PubMed1996

A prospective outcome study of patients with clot in an ulcer and the effect of irrigation.

BACKGROUND: The proper management of patients with clots in an ulcer base has not been clearly defined by prospective studies. Variable prevalence and rebleeding rates may be explained by differing degrees of vigor used to clear the clot, as removal may reveal other stigmata. We prospectively assessed the natural histories of patients with clots after vigorous irrigation, employing a management strategy of endoscopic therapy for patients with high-risk stigmata and observation of those with clots resistant to washing or low-risk findings. METHODS: Forty-six patients with upper gastrointestinal bleeding found to have a clot in an ulcer had irrigation with a 3.2 mm bipolar probe for up to 5 minutes. Stigmata after washing were recorded; endoscopic therapy was given for active bleeding that persisted > or = 5 min or for nonbleeding visible vessels. Patients were observed in the hospital for > or = 3 days. RESULTS: Findings revealed after irrigation were adherent clot, 26 (57%); clean base, 1 (2%); flat spot, 5 (11%); nonbleeding visible vessel, 7 (13%); oozing, 6 (13%); and spurting, 1 (2%). Two of the 26 (8%) with adherent clots after washing rebled; endoscopic therapy resulted in no further bleeding. One of the 14 (7%) with active bleeding or visible vessels treated with hemostatic therapy rebled; repeat endoscopic therapy resulted in no further bleeding. No deaths occurred. CONCLUSIONS: Irrigation appears to be useful in patients with upper gastrointestinal bleeding who have ulcers with clots. The endoscopic findings present after washing can be used to dictate the appropriate management at initial endoscopy. Application of hemostatic therapy in patients with active bleeding or nonbleeding visible vessels and observation of patients with other stigmata, including clots resistant to washing, resulted in an excellent outcome.

Blood Coagulation↗
PubMed2002

The effect of irrigation on tile sediment transport in a headwater stream.

A field-scale no-till corn plot (120 m x 90 m) located on a tile drained silt loam soil near Kintore, Ontario was irrigated with 2.5 cm of water over a 3 h period to examine the effects of irrigation on tile sediment transport in a headwater stream. Flow characteristics and the composition, concentration and size distribution of suspended solids were measured at the tile outlet, an upstream reference site and three sites located downstream of the tile drain. Results show that tile sediments at the study site are fine-grained (D50 approximately 5.0 microm) and consist primarily of quartz, anorthite/albite, dolomite and calcite. Sediment concentrations in tile effluent increased from 8 to 57 mg L(-1) after 1.5 h of irrigation and reached a maximum of 72 mg L(-1). The sediment yield from the tile drain for the irrigation event was 4.6 kg ha(-1). An unsteady, mobile boundary flow model (MOBED) was used to predict flow characteristics in the stream. According to the MOBED model, bed shear stress in the stream was approximately 6 N m(-2). This value is significantly greater than the critical shear stress for complete suspension of 1 N m(-2) for tile sediments as determined from laboratory experiments using a rotating circular flume. Grain size distributions of suspended solids in the stream were close to the dispersed size distribution because of the high shear stress in the receiving stream.

Agriculture↗
PubMed1994

Iodination of irrigation water as a method of supplying iodine to a severely iodine-deficient population in Xinjiang, China.

Severe iodine deficiency still occurs in many countries, and causes cretinism and mental impairment. In southern Xinjiang province, China, after usual methods of iodine supplementation had failed, we iodinated irrigation water to increase iodine in soil, crops, animals, and human beings. 5% potassium iodate solution, dripped into an irrigation canal for 12 or 24 days, increased soil iodine 3-fold, and crop and animal iodine 2-fold. Median urinary iodine excretion in children increased from 18 to 49 micrograms/L (two groups of similar age). The cost for iodine was US $0.05 per person per year. Soil iodine remained stable over one winter, and dripping of iodine during the second year (US $0.12 per person per year) resulted in a further 4-fold increase in soil iodine and a 1.8-fold increase in iodine in crops. We conclude that iodination of irrigation water is an advantageous and cost-effective method of supplying iodine in southern Xinjiang, and may be useful in other areas dependent on irrigation.

Agriculture↗
PubMed2000

Investigation of a ponding irrigation system to recycle agricultural wastewater.

This article presents the results of natural carrying capacity of ponding irrigation system in Taoyuan agricultural zone, Taiwan. Both the systematic water quality and the ponding effects were examined. The ponding irrigation system included a flow channel and storage ponds. The data showed that most water characteristics deteriorated gradually from upper- to down-stream in the flow channel and the flow channel was not attributed to any self-purification in agricultural returning water practically. On the other hand, the results of storage ponds indicated that they can provide a natural treatment (i.e., the outlet water quality of the ponds is more desirable than that of the inlet). Consequently, the ponding irrigation system offers the natural self-purification in ponds to reuse and recycle the returning agricultural wastewater and to extend the irrigation capacity and efficiency.

