Additional Irrigation Research Articles

Perforating the atretic pulmonary valve with CTO hardware: Technical aspects.

To review the success and technical aspects of pulmonary valve (PV) perforation using chronic total occlusion (CTO) hardware in patients with pulmonary atresia and intact ventricular septum (PA-IVS). Interventional therapy is possible in selected patients with PA-IVS. Among the various interventional options available, radiofrequency and laser assisted perforation may be more successful, but require expertise and may be substantially costly. We describe the technique of mechanical catheter PV perforation using currently available coronary hardware meant for coronary CTO in nine cases with PA-IVS. After complete echocardiographic evaluation and informed parental consent was obtained, patients were electively intubated, mechanically ventilated, adequately heparinized and were placed on intravenous prostaglandin infusion. Basic steps involved were-localizing the atretic segment and accomplishing coaxial alignment of catheters using biplane fluoroscopy, crossing the atretic segment with the soft end of perforating guidewire, stabilizing the assembly and performing graded balloon dilatation with the balloon size never exceeding 130% of pulmonary annulus diameter. For crossing the atretic PV, a retrograde approach was used in one patient where the antegrade approach was not possible. The procedure was successful in 8/9 cases (89%). Valve opening was achieved in all eight patients with immediate fall in right ventricular (RV) systolic pressures. One neonate died following surgery after catheter induced RV perforation. All surviving cases were discharged from the hospital in good general condition with no evidence of heart failure and a room air oxygen saturation of >85%. No patient required an additional pulmonary irrigation procedure. With appropriate patient and hardware selection, PV perforation using readily available coronary hardware is feasible in PA-IVS. © 2014 Wiley Periodicals, Inc.

Interannual Variation in Long-Term Center Pivot–Irrigated Maize Evapotranspiration and Various Water Productivity Response Indices. II: Irrigation Water Use Efficiency, Crop WUE, Evapotranspiration WUE, Irrigation-Evapotranspiration Use Efficiency, and Precipitation Use Efficiency

AbstractQuantification of various water use efficiency (crop water productivity) indices for different irrigation regimes can aid in making effective in-season water management decisions and developing crop water productivity models. However, these critical variables can be affected by interannual variation in climatic conditions, and long-term research that provides such data and information is extremely rare. Maize (Zea mays L.) irrigation water use efficiency (IWUE), crop water use efficiency (CWUE), evapotranspiration water use efficiency (ETWUE), annual precipitation use efficiency (ANNPUE), growing season precipitation use efficiency (GRSPUE), and the newly developed growing season precipitation use efficiency with respect to rainfed yield (GRSPUErainfed) were measured under full and limited irrigation and rainfed conditions from 2005 to 2010 in south-central Nebraska. An additional new irrigation efficiency term [irrigation-evapotranspiration use efficiency (IRRETUE)] was developed and tested to ev...

Nutrient loads and sediment losses in sprinkler irrigation runoff affected by compost and manure

High water application rates beneath the outer spans of center pivot sprinkler systems can cause runoff, erosion, and nutrient losses, particularly from sloping fields. This field study determined runoff, sediment losses, and nutrient loads (dissolved organic carbon [C], nitrate-nitrogen [NO3-N], ammonium-nitrogen [NH4-N], total phosphorus [TP], ferric-oxide strip phosphorus [FeO P], dissolved reactive phosphorus [DRP], potassium [K], calcium [Ca], magnesium [Mg], and sodium [Na]) in sprinkler runoff for two years after a single application of either stockpiled or composted dairy manure. We studied five treatments, including a nonamended control, in each of six blocks, with each block situated under a different span of a low-pressure, moving-lateral sprinkler system. In October of 1999, we incorporated 29.1 Mg ha−1 (13 tn ac−1) or 71.7 Mg ha−1 (32 tn ac−1) of dry manure or 22.4 Mg ha−1 (10 tn ac−1) or 47 Mg ha−1 (21 tn ac−1) of dry compost into a calcareous silt loam soil on slopes from 0.8% to 4.4%. In the spring of 2000 and 2001, we collected surface soil (0 to 30 mm [0 to 1.2 in]) from furrows to determine soil test phosphorus (STP). We applied 21 to 46 mm (0.8 to 1.8 in) of water at an average application intensity of 28 mm h−1 (1.1 in hr−1; peak intensity of 40 mm h−1 [1.6 in hr−1]) to 6.4 × 36.6 m (21 × 120 ft) plots six times in 2000 and two times in 2001. Additional nonmonitored irrigations were made as needed to produce corn ( Zea mays L.) silage each year. At 15 to 30 minute intervals after runoff began, we measured runoff rates and collected runoff samples to determine sediment and constituent losses for each monitored irrigation. None of the amendment treatments significantly affected runoff, sediment losses, or loads of dissolved organic C, NO3-N, NH4-N, TP, FeO P, or Mg when averaged across irrigations. Without exception, runoff, sediment losses, and loads of every measured constituent varied among irrigations after accounting for differences in water applied. Treatments influenced DRP, K, and Ca runoff loads. Loads of Ca decreased, but Na increased with increasing manure application rates. Relative to the control, manure DRP loads were five to six times greater, whereas compost DRP loads were similar.

