Showing 82 results for Karimi
A. Reyhani Tabar, N. Karimian, M. Muazardalan, G. R. Savaghebi, M. R. Ghannadha,
Volume 10, Issue 3 (fall 2006)
Abstract
Information about forms of zinc (Zn) is important for the evaluation of its status in soil and also understanding of the soil fertility and chemistry. To obtain such information, amounts and distribution of Zn in different fractions of 20 soil samples of Tehran province, Iran were determined by sequential extraction method and their relationships with each other and with soil characteristics were investigated. Total Zn of soils ranged from 70 to 169.9 mg/kg-1. The amount of different Zn forms relative to the sum of forms was determined to be as follows: organic less than 0.1, soluble+exchangeable 0.1, manganese-oxide-associated 0.9, carbonate 1.6, crystalline iron-oxide-associated 3.8, amorphous iron-oxide-associated 4.2, and residual form 89.3%. Simple correlation coefficients showed that pH had a negative significant correlation with all forms of Zn except organic. Silt and clay contents had significant positive correlations with total, residual, and crystalline iron-oxide-asociated Zn but CEC had significant correlation only with total Zn. Calcium carbonate equivalent showed a significant correlation with soluble+exchangeable, manganese-oxide-associated and amorphous iron-oxide-associated Zn. DTPA-extractable Zn was significantly correlated with soluble+exchangeable, carbonate, and amorphous iron-oxide-associated Zn. A significant correlation was also observed between the Zn forms themselves, which is presumably a reflection of the existence of a dynamic relation between the chemical forms of an element in soil.
H. Majdi, M. Karimian- Eghbal, H. R. Karimzadeh, A. Jalalian,
Volume 10, Issue 3 (fall 2006)
Abstract
Stabilizng sand dunes has been one of the main challenges in the arid regions. So far, different kinds of mulches have been used extensively for sand dune stabilization. This study was carried out to determine the optimum composition, concentration and thickness of clay mulch for sand dune stabilization. For this purpose two soil samples from clay flats of a playa with different amount of salinity from Ardestan area were used to make clay mulches. A sand dune sample was selected as bed for applying the mulch. To select the right ingredient and treatments, clay samples were mixed with sand and different amount of water, and sprayed on sand dune bed. In addition, wheat straw was added to some mixture to test its effect on stability of the mulch. Treatments with lowest crack and highest penetration of mulch in sand bed were selected for the experiment in this study. Mulch treatments contained (1): 250g sand dune + 250g clay + 25g straw (2) 250g clay + 25g straw (3) 250g sand + 250g clay (4) 250g clay (5) 125g sand + 125g clay and (6) 125g clay. All treatments were mixed with 500ml water. The experimental design was a CRD with a 6(mulch) * 2(thickness)* 2 EC factorial method with 3 replications. The results showed that clay mulch were resistant to wind erosion, but erosion took place when they had been bombarded with sandblast. The mulches with straw showed the highest resistance to erosion as compared to other treatments. With increasing the number of mulch layers, resistant to erosion also increased. The added stability of mulch was due to the increase in mulch thickness and also increases in clay and silt content. The overall result of this study shows that the mulch with two layers and higher mixture of clay and sands was the best treatment for the stabilization of sand dunes.
A. Koocheki, S. A. Mortazavi, M. N. Mahalati, M. Karimi,
Volume 10, Issue 3 (fall 2006)
Abstract
In order to determine the effects of emulsifiers (Lecithin, E471 and E472) and their levels (0, 0.25, 0.5, 0.75 and 1%) and also addition of fungal α-amylase (0, 5, 10 and 20 g/100 kg flour) on bread staling, a completely randomized experiment with factorial design and 3 replications was conducted. Bread staling was determined after 0, 24, 48 and 72 hours of storage. Correlation between variables was analyzed by simple and multivariate regression. Results indicated that addition of emulsifiers reduced the firmness of bread. E472 had the most and E471 had the least effect on bread firmness after 72 hours of storage. Addition of α-amylase reduced the bread firmness and this effect was less pronounced after 72 hours of storage. Correlation between variables based on the development of a model showed that in the first day of bread production, optimal levels of emulsifiers were 1%, 0.25% and 0.5% for Lecithin, E471 and E472, respectively. In case of simultaneous application of emulsifiers and enzyme, the optimal level of enzyme was 5 g/100 kg flour.
