• Authors:
    • Lei, T.
    • Cao, L.
    • Liu, S.
    • Wang, X. S.
    • Jiang, C. L.
    • Chun, C. P.
    • Peng, L. Z.
    • Ling, L.
  • Source: ACTA HORTICULTURAE SINICA
  • Volume: 38
  • Issue: 1
  • Year: 2011
  • Summary: A field experiment was conducted during 2002-2007 to evaluate effects of various drip fertigation frequencies (4 times/year, 10 times/year, 16 times/year) on tree growth, fruit yield and quality of Trovita sweet orange ( Citrus sinensis Osbeck) on 'Carrizo' citrange [ Poncirus trifoliata (L.) Raf.] * [ Citrus sinensis Osbeck] rootstock (planted in 2001) in calcareous purple soil in Zhongxian County of Chongqing. The control trees were fertilized (10 times/year) by broadcast application. The results showed that tree trunk circumference, tree height and canopy diameter did not show significant response to fertigation frequency; And no significant difference existed between fertigation treatments and control for tree growth. However, fertigation treatments showed significant effects on increasing fruit yield with 29.4%-36.5% more accumulative yield than the control, but high fertigation frequency did not increase fruit yield. No significant effects was observed for fertigation on fruit quality. It is recommended that citrus growing in calcareous purple soil should be drip fertigated 4 times a year.
  • Authors:
    • Pires, L. F.
    • Nova, N. A. V.
    • Pereira, A. B.
    • Alfaro, A. T.
  • Source: Revista Brasileira de Meteorologia
  • Volume: 26
  • Issue: 2
  • Year: 2011
  • Summary: The uptake of water from the roots of crops comes to being a physiological response of the plant to the water loss process through its stomata. Getting to know the daily transpiration rates throughout the phenological cycle allows for the application of the ideal amount of irrigation water at the right moment to maximize production with environmental protection. Since transpiration direct measurements at the field, mainly for trees in general, are to be of operational difficulty and relatively high cost we came up with a methodology that allows one to calculate the daily transpiration rates of apple trees and citrus orchards from variables of both the physical environment and the crop. The input data of the proposed model are air temperature, air relative humidity, photoperiod duration, and leaf area. Estimated transpiration rates based on the water potential gradient between the air and leaf approach were comparable in apple trees and citrus orchards. Sap flow daily values were obtained by means of the heat balance method at Bordeaux, France, and Piracicaba, SP, Brazil. All the coefficients of determination of the regression equations obtained herein were higher than 0.93. This allows one to calculate the amount of irrigation water to be applied throughout the crop growing seasons with a high precision as a function of meteorological data and crop covering density at the sites in the study.
  • Authors:
    • Stoffella, P. J.
    • He, Z. L.
    • Pereira, B. F. F.
    • Melfi, A. J.
  • Source: Agricultural Water Management
  • Volume: 98
  • Issue: 12
  • Year: 2011
  • Summary: The effects of irrigation with reclaimed wastewater (RWW) were compared with well water (WW) on citrus ( Citrus paradisi Macfad. * Citrus aurantium L.) nutrition. The deviation from the optimum percentage (DOP) index of macro- and micro-nutrients were used to evaluate the nutritional status: optimal (DOP=0), deficiency (DOP0). After 11 years of RWW irrigation the influence on nutrient concentration in plants decreased in the order: B > Zn > Mn=Ca > Cu > Mg > P > K. Reclaimed wastewater irritation positively affected citrus nutrition as it rendered the concentration of macro-nutrients, i.e. P, Ca, and K. closer to their optimum levels (SigmaDOP macro=7). However micro-nutrients tended to be excessive in plants (SigmaDOP micro=753) due to imbalanced supply of these elements in the RWW, particularly, for B and Cu. Citrus groves with long-term RWW irrigation may exercised caution in monitoring concentrations of B and Cu to avoid plant toxicity and soil quality degradation.
  • Authors:
    • Reyes Serrano, H. F.
    • Alvarez Latorre, P.
    • Poncet, Y.