Improved leaching practices save water, reduce drainage problems

Improved leaching practices save water, reduce drainage problems

Hydrogeological investigation for assessment of the sustainability of low-arsenic aquifers as a safe drinking water source in regions with high-arsenic groundwater in Matlab, southeastern Bangladesh

• The risk of cross-contamination of deep aquifers by As in Bangladesh was assessed. • Groundwater flow simulations identified regional and local flow-systems. • Cross-contamination is likely to be limited to areas with many irrigation wells. • When groundwater at depth has low As, it can be used for drinking water purposes. • However, installation of deep irrigation wells is strongly discouraged. Exploitation of groundwater from shallow, high prolific Holocene sedimentary aquifers has been a main element for achieving safe drinking water and food security in Bangladesh. However, the presence of elevated levels of geogenic arsenic (As) in these aquifers has undermined this success. Except for targeting safe aquifers through installations of tubewells to greater depth, no mitigation option has been successfully implemented on a larger scale. The objective of this study has been to characterise the hydrostratigraphy, groundwater flow patterns, the hydraulic properties to assess the vulnerability of low-arsenic aquifers at Matlab, in south-eastern Bangladesh, one of the worst arsenic-affected areas of the country. Groundwater modelling, conventional pumping test using multilevel piezometers, hydraulic head monitoring in piezometer nests, 14 C dating of groundwater and assessment of groundwater abstraction were used. A model comprising of three aquifers covering the top 250 m of the model domain showed the best fit for the calibration evaluation criteria. Irrigation wells in the Matlab area are mostly installed in clusters and account for most of the groundwater abstraction. Even though the hydraulic heads are affected locally by seasonal pumping, the aquifer system is fully recharged from the monsoonal replenishment. Groundwater simulations demonstrated the presence of deep regional flow systems with recharge areas in the eastern, hilly part of Bangladesh and shallow small local flow systems driven by local topography. Based on modelling results and 14 C groundwater data, it can be concluded that the natural local flow systems reach a depth of 30 m b.g.l. in the study area. A downward vertical gradient of roughly 0.01 down to 200 m b.g.l. was observed and reproduced by calibrated models. The vertical gradient is mainly the result of the aquifer system and properties rather than abstraction rate, which is too limited at depth to make an imprint. Although irrigation wells substantially change local flow pattern, targeting low-As aquifers seems to be a suitable mitigation option for providing people with safe drinking water. However, installing additional irrigation- or high capacity production wells at the same depth is strongly discouraged as these could substantially change the groundwater flow pattern. The results from the present study and other similar studies can further contribute to develop a rational management and mitigation policy for the future use of the groundwater resources for drinking water supplies.

