Effects Of Irrigation Practices Research Articles

Hydrogeochemical evidence for fluoride behavior in groundwater and the associated risk to human health for a large irrigation plain in the Yellow River Basin

A hydrochemical analysis of groundwater (GW) was conducted to investigate the factors controlling GW fluoride (F) in a large irrigation plain in the Yellow River Basin, Guanzhong Plain, China. Area-dependent variations in F were observed in the study region. The F concentrations of 93% of samples on the south bank of the Weihe River and the western part of the Qishui River were <1 mg L−1, whereas those of 73% of GW samples for the eastern part of the Qishui River exceeded the national limit. A forward model based on mass budget equations identified carbonate weathering as the dominant factor regulating hydrochemistry in low-F GW, whereas the factors in the high-F zone were evaporate dissolution and evaporation. The high-F GW displayed a distinctive major ion chemistry, which could be attributed to a high pH, low Ca2+, and high HCO3− and Na+ concentrations. An analysis of the correlation between F/Cl and F concentrations and fluid-mineral equilibria indicated distinct forces driving the behavior of F in the subparts of the high-F GW zone, including irrigation-induced F dilution, F enrichment through Na-Ca exchange, and adsorption of F on clay minerals. The order of vulnerable segments of the population in terms of risk posed by F in GW was: infants > children > adults. These results can enhance the understanding of F behaviors in GW and provide insights into the effect of irrigation practices on GW F concentration.

Effect of irrigation practices upon yield and fruit quality of four grapefruit (Citrus paradisiMac.) cultivars

AbstractTwo strategies of irrigation were applied during the phase of fruit growth in 30-year-old grapefruit trees (Citrus paradisi Mac.) of four varieties (cv. Marsh SRA 8, cv. Shambar SRA 22, cv. Frost Marsh, cv. Ruby). For the first strategy (T1), the trees were irrigated every week at 100% crop evapotranspiration (ETc), while for the second strategy (T2) at 60% ETc. At harvest time, tree yield was estimated along with fruit quality and water productivity. T1 strategy significantly increased the tree yield, the fruit weight and the juice content. Although an increase in water productivity (crop yield/total water use) was achieved during the water stress experiment for three out of the four varieties. The main effect of the T2 strategy was a significant increase of qualitative (commercial and nutritional) attributes like total soluble solids (TSS), citric acid, ascorbic acid (Vitamin C) and phenolic content. In addition, strategy T2 increased the maturation index and the fruits had sweeter flavor for two varieties. These results lead to the conclusion that in mature grapefruit trees, optimal irrigation practice provided better fruit yield, while water stress practices favor the accumulation of specific nutritional elements and improve specific fruit quality parameters, especially for cv. Ruby.

Survivorship of Anopheles gambiae sensu lato in irrigated sugarcane plantation scheme in Ethiopia

BackgroundTo ensure food security, sub-Saharan Africa has initiated massive water resource development projects, such as irrigated agriculture, in recent years. However, such environmental modifications affect the survivorship and development of mosquitoes, which are vectors of different diseases. This study aimed at determining the effects of irrigation practices on development and survivorship of Anopheles gambiae s.l. in Ethiopia.MethodsA life table experiment was conducted to examine the effect of environmental modification on survivorship of both immature and adult An. gambiae s.l. in irrigated and non-irrigated areas. The pupation rate and development time of the immatures and adult longevity and fecundity were compared between the two settings.ResultsThe estimated mean survival time of female An. gambiae s.l. in the irrigated and non-irrigated areas was 37.9 and 31.3 days, respectively. A survival analysis showed that adult females of An. gambiae s.l. placed in an irrigated area lived significantly longer than those in a non-irrigated area (χ2 = 18.3, df = 1, P <0.001), and An. gambiae s.l. females lived significantly longer than males in both areas (P < 0.001).ConclusionsAdult An. gambiae s.l. survivorship was found to be enhanced in the irrigated area compared to non-irrigated area. Longer survival of adult mosquitoes in irrigated areas could have important implications for vectorial capacity and hence malaria transmission.Graphical

