灌漑・排水システム工学

Correlating the physicochemical parameters for assessment of the groundwater quality has emerged as a very useful approach for water use. Taking water samples from the Toba Tek Singh District of Pakistan, this study assess the water quality for drinking and irrigation purposes. A sum-total of 72nos. groundwater samples were collected and analyzed for the purpose of different water quality parameters including sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), bicarbonate (HCO- 3), chloride (Cl-), sulphate (SO4 2-), pH, electrical conductivity (EC), total dissolved solids (TDS) and total hardness (TH). The results obtained were, then, compared with the standard desirable limits of physicochemical parameters prescribed by World Health Organization (WHO), Pakistan Standards and Quality Control Authority (PSQCA) and Pakistan Council of Research in Water Resources (PCRWR) for drinking purposes. In order to classify the groundwater suitability for irrigation purpose, parameters such as sodium adsorption ratio (SAR), percent sodium (PS), permeability index (PI), residual sodium bicarbonate (RSBC), Kelly’s ratio (KR), and magnesium adsorption ratio (MAR) were also calculated on the basis of chemical data. After that, the correlation coefficients between different physicochemical parameters were calculated to identify the highly correlated and interrelated parameters for water quality. Different plots like Piper, Durov, Schoeller and Stiff diagrams were drawn to classify the groundwater ability for different purposes. These several classifications show most of groundwater samples falling within the safe limits and thus suitable for drinking and irrigation purposes, except of a few samples with a caution that it may get worse in the future.

The aim of this work was to evaluate gas exchanges, photochemical efficiency and yield of common bean grains (crioula variety) grown under different irrigation levels in the state of Alagoas. The experimental design was a randomized block design with four replications. Treatments were composed of crop evapotranspiration fractions (25, 50, 75, 100, 125 and 150% of crop evapotranspiration). Gas exchanges were determined from measurements of internal CO2 concentration, transpiration, stomata conductance, photosynthetic rate, instantaneous water use efficiency and instantaneous carboxylation efficiency. Chlorophyll a fluorescence evaluations were determined through the potential and effective quantum yield of photosystem II. Chlorophyll content was indirectly measured. The following production components were evaluated: number of pods per plant, number of grains per pods, mass of 1000 grains and grain yield. The water application variation promoted a significant difference for gas exchanges, causing a reduction in the potential and effective photochemical efficiency of common bean. The increase in the application of the irrigation levels directly influenced the SPAD index and the following production components: number of pods per plant and grain yield, obtaining significant values with irrigation level of 125% of ETc.

The leading causes of emitters’ clogging are known, although the processes involved are seldom studied. The present research is based on the hypothesis that the susceptibility of drippers to clogging is influenced by the emitter discharge, the type of clay, and the concentration of clay in the irrigation water. The objective of this study was to analyse the susceptibility of drippers to clogging caused by water containing suspended clay particles. The susceptibility of the drippers to the clogging was analysed with respect to the following factors: the concentration of suspended clay in water, the discharge of emitters of same labyrinth geometry, and the type of clay particles in suspension. We used four concentrations of kaolinite and montmorillonite (500, 750, 1,000, and 2,000 mg L−1) and two drip line models with similar labyrinth geometries, one model having a lower flow rate (0.6 L h−1) than the other (1.7 L h−1). The concentration of suspended clay particles affected the flow rate of the drippers, particularly at concentrations above 1000 mg L−1. The drip line model with the lower flow rate was more susceptible to variations in the flow rate than the higher-flow rate model. The type of clay had no significant effect on the dripper clogging.

The primary focus of our study is to identify the challenges and difficulties that we face and to find some feasible solutions while constructing and maintenance of roads in the state of Jammu and Kashmir. The roads pass through the swathes, that are mostly frost prone, located at high altitudes and we experience sub-zero temperature there. Apart from its mountainous nature, the climatic conditions are very harsh for most part of the year, in which the precipitation is more, mostly in the form of snow that covers the whole of the land including roads. The valley has a few exits in the form of national highways that pass through mountainous ranges at very high altitudes, where the snowfall is heavy during winter months. The state being dominated by undulating topography, road is the prime means of transport. The carving of roads and their maintenance through the continuous mountainous ranges has become a challenge for the engineers and constructors. The cause of concern is that Kashmir has the road density of 35. 71 km per 100 sq km, this is one of the lowest in the country. In this paper, we introduce some of the materials and some of the improved methods in road construction in order to overcome the challenges that we encounter during construction and maintenance of roads in Kashmir.