Special features of drip-sprinkler irrigation technology

Irrigation techniques and technology based on principle of regular accumulation of moisture in active layer (surface irrigation, regular sprinkler irrigation) are most common in science and in practice. More progressive is principle of non-stop water supply of plants and soil in conformity to their water consumption. Drip irrigation and impulse sprinkling are based on this principle. The main advantage of drip irrigation is establishment of optimal water and nutritive regime directly in the plant root system. However, such irrigation is not effective enough under conditions of high air temperatures (over 25–35 °С), as growing process of several agricultural plants is known to slow down at 30–35 °С and photosynthesis, consequently, stops, which, in turn, affects plants yielding capacity. Sprinkling irrigation provides improvement of both microclimate in plant's environment and their water regime. Combination of drip and sprinkling irrigation permits the positive characteristics of each individual technology to be united, and to remove a series of disadvantages of their separate use as well as to use drip-sprinkler irrigation technology to create optimal conditions for plant development. Drip-sprinkler irrigation technology facilitates saving of irrigation water through drip irrigation in the main vegetation period and through improvement of microclimate and water regime of agricultural plants with additional sprinkling irrigation within the period of high temperatures and low air humidity that affects the growing process and increases yielding capacity of grown cultures.

Punjab scavenger wells for sustainable additional groundwater irrigation

We aim to solve the longstanding problem of sustainable groundwater extraction in the Pakistani Punjab (Indus Basin). Since public scavenging wells were abandoned in the 1990s, farmers have largely embraced the practice of skimming wells to prevent or reduce salinity in their abstracted water. Although this may be an effective short-term solution, salinity levels will continue to rise over time, rendering groundwater unsuitable for irrigation. We investigate the creation of balanced scavenging wells to reduce salinization so that sustainable groundwater use is possible as an additional source for irrigation. To achieve such sustainability, a certain amount of brackish water must be discharged, and this amount is determined by assessing the combined salt and water budgets. MATLAB-based SEAWAT models were used to show that (1) recirculation wells can substantially delay (but not prevent) salinization as a mid-term solution and (2) scavenging is the only long-term option to solve the salinization problem. Final (i.e., long-term) salinity does not depend on hydraulic parameters or initial groundwater salinity, which can only delay or speed up the process of salinization. A sensitivity analysis showed that vertical anisotropy (ratio of horizontal to vertical hydraulic conductivity) is the most important hydraulic variable for reducing the depth reached by streamlines, which reduces the time required to reach the equilibrium salinity. We conclude: (1) the extraction of freshwater can be determined from leakage, return flow and saltwater extraction; (2) the required saltwater extraction does not depend on freshwater extraction, although for recirculation, saltwater extraction does depend on saltwater injection; and (3) the final salinity in the saturated zone only depends on the salinity of the irrigation water, saltwater extraction, leakage from the irrigation canal system and, in the case of recirculation, the saltwater injection.

The sky is falling II: Impact of deposition produced during the static testing of solid rocket motors on corn and alfalfa

Tests of horizontally restrained rocket motors at the ATK facility in Promontory, Utah, USA result in the deposition of an estimated 1.5millionkg of entrained soil and combustion products (mainly aluminum oxide, gaseous hydrogen chloride and water) on the surrounding area. The deposition is referred to as test fire soil (TFS). Farmers observing TFS deposited on their crops expressed concerns regarding the impact of this material. To address these concerns, we exposed corn and alfalfa to TFS collected during a September 2009 test. The impact was evaluated by comparing the growth and tissue composition of controls relative to the treatments. Exposure to TFS, containing elevated levels of chloride (1000 times) and aluminum (2 times) relative to native soils, affected the germination, growth and tissue concentrations of various elements, depending on the type and level of exposure. Germination was inhibited by high concentrations of TFS in soil, but the impact was reduced if the TFS was pre-leached with water. Biomass production was reduced in the TFS amended soils and corn grown in TFS amended soils did not develop kernels. Chloride concentrations in corn and alfalfa grown in TFS amended soils were two orders of magnitude greater than controls. TFS exposed plants contained higher concentrations of several cations, although the concentrations were well below livestock feed recommendations. Foliar applications of TFS had no impact on biomass, but some differences in the elemental composition of leaves relative to controls were observed. Washing the TFS off the leaves lessened the impact. Results indicate that the TFS deposition could have an effect, depending on the amount and growth stage of the crops, but the impact could be mitigated with rainfall or the application of additional irrigation water. The high level of chloride associated with the TFS is the main cause of the observed impacts.

Grasses for biofuels: A low water-use alternative for cold desert agriculture?