R. Karimizadeh, H. Dehghani, Z. Dehghanpour,
Volume 10, Issue 3 (fall 2006)
Abstract
To facilitate the interpretation of data from a genotype by environment experiment (GE), a cluster method is proposed to group genotypics according to their response to the environments especially when the GE interaction is large. The interaction structure of two-way classification data often can be identified if the data stratified into homogeneous subsets. In this paper four GE interaction cluster methods are proposed for this purpose. The stability of the 10 maize hybrids including 9 hybrids that were the best hybrids in yield trials and KSC 301 (check hybrid) were evaluated for 2 years in 4 locations of Iran. The randomized complete block design with 4 replications was conducted for each environment with different layouts. Simple analysis of variance revealed significant genetic differences between hybrids for grain yield. The results of combined analysis of variance indicated that genotype × year, genotype × location, and genotype × year × location interaction effects were significant (P < 0.01). Results also showed that models 1 and 3 and models 2 and 4 had the same responses. Hybrids 8 (K1263/1 × KE8212/12) with high yield stability in both models 1 and 3 were in one group and other hybrids were in another group. In models 2 and 4 results led to 3 groups: Group1 included hybrids 3, 7 and 9 that were very stable and had high yield group 2 included hybrid 1 alone that had medium stability and yield and group 3 included other hybrids that had low stability and yield.
A. Aboutalebi, E. Tafazoly, B. Kholdebarin, N. Karimian,
Volume 11, Issue 1 (spring 2007)
Abstract
This study was conducted to evaluate the effect of salinity on concentration of potassium (K), sodium (Na) and chloride (Cl) ions, in sweet lime budded on five citrus rootstocks, including Bakraii (mandarin x sweet lime), Volcameriana, Sour orange, Sweet lime and Mexican lime in a glasshouse, using a randomized completely design with factorial arrangement and four replications. Rootstocks had great effect on the concentration of ions in scion. Concentration and distribution of ions were significantly different in control and other treatments. Salinity increased Na and Cl ions in shoots and roots, but the rate of increase varied among rootstocks and treatments. Lowest concentration of Na and Cl ions were in shoot of scion on Volkameriana. Under salinity stress, K concentration increased in shoots of scion on Sour orange and Bakraei and decreased it on other rootstocks. Salinity increased K concentration in roots of all rootstocks except for Mexican lime.
M. Rajaie, N. Karimian,
Volume 11, Issue 1 (spring 2007)
Abstract
Cadmium (Cd) and its rate in soil have received lots of attention because it is easily taken up by plant root, making it 20 times more toxic in comparison with other heavy metals. Knowledge about the factors affecting Cd availability and conversion of its chemical forms is, therefore, important. Sequential extraction has been used as a suitable method for identification of chemical forms and their relationship with plant availability, but in soils of Iran less attention has been paid to studying the change in chemical forms as affected by time. The present research was designed to study the change in Cd chemical forms as affected by application rate and time of incubation in two soil textural classes. A clay loam calcareous soil [Fine, mixed (calcareous), mesic Typic Calcixerepts] was converted to sandy loam soil by adding pure quartz sand and both soils were treated with 0, 5, 15, 30, and 60 mg Cd / kg soil as cadmium sulfate and incubated at room temperature near field capacity moisture. After 0, 1, 2, 4, 8, and 16 weeks, chemical forms of Cd were determined by sequential extraction. Results showed that, depending on the textural classes, about 82 and 87 % of applied Cd was converted to soluble+exchangeable, carbonate, and organic forms. In both soils carbonate fraction was dominant. Conversion of applied Cd to soluble+exchangeable and carbonate forms in sandy loam was higher than in clay loam. For organic, manganese oxide, amorphous iron oxide, and residual forms, the reverse was true. The crystalline iron oxide form was less than detection limit of atomic absorption in both textural classes. Increasing the application rate caused an increase in all forms of Cd but the percentage increase depended on the capacity of different soil components for Cd retention. Carbonate showed the highest capacity for retention. The effect of incubation time on conversion of Cd to different forms was significant. However, in almost all treatments more than 80 % of added Cd was converted to carbonate and organic forms immediately, and the proportion approximately stayed the same throughout the course of experiment.
