JOURNAL OF AGRICULTURAL ENGINEERING RESEARCH
Year:2003 | Volume:4 | Issue:16|Papers Count:6

Determination of saturated hydraulic conductivity Ks is needed for many studies in water movement and solute transport in the soil. Although some advances are made for direct measurements of ks, they are usually time consuming and costly. Some attempts have been made to indirectly predict the saturated hydraulic conductivity from the easily/readily obtainable parameters. The so-called pedo-transfer functions (PTF) proved to be a valuable tool to predict the Ks from the available soil data. The objective of this study was to derive some PTFs for different soil textures, requiring minimum input parameters. Consequently, 45 soil samples were taken and their Ks were directly measured, using the Geulph permeameter. The multilinear regression method was used to develop the pedo-transfer functions. The measurements were consisted of bulk density, particle density, field capacity, effective porosity (θe), particle size distributions, effective particle diameters, geometric mean diameter (dg) and geometric standard deviation of soil particles (δg). The normality and multi-colinearity of the parameters were tested by Minitab package. Three PTF functions were then derived, using different input parameters. The results indicated that accuracy of the derived PTFs can well predict (R2=0.73) the Ks from θe, dg and δg.

In order to improving the methods of peeling, smoking and drying of plum var Bokhara (Santorosa), a research was dome in The experimental factorial in frame of completely randomised design with 3 replicate. The factors were: peeling methods (Peeling with brine 700, peeling 1.5% boiling NaOH for 30 seconds, peeling by steam), preventing of browning (without sulphure, burning of sulphure, 2.5% Sodium-Meta-Bisulfite for 3 minutes), drying (Traditional, industrial). The test including pH, acidity, brix were done in peeling and smoking stages and the tests including sulphure residues and after drying, organoleptic tests were done. The results showed that peeling by NaOH had significant effect on pH, brix and acidity. Application of sulphure and Sodium-meta-Bisulfate reduced pH in fresh and dried plum. Finally the result of organoleptic tests showed that the best condition for processing dried plum is using peeling by NaOH and suing Sodium-Meta-Bisulfite and industrial method.

Cumin in khorasan province is one of the important plants using in medicine and exports to the other countries. Due to this importance, a study was conducted to investigate different land preparation methods in dry wet planting on cumin for two years in Mashhad region. A Split block design with randomized completely randomized block layout used in this study. Horizontal factors (main factors) were: a) Conventional tillage and planting (Plowing with mold board plow + Disk harrow + Land leveler + Drill planting), b) Minimum tillage and planting (in summer harrow disk + deep harrow disk before planting + Land leveler + drill Planting). Vertical factors were: a) Wet planting, b) dry planting. The Measured parameters were: Plant height, Number of umbrella in Plant, number of seed in umbrella, number of seed in plant and 1000 seed weight. It was concluded that there was no significant difference between tillage methods and wet and dry planting in 5% probability area. All statistical means were compared using Duncan multiple range tests. It was showed that tillage methods had significant difference on number of umbrella and number of seed in plant in the second year. However the advantages of minimum tillage systems are: decreasing of operation costs, decreasing of soil erosion, decreasing of soil compaction, etc. minimum tillage with wet planting can be recommended.

As the Kor river water is applied for agricultural uses in Fars province and also urban, agricultural and industrial wastewater are poured to it, a study was carried out on variation of dissolved oxygen concentration and water quality parameters along the Kor river, from Band-e Amir to the Bakhtegan lake (specially in critical time) . Industrial pollution sources are located up the Band-e Air and also urban and agricultural pollutants are poured to the river through the Ahoochar drain. Therefore, 11 sampling stations were selected down the band-e Amir. Most of the selected stations are located in diversion barrages established for agricultural uses. In each station, two samples were taken for determination of dissolved oxygen, one sample for measurement of biochemical oxygen demand for seven days (BOD7) and the other for some parameters such as TDS, PH,… Then, dissolved oxygen content and its variation along the distance were studied and also effective factors in decrease and in create of it were calculated by means of Qualkor model which was compiled in visual basic. Results of such experiments are the presentation of oxygen sag curve which is applied for the Kor river in two separate situations (critical condition and under study condition). In this study, dissolved oxygen content along the distance was not decreased from 4 mg/L (standard Limit for aquatics), but in critical conditions, this amount was less than standard limit in all the stations except in the first station. Dissolved oxygen content reached zero between the stations 2 and 4, so aquatic life is confronted in danger.

This research investigated the effect of physical condition of osmotic dehydration including temperature (45, 50 and 55°C), kind (sucrose or glucose) and concentration (60-70-80%) of sugar solution and different amount of NaC1 (0,0.5 and 1%) as active agent, on quantitative properties of dried apricot c.v. "Shekar Pareh of Isfahan". For this purpose halfed apricots were mixed with osmotic solution in the ratio of 1 to 4 (w/v) for 6.5 hourse and them dried in a laboratorial cabinet drier till R.H.=14%. This study showed that increasing of temperature till 50°C caused escalating in shrinkage, hardness, vitamin C content and sugar of slabs, but decreasing in optical density (browning) and water uptaking capacity of them. By adding to the sugar concentration of osmotic solution, the quantity of shrinkage, browning and water uptaking power of slabs diminished; while firmness, sugar percent and vitamin C content of texture augmented. In most of the cases and in equal condition, the outcome of glucose solution on increasing of shrinkage, firmness and sugar and sugar percent and decreasing of water uptaking capacity was more intensity than the sucrose one. Rising the amount of NaCl in osmotic solution up to 1% caused declining of hardness and sugar content of texture. Mean while shrinkage and water uptaking capacity enlarged slightly. In all of the 54 osmotic treatments content of sugar, vitamin C, shrinkage and color of the slabs was better than the control ones. On the whole, quantitative studies of slabs distinguished that the best solution for osmotic dehydration of apricot has been a 70% (w/w) sucrose solution, containing 1% (w/w) NaCl in 45°C.