In arid regions, reductions in the amount of available agricultural water are fueling interest in alternative, low water-use crops. Perennial grasses have potential as low water-use biofuel crops. However, little is known about which perennial grasses can produce high quantity, high quality yields with low irrigation on formerly high-input agricultural fields in arid regions. We monitored biomass production, weed resistance, rooting depth, and root architecture of nine perennial grasses under multiple irrigation treatments in western Nevada. Under a low irrigation treatment (71 ± 9 cm irrigation water annually), cool-season grasses produced more biomass and were more weed-resistant than warm-season grasses. With additional irrigation (120 ± 12 cm water annually), warm- and cool-season grasses had similar biomass production, but cool-season species remained more weed-resistant. Among species within each grass type, we observed high variability in performance. Two cool-season species (Elytrigia elongata and Leymus cinereus) and one warm-season species (Bothriochloa ischaemum) performed better than the other tested species. Root depth was not correlated with biomass production, but species with deeper roots had fewer weeds. Abundance of fine roots (but not large roots) was correlated with increased biomass and fewer weeds. Both L. cinereus and E. elongata had deep root systems dominated by fine roots, while B. ischaemum had many fine roots in shallow soil but few roots in deeper soil. Cool-season grasses (particularly E. elongata, L. cinereus, and other species with abundant fine roots) may be worthy of further attention as potential biofuel crops for cold desert agriculture.

Treatment of drug-induced gingival overgrowth by full-mouth disinfection: A non-surgical approach.

Background:Drug-induced gingival overgrowth is a common finding in the modern era. These gingival overgrowths are usually treated by various modalities namely substitution of drugs, surgical, and non-surgical treatment. The recent concept mainly involves full-mouth scaling and root planing (the entire dentition in two visits within 24 hours, i.e., two consecutive days) followed by chair side mouth rinsing by the patient with a 0.2% chlorhexidine solution for 2 minutes and brushing the tongue of the patient with 1% chlorhexidine gel. This is followed by an additional subgingival irrigation (three times, repeated within 10 minutes) of all pockets with a 1% chlorhexidine gel.Materials and Methods:Twenty patients between the ages of 20 and 50 years with drug-induced gingival overgrowth were treated using the full-mouth disinfection approach. The patients were evaluated at 3 months and 6 months after therapy. The data obtained for plaque index, bleeding on probing index, probing pocket depth, and gingival overgrowth scores were tabulated and compared statistically using the one sample unpaired t test.Statistical Analysis:Statistically significant difference (P < 0.05) was found in PI GBI, PPD, and GO score between baseline, 3 months, and 6 months.Results:All clinical parameters improved significantly after therapy without the need of further surgical treatment.Conclusions:Full-mouth disinfection might be a beneficial treatment concept in patients with drug-induced gingival overgrowth, thus decreasing the need for surgical therapy.

Ocena kapaciteta infiltracije na zemljište tokom mere navodnjavanja

Ocena kapaciteta infiltracije na zemljište tokom mere navodnjavanja

Optimizing Irrigation of Fresh Market Tomato Grown in the Mid-Atlantic United States

Determining irrigation requirements for fresh market tomato (Solanum lycopersicum) production is essential to obtain optimum yields, cost-effective water use, and minimize nitrate leaching. The objective of this study was to determine the appropriate irrigation rate for polyethylene-mulched fresh market tomato grown in Virginia. This study investigated irrigation regimes by applying water based on evapotranspiration (ET) calculations in three spring and three fall seasons. Plants were grown using 0.0 × ET, 0.5 × ET, 1.0 × ET, 1.5 × ET, and 2.0 × ET. Additional irrigation treatments involved tensiometers installed at 12-inch depth in the bed, programmed to irrigate at soil moisture set points of −20, −40, and −60 kPa. Tensiometer treatments were able to irrigate up to nine times per day if soil moisture fell below the designated moisture set point. Measurements included fruit yield, plant and fruit nitrogen (N) uptake, and inorganic soil nitrate-N (NO3-N) at 0 to 10-, 10 to 20-, and 20 to 30-inch depths. Overall, the 0.5 × ET treatment provided optimum yields in all growing seasons except Spring 2010, which was unseasonably hot and dry. A tensiometer treatment (−40 kPa) provided optimum yields in all growing seasons, and was able to adjust irrigation in a hot and dry season. Residual soil NO3-N at 0 to 10 inches generally exhibited an inverse relationship with yield; greater yields resulted in less residual soil NO3-N. In most treatments throughout the duration of this study, plant N uptake + fruit N uptake accounted for most of the N fertilizer applied (68% to 151%). In conclusion, an irrigation rate of 0.5 × ET and a tensiometer treatment (−40 kPa) provided minimal irrigation inputs to obtain optimum marketable yields while also minimizing residual soil nitrate that may be prone to leaching after the season.