S. A. Ghaffari Nejad, N. Karimian,
Volume 11, Issue 1 (spring 2007)
Abstract
In order to investigate mineral manganese forms and their relations with plant responses, 22 soil samples from Fars province (0-20 cm) were in a greenhouse experiment filled in 3 liter pots, and soybean (Glycine max (L.) merr.,CV.Williams) was grown for 7 weeks. Chemical forms of manganese were determined in soils by warden and Reisenauer sequential extraction method (readily soluble, weakly adsorbed, carbonate bound and oxide bound extracted with Ca(No3)2, Ca DTPA +Na2B4O7, HNO3 and NH2OH. HCl, respectively) after harvesting the plants. Results showed that the amount of Mn in different forms was in the following order: Carbonatic Mn >Mn Oxides >Weakly adsorbed Mn > Soluble Mn. Regression equations between soil properties and Mn forms showed a significant correlation between calcium carbonate equivalent and carbonate bound Mn. Significant correlation between Carbonate bound Mn and concentration of Mn in the aerial part of soybean showed that this fraction plays an important role in plant nutrition.
A. Karimi, M. Mazardalan, M. Homaeia, A. M. Liaghat, F. Raissi,
Volume 11, Issue 40 (summer 2007)
Abstract
In Iran, fertilizers are mainly applied directly to soil. In such conditions, the yield and fertilizer use efficiency are usually low. The simultaneous application of fertilizers and irrigation water (fertigation) is an appropriate alternative to increase the efficiency of applied water and fertilizers. The objective of this study was to investigate the effect of various irrigation and fertilizer amounts on efficiency of applied fertilizers when used as fertigation in a Tape irrigation system. A field experiment was carried out with sunflower as a completely randomized design with 20 treatments and 3 replicates. The fertilizers were applied by fertigation. Four levels of the water (60, 80, 100 and 120% treatments I1 to I4) and five rates of the recommended fertilizers (0, 60, 80, 100, and 120% treatments F0 to F4) were applied.The recommended amounts consisted of 400 kg CO(NH2)2, 50 kg KCl, 30 kg FeSO4, 30 kg MnSO4, 50 kg ZnSO4, 30 kg CuSO4, and 30 kg H3BO3 per ha. Tape irrigation was used for every treatment. The results indicated that in fertigation method, there were significant differences ( P≥0.01) in fertilizer use efficiency (FUE) for the total dry matter and grain yield between treatments. The results showed that by increasing applied water, fertilizer use efficiency was increased and affected by fertilizers treatments. Thus due to higher availability of nutrients, fertilizer use efficiency increased. was Fertilizer use efficiency also decreased by increasing fertilizer rate. The results also demonstrated there were significant differences in all the treatments. The results showed that fertilizer use efficiency of K is higher than N and N is higher than P.
E. Zandi Esfahan, S. J. Khajedin, M. Jafari, H. Karimizadeh, H. Azarnivand,
Volume 11, Issue 40 (summer 2007)
Abstract
In order to determine the reciprocal relationship between the important characteristics of soil and the growth of Haloxylon ammodendron (C.A. Mey) plant in segsi plain of Isfahan., ordination method was used. The study was performed through the stratified random sampling and the regions were separated according to the plant age and physical physiognomy, then 10 samples of Haloxylon ammodendron (C.A. Mey) of the same age were selected in each region. Meanwhile, factors such as height, canopy cover area, canopy cover perimeter, canopy cover diameter, and basal area were considered. Also, 30 profiles from viewpoint of growth situations in 10 different regions were dug. Soil characteristics such as : pH, Ec, total soluble Ca2+ and Mg2+, Cl-, CO3--, HCO3-, SP%, CaCO3%, CaSO4%, organic matter%, total nitrogen percentage, phosphorous, Na+, K+, SAR, and hardpan depth were measured. Data was analyzed using ordination method. According to the results, samples of the same age showed significant differences in plant features. Other results showed that physical characteristics such as depth of hardpan from soil surface, SP%, and chemical characteristics such as salinity, alkalinity and total nitrogen had the highest effect on qualities of this kind of plant. In other words, the results mentioned above showed the important role of Haloxylon ammodendron (C.A. Mey) in sharp increase of salinity and alkanity in it's stratum.
