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Promoting Irrigation Water Utilization Efficiency in Superior Vineyards  [PDF]
A.S. El-Khawaga
Asian Journal of Crop Science , 2013,
Abstract: The effect of different laterals and emitters frequency on growth, leaf content of N, P, K, Mg, S, Zn, Fe and Mn, berry setting, yield as well as physical and chemical characteristics of superior grapes were investigated during 2009 and 2010 seasons. Eight years old superior grape vines grown at 1.75x2.75 m apart in sandy loam soil in Qena Governorate under drip irrigation system with 4 L h-1 emitters were used in this study. One or two laterals and two to six emitters per vine were used. Results revealed that leaf area, main shoot length, leaf content of N, P, K, Mn, S, Zn, Fe and Mn, berry setting, yield, cluster weight as well as physical and chemical characteristics of the grapes markedly improved with increasing number of laterals from one to two and number of emitters from two to six. Increasing emitters' frequency from four to six on double laterals gave significant effect on the above mentioned characters. The best recommended treatment for increasing irrigation water utilization efficiency in Superior vineyards as well as improving yield quantitatively and qualitatively is double laterals and six emitters/ vine.
Water application uniformity and fertigation in a dripping irrigation set
Borssoi, Adilson L.;Vilas Boas, Marcio A.;Reisd?rfer, Marcelo;Hernández, Ricardo H.;Follador, Franciele A. C.;
Engenharia Agrícola , 2012, DOI: 10.1590/S0100-69162012000400011
Abstract: the purpose of this study was to evaluate the uniformity of distribution coefficient (udc) and coefficient of variation (cv) of a familiar set of irrigation, classifying it the asae standard. the irrigation and fertigation are determined by two methods the keller & karmeli and denículi . the two experiments were subjected to varying pressures: 12, 14, 16 and 18 kpa, in a completely randomized design of twenty samples composed of flows with three replications. urea, potassium chloride (kcl) and ammonium phosphate (map) were the elements used for fertigation. the system consisted of a 200 l tank, which supplied another container of 30 l, it was moved vertically to control the pressure. the data was statistically compared between treatments for each methodology. in fertigation the best pressure was 16 kpa and was classified as "excellent" for udc (91.03%) and "marginal" for c.v. (7.47%). for the irrigation treatment, the best pressure was 16 kpa rated "excellent" for udc (91.2%) and "marginal" for c.v. (7.68%). the denículi et al. (1980) methodology proved more reliable for the evaluation of drip systems. it was observed that this set has good uniformity of distribution, but with great variability in flows.
Dimensioning the Irrigation Variables for Table Grape Vineyards in Litho-soils
Pasquale Campi,Francesca Modugno,Domenico A. Palumbo,Marcello Mastrorilli
Italian Journal of Agronomy , 2010, DOI: 10.4081/ija.2010.315
Abstract: The pedo-climatic and farm characteristics of Bari’s hinterland have allowed for the diffusion of prestigious table viticulture. The typical “tendone” vineyard structure is set up after managing the surface of the soil. The karstic nature of the region and the thermo-rainfall trend during the vegetative season impede the vineyard from producing adequately without irrigation. Given the importance of water contributions to table grapes, it is necessary to correctly measure the water variables for economic and environmental reasons. Farmers often irrigate according to “fixed” turns and volumes, against the rules of “good irrigation practice” which consider monitoring the water status of the soil or plant as a prerequisite of irrigation scheduling. During this experiment, two methods of irrigation management were compared: “fixed-turn” and “on demand”. For “on demand” irrigation, the irrigation volume is calculated on the basis of the soil water status (estimated according to the “water balance” method described in the “Paper n. 56 FAO”) and the irrigation is scheduled on the basis of the experimental relationship between “pre-dawn” leaf water potential and the water available in the soil. For this comparison, data from a 2-year “on farm” experimentation, in an area typical of table grape cultivation in Southern Italy, have been used. The results obtained show that, in respect to the “fixed-turn” management, the “on demand” management allows for a 20% reduction in water volumes, without compromising production. The water balance method proved to be a promising criterion for irrigation scheduling in these shallow soils, rich in stones (litho-soils). This only held true when the depth of the soil layer explored by the root system was defined by the “equivalent depth” and not by the actual soil’s depth.
膜下滴灌前后表层土壤水分空间变异性
The variability of surface layer soil water content under plastic mulch dripping before and after irrigation
 [PDF]

谭帅,王全九,罗小东,马媛
- , 2016, DOI: 10.7606/j.issn.1000-7601.2016.01.07
Abstract: 以2 m×2 m的网格布点,采用经典统计学和地统计学结合的方法研究了一次灌溉前后膜下滴灌棉田的表层土壤体积含水量的空间变异性特征。结果表明:(1) 灌溉前后表层土壤含水量变异系数(CV)分别为28.7%和21.8%,均表现出中等变异特性,颗粒分布能为灌溉前后表层土壤含水量的变异系数变化提供参考。(2) 灌溉前后表层土壤含水量的半方差函数均可用高斯模型很好地描述(R2>0.9),对应的空间异质比(C0/(C0+C))分别为0.201和0.324,表现出强烈和中等的空间依赖性;灌溉后,表层土壤含水量空间自相关性减小,4.373 m可作为该研究区域的参考取样步长。(3) 灌溉前后表层土壤含水量的Moran’s I随滞后距离变化的趋势大体一致,且灌前表层土壤含水量的自相关性较灌后显著。(4) Kriging插值结果表明,灌溉前后含水量空间分布较相似,表现出显著的变异性,且灌后含水量分布较灌前复杂。
In this research, classical statistics and geostatistics were combined to research the characteristics of spatial variability for surface layer soil water content in a area of 20 m×20 m cotton field by dripping under mulch before and after the irrigation. The primary results showed that the variation coefficients (CV) for surface layer soil water before and after irrigation were 28.7% and 21.8%, respectively, exhibiting moderate variability. The particle distribution could provide a basis for the variations in CV of water content before and after irrigation. Additionally, the semivariogarm function for surface layer soil water content before and after irrigation could be described well by Gaussian model (R2). The corresponding ratios of spatial heterogeneity (C0/(C0+C)) were 0.201 and 0.324, respectively, indicating strong and moderate spatial dependences, respectively. After irrigation, the spatial autocorrelation of surface layer soil water content became decreased. The reference sample step lag of study region could be adopted by 4.373 m. Moreover, Moran’s I for surface layer soil moisture before and after irrigation followed similar trends with the lag distance. The autocorrelation of surface layer soil water content before irrigation was more significant than that after irrigation. Lastly, the results of Kriging interpolation showed that spatial distributions for water content before and after irrigation were similar and showed obvious variabilities. Water content after irrigation was more complex than that before irrigation.
