JWSS - Journal of Water and Soil Science

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In order to determine the effects of using macaroni wastes instead of barley on dry matter intake (DMI), milk yield and composition, and nutrient digestibility, eight lactating Holstein cows (4 primiparous and 4 multiparous) in midlactation were used in a 44 Latin square design. The experimental periods were 21 d with 16 d for adjustment and 5 d for data collection. Treatments included a control diet (1) and diets 2, 3, and 4 containing 15, 30, and 45% macaroni wastes, respectively, which were fed three times a day as total mixed rations. During the last 5 days of each period, feed and fecal samples were taken for determination of DMI and apparent digestibilities and milk samples for fat, protein, lactose, and solids no fat (SNF). During the last day of collection period, urine samples were collected 3 and 5 h postfeeding for pH determination. The results showed no significant differences among experimental traits in either primiparous or multiparous, and across all cows. Milk yield and efficiency of feed conversion were nonsignificantly higher for diets 2, 3, and 4 compared with control cows. Compared to the control diet, DMI, fat, protein and SNF percentages did not significantly decrease in diets 3 and 4. From the results of this expriment, it may be concluded that replacing barley with macaroni wastes up to 45 percent could increase energy intake without any adverse effects on milk production and composition or on metabolic function in midlactating dairy cows.

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Ascochyta blight caused by Ascochyta rabiei is one of the major diseases of chickpea (Cicer arientinum) in Iran. Many phytopathogenic microorganisms, incuding A .rabiei, attack their host plant by secreting pectic enzymes including polygalacturonase (PG) which causes modification of cell-wall structure, increasing accessibility of cell-wall components for degradation by other enzymes. Polygalacturonase is the major factor in the initiation of Ascochyta blight disease, therefore in this study, the enzyme was purified from a virulent isolate of A .rabiei (IK06). Fungi were cultured in PZ medium culture media were harvested and after dialysis used for purification. Purification was achieved by Carboxy Methyl Sepharose Fast Flow ion exchange column equilibrated to pH= 5.5. Zero to one molar NaCl gradient was used for elution of the proteins from the column. Determination of protein content and enzyme activity of each fraction showed that PG was eluted from the column in 0.3 to 0.4 M salt. The purity of the protein and the MW of the enzyme were determined using SDS-PAGE technique. The MW was found to be around 27 KDa. The activity of the purified protein was also evaluated using polyacrylamide gel containing pectin as substrate (zymogram gel). Optimum pH for the purified enzyme was 7.5.

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It is necessary to use organic fertilizers and decrease chemical fertilizers consumption to reach sustainable agriculture. Thus, to study the effects of manure incorporation methods, and integrated effects of poultry manure with chemical fertilizers on the grain yield and yield components of maize, an experiment was conducted in 2004 at the Agricultural Research Farm of Lorestan Weather Department, 30 kms northeast of Khorramabad. The treatments were arranged in a split plot layout based on randomized complete block design with four replications. The main plots consisted of incorporation of fertilizer with soil by furrower or disk. The subplots included T0: control (no consumption of fertilizer and poultry manure) T1: 200, 100, and 100 kg ha^-1 of nitrogen, phosphorus, and potassium, respectively T2: 80% of T1+ 4 ton ha^-1 of poultry manure T3: 60% of T1+ 8 ton ha^-1 of poultry manure T4: 40% of T1+ 12 ton ha^-1 of poultry manure T5: 20% of T1+ 16 ton ha^-1 of poultry manure and T6: 20 ton ha^-1 of poultry manure. The results showed that incorporation of fertilizer by furrower, compared with disk, led to significant increase in plant height, 1000 seed weight and grain and biological yields. However, there were not significant differences in the number of seed per ear and harvest index between the two fertilizer incorporation methods. Fertilizer treatments caused significant increase of the treats mentioned except for the harvest index. The interaction effects were not significant for any traits. T5 treatment produced the highest grain yield, and was significantly different from T0, T1, T3 and T6 treatments. The differences between T1 (chemical nutrition system) and T6 (organic nutrition system) were not significant either. Effectiveness of integrated poultry manure and chemical fertilizers on maize yield components was higher than either poultry manure or chemical fertilizer. The results of this experiment indicated that incorporation of 16 ton poultry manure + 40, 20 and 20 kg ha^-1 N, P and K with furrower might be appropriate for maize prodution under conditions similar to this experiment.

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To study the effects of planting date and density on yield and its components in chickpea (Cicer arietinum L.) genotypes under dryland conditions of Khorram-Abad, an experiment was conducted during 2005-2006 growing season at the Agricultural Research Station of Lorestan Weather Department. Three sowing dates (March 6, March 21, and April 5) and two chickpea genotypes (Greet and Flip 93-93) with four plant densities (18, 24, 30 and 36 plants m^-2 ) were evaluated using a randomized complete block design with split-factorial design in three replications. Dates of planting were considered as the main plots, genotypes and plant densities were randomly distributed in sub-plots with factorial arrangement. The result showed that delay in planting from March 6 to April 5 significantly reduced number of pods per plant, number of grains per pod, 100-grain weight, grain yield and dry matter. Increasing plant density led to a significant decrease in number of pods per plant, number of grains per pod and 100-grain weight. However, grain yield and dry matter increased firstly with increasing plant density and then decreased. Planting date and density had no significant effect on harvest index, while genotype of Greet produced a larger number of pods per plant, grain yield as well as final dry matter. Also Flip93-93 produced a bigger number of grains per pod, greater grain weight and harvest index. The maximum grain yield was obtained with genotype of Greet at the first planting date in 30 plants m^-2 density. It could be concluded that due to thermal and drought stress occurring in late spring,, early planting of Greet genotype at 24-30 plants/m² may lead to a suitable increase in grain yield.

