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PubMed2001

Comparison of an immunochromatographic method and the TaqMan E. coli O157:H7 assay for detection of Escherichia coli O157:H7 in alfalfa sprout spent irrigation water and in sprouts after blanching.

An immunochromatographic-based assay (Quixtrade mark E. coli O157 Sprout Assay) and a polymerase chain reaction (PCR)-based assay (TaqMan E. coli O157:H7 Kit) were used to detect Escherichia coli O157:H7 strain 380-94 in spent irrigation water from alfalfa sprouts grown from artificially contaminated seeds. Ten, 25, 60, or 100 seeds contaminated by immersion for 15 min in a suspension of E. coli O157:H7 at concentrations of 10(6) or 10(8) cfu/ml were mixed with 20 g of non-inoculated seeds in plastic trays for sprouting. The seeds were sprayed with tap water for 15 s every hour and spent irrigation water was collected at intervals and tested. E. coli O157:H7 was detected in non-enriched water by both the TaqMan PCR (30 of 30 samples) and the immunoassay (9 of 24 samples) in water collected 30 h from the start of the sprouting process. However, enrichment of the spent irrigation water in brain heart infusion (BHI) broth at 37 degrees C for 20 h permitted detection of E. coli O157:H7 in water collected 8 h from the start of sprouting using both methods, even in trays containing as few as 10 inoculated seeds. The TaqMan PCR assay was more sensitive (more positive samples were observed earlier in the sprouting process) than the immunoassay; however, the immunoassay was easier to perform and was more rapid. At 72 h after the start of the sprouting process, the sprouts were heated at 100 degrees C for 30 s to determine the effectiveness of blanching for inactivation of E. coli O157:H7. All of the 32 samples tested with the TaqMan assay and 16 of 32 samples tested with the Quixtrade mark assay gave positive results for E. coli O157:H7 after enrichment of the blanched sprouts at 37 degrees C for 24 h. In addition, the organism was detected on Rainbow Agar O157 in 9 of 32 samples after 24 h of enrichment of the blanched sprouts. In conclusion, E. coli O157:H7 was detected in spent irrigation water collected from sprouts grown from artificially contaminated seeds by both the TaqMan and Quixtrade mark assays. The data also revealed that blanching may not be effective to completely inactivate all the E. coli O157:H7 that may be present in sprouts.

Chromatography↗

PubMed2001

Breeding of Anopheles mosquitoes in irrigated areas of South Punjab, Pakistan.

As part of investigations on potential linkages between irrigation and malaria transmission, all surface water bodies in and around three villages along an irrigation distributary in South Punjab, Pakistan, were surveyed for anopheline mosquito larvae (Diptera: Culicidae) from April 1999 to March 2000. Samples were characterized according to exposure to sunlight, substratum, presence of vegetation, fauna, inorganic matter and physical water condition (clear/turbid/foul). Also water temperature, dissolved oxygen (DO), electroconductivity (EC) and pH of sites were recorded. A total of 37982 Anopheles larvae of six morphological types were collected from 2992 samples taken from irrigation/agricultural and village/domestic aquatic habitats. Anopheles subpictus Grassi sensu lato was by far the most abundant (74.3%), followed by An. culicifacies Giles s.l. (4.1%), An. stephensi Liston s.l. (2.6%), An. pulcherrimus Theobald (1.8%), An. peditaeniatus Leicester (0.3%) and An. nigerrimus Giles (0.1%). The four most abundant species were significantly associated with waterlogged fields and communal village drinking-water tanks. Habitat characteristics most correlated with occurrence of anophelines were the physical water condition and the absence/presence of fauna, particularly predators. Occurrence and abundance of Anopheles immatures were not significantly correlated with water temperature, DO, EC or pH. Malaria vectors of the Anopheles culicifacies complex occurred at relatively low densities, mainly in irrigated and waterlogged fields. In South Punjab, where rainfall is very low, it should be possible to reduce anopheline breeding through water management, as larvae develop mainly in water bodies that are directly or indirectly related to the extensive canal-irrigation system.

Animals↗

PubMed2003

Living in the paddies: a social science perspective on how inland valley irrigated rice cultivation affects malaria in Northern Côte d'Ivoire.