M. Sheklabadi, H. Khademi, M. Karimian Eghbal, F. Nourbaksh,
Volume 11, Issue 41 (fall 2007)
Abstract
The effect of overgrazing on vegetation changes in central Zagros has been studied by a few scientists, but there is no detailed information on the impact of such practices on soil properties. The objective of this study was to assess the effect of climate and grazing management on selected soil biochemical properties. Fourteen experimental range sites protected against grazing as well as their adjacent overgrazed sites in Chadegan, Pishkuh and Poshtkuh were selected. In each site, samples were collected from the depths 0-5 and 5-15 cm. Soil organic C (OC), microbial biomass C (MBC), total nitrogen (TN), organic C to total N ratio (C/N), microbial biomass C to organic C ratio (Cmic/Coc) and metabolic quotient (qCO2) were measured and/or calculated. The results showed that the lowest SOC, MBC, TN and Cmic/Coc occur in Chadegan due to low fresh materials input. The above parameters in Pishkuh and Poshtkuh regions are 2.5 to 3 times greater than those in Chadegan area. Grazing intensity in Pishkuh is less than that in Poshtkuh region and there is no significant difference between grazed and protected sites in Pishkuh. But, there is a significant difference between grazed and protected plots in Poshtkuh due to a higher grazing intensity. Higher Cmic/Coc and lower qCO2 suggest that the quality of organic matter is better in Poshtkuh and Pishkuh. In conclusion, highly degraded rangelands in Pishkuh and Poshtkuh seem to be able to recover very quickly with proper management, while Chadegan region needs a much longer period of time to restore.
E. Karimi, H. Rouhani, D. Zafari1, Gh. Khodakaramian, M. Taghinasab,
Volume 11, Issue 41 (fall 2007)
Abstract
In order to study the biological control of carnation vascular wilt disease caused by Fusarium oxysporum f.sp. dianthi, 141 bacterial strains were isolated from carnation rhizosphere, and their antagonistic activity was evaluated against fungal pathogen in dual culture method. Among the tested strains, 16 strains showed antagonistic activity seven of them with more activity were selected for further investigation. Based on phenotypic features, strains E31 and E57 were identified as Bacillus cereus E76, E93, E102 and E121 as Bacillus subtilis and E130 as Pseudomonas fluorescens bv. III. All bacterial strains inhibited mycelial growth of F. o. f. sp. dianthi by production of non-volatile and volatile metabolites under laboratory condition. Microscopical analysis showed that all strains caused deformation of pathogen mycelium, and metabolites of these strains reduced conidia production rate and as well as the ability of conidia germination. In the in vivo tests, in sterilized and nonsterilized soils, the effect of bacterial strains was studied on disease severity, percentage of healthy plants and the growth rate of plants using soil inoculating and root-dipping into bacteria-methyl cellulose mixture methods. The E57 and E121 strains, in both methods, and E130 in root-dipping method showed highest effect on decreasing of disease severity and increasing of healthy plants percentage. Strains E57, E121 and E130 significantly increased total dry weight of carnation. Maximum dry weight was obtained by E57 and E130 in soil inoculating and root –dipping methods respectively.
E. Karimi, A. Lakzian, K. Khavazi, A. Asgharzadeh, G.h. Haghnia,
Volume 11, Issue 42 (winter 2008)
Abstract
It is important to investigate the genetic diversity and evaluate symbiotic effectiveness of the indigenous rhizobial population. It helps understand the responses of indigenous isolates to different rhizobial inoculants. In spite of the importance of bacterial diversity, there are a few scientific reports about it in Iranian soils. Genetic diversity of 150 isolates of Sinorhizobium isolated from Hamadan soils was studied by using PCR / RFLP 16S-23S rDNA technique. The results showed that all isolates clustered in three different groups. Group (I) formed 122 isolates and they were quite similar to Sinorhizobium meliloti from viewpoint of genetic characteristics. Twenty five isolates were clustered in Group (II) and they belonged to Sinorhizobium medicae. Group (III) had two isolates and they were new species and quite different from the other groups. Shannon diversity index was different within eleven different land units (Medium gradient mountains, Level lands, Plateau, Foot slopes, Depressions and Composite land) and there was a correlation between Shannon index and some soil properties. Difference in Similarity index showed that Sinorhizobium groups in each land unit were different.