Subsurface drip irrigation reduces cadmium accumulation of pepper (Capsicum annuum L.) plants in upland soil

Given that Cd pollution in dry land has aroused wide public concern, numerous remediation technologies has been utilized, yet there are limited cost-effective techniques that do not affect the original planting patterns. Fortunately, irrigation management can meet these requirements, while the effects of irrigation practices on Cd uptake by crops in slightly Cd-polluted upland soil remain elusive. Here, we aimed to investigate how the irrigation methods altered the Cd availability in soil, Cd accumulation in plants, microorganism population in soil, root morphology, and enzyme activities in soil and plants. We examined three irrigation treatments - surface drip irrigation (DI), subsurface drip irrigation (SDI), alternate-rows irrigation (ARI), and the control conventional furrow irrigation (CFI). The results showed that SDI remarkably reduced Cd content in roots, shoots and fruits, increased yield, and improved root growth and activity in soil of 20–40 cm compared to other treatments, though the Cd concentration in rhizosphere was not decreased significantly. The microbial population and enzyme activities in rhizosphere and enzyme activities in leaves and roots in SDI and ARI were basically higher than DI and CFI. Therefore, SDI has the prominent potential to reduce Cd uptake by crops in upland soil polluted with low Cd.

Application of STICS Model in Assessment of the Effects of Irrigation Practices and Soil Properties on Yield of a Durum Wheat (Triticum durum Desf.) Cultivar in the Irrigated Area of Oued Rmel in Tunisia

The progress in computer technology has enabled the development of crop models reproducing the behavior of a crop in a wide range of pedoclimatic conditions and technical itineraries. This work aims to study the impact of total available soil water in the root zone (TAW) on durum wheat yield (Triticum durum Desf.) as affected by irrigation regime in Mediterranean climatic conditions of Tunisia. In this work, STICS model was used to simulate effects of farmer’s irrigation practices in wheat in the pedoclimatic conditions of the irrigated area of Oued Rmel in Tunisia over a 20-year period. Assessment of irrigation practices in the study area was performed, compared to rainfed system, in terms of yield Original Research Article Annual Research & Review in Biology, 4(5): 747-765, 2014 748 and produced biomass at harvest. The model was calibrated to simulate the growth and development of winter wheat using the field observed crop data collected from three growing seasons in two locations in Tunisia. To carry out the study, three types of soil (S1, S2 and S3) in the Oued rmel irrigation scheme were chosen on the basis of their available soil water in the root zone (TAW). The study showed that the model adequately predicts crop yield and biomass. Simulation results showed that the farmers’ irrigation practice results, in higher grain yield and dry matter at harvest as compared to rainfed system. Simulated grain yield was significantly higher in soil with high TAW than in the other soils. Results showed that the highest difference (30%) in simulated grain yield, between the two water regimes, was obtained in soil having high TAW. Depending on the soil type, simulated dry matter at harvest increased from 4% to 12% compared to rainfed system.

Bean common bacterial blight: pathogen epiphytic life and effect of irrigation practices

In recent years, bean common bacterial blight (CBB) caused by Xanthomonas axonopodis pv. phaseoli (Xap) has caused serious yield losses in several countries. CBB is considered mainly a foliar disease in which symptoms initially appear as small water-soaked spots that then enlarge and become necrotic and usually bordered by a chlorotic zone. Xap epiphytic population community has a critical role in the development of the disease and subsequent epidemics. The epiphytic population of Xap in the field has two major parts; solitary cells (potentially planktonic) and biofilms which are sources for providing and refreshing the solitary cell components. Irrigation type has a significant effect on epiphytic population of Xap. The mean epiphytic population size in the field with an overhead sprinkler irrigation system is significantly higher than populations under furrow irrigation. A significant positive correlation between the epiphytic population size of Xap and disease severity has been reported in both the overhead irrigated (r=0.64) and the furrow irrigated (r= 0.44) fields.