The potential impact of irrigated agriculture on water-related vector-borne diseases has been an increasing source of concern for researchers from the bio-medical sector. While most research on the potential impacts of irrigation on the health of local populations focuses on vector densities, levels of exposures, health services and technologies (prophylaxis, mosquito nets), we argue that it is essential to enlarge the scope of investigation and consider the complex mechanisms by which factors such as agriculture-generated changes in ecosystems, gender repositioning in the family organization as a result of access to new crops, and production activities combine together in increasing disease risks and producing new scenarios in the management of disease. This paper presents the results of an investigation of how transformations induced on the local society by the intensification of inland valley irrigated rice cultivation influence malaria health care systems and modulate risks to the health of local populations, within well-defined geographical boundaries in northern Côte d'Ivoire. Our results indicate that socio-economic transformations and gender repositioning induced, or facilitated, by the intensification of inland valley irrigated rice cultivation lead to a reduction of the capacity of women to manage disease episodes, contributing therefore to increase malaria incidence among farming populations.

Agriculture↗

PubMed2005

Cooled needle catheter ablation creates deeper and wider lesions than irrigated tip catheter ablation.

OBJECTIVES: To design and test a catheter that could create deeper ablation lesions. BACKGROUND: Endocardial radiofrequency (RF) ablation is unable to reliably create transmural ventricular lesions. We designed an intramural needle ablation catheter with an internally cooled 1.1-mm diameter straight needle that could be advanced up to 14 mm into the myocardium. The prototype catheter was compared with an irrigated tip ablation catheter. METHODS: Ablation lesions were created under general anesthesia in 14 male sheep (weight 44 +/- 7.3 kg) with fluoroscopic guidance. Each of the catheters was used to create two ablation lesions at randomly allocated positions within the left ventricle. The irrigation rate, target temperature, and maximum power were: 20 mL/min, 85 degrees C, 50 W for the intramural needle catheter and 20 mL/min, 50 degrees C, 50 W for the irrigated tip catheter, respectively. All ablations were performed for 2 minutes. After the last ablation, blue tetrazolium (12.5 mg/kg) was infused intravenously. The heart was removed via a left thoracotomy after monitoring the sheep for one hour. RESULTS: There was no evidence of cardiac tamponade in any sheep. The intramural needle catheter lesions were significantly wider (10.9 +/- 2.8 mm vs 10.1 +/- 2.4 mm, P = 0.01), deeper (9.6 +/- 2.0 mm vs 7.0 +/- 1.3 mm, P = 0.01), and more likely to be transmural (38% vs 0%, P = 0.03). CONCLUSIONS: Cooled intramural needle ablation creates lesions that are significantly deeper and wider than endocardial RF ablation using an irrigated tip catheter in sheep hearts. This technology may be useful in treating ventricular tachycardia resistant to conventional ablation techniques.

Analysis of Variance↗

PubMed2002

Pesticides distribution in sediments of a tropical coastal lagoon adjacent to an irrigation district in northwest Mexico.

This work presents the content of organochlorine (OCs) pesticides in sediments of both, agricultural drains from the Irrigation District 076, El Carrizo, Sinaloa, and of the adjacent coastal lagoon ecosystem of Agiabampo-Bacorehuis-Jitzamuri, located in northwest Mexico. A questionnaire was applied to the farmers of this irrigation district, to evaluate the usage of pesticides and to determine if banned OCs are still used. Around 31 tons of active ingredients were applied in the autumn-winter cycle (1997-1998). There were eighteen different pesticides; of them 61% are insecticides, 28% herbicides, 6% fungicides and 6% other compounds. Around 73% of the pesticides applied are organophosphorus, carbamates and sulfur, OCs are still applied and represent 4% of the total. All the pesticides applied in the irrigation district are authorized in the Official Pesticide Catalog, nevertheless forbidden and restricted compounds were detected in the sediment samples. The presence of heptachlor, heptachlor epoxide, alpha-endosulfan, beta-endosulfan, endosulfan sulfate, alpha-HCH, beta-HCH, lindane, delta-HCH, aldrin, dieldrin p,p'-DDT, p,p'-DDE and p,p'-DDD was recorded in the sediment sample. The analysis of the sediments suggest that the principal pesticides input to the coastal ecosystem is mainly through three of the seven agricultural drains, that collect the excess irrigation water and runoff from the district surface. A gradient of pesticide residues in sediments exists from the agricultural drains (52 ng OCs g(-1) dry weight) to the Jitzamuri bay (32 ng OCs g(-1) dry weight).

