JWSS - Journal of Water and Soil Science

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Feeding high levels of barley to laying hens is accompanied with dirty eggs, decreasing the feed intake and egg size. To improve the diet with barley for layers, different chemicals including a commercial enzyme effective on barley (Fin Feed), cupric sulfate pentahydrate, sodium bicarbonate, magnesium sulfate and oxytetracycline antibiotic were supplemented to experimental barley based diets. It was found that the commercial enzyme had a significant effect on layer performance. Other treatments didn't have any considerable effects on their performances. Enzyme supplementation significantly (P < 0.05) improved feed intake, production rate and daily egg mass production of laying hens. No significant difference were observed in laying performance of mature birds fed with barley-based diet or soybean corn diet.

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An experiment with 720 pullets was conducted to investigate the effect of dietary energy levels of pullet and dietary energy and fat of laying ration on subsequent performance parameters during 14-20 and 22-44 weeks of age. In the first period, white leghorn pullets were fed with two diets of low and high density energy (2600 and 3200 Kcal ME/kg). In the lating period (second period), birds, in each treatment of pullet period, were fed with six diets containing three levels of low, medium and high energy (2600, 2750 and 2900 kcal/kg) at two levels of supplemental fat (zero and 2%). All diets were formulated to meet minimum NRC (1994) requirements of amino acids and protein. This experiment was done in randomized complete block designs with 5 replicates. The levels of energy in the growing period did not affect egg production, egg weight, daily feed intake, feed conversion rate and age of pubertal maturity in laying period, but pullets fed with high energy diet had significantly higher weights as compared to low energy diet in the beginning of laying period. In the laying period, the use of supplemental fat (2%) improved egg production and egg weight, but feed intake and feed conversion rate were not affected. Means of feed conversion rate, feed intake and egg production during laying period in low energy diet were greater than those as compared to high energy diet, but egg weight was not affected by energy level of diets. Low energy intake to protein intake ratio in low energy diet versus high energy diet may be a reason for greater egg production in lower energy than in higher energy diets.

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This experiment was conducted to determine the requirements of vitamin supplement and available phosphorus in broiler chickens from 42 to 56 days of age. In a completely randomized design, with a 3×3×3 factorial arrangement, 270 one-day-old commercial broiler chicks were divided into 27 groups (replicates) with 9 treatments, 3 replicates and 10 chicks in each group. Each of the nine diets was given to each treatment from 42 days of age. Levels of vitamin supplement were 0.5, 0.25, 0% and available phosphorus levels were 0.27, 0.22, 0.16%. Diets were isocaloric and isoprotein. Group weight and feed consumption of each replicate were determined after 42 and 56 days of age and daily gain, daily feed consumption and feed conversion were calculated. Percent of carcass components and tibia ash were determined.

Results indicated that removal of vitamin supplement from 42 to 56 days of age did not have any significant effects on daily gain, daily feed consumption, feed conversion, live weight, viscera, abdominal fat, carcass weight, wings, neck and back bone. Also, reduction of available phosphorus did not have any significant effect on daily feed consumption, feed conversion, live weight, viscera, abdominal fat, carcass weight, breast meat, femurs, wings, neck and tibia ash. Interaction between vitamin and phosphorus were significant for daily gain, daily feed consumption, live weight, wings, neck and tibia ash (P<0.005) and were highly significant for breast meat, femurs, and back bone (P<0.00l).

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In order to study the effects of different protein feeds on honey bees (Apis mellifera L), experiments were conducted in a completely randomized block design with 15 treatments and 4 replicates. The nutritional effects of different treatments on caged bees were studied through recording half-life time (50% mortality). Pollen substitutes were soybean flour, soybean meal, bread yeast, wheat gluten, soybean flour + soybean meal, soybean flour + bread yeast, soybean flour + wheat gluten, soybean meal + wheat gluten, and wheat gluten + bread yeast. Pollen supplements were wheat gluten + pollen , soybean flour + pollen, soybean meal + pollen, bread yeast + pollen and two controls as pollen and honey. The nutritional effects of different protein sources provided by pollen substitutes and supplements were recorded on the amount of carcass protein and fatbody of honey bee workers in experimental colonies. The wheat gluten supplement and the soybean substitute showed the longest (60.58 days) and the shortest (10.53 days) half-life time of worker bees, respectively. The amount of food consumption in different treatments was not significantly different (P>0.05). The greatest DM of worker bees (dry matter of carcass) was related to soybean (34%) and the least related to yeast supplement (31.54%), which were significantly different (P<0.05). The highest carcass protein belonged to wheat gluten supplement (22.57%) and the lowest was related to yeast supplement (20.01%). The greatest carcass fat was related to soybean supplement (4.75%) and the lowest to wheat gluten supplement (3.84%). Results of the present experiments showed that soybean flour, soybean meal, wheat gluten and bread yeast can be used in pollen supplement and substitute cakes.

