In order to study of drought tolerance levels in some wheat lines and cultivars based on uniform regional wheat yield trial (URWYT-M-75) an experiment was carried out using a strip plot design based on complete block design with 3 replications for two years (1998-2000) in Torogh Agricultural Research ...
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In order to study of drought tolerance levels in some wheat lines and cultivars based on uniform regional wheat yield trial (URWYT-M-75) an experiment was carried out using a strip plot design based on complete block design with 3 replications for two years (1998-2000) in Torogh Agricultural Research Station (Mashhad, Iran). The main plots (Horizontal factor) were 3 levels of irrigation: 10, 20 and 30 days irrigation interval. For irrigation were used on drip irrigation system. The sub plots (Vertical factor) were 20 lines or cultivars of spring bread wheat set up for URWYT (M-75-1-20). Sowing date, the amount of seed and fertilizer were as normal rates in region. For measuring of water requirement and irrigation, were used on drip irrigation system. For each irrigation, measured the soil moisture before that. The results showed that when irrigation interval was 10 days, the lines yield of M-75-8, M-75-6, M-75-2 and M-75-16 were higher than other lines. When the irrigation interval was 20 days, the lines of M-75-2, M-75-14, M-75-16 and M-75-12 produced the highest. In 30 days irrigation interval, the lines of M-75-15, M-75-4, M-75-2 and M-75-14 had maximum yields. As summery, M-75-2 line was better than other because indicated good flexibility and water use efficiency, in normal and stress condition.
The plain carbon steel “CK45” has relatively well mechanical and metallurgical properties and low cost. The purpose of this research was the property evaluation of this steel on abrasive wear and impact for using in plows and other tillage tools. Tillage tool should resist in abrasive wear ...
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The plain carbon steel “CK45” has relatively well mechanical and metallurgical properties and low cost. The purpose of this research was the property evaluation of this steel on abrasive wear and impact for using in plows and other tillage tools. Tillage tool should resist in abrasive wear and impact simultaneously. Several heat treatments were done on specimens of this steel. A standard test device for abrasive wear “Standard Test Method for Conducting Wet Sand/Rubber Wheel Abrasion Tests, G105-89” was made. This device and standard charpy test apparatus determined the abrasive and impact resistance, respectively. Results showed that the impact and abrasive resistance of this steel can be improved by simple heat treatment and used properly for tillage tools.
Center pivot irrigation system is used as a modern irrigation method in different parts of Iran. Unfortunately due to lack of proper design and hydraulic shortcomings of the system in several agricultural lands in Iran, the efficiency of the center pivot irrigation system is low or unacceptable. Low ...
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Center pivot irrigation system is used as a modern irrigation method in different parts of Iran. Unfortunately due to lack of proper design and hydraulic shortcomings of the system in several agricultural lands in Iran, the efficiency of the center pivot irrigation system is low or unacceptable. Low system efficiency results in non-uniformity of water distribution along the lateral and on the cultivated land. This non-uniformity also causes ponding of water on the cultivated land and run off from the field. Above problems and initially large investment required by the system would make the evaluation of the system during the operation a necessary task. The main objective of this research is the hydraulic evaluation of the center pivot irrigation system located in the agricultural land in the College of Agriculture of Shiraz University in Badjgah, and also determining the uniformity parameters such as CU, DU, AELQ, and PELQ. Field tests were conducted using ASAE standard procedure. The results show that the uniformity of water distribution obtained from the catch cans were not similar to the uniformity of the soil moisture content. It was also found that the average values of the distribution uniformity (DU), coefficient of uniformity (CU), actual efficiency of low quarter (AELQ), and potential application efficiency of low quarter (PELQ) were 0.63, 0.75, 0.55, and 0.55 respectively. Based on these results and according to the ASAE standards, these values are low, indicating that the system is not properly designed or this system is not suitable for this area. Equal values of AELQ and PELQ shows that in all cases during growing season the soil moisture deficit (SMD) was higher than the low quarter value (LQ). This means the irrigation depth was not sufficient and the crop was in stress during growing season. Electromotor damaged due to lack of metal cover and lack of proper design of electromotor adjacent nozzels were the main technical problems for the system.
In this research, the effect of different storage conditions (cold, semi technical and traditional storages) at 180 days after storage on the qualitative and quantitive properties of garlic populations were investigated. White and pink populations were packaged in wooden boxes and net pockets and factors ...