Ecosystem↗

PubMed2000

Repetitive endoscopy and continuous alkaline gastric irrigation in a case of arsenic poisoning.

BACKGROUND: The poor prognosis of patients with persistent gastrointestinal radio-opacities after oral arsenic poisoning supports efficient gastrointestinal decontamination as critical for survival. In a case of massive arsenic ingestion, we performed repetitive gastric endoscopy and a continuous alkaline irrigation of the stomach over several days. CASE REPORT: A 41-year-old woman was admitted 4 hours after intentional ingestion of trivalent arsenic powder 5 g. The admission abdominal X-ray confirmed the presence of multiple gastric opacities. Initial treatment was gastric lavage with normal saline, dimercaprol chelation, and supportive therapy. Since gastric opacities persisted on the abdominal X-ray at 34 hours despite repeated gastric lavage, a gastroscopy was performed showing nonremovable agglomerates. In an attempt to achieve further gastric decontamination, we performed a continuous gastric alkaline irrigation. After 3 days of alkaline irrigation, the abdomen was normal on X-ray but the gastroscopy still showed arsenic concretions. Alkaline irrigation was continued for another 3 days until total disappearance of arsenic agglomerates at the gastroscopy. Admission urinary arsenic was 3663 microg/L. A total of 46.2 mg of inorganic arsenic, or less than 1% the ingested dose, was extracted from the stomach by this technique. The patient was discharged from the intensive care unit 20 days after admission without sequelae.

Adult↗

PubMed2001

Feasibility study of treated sewage irrigation on paddy rice culture.

A feasibility study was performed to examine the agronomic application of the treated sewage on paddy rice culture through field experiment. The domestic sewage was treated using a constructed wetland system, a subsurface flow type consisting of sand and macrophyte. The effluent of the wetland system was diluted to maintain the total nitrogen concentration below 25 mg/L and was used as irrigation water. Addition of the treated sewage to the irrigation water showed no adverse effect on the paddy rice culture; in fact some enhancement was noticed in both growth and yield. Irrigation with the treated sewage after the concentration was adjusted accompanied by conventional fertilization showed a better result, with the yield exceeding that of the control where clean water was used, thus suggesting that reuse of the treated sewage as supplemental irrigation water could be a feasible and practical alternative. For a full-scale application, however, further study is recommended on the specific guideline for controlling the major water quality components in the treated sewage.

Agriculture↗

PubMed2006

Effect of fluid irrigation on core body temperature during laparoscopic common bile duct exploration.

BACKGROUND: Laparoscopic common bile duct exploration uses large volumes of intraperitoneal irrigation fluid. Much of this fluid crosses the peritoneal cavity. This study was performed to examine its effect on core body temperature. MATERIALS AND METHODS: Ten patients undergoing laparoscopic bile duct exploration were studied. Core temperature was measured intraoperatively. Patients were covered with a warming blanket. The volume of fluid irrigated, carbon dioxide used, and intravenous fluid infused were recorded. Ten patients having cholecystectomy alone were studied as a control group. RESULTS: There was a small but significant rise in core temperature in both the study (P = 0.010) and control (P = 0.002) groups. There was no significant difference in the change in core temperature between the groups (P = 0.706).The mean volume of irrigation fluid used was 2640 mL in the study group and 915 mL in the control group. Mean gas volume used was 162.9 L and 73.3 L and the volume of intravenous fluid infused was 1620 mL and 1190 mL in the study and control groups, respectively. CONCLUSION: The use of large volumes of irrigation fluid during laparoscopic bile duct exploration does not cause a fall in core temperature.

Body Temperature↗

PubMed1997

Leaf nutrient variation in mature carob (Ceratonia siliqua) trees in response to irrigation and fertilization.