  • Source: Sécheresse
  • Volume: 22
  • Issue: 4
  • Year: 2011
  • Summary: The Coquimbo region, in Chile, receives a rainfall of 110 mm (annual mean), winter rains, which allow only small scale cereal cropping and pastures for goat and sheep raising. However, thanks to subtle irrigation processes, practiced for centuries, the region used to export high value agricultural products up to mining and transportation workers and facilities settled in the northern arid area of the country. The history of ground occupation and soil uses, throughout the colonial era then in an independent Chile, designed not only the land property modalities, but also the sharing of rights of water usage. During the last sixty years, this system has changed considerably, with both technical causes (artificial lakes to stock water, cheap electric energy in rural areas) and with political and social causes (agrarian reform, agricultural foreign capital). The scientific research program " Suivi de la desertification, connaissance des systemes d'elevage caprin, gestion de la ressource en eau: trois aspects pour la definition d'une politique environnementale incluant la participation des populations dans la IVeregion du Chili ( ECOS-Conicyt)" studied theses changes and their consequences, in order to anticipate consequences and foresee negative ones: the "Limari model" is frequently given as an example of successful economic development and is to be copied in other arid valleys. The irrigation graphic scheme of the valley of Limari is hereafter presented in four dynamic figures, as one of the multidisciplinary supports for research into the well-known problems of geographic and economic balance between rural and urban development, between irrigated and arid areas, and upon the long range effects of the disconnection between land rights and water rights. The new social and economic order will be effected as a consequence of the relationship between new technical applications and new laws and rights. This graphic demonstration is contrived to organise and discuss available information about water, energy, irrigated areas and regulation by law.
  • Authors:
    • Stepannikov, V.
    • Popova, E.
    • Popov, N.
  • Source: Mezhdunarodnyi Sel'skokhozyaistvennyi Zhurnal
  • Issue: 4
  • Year: 2011
  • Summary: Problems associated with the organization and provision of irrigation in the arid regions of Astrakhan Province, Russia, for the efficient use of both water and land are discussed. Recommendations are made for modernizing the structures of irrigated land use on the basis of scientifically based crop rotations. Economic evaluations of the main indicators of irrigated farming efficiency allowed farming systems to be developed for the Province's various natural and climatic zones and according to farm type (for example, meat or dairy farms, and farms devoted to growing cereals, rice, vegetables, cucurbit crops, fodder crops or potatoes).
  • Authors:
    • Nalley, L. L.
    • Popp, M.
  • Source: Journal of Agricultural and Applied Economics
  • Volume: 43
  • Issue: 3
  • Year: 2011
  • Summary: Arkansas cropping pattern changes at the county level were estimated under various scenarios involving a likely decline in water availability, the development of a biomass market for renewable energy production, and the potential of a widely used carbon offset market. These scenarios are analyzed separately and jointly to determine which of the three scenarios is expected to have the largest impact on net (emissions - sequestration) greenhouse gas (GHG) emissions, renewable fuels feedstock supply, and producer net returns. Land use choices included conventional crops of rice, cotton, soybean, corn, grain sorghum, pasture, and hay. Specialty crops of loblolly pine and switchgrass were modeled for their respective potential to sequester carbon and provide feedstock for renewable fuels. GHG emissions were measured across an array of production methods for each crop. Soil and lumber carbon sequestration was based on yield, soil texture, and tillage. Using the concept of additionality in which net GHG emissions reductions compared with a baseline level were rewarded at a carbon price of $15 per ton along with $40 per dry ton of switchgrass, baled at field side, revealed that irrigation restrictions had the largest negative impact on producer net returns while also lowering net GHG emissions. Introducing the higher carbon price led to minor positive income ramifications and greatly reduced net GHG emissions. Biomass production returns were higher than the returns from the carbon offset market, however, at the cost of greater net GHG emissions. The combination of all factors led to a significant increase in switchgrass and pine production. In this scenario, approximately 16% of the total income losses with lower nonirrigated yields were offset with returns from biomass and carbon markets. Lowest statewide net GHG emissions were achieved given least irrigation fuel use and a greater than 15% increase in carbon sequestration with pine and switchgrass.
  • Authors:
    • Vaseghi, E.
    • Bagheri, A.
    • Pour, A. S.
  • Source: Journal of Agricultural Economics Research
  • Volume: 3
  • Issue: 1
  • Year: 2011
  • Summary: In this study, three irrigation methods, namely, clouding tape, sprinkler and furrow in Rozveh Agricultural Research station (Fereidan Region in Isfahan) were evaluated. This study was conducted as randomized complete blocks design as a split-split strip plot layout with three replication during two years. Three irrigation systems were considered as main plots, two planting methods (one-row planting and two-row planting) as split subplots and two potato cultivars (Marfuna and Agria) as split-split subplots. Significant difference way observed between irrigation method treatments and planting method by analyzing two years results. Results of the 1st year showed the advantage of production mean in sprinkler and tape methods comparing to furrow method while the second year results showed the advantage of sprinkler method to tape method and tape method to furrow method. Comparison of yield mean of cultivars indicated that although Agria cultivar was preferred to Marfona cultivar in the 1st year, two year comparison of yield mean showed no significant difference between Agria and Marfuna cultivars with yield means of 24083 kg. and 23233 kg., respectively. The two year comparison results of yield means using different planting methods indicated that one row planting with mean yield of 24839 kg. was preferred significantly compare to two row planting with mean yield of 22927kg. One row planting showed significant preference in the 1st and 2nd year. Two year interaction effect of treatments showed that, except cultivar * year source, other interaction effects were not significant. Tape irrigation led to highest mean of WUE equal to 4.92 kg/m3. Economic evaluation of the project was carried out using benefit-cost ratio and present value of net benefits. The results indicated that sprinkler system was more beneficial. Tape and furrow methods for potato planting stood in the next place.