M. Naderi Khorasgani, A. Karimi,
Volume 11, Issue 42 (winter 2008)
Abstract
This research was carried out to study the impacts of geomorphologic characteristics of claypan on land use and land degradation. Databank of the study area was constructed and digital terrain model of claypan was prepared. By using GIS techniques spatial distributions of the subsurface drainage network, sediment transportation index and wetness index were calculated. The results indicate that the depth to the claypan is between 0 (where the pan is exposed at the surface) to 605 cm. There are several depressions in the claypan which are filled by new sediments. Each depression has a catchment which is charged by the drainage water of its attributed lands. While a depression drains naturally or synthetically, the attributed soils over the depression are in non saline or moderate salinity condition otherwise, a marshland, a waterlogging area or a salt crust zone develops over there. The results also indicated that soil surface salinity is a function of depth to claypan and drainage condition of area. The trends of salinity extension are different for closed and open catchments and the depth to the claypan could be estimated using electrical conductivity. The results also show that analysis of microtopography of soil surface and soil stratification should be considered for designing irrigation and drainage networks.
M. Karimi, M. Hassanpour Asil, H. Samizadeh Lahiji, S. Talesh Sasani,
Volume 12, Issue 43 (spring 2008)
Abstract
Experiments were conducted to study the effects of temperature and chemical treatments on the vase life of cut Asiatic hybrid lily cultivar Pisa, with sixteen chemical treatments using factorial design with 3 replication arrangements. Lilium cut flowers were harvested when the first flower colored fully. Following chemical treatments, they were grouped in different combinations before storage. The treatments included sucrose, 8- hydroxy quinoline sulfate (HQS), citric acid (CA), gibberellic acid (GA3), kinetine (KI) and distilled water as control. Lilium cut flowers were pulsed for 24 hours in different solutions, then brought out and kept in the distilled water at temperatures of 4°C and 22 ° C .Effects of applied treatments were evaluated on different characteristics like vase life, the amount of water absorbed, flower diameter, total soluble solids and fresh weight. Results showed that the temperature of 4°C had the most effect on vase life, keeping the quality of lilium cut flowers. The results also displayed that the chemical treatments kinetine + sucrose had the most effect on vase life and percentage of sucrose, gibberellic acid + kinetine delayed yellowing of the foliage, 8- hydroxy quinoline absorbed the most amount of water, and treatments sucrose + kinetine , gibberellic acid + 8- hydroxy quinoline sulfate and gibberellic acid + citric acid were most effective in increasing the flowers diameter.
R. Karimizadeh, M. Safikhani Nasimi, M. Mohammadi, F. Seyyedi, A.a. Mahmoodi, B. Rostami,
Volume 12, Issue 43 (spring 2008)
Abstract
One of the applications of Non-Parametric methods is determination of genotypes rank in different environments, which is also used as a measuring stability. A stable genotype shows similar ranks across different environments and has minimum rank variance in different environments. Non-Parametric Stability Statistics require no statistical assumptions about the distribution of the phenotypic values and are easy to use. This study was carried out to determine the ranks of 10 Lentil genotypes (Lens culinaris Medikus) across ten environments in 2002-2004, using a randomized complete block design with four replications. Analysis of Thennarasu non-parametric statistics showed that genotypes 8 and 9 had high stability by NP(1) statistic and genotypes 9, 8 and 1 had stable yield in NP(2) method. Result of the NP(3) statistic was similar to NP(1) statistic. NP(4) statistic selected genotypes 9 and 1 as the most stable genotypes and ultimately NP(5) statistic introduced 9 and 1 genotypes as stable genotypes in this experiment. Also analysis of Nassar and Huhn non-parametric statistics revealed that genotypes 1 and 2 were most stable and well adapted across ten environments. In addition, it was concluded that plots obtained by both mean yield (kg ha-1) vs.Si(1) and mean yield (kg ha-1) vs. Si(2) values could enhance visual efficiency of selection based on genotype × environment interaction. According to these configurations, genotypes in section 1 can be considered as stable and well adapted to all environments, having general adaptable ability. For recognition a daptability,Si(1) and Si(2) take preferred over other non-parametric statistics.