Seasonal variations in leaf nitrogen, phosphorus and potassium concentrations were studied in a mature carob (Ceratonia siliqua L. cv "Mulata") orchard subjected to a 4-year irrigation and fertilization experiment. Three irrigation regimes (0, 50 and 100%), based on the evaporation values obtained from a class A pan, were tested in combination with two nitrogen (N) supply regimes in which 21 kg ha(-1) year(-1) (low-N) and 63 kg ha(-1) year(-1) (high-N) were supplied as ammonium nitrate. Leaf nitrogen concentration increased throughout the experiment, independently of treatments. There were no significant differences in leaf N concentration between trees in the high-N and low-N treatments. Irrigation regimes had no effect on leaf mineral concentration but influenced the amount of leaves shed and slightly modified the pattern of leaf shedding that occurred during the summer drought period. Nutritional balances between N and P and N and K were both closely and significantly correlated. Potassium was translocated from leaves to fruits during spring, independently of treatments. Severe water stress periods occurring during spring or autumn induced shedding of leaves leading to nutrient mobilization. Nutrient retranslocation during these drought periods may represent an adaptive mechanism. Nitrogen retranslocation was higher for trees in the high-N treatments than for trees in the low-N treatments, whereas phosphorus retranslocation was independent of the irrigation and fertilization treatments.

Journal Article↗

PubMed1976

Risk of communicable disease infection associated with wastewater irrigation in agricultural settlements.

The incidence of enteric communicable diseases in 77 kibbutzim (agricultural communal settlements) practicing wastewater spray irrigation with partially treated nondisinfected oxidation pond effluent is compared with that in 130 kibbutzim practicing no form of wastewater irrigation. The incidence of shigellosis, salmonellosis, typhoid fever, and infectious hepatitis is two to four times higher in communities practicing wastewater irrigation. No significant differences are found for the incidence of streptococcal infections, tuberculosis, and laboratory-confirmed cases of influenza. Nor are differences found for enteric disease rates during the winter nonirrigation season. Strong wastewater treatment measures, including effective bacterial and viral inactivation through disinfection, are recommended for all cases of sewage irrigation or land disposal near residential areas in light of the potential public health risks involved.

Agriculture↗

PubMed2004

Fate of Salmonella enterica serovar Typhimurium on carrots and radishes grown in fields treated with contaminated manure composts or irrigation water.

Three different types of compost, PM-5 (poultry manure compost), 338 (dairy cattle manure compost), and NVIRO-4 (alkaline-pH-stabilized dairy cattle manure compost), and irrigation water were inoculated with an avirulent strain of Salmonella enterica serovar Typhimurium at 10(7) CFU g(-1) and 10(5) CFU ml(-1), respectively, to determine the persistence of salmonellae in soils containing these composts, in irrigation water, and also on carrots and radishes grown in these contaminated soils. A split-plot block design plan was used for each crop, with five treatments (one without compost, three with each of the three composts, and one without compost but with contaminated water applied) and five replicates for a total of 25 plots for each crop, with each plot measuring 1.8 x 4.6 m. Salmonellae persisted for an extended period of time, with the bacteria surviving in soil samples for 203 to 231 days, and were detected after seeds were sown for 84 and 203 days on radishes and carrots, respectively. Salmonella survival was greatest in soil amended with poultry compost and least in soil containing alkaline-pH-stabilized dairy cattle manure compost. Survival profiles of Salmonella on vegetables and soil samples contaminated by irrigation water were similar to those observed when contamination occurred through compost. Hence, both contaminated manure compost and irrigation water can play an important role in contaminating soil and root vegetables with salmonellae for several months.

Agriculture↗

PubMed2005

Source bioaerosol concentration and rRNA gene-based identification of microorganisms aerosolized at a flood irrigation wastewater reuse site.

Reuse of partially treated domestic wastewater for agricultural irrigation is a growing practice in arid regions throughout the world. A field sampling campaign to determine bioaerosol concentration, culturability, and identity at various wind speeds was conducted at a flooded wastewater irrigation site in Mexicali, Baja California, Mexico. Direct fluorescent microscopy measurements for total microorganisms, culture-based assays for heterotrophs and gram-negative enteric bacteria, and small-subunit rRNA gene-based cloning were used for microbial characterizations of aerosols and effluent wastewater samples. Bioaerosol results were divided into two wind speed regimens: (i) below 1.9 m/s, average speed 0.5 m/s, and (ii) above 1.9 m/s, average speed 4.5 m/s. Average air-borne concentration of total microorganisms, culturable heterotrophs, and gram-negative enteric bacteria were, respectively, 1.1, 4.2, and 6.2 orders of magnitude greater during the high-wind-speed regimen. Small-subunit rRNA gene clone libraries processed from samples from air and the irrigation effluent wastewater during a high-wind sampling event indicate that the majority of air clone sequences were more than 98% similar to clone sequences retrieved from the effluent wastewater sample. Overall results indicate that wind is a potential aerosolization mechanism of viable wastewater microorganisms at flood irrigation sites.