  • Authors:
    • Manmohan, J. R.
    • Singh, J.
    • Kaul, M. K.
    • Bhatnagar, P.
    • Chauhan, P. S.
  • Source: The Indian Forester
  • Volume: 137
  • Issue: 12
  • Year: 2011
  • Summary: Comparative effects of drip and micro sprinkler systems under kinnow+kinnow and kinnow+poplar silvi-horti system were studied under sub tropical climate. Drip system of irrigation was found promising in maintaining better growth of kinnow plants. Kinnow+Poplar system of plantation was found superior over kinnow+kinnow system of plantation under drip irrigation system. Under this system (kinnow+poplar) of plantation, values of plant height at 70% ETC were 2.55 m, canopy volume 23.51 m 3, rootstock girth 11.13 cm, scion girth 10.76 cm, and leaf area were 16.07 cm 2. Of course, values for all these traits were higher at 100% ETc under kinnow+kinnow system of plantation over kinnow+poplar system of plantation under drip system but these were at par with each other. Irrigation of kinnow orchards at 100% ETc was found better irrespective of the systems of irrigation.
  • Authors:
    • Faridi, I. A.
    • Gillani, S. R.
    • Imran, M
    • Mahmood. Z.
    • Shaheen, Q.
  • Source: ASIAN JOURNAL OF CHEMISTRY
  • Volume: 23
  • Issue: 12
  • Year: 2011
  • Summary: This work evaluates the effects of water of irrigation in comparison with the source of water with special reference to chromium contamination in vegetables grown in various areas of Pakistan. Twenty samples of each vegetable, i.e., spinach ( Spinacia oleracea), lettuce ( Lactuca sativa), carrot ( Daucus cariota), capsicum ( Capsicum fistulosus), sweet pea ( Lathyrus odoratus), potato ( Solanum tuberosum) and cabbage ( Brassica oleracea), were collected during the year 2006 and replicated in 2007 and 2008. The range of concentration of chromium in vegetables irrigated with tube well water, canal water and municipal sewage water was in between 0.3-5.3, 1.01-13.09 and 1.11-29.89 ppm, respectively. Statistical analysis shows that the vegetables grown by tube well water and canal irrigation are quite safe and show less than 1% samples of vegetables showing chromium concentration more than that of permissible ambient levels. In case of vegetables irrigated by municipal sewage water more than 50% samples contained Cr more than that of permissible ambient levels. The results reflect that the uptake of chromium in vegetables is facilitated under the condition where the source of irrigation is sewage water.
  • Authors:
    • Pu, Y. L.
    • Xiao, H. L.
    • Wang, D.
    • Zhang, J. L.
    • Qin, S. H.
  • Source: Acta Agronomica Sinica
  • Volume: 37
  • Issue: 1
  • Year: 2011
  • Summary: Water supply scarcity is the main limiting factor for sustainable agriculture development in semiarid areas on the Western Loess Plateau. Because of imbalance for rainfall distribution, yield and water use efficiency (WUE) of potato, one of the dominant crops in middle Gansu province, are relatively low. To optimize supplemental irrigation system using limited catchment rainfall for rain-fed potato in the area, field experiments were carried out in 2008-2009 to determine evapotranspiration, WUE, yield, yield traits and quality of rain-fed potato under different supplemental irrigation amounts and timings. The results showed that WUE of potato increased significantly in the supplemental irrigation treatment of 45 mm, and decreased with increasing of irrigation amount. WUE and irrigating water use efficiency (IWUE) of potato were higher with supplemental irrigation at the seedling than the tuber expanding stage. WUE and IWUE were the highest under the 45 mm of irrigation at the seedling stage. Yield, rates of bigger tuber and middle tuber in rain-fed potato were increased, and small tuber rates were decreased by supplemental irrigation. Big tuber rates were increased by supplemental irrigation at the seedling stage, while medium tuber rates were increased by supplemental irrigation at the tuber expanding period. Potato numbers per plant were decreased, but tuber yield per plant was increased by supplemental irrigation. With increasing of irrigation amount, the yield of potato was not increased significantly, but green tuber rate and blet tuber rate were increased significantly. Starch content of potato was reduced, while protein content of tuber was increased by supplemental irrigation. Supplemental irrigation of 45 mm at seedling is optimal irrigation system for rain-fed potato in the area.