Agriculture↗
PubMed2002

Post-irrigation impact of domestic sewage effluent on composition of soils, crops and ground water--a case study.

Long-term irrigation with sewage water adds large amounts of carbon, major and micro- nutrients to the soil. We compared the spatial distribution of N, P, K and other micronutrients and toxic elements in the top 0.6 m of an alluvial soil along with their associated effects on the composition of crops and ground waters after about three decades of irrigation with domestic sewage effluent as a function of distance from the disposal point. Use of sewage for irrigation in various proportions improved the organic matter to 1.24-1.78% and fertility status of soils especially down to a distance of 1 km along the disposal channel. Build up in total N was up to 2908 kg ha(-1), available P (58 kg ha(-1)), total P (2115 kg ha(-1)), available K (305 kg ha(-1)) and total K (4712 kg ha(-1)) in surface 0.15 m soil. Vertical distribution of these parameters also varied, with most accumulations occurring in surface 0.3 m. Traces of NO3-N (up to 2.8 mg l(-1)), Pb (up to 0.35 mg l(-1)) and Mn (up to 0.23 mg l(-1)) could also be observed in well waters near the disposal point thus indicating initiation of ground water contamination. However, the contents of heavy metals in crops sampled from the area were below the permissible critical levels. Though the study confirms that the domestic sewage can effectively increase water resource for irrigation but there is a need for continuous monitoring of the concentrations of potentially toxic elements in soil, plants and ground water.

Agriculture↗
PubMed1999

The effect of waste water reuse in irrigation on the contamination level of food crops by Giardia cysts and Ascaris eggs.

In Marrakech, raw sewage has been used for farming purposes for several decades for many types of crops. This study aimed to determine the contamination level of Giardia cysts and Ascaris eggs for crops designated for human consumption. Collected crops in irrigated fields were turnip, marrow, squash, potatoes, pepper and eggplant. Field trials were also carried out on four crops, coriander, carrots, mint and radish, using three water types for irrigation, i.e. raw waste water, treated waste water (sedimentation and 16 days retention) and fresh water. Giardia cysts were detected at a level of 5.1 cysts/kg in potatoes, while Ascaris eggs were observed in numbers varying between 0.18 eggs/kg in potatoes and 0.27 eggs/kg in turnip. Field trials confirmed that irrigation of crops by raw waste water leads to contamination. Giardia and Ascaris were isolated in coriander at concentrations of 254 cysts/kg and 2.7 eggs/kg, respectively; mint was also highly contaminated with numbers reaching 96 cysts/kg and 4.63 eggs/kg. Carrots and radish were contaminated and respective numbers observed for Giardia were 155 and 59.1 cysts/kg; Ascaris was discovered in numbers of 0.7 and 1.64 eggs/kg, respectively. However, cultures irrigated with treated waste water and fresh water were free from contamination. Cysts and eggs on coriander persisted for a maximum of 8 days.

Agriculture↗
PubMed2001

Seasonality in the transmission of schistosomiasis and in populations of its snail intermediate hosts in and around a sugar irrigation scheme at Richard Toll, Senegal.

Irrigation for intensive sugar cultivation started in the early 1980s at Richard Toll, some 100 km from the mouth of the Senegal River. Infections with Schistosoma mansoni were first seen in late 1988. This study records quantitative snail surveys for over 3 years from 1992 at sites representing different habitats in and around the irrigation scheme. Populations of both Biomphalaria pfeifferi (the intermediate host of S. mansoni) and Bulinus spp. (mainly B. truncatus, the local host of S. boris) peaked in late 'spring' or early 'summer', depending on the habitat, and then remained low until the following spring', B. pfeifferi favoured smaller, man-made habitats with most transmission between May and August each year. The less abundant Bulinus spp. favoured larger natural and man-made habitats with most S. bovis transmission between April and July. S. mansoni infections were more, but S. bovis infections were less abundant than other trematodes in their respective snail hosts. Ecological changes in the early 1980s due to sugar irrigation pre-dated similar, more widespread changes in the late 1980s when the completion of dams across the Senegal River prevented seasonal rain fed floods and sea water intrusion. S. mansoni has since spread rapidly around Richard Toll. The incompatibility of the local S. haematobium strains with the dominant bulinid snails has so far prevented an epidemic of urinary schistosomiasis at Richard Toll, but the invasion of similar downstream habitats by susceptible B. globosus is worrying. The principal control measure, chemotherapy, given in the 'winter' would minimise the rate of reinfection. It could be reinforced by judicious mollusciciding within the sugar irrigation scheme but not elsewhere.