AUTOMATED IRRIGATION CONTROL FOR IMPROVED GROWTH AND QUALITY OF GARDENIA JASMINOIDES©

Sustainable use of water resources is of increasing importance in container plant production as a result of decreasing water availability and an increasing number of laws and regulations regarding nursery runoff. Soil moisture sensor-controlled, auto- mated irrigation can be used to irrigate when substrate volumetric water content (u) drops below a threshold, improving irrigation efficiency by applying water only as needed. We compared growth of two Gardenia jasminoides cultivars, slow-growing and challenging 'Radicans' and easier, fast-growing 'August Beauty', at various u thresholds. Our objective was to determine how irrigation can be applied more efficiently without negatively affecting plant quality, allowing for cultivar-specific guidelines. Soil moisture sensor-controlled, automated irrigation was used to maintain u thresholds of 0.20, 0.30, 0.40, or 0.50 m 3 ·m L3 . Growth of both cultivars was related to u threshold, and patterns of growth were similar in both Watkinsville and Tifton, GA. High mortality was observed at the 0.20-m 3 ·m L3 threshold with poor root establishment resulting from the low irrigation volume. Height, width, shoot dry weight, root dry weight, and leaf size were greater for the 0.40 and 0.50 m 3 ·m L3 than the 0.20 and 0.30-m 3 ·m L3 u thresholds. Irrigation volume increased with increasing u thresholds for both cultivars. For 'August Beauty', cumulative irrigation volume ranged from 0.96 to 63.21 L/plant in Tifton and 1.89 to 87.9 L/plant in Watkinsville. For 'Radicans', cumulative irrigation volume ranged from 1.32 to 126 L/plant in Tifton and from 1.38 to 261 L/plant in Watkinsville. There was a large irrigation volume difference between the 0.40 and 0.50-m 3 ·m L3 u thresholds with little additional growth, suggesting that the additional irrigation applied led to over- irrigation and leaching. Bud and flower number of 'Radicans' were greatest for the 0.40-m 3 ·m L3 u threshold, indicating that overirrigation can reduce flowering. The results of this study show that growth of the different G. jasminoides cultivars responded similarly to u threshold at both locations. Similarities in growth and differences in irrigation volume at the 0.40 and 0.50-m 3 ·m L3 u thresholds show that more efficient irrigation can be used without negatively impacting growth.

Shallow saline groundwater use by Black cumin (Nigella sativa L.) in the presence of surface water in a semi-arid region

Lysimetric experiments were conducted to investigate the percentage of groundwater contributions made by Black cumin (Nigella sativa L.). The plants were grown in 27 columns, each with a diameter of 0.40m and packed with Silty clay soil. The factorial experiments were carried out using three replicates with randomized complete block design and different treatment combinations. Nine treatments were applied during each experiment via maintaining groundwater with an EC of 1, 2 and 4dSm−1 at three different water table depths (0.6, 0.8 and 1.10m). The groundwater contribution was measured as a part of crop evapotranspiration by taking daily readings of water levels in Mariotte tubes. The additional irrigation water requirement for each treatment was applied by adding surface water with EC of 0.5dSm−1. The results showed that for different treatments with EC values of 1, 2 and 4dSm−1 and different water table levels of 0.60, 0.80, and 1.10m, the average percentage of groundwater contributions were determined to be 67.25, 55 and 45.75%, 60.75, 50 and 41.5% and 54.25, 43.5 and 36% of the average annual Black cumin water requirements, respectively. This investigation shows that groundwater use and crop yield decrease as both groundwater salinity and water-table depth increase.