Irrigation frequency influences establishment of silvery thread moss (Bryum argenteum Hedw.) and rooting of creeping bentgrass (Agrostis stolonifera L.) on simulated golf greens

The encroachment of moss on creeping bentgrass (Agrostis stolonifera L.) golf greens is a significant problem throughout the world. Although chemical control products for moss exist many are not registered for this use in Europe and Canada. As a result turfgrass managers must rely on cultural methods to manage moss encroachment. A survey of 15 golf courses in southwestern Ontario positively identified silvery thread moss (Bryum argenteum Hedw.) (STM) as the primary species of moss present. In order to determine the effects of irrigation practices on STM establishment two independent greenhouse experiments were conducted in which the quantity and frequency of irrigation were altered. Pots containing creeping bentgrass were inoculated with STM and irrigated at either 75% or 100% open pan evaporation (Eo) and at 1-, 2-, 4-, or7-day intervals. Volumetric water content was measured in the top 5.7 cm of the pots to confirm that changes in water availability were a result of irrigation practices. Between the two levels tested, irrigation quantity had no effect on the presence of STM. In the first experiment irrigation at 1-day and 2-day intervals had significantly more STM invasion than irrigation at 4- and 7-day intervals. In the second experiment point quadrat counts showed that irrigating at both 1-day and 2-day intervals resulted in significantly more STM and that the most moss was observed with the daily irrigation regime. Root data were also collected to determine the effect of irrigation practices on root mass. The daily irrigation treatments in both experiments had reduced root mass although in the first experiment only the root mass below 12 cm was lower. In the second experiment the total root mass was highest for the 4-day irrigation interval with the 2- and 7-day intervals having intermediate root mass and daily irrigation resulting in the least.

Effect of mulch and irrigation practices on soil water, soil temperature and the grain yield of maize (Zea mays L) in Loess Plateau, China

Agricultural management practices, such as mulching and irrigation can change the characteristics of the soil surface and hence influence the hydrothermal properties of the soil. A two-year field experiment was conducted at the Changwu agro-ecosystem research station to evaluate the effects of mulch and irrigation practices on moisture and temperature in the upper layers of the soil and on crop growth and yield performance in spring maize (Zea mays L) fields. Four mulching and irrigation treatments were examined: supplementary irrigation (SI), film mulching (FM), straw mulching (SM; in 2008 only) and a rain-fed (RF) control. The soil water (0 - 15 cm depth range) and soil temperature (0 - 5 cm depth range) were studied during the crop growing season and the treatments' yield performances were compared. Over the whole season, the average topsoil water content was significantly higher (P < 0.05) under the SM (23.3% in 2008), SI (21.4% in 2007, 22.5% in 2008) and FM (20.0% in 2007, 21.6% in 2008) treatments than under RF (17.1% in 2007, 19.6% in 2008). The seasonal trends in atmospheric and soil temperatures were similar under all treatments. The seasonally-averaged soil temperature at 07:00 and 14:00 h was highest under the FM treatment and lowest under the SM treatment. Plant height and leaf and stem biomass were significantly higher (P < 0.05) under the SI treatment than under the RF and FM treatments from silking to physiological maturity. Both the FM and SI treatments significantly improved (P < 0.05) the crop grain yield (GY) and yield components. Key words: Loess Plateau, soil water, soil temperature, spring maize.

Impact of irrigated agricultural practices on environmental quality and human health in the West Bank

AbstractThis paper examines the effects of irrigation practices and related activities on the environment and human health in the West Bank. Irrigated agriculture in the West Bank covers an area of 9,473 ha and utilizes 93 million cubic meters of irrigation water annually. The current annual use of fertilizers in the irrigated areas is 18,980 tons of chemical fertilizers and 198,900 to 265,200 tons of organic fertilizers. The total annual use of pesticides (excluding methyl bromide) in irrigated agriculture is 153 tons, of which 27 tons are internationally banned products. Methyl bromide is a dominant soil fumigant in the West Bank with a total estimated annual use of 400 tons, 44% of which is used on vegetables planted in plastic houses and high plastic tunnels. The soil solarization method to control soil-borne diseases is used by only 0.5% of the surveyed farmers. This study indicates that some farmers have suffered health problems due to exposure to pesticides, from the lack of protective clothing. Of the surveyed farmers, 19% suffer from poisoning symptoms and 1% are affected by methyl bromide fumigants. The total quantity of plastic sheets was estimated at 4,750 tons, at least 50% of which becomes waste. Eighty-eight percent of the surveyed farmers collect and burn the plastic wastes on the field, which could harm both the environment and human health through toxic fumes. Some water-related diseases occurred in the study area. Seventy-nine people were affected by leishmaniasis and 14 others by dysentery. Despite the heavy use of fertilizers, water quality analysis did not show high concentrations of nitrate.