Animals↗
PubMed2004

Faecal contamination indicators, Salmonella, Vibrio and Aeromonas in water used for the irrigation of agricultural products.

The faecal contamination indicators (total coliforms, faecal coliforms, Escherichia coli, enterococci) and the genera Salmonella, Vibrio, Aeromonas were investigated in water samples used for irrigation. During 4 months, 52 samples were taken. The methods used were: multiple tube fermentation method for faecal contamination indicators and membrane filtration techniques for salmonella, aeromonas and vibrio. Two samples were positive for Salmonella spp., fourteen for Aeromonas spp. and no samples for Vibrio spp. No correlation was found between aeromonas and the indicators of faecal contamination. Regarding Aeromonas spp., 21.6% of the strains were adhesive and 12.6% cytotoxic: this confirms the possible role of aeromonas in human pathologies. These results are important to determine the quality of irrigation water in relation to human health. In fact, the spray or sprinkler irrigation produces bioaerosol, which can contaminate the crops that are likely to be eaten uncooked. In addition, the flood or furrow irrigation represents a risk to field workers.

Aeromonas↗
PubMed2006

Spray irrigation of treated municipal wastewater as a potential source of atmospheric PBDEs.

Spray irrigation facilities utilizing treated municipal wastewater are a potential source of polybrominated diphenyl ethers (PBDEs) to the atmosphere. PBDEs are used as flame retardants in many household items and have been found in wastewaters and biosolids. Evidence of PBDE release from spray irrigation facilities was discovered during a multiyear project to measure semivolatile organic chemical concentrations in air. Four BDE congeners (47, 99, 100, and 154) were monitored at three remote/ rural locations in Maryland and Delaware from 2001 to 2003. Average concentrations at two of the sites (BDE-47, 10-17 pg/m3; BDE-99, 5.3-7.7 pg/m3) reflect background levels. Average concentrations at the third location were 5-10 times higher (BDE-47, 175 pg/m3; BDE-99, 26 pg/m3) and were significantly correlated (p < 0.0001) with temperature indicating local source(s). Several spray irrigation facilities are located south and west of the third site, the prevailing wind direction during the spring and summer when most samples were collected. The fine mist released from the irrigation equipment may enhance release to the atmosphere via air-water gas exchange from water droplets. Temporal trends indicate that aerial concentrations of PBDEs in this area are increasing at an exponential rate; the atmospheric doubling times for the different congeners range from 1.1 to 1.7 yrs.

Ethers↗
PubMed2005

Human pharmaceuticals, hormones, and personal care product ingredients in runoff from agricultural fields irrigated with treated wastewater.

Irrigation of crops with treated wastewater has the potential to introduce effluent-derived organic microcontaminants into surface waters through agricultural runoff. To determine whether compounds indicative of the presence of treated effluent in irrigation water could be identified in agricultural runoff, surface runoff samples collected from effluent-irrigated and rain-fed cultivated fields were analyzed for a broad spectrum of organic compounds. A variety of compounds was identified that appeared to be associated with irrigation with treated wastewater. These compounds included human pharmaceuticals (e.g., carbamazepine, gemfibrozil, carisoprodol), personal care product ingredients (e.g., insect repellent, polycyclic musks), and alkyl phosphate flame retardant chemicals. Most of these compounds appear not to have been previously reported in agricultural runoff. These compounds were present at concentrations below the few published aquatic toxicology data available; however, their potential to elicit more subtle effects in aquatic organisms cannot be excluded. None of these compounds were detected by broad-spectrum analysis in samples from the same fields during runoff-producing rain events.

Agriculture↗
PubMed2001

Effects of cultivar and irrigation management on population growth of the twospotted spider mite Tetranychus urticae on greenhouse ivy geranium.

Greenhouse experiments were conducted to determine whether different ivy geranium cultivars and different irrigation frequencies influenced population growth of the twospotted spider mite (TSM), Tetranychus urticae. Results showed that mite numbers at harvest (about 4 weeks after plants were artificially infested) were very low on 'Sybil Holmes', but significantly higher on 'Amethyst 96'. Irrigation frequency of ivy geraniums had no measurable effect on TSM populations over a range in which water was applied when pot weight dropped 15, 30 or 45% from container capacity. However, the most frequently irrigated plants (15% treatment) produced as much or more growth than plants that received less water. These plants also had the lowest incidence of oedema. There was no significant interaction between water management and host plant resistance, implying the difference in host plant resistance to TSM between the two cultivars should remain constant, at least within the range of the irrigation frequencies studied. Our findings suggest that growers can take advantage of plant resistance to TSM on ivy geranium cultivars of current commercial importance, and that watering practices can be adjusted to optimize plant production without affecting pest populations.

Agriculture↗