A modified empirical model for estimating the wetted zone dimensions under drip irrigation

Drip irrigation system has become one of the most common irrigation systems especially in arid and semi-arid regions due to its advantages in saving water. One of the most essential considerations in designing these systems is the dimensions of the wetted soil volume under emitters. These dimensions are significant in choosing the proper emitter spacing along the laterals and the suitable distance between laterals. In this study, a modified empirical equations for estimating the horizontal and vertical extend of the wetted zone under surface emitters were suggested. Data from published papers includes different conditions of soil properties and emitter discharge were used in deriving the empirical model using the nonlinear regression. The developed model has high value for coefficient of determination, R2. The results from the developed model were compared with results of other empirical models derived by other researchers. Some statistical criteria were used to evaluate the model performance which are the mean error ME, root mean square error RMSE, and model efficiency EF. The results revealed that the modified model showed good performance in predicting the wetted zone dimensions and it can be used in design and management of drip irrigation systems

Assessment of water application losses through irrigation surveys: a case study of Mirpurkhas subdivision, Jamrao irrigation scheme, Sindh, Pakistan

A study was conducted to demonstrate the applicability and efficiency of an irrigation survey method for digging up reliable information to estimate application losses. A sample of 220 tertiary channels was drawn randomly to get information from the growers of the Mirpurkhas subdivision, Jamrao canal irrigation scheme. Pre and post soil moisture status based practical measurements of losses were also carried out at 20 different sites. The results showed that the irrigation methods and soil types have a pronounced effect on application losses whereas crop type has no effect on application efficiency. Drip, sprinkler and furrow irrigation methods showed better performance as compared to other methods (wild flooding, border and basin) used in the study area. The survey based losses results were validated against measured losses whilst values available in literature compared favorably. The overall application losses in the study area were calculated as 23%. The main assumption for the irrigation survey of knowing the irrigation depth (not target depth in accordance with crop actual demand) and cutoff time for a single irrigation event by farmers was almost fulfilled. Based on the encouraging results of this study, it is concluded that irrigation survey studies are useful in understanding the irrigation scheme losses pattern which in turn provide opportunities for improvement

The influence of magnetized water on soil water dynamics under drip irrigation systems

Soil water dynamics under drip irrigation systems are of considerable importance in designing, managing and operating these systems. Emitter discharge, soil type, soil chemical properties, crop water-requirements, and quality of applied water are the main factors affecting soil water dynamics under drip irrigation. In this study, laboratory experiments were conducted to study the effect of magnetized water on wetting pattern dimensions and water content distributions under surface emitter. Passing water through permanent or electro magnets installed on feeding pipeline resulted in producing magnetized water. Two emitter discharges (3 and 4.5 l/h, in average), two soil types (sand and clay), two soil profiles (homogeneous and layered-textural) and two water types (plain and magnetized water) were considered in the experiments. It was found that using magnetized water led to increase surface wetted radius by 6.2% and decrease vertical wetted depth by 6.3% in homogeneous soil profiles. In layered-textural soil profiles, the surface wetted radius slightly decreased by 1.8% while the vertical wetted depth increased by 7.0% in case of sand over clay and decreased by 2.0% in case of clay over sand when using magnetized water. As a result of using magnetized water, the total wetted area decreased for homogeneous profiles and increased for layered-textural profiles. It was concluded that the impact of magnetized water is statistically significant on wetted bulb dimensions and not statistically significant on water content distributions. The results revealed that using magnetized water is recommended especially in homogeneous soil profiles

Estimation of soil loss in Seremban, Malaysia using GIS and remote sensing technique

Runoff causes soil loss and is a continuous ecological problem in Seremban, Malaysia. It is crucial to collect data on soil loss for improved agricultural productivity and to manage natural resources effectively. This research maps the distribution and estimates the yearly mean value of soil erosion through the utilization of techniques of remote sensing and GIS by implementing the Revised Universal Soil Equation (RUSLE). To determine the variables of RUSLE's soil loss and analyze them in an integrated GIS environment, we used a scale of 1:50,000 according to criteria of topographic map, Aster Digital Elevation Model (DEM) which has a feature of spatial resolution that extends up to 20 m, a soil map which is digitally programmed with a scale of 1:250,000, and a decade of rainfall records for 12 stations. The data revealed that Seremban records an annual soil loss that ranges from no soil loss in forested areas (Lenggeng - Panti - Ampangan - Seremban) to >100 tone hectare per year in the open area ((Labu - Renggam - Lenggeng). The total annual soil loss is estimated at 883 tonnes/hectare/year and is distributed across different land cover as follows: 198 tonnes from agriculture areas, 39 tonnes from forest areas, and 20.45 from rural areas, 610 tonnes from open area, 12 tonnes from urban areas, and 1.4 tonnes from inland water areas

GIS-based land suitability mapping for rubber cultivation in Seremban, Malaysia

Land suitability evaluation (LSE) is a valuable tool for land use planning in major countries of the world, including Malaysia. Previous LSE studies focused mostly on the use of biophysical and ecological datasets for the design of equally important socio–economic variables. This study presents sub national level estimation of suitable agricultural lands for Rubber crops in Seremban, Malaysia, combining physical, biophysical and ecological variables. The objective of the study was to provide an up–to-date GIS-based agricultural land suitability evaluation (ALSE) for determining suitable agricultural land for Rubber crops in the study area. Biophysical and ecological factors that influence agricultural land use were assembled and the weights of their respective contributions were assessed using analytic hierarchical process. For Rubber cultivation, Lenggeng, Pantai and Setul are the most suitable; while Ampangan, Seremban, Rasah, and Rantau are moderately suitable. Since Seremban, Labu, and Pantai are not suitable for growing rubber. The total suitable land for rubber cultivation in Seremban district is 35575 hectares distributed among the classes as: 16048 hectares is highly suitable, 15399 hectares moderately suitable and 4128 hectares is marginally suitable. These values represent 45%, 43% and 12% respectively Quantitative assessment of the model’s detection accuracy reveals to what extent it is sensitive to suitable and non-suitable land with sensitivity and specificity values of 84.14% and 76% respectively and overall accuracy (area under the ROC curve) of 0.80 (80%) with p-value of <0.0001 at 95% confidence interval