Simulation of a Dripping Faucet  [PDF]
Nobuko Fuchikami,Shunya Ishioka,Ken Kiyono
Physics , 1998, DOI: 10.1143/JPSJ.68.1185
Abstract: We present a simulation of a dripping faucet system. A new algorithm based on Lagrangian description is introduced. The shape of drop falling from a faucet obtained by the present algorithm agrees quite well with experimental observations. Long-term behavior of the simulation can reproduce period-one, period-two, intermittent and chaotic oscillations widely observed in experiments. Possible routes to chaos are discussed.
A superconducting "dripping faucet"  [PDF]
Stuart B. Field,Gheorghe Stan
Physics , 2006,
Abstract: When a current is applied to a type-I superconducting strip containing a narrow channel across its width, magnetic flux spots nucleate at the edge and are then driven along the channel by the current. These flux "drops" are reminiscent of water drops dripping from a faucet, a model system for studying low-dimensional chaos. We use a novel high-bandwidth Hall probe to detect in real time the motion of individual flux spots moving along the channel. Analyzing the time series consisting of the intervals between successive flux drops, we find distinct regions of chaotic behavior characterized by positive Lyapunov exponents, indicating that there is a close analogy between the dynamics of the superconducting and water drop systems.
Nature and regulation: Management of vineyards and orchards on terraces  [PDF]
Andreja ?kvar?,Ivan Kodri?
Urbani Izziv , 2006,
Abstract: The article deals with vineyards and terrace building as the best method of managing agricultural land on the steep slopes of the Primorska region. Data was gathered about the share of terraced vineyards and shares of vineyards according to inclination classes. We explained what the term renewal of permanent plantation implies and especially vineyards, as well as its scope. Reasons for terracing are elaborated, as well as difficulties that are coupled with such land management. We also point out the consequences of abandonment of vineyards on terraces.
Hydro-dynamical models for the chaotic dripping faucet  [PDF]
P. Coullet,L. Mahadevan,C. S. Riera
Physics , 2004, DOI: 10.1017/S0022112004002307
Abstract: We give a hydrodynamical explanation for the chaotic behaviour of a dripping faucet using the results of the stability analysis of a static pendant drop and a proper orthogonal decomposition (POD) of the complete dynamics. We find that the only relevant modes are the two classical normal forms associated with a Saddle-Node-Andronov bifurcation and a Shilnikov homoclinic bifurcation. This allows us to construct a hierarchy of reduced order models including maps and ordinary differential equations which are able to qualitatively explain prior experiments and numerical simulations of the governing partial differential equations and provide an explanation for the complexity in dripping. We also provide a new mechanical analogue for the dripping faucet and a simple rationale for the transition from dripping to jetting modes in the flow from a faucet.
Climatic specifications of Ohrid area of vineyards  [PDF]
Ili?-Popova Srebra
Journal of Agricultural Sciences , 2003, DOI: 10.2298/jas0302143i
Abstract: The purpose of the research is the examination of the climatic characteristics, indexes and coefficients in the Ohrid area of vineyards. In the region under study the average annual air temperature was 11.5oC, and the vegetative air temperature had a value of 16.7oC. The annual temperature sum was 4198oC, and ranged from 4033oC to 4524oC. The vegetative sum had a value of 3570oC, and it ranged from 3326oC to 3754oC. The annual rain sum was 665 mm, and ranged from 483 mm to 927 mm. The vegetative rain sum had a value of 342 mm, and ranged from 200 mm to 541mm. On the basis of the values of effective temperature sum, it can be concluded that the Ohrid area of vineyards belongs to the climatic zone B. The values of the hydro-thermic coefficient indicated that in the area of vineyards, where the research was conducted, there was an irregular schedule of humidity. The helio-thermic coefficient had a value of 4.4. The bio-climatic index had a value of 7.7 and ranged from 4.8 to 15.2. The results of this research indicate that the Ohrid area of vineyards is favorable for production of table and wine grape for varieties that ripen from I to II epoch.
Dependence of Dripping on the Orifice Diameter in a Leaky Faucet  [PDF]
Polina Vexler,Daniel Golubchik,Yosi Vaserman,Ariel Maniv
Physics , 2006,
Abstract: We report the results of experiments that examined the dependence of the dripping dynamics of a leaky faucet on the orifice diameter. The transition of the dripping frequency between periodic and chaotic states was found to depend on the orifice diameter. We suggest a theoretical explanation for these transitions based on drop formation time scales. In addition, short-range anti-correlations were measured in the chaotic region. These too showed a dependence on the faucet diameter. Finally, a comparison was done between the experimental results with a one-dimensional model for drop formation. Quantitative agreement was found between the simulations and the experimental results.
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