National River Linking Project of India

India plans to transfer water from the water surplus region of the north-east to the water scarce regions of western and southern India. The plan is called the National River Linking Project (NRLP). Sixteen links in the Himalayan region and 14 links in the Peninsular region are proposed that will transfer annually about 174 Billion m3 (Bm3) of water through a canal network of 14,900 km. It will involve connecting 37 rivers and construction of dams/storages in 3,000 places. It is estimated to cost US$ 120 Billion (in 2000 price). The projected benefits are additional irrigation to 34 million hectares of land, generation of 34,000 MW of electricity, reduction of floods, and social upliftment. Many prominent experts and personalities have criticized the project claiming that it will be a financial, social and environmental disaster. Both the proponents and opponents think that India will be doomed depending on whether the NRLP is implemented or not (Amarsinghe 2009). The International Water Management Institute (IWMI) in collaboration with the Challenge Program for Water &amp; Food (CPWF) undertook a three year Strategic Analysis of the NRLP to evaluate the NRLP concept with a detailed analysis. This paper is a general description of the NRLP, and it summarizes the findings of the Strategic Analysis of this Project undertaken by IWMI-CPWF. Further, it explores the possible consequences to India's neighbors in general and Nepal in particular.Hydro Nepal; Journal of Water, Energy and EnvironmentVol. 12, 2013, JanuaryPage: 13-19DOI: http://dx.doi.org/10.3126/hn.v12i0.9026Uploaded Date : 10/28/2013

Sustainable conjunctive use of groundwater for additional irrigation

AbstractThe key to ‘sustainable conjunctive use of groundwater for additional irrigation’ is the salt balance of groundwater below an irrigated field. This paper aims to develop a mathematical tool to study the accumulation of salt in the groundwater below an irrigated field as caused by irrigation recirculation. This study derives a salt balance of groundwater to ensure that the additional irrigation from groundwater remains possible in the future. The water and salt budgets by themselves do neither provide information concerning farmers' options nor on the limits of the individual terms in the budget equations. It is presumed that farmers will intuitively aim for (1) an optimal value of the actual evapotranspiration, and (2) a return flow as a feasible low fraction of the available water. We, therefore, derive the irrigation from groundwater Q as a consequence of the predefined farmers' aims to achieve a high actual evapotranspiration in combination with a given optimally used irrigation system. Our model concludes that the required amount of drainage is only dependent on the ratio of the salinity in the surface irrigation water and the acceptable salinity of the groundwater. The final salinity in the saturated zone only depends on salt‐carrying inflows and outflows. From the aforesaid model, it is further concluded that sustainable conjunctive use of groundwater for additional irrigation requires long‐term salt management, which should be founded on the essential controlling factors as derived in this paper. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Intercropping Competition between Apple Trees and Crops in Agroforestry Systems on the Loess Plateau of China

Agroforestry has been widely practiced in the Loess Plateau region of China because of its prominent effects in reducing soil and water losses, improving land-use efficiency and increasing economic returns. However, the agroforestry practices may lead to competition between crops and trees for underground soil moisture and nutrients, and the trees on the canopy layer may also lead to shortage of light for crops. In order to minimize interspecific competition and maximize the benefits of tree-based intercropping systems, we studied photosynthesis, growth and yield of soybean (Glycine max L. Merr.) and peanut (Arachis hypogaea L.) by measuring photosynthetically active radiation, net photosynthetic rate, soil moisture and soil nutrients in a plantation of apple (Malus pumila M.) at a spacing of 4 m × 5 m on the Loess Plateau of China. The results showed that for both intercropping systems in the study region, soil moisture was the primary factor affecting the crop yields followed by light. Deficiency of the soil nutrients also had a significant impact on crop yields. Compared with soybean, peanut was more suitable for intercropping with apple trees to obtain economic benefits in the region. We concluded that apple-soybean and apple-peanut intercropping systems can be practical and beneficial in the region. However, the distance between crops and tree rows should be adjusted to minimize interspecies competition. Agronomic measures such as regular canopy pruning, root barriers, additional irrigation and fertilization also should be applied in the intercropping systems.