6Increasing production and productivity of crop farming ,improving income of resource poor farmers and thereby enabling the producers to build assed in Southern Ethiopia in General and Damot Sore Woreda in particular require some form of transformation of the subsistence, low-input and low-productivity farming systems to full agricultural packages utilization and awareness creation. The study was employed in Irish AID Operational Research and Technology Dissemination Project (ORTDP) areas of Areka mandate. This study was undertaken to analyse factors affecting level of income earned from Potato and summarize benefits of utilizing improved potato variety and full agricultural packages in the district. A multi-stage sampling technique was used to select 80 sample households from two sample kebele. In the study, both primary and secondary data sources were used. Simple Linear Regression Model was employed to identify factors affecting level of income earned from improved potato production by resource poor farmers in the district. Results showed that using improved potato variety increase the production and productivity of the specific commodity and there help the resource poor farmers to build asset. From eight explanatory variables used the six determinant factors that affected significantly the level of income earned from improved potato adoption were comprised of Tropical livestock unit, Being beneficiary or not, family size and intervention period.

Water scarcity, due to abruptly accruing phenomenon of climate change, is perilously disturbing agricultural crops such as rice as well as its quality in many countries of the world. It is an acute threat to livelihood of residents of those countries where water resources are already a limiting factor to agriculture. Therefore, an experiment was conducted to ascertain and compare yield and water productivity of rice (Oryza sativa L.) hybrids in response to transplanting dates and cultivar duration in irrigated sub-tropical regions of Punjab, Pakistan. The experiment was conducted in experimental fields of Rice Research Institute, Kala Shah Kaku. It was determined that the water productivity was increased with the shifting of transplanting date towards shorter water demand period and variety to shorter life duration. Water stress is more damaging to those varieties or hybrids that have longer life cycle as compared to early maturing hybrids and varieties. Conclusively, same method may be used to test other rice varieties and hybrids to ascertain their minimum water requirements for maximum yield returns.

A field study was conducted with the aim of evaluating effects of slope, furrow length and flow rate on irrigation performances, cane and sugar yield at Metehara sugar estate. The field experiment was arranged in a split-split plot design with 0.05, 0.08 and 0.1% slopes; 100, 150 and 200 m furrow length and 4, 5 and 6 L flow rate. The analysis of performance indices indicated that the effect of slope was not statistically significant except distribution uniformity and uniformity coefficient; furrow length and flow rate were highly significant on all performance indicators. All indices except deep percolation ratio and storage efficiency have shown an increasing trend as flow rate increases. The range of cane and sugar yield found was from 9.54 to 13.33 t/ha/month and from 1.12 to 1.23 t/ha/ month, respectively. Flow rate had significant variation on both cane and sugar yield. The interaction of 200 m furrow length of and 6 lit/s flow rate gave better distribution uniformity and cane yield with slope of 0.08% was recommended for Metehara Sugarcane Plantation.

In modern farming systems, fertigation is widely practiced as a cost effective and convenient method for applying soluble fertilizers to crops. Along with efficiency and adequacy, uniformity is an important fertigation performance evaluation criterion. Fertigation uniformity is defined here as a composite parameter consisting of irrigation and fertilizer application uniformity indicators. The field and computational procedures for sprinkler irrigation uniformity evaluation have been the subject of various studies. The objective of the study reported in this paper, however, is the development of an analytical framework for the evaluation and analyses of test-plot scale fertilizer application uniformity under solid-set sprinkler irrigation systems. Irrigation uniformity indices are adapted for use in fertilizer application uniformity evaluation. Fertilizer application rate, given as a function of irrigation depth and fertilizer concentration, is identified as the appropriate variable to express fertilizer application uniformity indices. Pertinent mathematical properties of the uniformity indices along with their practical fertigation management implications are outlined. Carefully designed hypothetical fertigation scenarios were analyzed to examine the significance of the interactive effects, of the local spatial trends of depth and concentration data, on the test-plot scale uniformity of the resultant fertilizer application rate data. The results of the study show that the spatial overlap patterns between depth and concentration data sets are the main determinants of test-plot scale fertilizer application rate uniformity. The study also shows that often the uniformity levels of irrigation and fertilizer concentration data sets cannot be uniquely related to the uniformity of the resultant application rate data. However, some practically useful qualitative relationships between the uniformity of irrigation depth, solute concentration, and application rate data sets are defined. Application of the approach presented here in the evaluation and analysis of fertigation uniformity data sets, measured under sprinkler irrigated conditions, is highlighted.