A. Karimi, H. Khademi, A. Jalalian,
Volume 12, Issue 44 (summer 2008)
Abstract
Despite the existence of highly silty soils in southern Mashhad, there is no information about the aeolian and /or in situ formation of these soils. The main objective of this study was to determine the source of silt generation in this area. Granitic hilly lands in southern Mashhad have been covered by silty deposits. Based on the soil origin, four profiles including a residual soil covered by a silty layer, a residual soil with low amount of silt, a highly silty soil and an alluvial soil as well as a deep profile containing a succession of silty and alluvial materials were studied. Cumulative particle size distribution curve (CPSDC), depth distribution curves of silt/sand ratio (Si/S), Folk inclusive graphic standard deviation, Folk inclusive graphic skewness (SKI) and sand grain morphology analyzed by scanning electron microscopy (SEM) were determined and used to identify the source of the silty materials. Based on the results obtained, silty (L), residual-silty (R-L), residual (R), alluvial (A) and alluvial-silty (A-L) horizons were identified. CPSDC of L horizons is sigmoidal in shape and is easily distinguishable from that of the other horizons. In contrast, the CPSDC of alluvial and residual horizons is spherical in shape. CPSDCs for R-L and A-L horizons are neither sigmoidal nor spherical, but something in between. The L horizons have the highest SKI (very skewed to fine particles) and the lowest Folk inclusive graphic standard deviation (very badly sorted). In this regard, alluvial and residual horizons are intermediate. Because of the silt addition to R-L and A-L horizons, these horizons have a nearly zero SKI (symmetrical) and the highest Folk inclusive graphic standard deviation (very badly sorted). Particle size distribution histograms of R-L and A-L horizons are bimodal, a mode for sand and a mode for silt, suggesting two different sources. Depth distribution of Si/S, SKI and Folk inclusive graphic standard deviation of highly silty and other horizonz show a drastic change between L horizons and the other horizons-an indication of lithologic discontinuity and difference in origin. In conclusion, despite the possible contribution of granitic parent rocks to silt generation in the area, loess deposits recognized appear to have mostly been transported by aeolian movement.
Z. Karimi , M. Rahemi,
Volume 12, Issue 45 (fall 2008)
Abstract
Pathogens are the most important factors inducing postharvest losses on citrus fruit. Experiments were conducted as a CRD with 4 replications on sweet lime (Citrus limetta) and Valencia orange (Citrus sinensis) in 2003 and 2004. Treatments were pure essential oils of clove and thyme and in 25% ethanol solution at concentrations of 0.1, 0.3 and 0.5% and imazalil (2 ml/l). Results indicated that in the first year, pure essential oils of clove and thyme reduced the decay percentage of blue mold of Valencia orange fruit from 90 % (control) to 0 and 12.5 %, respectively. Pure essential oils of clove and thyme reduced the decay percentage of sweet lime in the first year of experiment from 95 % (control) to 0 and 6 %, respectively. In the second year, with the same treatments decay percentage of blue mold was reduced from 90 % (control) to 0. Solutions of 0.1, 0.3 and 0.5 % of clove and thyme oil extracts in 25 % ethanol solution reduced decay percentage of sweet lime fruits form 85 % (control) to 65, 41 and 26 % for thyme oil and to 60, 30 and 22.5 % for clove oil. Comparison of pure clove and thyme oil extract with imazalil showed that pure clove and thyme oil extracts were not significantly different with fungicide treatment. Treatments of clove and thyme oils in 25 % ethanol treatment were not as effective as fungicide.
M. Majidian, A. Ghalavand, N. Karimian, A. A. Kamgar Haghighi,
Volume 12, Issue 45 (fall 2008)
Abstract
In order to investigate the effects of moisture stress, nitrogen fertilizer, manure and integrated nitrogen and manure fertilizer on yield, yield components and water use efficiency of SC 704 corn (late maturing, non-prolific and dent). In 2005, a field study was conducted in agricultural experiment station of the college of agriculture, Tarbiat Modares University. The type of design was randomized complete block with factorial arrangement and three replications. For the study, four levels of nitrogen fertilizer (0, 92, 184 and 276 kg N ha-1), integrated fertilizer (46 kg N ha-1 + 2/5 ton ha-1 FYM, 92 kg N ha-1 + 5 ton ha-1 FYM and 138 kg N ha-1 +7/5 ton ha-1 FYM ) and organic Farm Yard Manure (5, 10 and 15 ton ha-1 FYM ) along with three levels of irrigation (optimum irrigation (control), water stress 75% optimum irrigation and water stress 50% optimum irrigation) were used as treatments. The results showed maximum seed yield was produced with 92 kg N ha-1 + 5 ton ha-1 FYM and average of seed yield was 7976 kg ha-1. Maximum corn seed yield resulted when optimum irrigation water was applied and average seed yield was 7041 kg ha-1. When water stress was imposed in 50% and 75% of optimum irrigation, seed yield was decreased by 33 and 12%, respectively. The best seed yield was obtained with interaction of 5 ton ha-1 FYM and optimum irrigation. Also, maximum water use efficiency was obtained in using 50% of optimum irrigation. Maximum water use efficiency was obtained with interaction of 92 kg N ha-1 + 5 ton ha-1 FYM and imposition of water stress in 50% optimum irrigation. Results showed that adequate nitrogen fertilizer slightly increased corn seed yield under stress, and integrated (nitrogen and manure) fertilizer increased corn seed yield under stress. But seed yield greatly increased with optimum irrigation. Integrated fertilizer application increased seed yield even with severe moisture stress. Application of integrated chemical fertilizers and manure produced better seed yield and also decreased the amount of chemical fertilizers and improved soil physical and chemical characteristics.