Aerosols↗

PubMed1993

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 3--Survey of adult stages at the rice irrigation system and the emergence of Anopheles albitarsis in south-eastern, Brazil.

A study of adult Culicidae ecology was carried out from January 1992 through January 1993 at the rice irrigation system of the Ribeira Valley Experimental Station. The adaptation of Anopheles albitarsis to the anthropic environment became evident through the adult collections made at its various habitats represented by the irrigation system and the edge of the residual pond, as well as at those made within the local patchy residual woods. Other potential disease vectors were prevalent in the irrigated system too. There were Aedes scapularis, Culex nigripalpus and Cx. ribeirensis that were collected at various habitats. Remarkable differences among their prevalences were obtained such as between the natural forest and anthropic environments. In the former An. albitarsis was practically non-existent, thus suggesting that it might be considered as eusynathropic. As the populations of other species seemed to increase in the anthropic environment, they may be regarded as hemisynanthropes. Observations suggest the hypothesis that the development of irrigated land may be a factor in the emergence of An. albitarsis, and some other species, as well as the possibility of an increase in the transmission of mosquito-borne diseases such as malaria.

Agriculture↗

PubMed1988

Clinical and microbiologic effects of local tetracycline irrigation on periodontitis.

This investigation was conducted on seven individuals referred for treatment of moderate adult periodontitis. Twenty-eight sites with an average probing depth of 5.6 +/- 0.9 mm were evaluated. One tooth per jaw quadrant was randomly assigned to receive one of the following treatments: (I) no treatment, i.e., control; (II) saline irrigation; (III) tetracycline irrigation and (IV) scaling and root planing (SC/RP). A plaque control program was instituted one week prior to the experimental period and reinforced throughout the eight-week study. Irrigation was performed every 48 hours during the first two weeks of the experiment for Groups II and III, and the single treatment of SC/RP was carried out immediately following the baseline examination for Group IV. Clinical and microbiologic changes were monitored every two weeks using plaque and gingival indices, gingival fluid flow, probing depths, bleeding on probing and dark-field microscopic examination of the subgingival microbial flora. The tetracycline and SC/RP treatment modalities resulted in statistically significant clinical and microbiological improvements when compared with the control. Tetracycline irrigation alone and SC/RP alone had a similar effect in changing the subgingival microflora from one associated with disease to one associated with health. Thus, these treatment modalities are effective methods of producing statistically significant alterations in the subgingival microflora. The property of substantivity may contribute to the sustained duration of the effect of locally delivered tetracycline.

Adult↗

PubMed1993

The effect of chlorhexidine irrigation on tensile wound strength.

Chlorhexidine in an alcohol vehicle with flavoring agents has been used as a mouthrinse to reduce plaque accumulation in periodontal surgery patients. The purpose of this study was to evaluate the effects of a chlorhexidine-containing mouthrinse on the early tensile wound strength of healing surgical wounds in the rat. Standardized transdermal incisions were made on each lateral abdominal wall of 40 Sprague-Dawley rats. Wounds were irrigated with 10 ml of 0.12% chlorhexidine or 10 ml of normal saline prior to closure. Animals were sacrificed at 48 hours and 96 hours, and the wound area was excised by a standardized protocol. Wound strength was measured using constant speed tensiometry to determine the tensile strength of the healing incision. Results revealed a significantly reduced tensile wound strength at 48 hours for the chlorhexidine-treated group (127 +/- 18.5 gm) compared to the saline irrigation group (150 +/- 32.3 gm) (P < 0.001). However, by 96 hours a significantly increased tensile wound strength was demonstrated by the chlorhexidine treated group (202.1 +/- 21.7 gm) compared to the saline irrigation group (183.2 +/- 37.3 gm) (P < 0.05). These data suggest that chlorhexidine-containing mouthrinse irrigation of wounds produced a reduced early tensile wound strength, but ultimately resulted in shorter healing time.

Analysis of Variance↗

PubMedDate not supplied

Phosphorus losses in furrow irrigation runoff.