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  Photosynthesis and wheat grain yield responses to supplemental irrigation with different amount of applied water under dryland conditions were investigated. Therefore, a two-year field experiment was conducted research farm of College of Agriculture, Shiraz University during 2004-2005. Five levels of irrigation including dryland conditions, irrigation at stem elongation, booting, flowering and grain filling were main plots and two wheat cultivars: Agosta and Fin-15 were subplots, and three rates of nitrogen including zero, 40 and 80 kgha^-1 were sub sub-plots. The results showed that in both years, photosynthetic rate, stomatal conductance, substomatal CO₂ concentration and transpiration rate, were significantly higher under irrigation at stem elongation stage compared to other supplemental irrigation treatments. In all of the four supplemental irrigation treatments, photosynthetic rate, stomatal conductance, substomatal CO₂ concentration and transpiration rate decreased with decreasing the amount of applied water to each plot. In both years, the highest grain yield was obtained from supplemental irrigation at stem elongation stage, and the lowest yield was harvested at dryland conditions. The highest photosynthetic parameters, yield and yield components were obtained from interaction of supplemental irrigation at stem elongation stage × Fin-15 and 80 kg N ha^-1 in both years. The supplemental irrigation in 2004 and 2005 increased the grain yield 200 and 221 percent, respectively, compared to dryland conditions. Thus, supplemental irrigation at sensitive stem elongation stage could affect significantly wheat grain yield of rainfed wheat cultivars and provision of adequate water for a supplemental irrigation at the appropriate growth stage could double the grain yield of rainfed wheat.

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In tea plantation regions of northern part of the country, application of supplemental irrigation during dry periods (lacking rainfalls) in conjuction with proper nitrogen fertilizer application can significantly improve tea yield per unit of plantation area. In order to quantify the effectiveness of proper irrigation and nitrogen management on tea, the response of tea to various levels of irrigation and nitrogen applications was studied in Fouman suburb of Guilan province. Tea crop production function and its crop coefficient (K_C) were determined. A line source sprinkler irrigation was used for creatiating a variable irrigation application and a split-split-plot statistical design was used. Irrigation treatments consisted of full irrigation (I₄), deficit irrigation (I₃, I₂ and I₁) and no irrigation(I₀). Nitrogen application treatments were N₁, N₂ and N₃ (100, 180 and 360 kg/ha) in three replications randomly arranged as main plots, while irrigation treatments as sub plots were not randomized. During the growing period, soil moisture up to the depth of 90 cm was determined gravimetrically and actual crop water use was calculated from mass balance equation weekly. Reference evapotranspiration (ETo) was estimated by Penman-Montieth equation and was used to estimate tea crop coefficient. During growing period, the actual tea water use of I₄ and I₀ were computed to be 457 and 256 mm. Tea crop coefficient during dry period (June, July and Augest) ranged from 0.8 to 0.9. Crop resistance factor (K_y) for tea was found to be 1.37. Results indicated that optimum rate of nitrogen (180 kg/ha) along with supplemental irrigation, increased yield and water use efficiency (WUE). Futhermore, supplemental irrigation increased yield and WUE more than nitrogen application. In I₀ and I₁ treatments, application of 100 kg/ha nitrogen resulted the highest yield and WUE.

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In order to evaluate the effect of concentration and time of foliar spraying of nitrogen fertilizer as supplemenfary to soil nutrition on grain yield and some important traits of rapeseed (Hyola401), an experiment was conducted in complete randomized block design with 16 treatments and three replications in in 2008-2009, 2009-2010 growing seasons, and in 2003-2005 growing seasons in paddy fields of Rice Research Institute of Iran (Rasht). In this experiment, nitrogen concentration (from urea source) at two levels (5 and 100.00) and application time at seven levels including 1-seedling stage: 6-8 leaves 2: beginning of stem elongation 3: prior to flowering 4: 6-8 leaves + stem elongation 5: 6-8 leaves + prior to flowering 6: stem elongation+ prior to flowering 7: 6-8 leaves + stem elongation+ prior to flowering with two control treatments including zero nitrogen fertilizer and basal fertilization as 1/3 at seed sowing, 1/3 at stem elongation and 1/3 prior to flowering stages of 180 kg pure N ha were considered. Results of combined analysis showed significant differences between the experimental treatments in most traits. Spray application of nitrogen (100.00) in stem elongation+prior to flowering stage produced maximum silique length (6.8 cm), number of secondary branch (7.1) and plant height (141.1 cm). Also, the spray application (100.00) in 6-8 leaves+stem elongation+ prior to flowering stage had maximum biological yield (10684.6 kg.ha-1), grain and oil yields (3686.2 and 1489.3 kg.ha-1, respectively) and the maturity period (202 days). Spray application (100.00) in stem elongation+ prior to flowering stage did not induce significant difference with spray application (100.00) in the three stages. Maximum oil content was observed in control treatment (zero nitrogen fertilizer) with an average of (44 %). According to the results of the present experiment, it seems that spray application of nitrogen (100.00) at final growth stage of rapeseed (stem elongation+ prior to flowering stage) increases grain and oil yields.