S. A. Kazemeini, H. Ghadiri, N. Karimian, A. A. Kamgar Haghighi, M. Kheradnam,
Volume 12, Issue 45 (fall 2008)
Abstract
In order to evaluate the interaction effects of nitrogen and organic matter on growth and yield of dryland wheat, an experiment was conducted at the research station of the College of Agriculture, Shiraz University at Bajgah in 2005 and 2006. The experimental design was split plot in which three levels of nitrogen (0, 40, and 80 kg N ha -1) were main factors and additive organic matters including liquorice root residue at 15 and 30 Mg ha -1, municipal waste compost at 10 and 20 Mg ha -1, and wheat residues at 750 and 1500 kg ha -1 (all rates equivalent to 50 and 100%) were sub factors. A check treatment (no additive materials) was also included in the experiment. Results indicated that with increasing nitrogen level from zero to 40 and 40 to 80 kg ha-1, wheat yield increased significantly. Among yield components, number of seeds per spike increased significantly with zero to 40 and 40 to 80 kg nitrogen ha-1, but number of spikes m-2 increased significantly only when nitrogen level was increased from zero to 80 kg ha-1. Compared to check (no additive materials), maximum wheat grain yield (32%) was obtained from 100% compost application. Results of nitrogen and organic matters interaction effects indicated that 100% compost application and increasing nitrogen level from 40 to 80 kg ha -1 had no significant effect on dryland wheat yield. This showed the positive impact of compost application on the reduction of nitrogen fertilizer. Thus, it appears that 50% of the required nitrogen fertilizer could be replaced by compost. Applying organic matter increased soil water in both years, however, among organic matters, compost had a more pronounced effect on increasing soil water.
A Karimi, M Noshadi, M Ahmadzadeh,
Volume 12, Issue 46 (1-2009)
Abstract
In this research the effect of Super Absorbent Polymer (SAP) on the crop growth, wilting point, sunflower survival, water holding capacity, and irrigation interval was investigated. The experiment was conducted with different concentrations of absorbent hydrogel (Igeta): 0% (control treatment), 0.05%, 0.1%, 0.2%, and 0.3% (w/w). The soil textures were sand, loam, and clay. The experiment was a completely randomized design with three replications. The results of this research are: 1- Adding of Igeta to the soil changed solid, liquid, and gas phases. Application of 0.05%, 0.1%, 0.2%, and 0.3% (w/w) of Igeta increased the volume of clay, loam and sand soils between 10-40% , 5-32% and 9-37%, respectively. 2- With application of Igeta, absorption of nutrients (N, P, and K) was increased. Maximum absorption nutrients occurred at the level of 0.05%, 0.1%, and 0.3% with confidence level of 90% for clay, loam, and sandy soils, respectively. 3- Igeta increased water holding capacity and irrigation intervals. Increasing in irrigation interval was between 30-130% in clay, 60-120% in loam, and 150-300% in sandy soils. Water saving in clay, loam, and sandy soils was 30%, 40%, and 70%, respectively. 4- at the level of 0.3% Igeta, starting time of temporary wilting point was delayed from 4 to 10 days (150%) in clay and loam soils, and from 4 to 12 days (200%) in sandy soil. The starting time of permanent wilting point was delayed from 8 to 12 days (50%) in clay, 7 to 12 days (71.4%) in loam, and 9 to 14 (55.5%) days in sandy soils. Therefore, application of Igeta delayed starting time of permanent wilting point between 50-71% and temporary wilting point between 150-200%.