Phosphorus (P) often limits the eutrophication of streams, rivers, and lakes receiving surface runoff. We evaluated the relationships among selected soil P availability indices and runoff P fractions where manure, whey, or commercial fertilizer applications had previously established a range of soil P availabilities on a Portneuf silt loam (coarse-silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid) surface-irrigated with Snake River water. Water-soluble P, Olsen P (inorganic and organic P), and iron-oxide impregnated paper-extractable P (FeO-Ps) were determined on a 0.03-m soil sample taken from the bottom of each furrow before each irrigation in fall 1998 and spring 1999. Dissolved reactive phosphorus (DRP) in a 0.45-microm filtered runoff sample, and iron-oxide impregnated paper-extractable P (FeO-Pw), total P, and sediment in an unfiltered runoff sample were determined at selected intervals during a 4-h irrigation on 18.3-m field plots. The 1998 and 1999 data sets were combined because there were no significant differences. Flow-weighted average runoff DRP and FeO-Pw concentrations increased linearly as all three soil P test concentrations increased. The average runoff total P concentration was not related to any soil P test but was linearly related to sediment concentration. Stepwise regression selected the independent variables of sediment, soil lime concentration, and soil organic P extracted by the Olsen method as related to average runoff total P concentration. The average runoff total P concentration was 1.08 mg L(-1) at a soil Olsen P concentration of 10 mg kg(-1). Soil erosion control will be necessary to reduce P losses in surface irrigation runoff.

Agriculture↗

PubMedDate not supplied

Effect of turfgrass cover and irrigation on soil mobility and dissipation of mefenoxam and propiconazole.

Irrigation effects on pesticide mobility have been studied, but few direct comparisons of pesticide mobility or persistence have been conducted on turfgrass versus bare soil. The interaction of irrigation practices and the presence of turfgrass on the mobility and dissipation of mefenoxam [N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-D-alanine methyl ester] and propiconazole (1-[[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl]methyl]-1H-1,2,4-triazole) was studied. Sampling cylinders (20-cm diam.) were placed in either creeping bentgrass [Agrostis stolonifera L. var. palustris (Huds.) Farw.] or bare soil. Mefenoxam was applied at 770 g a.i. ha(-1) and propiconazole was applied at 1540 g a.i. ha(-1) on 14 June 1999. Sampling cylinders were removed 2 h after treatment and 4,8,16, 32, and 64 days after treatment (DAT) and the cores were sectioned by depth. Dissipation of mefenoxam was rapid, regardless of the amount of surface organic matter or irrigation. The half-life (t1/2) of mefenoxam was 5 to 6 d in turf and 7 to 8 d in bare soil. Most mefenoxam residues found in soil under turfgrass were in the 0- to 1-cm section at 0, 4, and 8 DAT. Residues were found in the 15- to 30-cm section at 4, 8, 16, 32, and 64 DAT, regardless of turf cover or irrigation. The t1/2 of propiconazole was 12 to 15 d in turfgrass and 29 d in bare soil. Little movement of propiconazole was observed in either bare soil or turf.

Agriculture↗

PubMedDate not supplied

Soil chemical changes under irrigated mango production in the Central São Francisco River Valley, Brazil.

Irrigated areas in Brazil's Central São Francisco River Valley have experienced declines in productivity, which may be a reflection of changes in soil chemical properties due to management. This study was conducted to compare the chemical composition of soil solutions and cation exchange complexes in a five-year-old grove of irrigated mango (Mangifera indica L. cv. Tommy Atkins) with that of an adjacent clearing in the native caatinga vegetation. A detailed physiographic characterization of the area revealed a subsurface rock layer, which was more undulating than the current land surface, and identified the presence of a very saline and sodic (1045 microS cm(-1), sodium adsorption ratio [SAR] = 5.19) ground water table. While changes in concentrations of Ca, Mg, and K could be attributed to direct management inputs (fertilization and liming with dolomite), increases in Na suggested average annual capillary rise from the ground water table of 28 L m(-2). Accordingly, soil salinity levels appeared to be more dependent on surface elevation than the elevation of the rock layer or sediment thickness. The apparent influence of land surface curvature on water redistribution and the solution chemistry was more pronounced under irrigated mango production. In general, salinity levels had doubled in the mango grove and nearly tripled under the canopies, after only five years of irrigation. Though critical saline or sodic conditions were not encountered, the changes observed indicate a need for more adequate monitoring and management of water and salt inputs despite the excellent water quality of the São Francisco River.

Agriculture↗