The effect of irrigation practices on the spatio-temporal increase of Asiatic citrus canker in simulated nursery plots in Reunion Island

Asiatic citrus canker is a potentially severe disease of several citrus species and cultivars in many tropical and subtropical areas. In such areas, infected nursery plants constitute an important source of primary inoculum for newly established citrus groves. The influence of overhead, drip, and mist irrigation systems on the development of Asiatic citrus canker was studied in simulated, Mexican-lime nurseries in Reunion Island. Overhead irrigation exacerbated the increase of disease incidence and severity caused by a streptomycin-resistant strain of Xanthomonas axonopodis pv. citri. The temporal development of Asiatic citrus canker for overhead irrigated nursery plots was best described by an exponential model, because disease incidence in these plots did not come close to an asymptote during the experimental period. This can be explained by the continuous production of new growth, susceptible to infection by Xanthomonas axonopodis pv. citri, and splash dispersal of Xanthomonas axonopodis pv. citri associated with overhead irrigation. Based on spatial correlation and spatio-temporal analyses, aggregated disease patterns were found irrespective of the irrigation system. In overhead-irrigated plots, the spread of Xanthomonas axonopodis pv. citri lacked directionnality. Rainstorms of short duration and high intensity were apparently associated with disease increase in drip-irrigated plots. There is a need to improve cultivation practices in Reunion Island citrus nurseries to minimize Asiatic citrus canker incidence in nurseries and to minimize the introduction of Xanthomonas axonopodis pv. citri to new groves.

The effect of irrigation practices in the Breë River Valley on the salt content of a small river

The effect of varying irrigation return flow volumes as a possible explanation for the fluctuations in the mean monthly baseflow TDS content of a tributary in the Bree River Valley (South-Western Cape Province, Rep. of South Africa) has been investigated. A conceptual computer model was used to simulate the movement of water and solutes in 769 ha of soil in an area where vineyards are irrigated intensively. Important input requirements of the model are the physical and chemical properties of the irrigated soils, consumptive use data, and root distribution patterns. It was found that the present system of vineyard irrigation which involves a large amount of water being applied as a pre-bud-burst irrigation in late August or early September, followed by more or less fixed amounts of water being applied at set frequencies during the rest of the irrigation season, results in deep percolation losses and accompanying salt loads which are much bigger during the last six months than during the first six months of the year. The results further indicate that during the period January to June, capillary rise will exceed deep percolation. On a half yearly time basis, these computer predictions were in fair accordance with the observed TDS content of the receiving river, which for three consecutive years (1978–1980) have been substantially higher during the period July to December than from January to June. However, on a monthly time basis, it was found that the fair comparison between predicted (in the irrigation return flow) and observed (in the river) mean monthly TDS contents for the months July to December does not apply to the period January to June.

Effects of Irrigation Practices on Vine Growth, Yield, and Quality of Muskmelons1

Abstract Higher yields, larger fruit size, and earlier maturity were achieved in muskmelons (Cucumis melo L.) by irrigating when soil moisture tensions at the 25-cm depth reached 50 and 75 kPa compared with tensions of 25 kPa. More fruits were culled in the wet treatment due to decay while the drier treatments produced more fruits with growth cracks. Melons from the drier treatments were higher in soluble solids. Irrigation did not affect the other storage and shipping quality factors measured. A prethinning irrigation caused restricted root development, vine growth, fruit size, and yield.