Beyond water-intensive agriculture: Expansion of Prosopis juliflora and its growing economic use in Tamil Nadu, India

Against the backdrop of expanding commercial crop markets and private well expansion, market-oriented agriculture has developed in villages with access to abundant water resources in Tamil Nadu, India. On the other hands, the villages that have failed to secure sufficient irrigation water have experienced sharp decline in cropping. Such land has been rapidly invaded by Prosopis juliflora, a tree species that has wide adaptability of the different environments and high coppicing ability. This species has traditionally been harvested as a fuel for domestic use and small-scale businesses, and recognised as “a tree for the poor”. However, since the establishment of the electricity act in 2003, which completely deregulated participation of private companies in the electricity generation industry, the new usage of Prosopis has been created: several small-scale electricity generating plants began to utilise this tree as an energy source. As a result, the demand for Prosopis tree rapidly increased and the real price of raw wood has more than doubled between 2003 and 2009. A census survey of household income revealed that income generated from Prosopis expansion compensated for the decrease of cropping, and contributed to an increase in the net household income, especially for the landless labourers and middle class land holders. This fact indicates that it is possible to reduce poverty in a semi-arid rural area without securing additional irrigation water, in case proper institutions and technologies are in place.

Climate and crop yields impacted by ENSO episodes on the North China Plain: 1956–2006

El Nino-Southern Oscillation (ENSO) contributes to climate anomalies, especially those related to regional rainfall, which affect crop production. Although the North China Plain (NCP) is the most important agricultural production region in China, the impact of ENSO events on local climate and crop production has received only limited attention. Therefore, the impact of different phases of ENSO on local climate and production of winter wheat and summer maize, both rain fed and irrigated, was investigated at three sites using the agricultural production systems simulator model. Data on daily temperature, precipitation, and sunshine hours for 50 years (1956–2006) were analysed to build climate scenarios for three categories of ENSO: years with El Nino events, years with La Nina events, and neutral years. The pattern of climate change was generally similar across the three sites: annual precipitation decreased slightly and annual mean sunshine hours decreased significantly, whereas annual mean minimum temperature increased significantly, leading to a significant increase in mean air temperature. Precipitation decreased and temperature and sunshine hours increased in both El Nino and La Nina years but remained stable in neutral years. Under full irrigation, the probability of exceeding distribution that crop yield would be higher was not markedly affected (P > 0.05), although the yields in both El Nino and La Nina years differed markedly from those in neutral years, especially in maize. Under rain-fed conditions, the yield of maize was decreased greatly (P 0.05) with the ENSO category: production of maize was more vulnerable than that of wheat in El Nino and La Nina years. El Nino and La Nina had similar effects on climatic variables across the NCP: low yields in El Nino and La Nina years due to lower precipitation and high yields in neutral years due to longer sunshine hours and additional irrigation.

Preventive Saline Irrigation of the Bile Duct After the Endoscopic Removal of Common Bile Duct Stones

Small stone fragments after an endoscopic stone extraction for choledocholithiasis may act as the nidus for recurrent choledocholithiasis. Therefore, efforts to eliminate the nidus might reduce the recurrence of choledocholithiasis and cholangitis related to choledocholithiasis. The purpose of this study was to determine whether an additional preventive saline irrigation of the bile duct after the endoscopic removal of common bile duct stones would decrease residual stones and the recurrence of cholangitis. A retrospective analysis was performed for the consecutively collected data about the patients who underwent the complete endoscopic treatment for common bile duct stone. Among 99 patients, 45 patients underwent saline irrigation. Residual stones were detected in 18 patients (18.2 %). The incidences of residual stones were 8.9 % (4 of 45 patients) in the irrigation group and 25.9 % (14 of 54 patients) in the non-irrigation group (P = 0.037). In multivariate analysis, preventive saline irrigation was found to be the only significant factor for the decrease of residual stones (HR = 0.258, P = 0.039). When analyzing the occurrence of recurrent cholangitis and the procedure related to complications, there were no significant differences according to the performance of preventive saline irrigation of the bile duct. Preventive saline irrigation could reduce the residual common bile duct stones without complications.