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Determination of carbohydrates in soil requires prior extraction and numerous extraction methods were suggested for this purpose. Three methods and five extractants were applied in order to extract carbohydrate fraction in three soil types forest, clayey and saline soils. The extraction methods were: 1) shaken in a plane rotary shaking machine for 16 h 2) heated in steam-bath for 2.5 h and 3) heated in oven for 24 h and extractants included 1) 0.5 M HCL, (2) 0.25 M H2SO4, 3) 0.5 M H2SO4, 4) 0.5 M K2SO4 and 5) distilled water. Carbohydrate content in soil was measured by phenol-sulphuric acid method. The addition of phenol to the extracted solution of HCl caused to milky precipitation. Therefore, this extractant can not be used for carbohydrate extraction in the phenol-sulphuric acid spectroscopic method. The results showed that in all soils and in the shaker extraction method, carbohydrate content was lower than in the oven and steam-bath extraction methods. In the forest and saline soils, the extracted carbohydrate content was not significantly different among the oven and steam-bath methods. For the clayey soil, the carbohydrate content was higher in the oven method than that of the steam-bath method. In all soils, the extracted carbohydrate by 0.5 M H2SO4 extractant was greater than those of other extractants. In the forest and saline soils, the extracted carbohydrate by distilled water was lower than those of other extractants. Using steam-bath method (for the forest and saline soils) and oven method (for the clayey soil) with 0.5 M H2SO4 extracted the highest amount of carbohydrates.

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The addition of organic and inorganic substrates to calcareous soils low in organic matter and nitrogen contents may change soil microbial biomass and activity. In order to investigate the effect of chemical and organic fertilizers on soil CO2 production and microbial biomass C, a field experiment was conducted under maize cultivation. The experimental design was split-plot arranged in randomized complete blocks with 7 treatments including 3.8, 7.6 and 11.5 ton ha-1 broiler litter and 100, 200 and 300 kg nitrogen ha-1 from urea and a control with 4 replications. The results showed that fertilizer, manure and sampling day had a significant effect (P<0.05) on soil CO2 fluxes. Mean soil CO2 emissions increased from 21.8 g C m-2 soil in control treatments to 24.1 in the second level of broiler litter. Furthermore, the CO2 fluxes in broiler litter treatments were significantly greater than those in urea-treated plots. Similar to CO2 fluxes, the amount of soil microbial biomass C was also affected significantly (P<0.05) by fertilizer and manure applications. Soil microbial biomass C was 28% higher in broiler litter-amended plots than that in urea-amended plots. In contrast, the microbial metabolic quotient (qCO2) in urea-treated soils was 10% higher than that in broiler litter-treated soils. In conclusion, broiler litter and urea fertilizer improved biological properties in this calcareous soil, but broiler litter, especially the highest litter loading, was more effective than urea fertilizer.

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The salt–affected lands in arid regions of central Iran are characterized by low rainfall, low fertility, high evaporation and salinity. The cultivation of salt–affected lands may have a major influence on soil quality. The aim of this study was to determine the response of soil quality indicators to reclamation and cultivation of salt–affected lands occurring in Abarkooh plain, central Iran. Soil quality indicators were evaluated in three land use systems including salt-affected land, wheat, and alfalfa fields. Composite soil samples were collected at 0–10, 10–20, 20–30, and 30–40 cm layers and analyzed for soil organic carbon, total nitrogen, carbohydrate, particulate organic carbon in macro-aggregates (POCmac) and micro-aggregates (POCmic), organic carbon mineralization and wet aggregate stability. The cultivation of salt–affected land caused a significant decrease in electrical conductivity at all layers and increased the amount of soil organic carbon, total nitrogen, carbohydrate, POCmac, POCmic, and organic carbon mineralization. At all layers, the POCmac/POCmic ratio in the alfalfa fields was higher than that in the wheat fields. The cultivation of salt-affected land caused a significant increase in soil aggregate stability (MWD) at all layers. In most cases, the amounts of soil organic matter and MWD were greater in alfalfa than in the wheat fields, reflecting a better soil quality and thus higher potential for increasing soil organic carbon sequestration in the alfalfa fields

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Prioritization of sub-watersheds is very important and necessary in order to implement soil and water conservation practices. This study has prioritized 13 sub-watersheds based on morphometric and land use characteristics using RS and GIS techniques in Haraz watershed to identify erosion-prone sub-watersheds. Morphometric characteristics including bifurcation ratio, drainage density, stream frequency, drainage texture, form factor, basin circularity, compactness coefficient, elongation ratio, length of overland flow, shape index, and basin relief were considered in morphometric analysis. Land use map was classified into seven classes of forest, water-body, irrigated farming, bare land, rangeland, orchard and residential area. Finally, sub-watersheds were classified into four categories as very high, high, medium and low in terms of priority for soil conservation. On the basis of morphometric analysis sub-watershed WS-4 was considered as high priority, whereas according to land use analysis, sub-watersheds WS-6, WS-8, WS-12 were in class of high priority. Sub-watershed WS-4 was categorized as a very high priority class based on the integration of morphometric and land use analysis. This region was identified as critical region therefore should be considered as priority class for implementation of soil and water conservation practices.

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