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In this research, the effect of different storage conditions (cold, semi technical and traditional storages) at 180 days after storage on the qualitative and quantitive properties of garlic populations were investigated. White and pink populations were packaged in wooden boxes and net pockets and factors i. e. weight loss, moisture content, spoilage, firmness and total pyruvic acid were measured monthly. Results showed that difference between weight loss and spoilage of garlic populations in all conditions were significant and their content in semi technical storage was more than cold storage and less than traditional storage. White and pink garlic in cold storage with 13.89 and 16.73% weight loss and 12.1 and 46% spoilage respectively had the least contents and in traditional storage with 25.9 and 47.2% weight loss and 56.3 and 100% spoilage respectively had the most contents. An increase of total pyruvic acid content in both garlic populations except pink population in cold storage was observed at 150 days after storage because of the degradiation of chief flavour component and its content in pink garlic population was more than white garlic population. Firmness of white garlic population decreased during storage but in semi technical and traditional storages, the firmness of pink garlic population increased within 120-180 days because of the drying of clove tissues.
Infiltration in furrow irrigation is 2-D which depends on both time and surface characteristics at which infiltration occurs. However, in many furrow irrigation models, infiltration is determined as a function of infiltration time opportunity, assuming the variation of weted perimeter is low along furrow. ...
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Infiltration in furrow irrigation is 2-D which depends on both time and surface characteristics at which infiltration occurs. However, in many furrow irrigation models, infiltration is determined as a function of infiltration time opportunity, assuming the variation of weted perimeter is low along furrow. In order to compare the proposed asumptions, two zero-inertia furrow irrigation models were developed; one was ZIWPV model, which considers the effectiveness of wetted perimeter, and the other was ZIWPC model, which assumes a constant surface for wetted perimeter. Solution of finite-difference equations is obtained with an explicit scheme. The results of two models were compared together using schwankl’s field data. The ZIWPV model predicted well the advance time which was measured 157 minutes in the field. But ZIWPC model understimated it which was 10.8%. CU and DU were estimated 77.4 and 68.5 by ZIWPV model and 93.1 and 89.4% by ZIWPC model, respectively. However, they were measured in the field 77 and 64%, respectively. The average infiltrated depth in the field was measured 7.47 cm. But it was estimted 8.6 and 7.43 cm by ZIWPV and ZIWPC models, respectively. Thus, taking into account the wetted perimeter effectiveness to calculate infiltration during irrigation improves infiltrated water uniformity, but overestimated the average depth of infiltration. Also, furrow irrigation models which assume infiltration to be 1-D, predict well the average infiltration depth. But, they overstimated infiltrated water uniformity.
A four - year field experiment (1999-2002) was conducted on a silty clay loam soil at Laklak research field of Hamedan to determine the effects of crop residue management and plowing depth on soil fertility and wheat yield in a maize-wheat rotation. In this investigation, four corn residue managements ...
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A four - year field experiment (1999-2002) was conducted on a silty clay loam soil at Laklak research field of Hamedan to determine the effects of crop residue management and plowing depth on soil fertility and wheat yield in a maize-wheat rotation. In this investigation, four corn residue managements were used consisting of 1) Stalk shredding by maize stalk shredder 2) Stalk shredding by disk 3) Stalk shredding by rotivator 4) removal of corn residue and two levels of plowing depth (20 and 30cm). Corn residue managements and plowing depths were combined in eight treatments. A factorial experiment based on randomized complete block design was used with three replications. Wheat residue were incorporated in soil by plowing to the depth of 20-25 cm in all plots. To evaluate the efficiency of shredding implement, percentage of chopped stalks were calculated. To study the C organic changes, this index was measured in three stages (1-13 Apr 1999, 2-17 Aug 2000 and 3-12 Jul 2002). Wheat yield and its components (spike/m2, number of grain per spike and kernel weight) and corn grain yield were determined. The results showed that machine type had significant effect on precentage of chopped stalks. Maize stalk shredder had higher shredding content than the other two machines (disk and rotivator). Also after four years, incorporation of corn - wheat residue increased C organic about 25% and incorporation of wheat residue and removal of corn residue increased C organic about 16%. It was also found, wheat yield and corn grain yield were not affected by residue management or plowing depth, but wheat yield in 2002 increased about 40% compared to 1999.