Laser-Assisted High Speed Machining of 316 Stainless Steel: The Effect of Water-Soluble Sago Starch Based Cutting Fluid on Surface Roughness and Tool Wear

Laser-assisted high speed milling is a subtractive machining method that employs a laser to thermally soften a difficult-to-cut material’s surface in order to enhance machinability at a high material removal rate with improved surface finish and tool life. However, this machining with high speed leads to high friction between workpiece and tool, and can result in high temperatures, impairing the surface quality. Use of conventional cutting fluid may not effectively control the heat generation. Besides, vegetable-based cutting fluids are invariably a major source of food insecurity of edible oils which is traditionally used as a staple food in many countries. Thus, the primary objective of this study is to experimentally investigate the effects of water-soluble sago starch-based cutting fluid on surface roughness and tool’s flank wear using response surface methodology (RSM) while machining of 316 stainless steel. In order to observe the comparison, the experiments with same machining parameters are conducted with conventional cutting fluid. The prepared water-soluble sago starch based cutting fluid showed excellent cooling and lubricating performance. Therefore, in comparison to the machining using conventional cutting fluid, a decrease of 48.23% in surface roughness and 38.41% in flank wear were noted using presented approach. Furthermore, using the extreme learning machine (ELM), the obtained data is modeled to predict surface roughness and flank wear and showed good agreement between observations and predictions

Agriculture land suitability analysis evaluation based multi criteria and GIS approach

Land suitability evaluation (LSE) is a valuable tool for land use planning in major countries of the world as well as in Malaysia. However, previous LSE studies have been conducted with the use of biophysical and ecological datasets for the design of equally important socio-economic variables. Therefore, this research has been conducted at the sub national level to estimate suitable agricultural land for rubber crops in Seremban, Malaysia by application of physical variables in combination with widely employed biophysical and ecological variables. The objective of this study has been to provide an up-to date GIS-based agricultural land suitability evaluation (ALSE) for determining suitable agricultural land for Rubber crops in Malaysia. Biophysical and ecological factors were assumed to influence agricultural land use were assembled and the weights of their respective contributions to land suitability for agricultural uses were assessed using an analytic hierarchical process. The result of this study found Senawang, Mambau, Sandakan and Rantau as the most suitable areas for cultivating Rubber; whereas, Nilai and Labu are moderately suitable for growing rubber. Lenggeng, Mantin and Pantai are not suitable for growing rubber as the study foresaw potential environmental degradation of these locations from agricultural intensification. While this study could be useful in assessing the potential agricultural yields and potential environmental degradation in the study area, it could also help to estimate the potential conversion of agricultural land to non-agricultural uses

WPEDIS – wetting pattern estimator under drip irrigation systems

The dimensions of the wetted soil zone under drip irrigation systems are of considerable practical importance in designing these systems. The selection of proper spacing between emitters and suitable distance between laterals is mainly related to the wetting pattern dimensions. In this study, an empirical model was developed to predict the dimensions of the wetted soil zone under drip irrigation systems. The developed model includes empirical equations to estimate the main dimensions of the wetted soil zone as well as its ability to predict the full shape of the wetting pattern. Series of laboratory experiments were carried out under surface and subsurface emitters using two soil textures, two application rates, and two soil profiles. Application time, emitter discharge, initial moisture content, saturated hydraulic conductivity, bulk density, and the percentages of sand, silt, and clay of the soil are the main inputs of the proposed model. The performance of the model was assessed by comparing the measured and predicted results statistically by considering some statistical criteria such as mean error, root mean square error, and model efficiency. A good agreement between the observed and predicted wetting patterns was achieved which reflects the model suitability in design drip irrigation systems

Potential effects of microorganism to reducebuilding defects in Malaysia

Over the last few years, building defects is major concern in Malaysian construction industry. Design mistake or building flaw define as a defect which reduces building value and make a hazardous situation. A Building defect arises due to various reason, such as low handiwork or the use of adherent components, climatic construction, and faulty design. Building defects never emerge to have been minimized in contempt of new improvement in building technology. Defective building construction contributes both final cost of the product and cost of maintenance, which can be generous. By using effective microorganism (EM) in concrete building defects such as surface cracks, fatigue cracks and thermal contraction can be reduced significantly. Previous works in Japan and Malaysia found that effective in agriculture microorganism makes it possible increasing crop yields to twice or three times what they are at present to do so without the agricultural chemicals or artificial fertilizers, 5% of EM mixed into the concrete the tensile, compressive and flexural strength were 25.23%, 143.90% and 19.17% that are compared to design compressive strength that signify improve the concrete strength and durability. By using 25% EM in concrete the tensile strength was higher than the lower dosage. From the previous study, fermentation is the main notion in EMC in which the process will not produce detrimental texture. The research was carried out to investigate the potential usage of effective microorganism and its application in concrete that can help to reduce the building defects and improve building strength and durability. It was observed that most cost-effective and maximum percentage of EM mixed into the concrete is 5% in which enhancing its compressive, tensile and flexural strength