جستجوی مقالات مرتبط با کلیدواژه « carbohydrate » در نشریات گروه « آب و خاک »

In this study, the effect of different levels of irrigation water and potassium fertilizer on Roselle was investigated. The experiment was conducted using split plot design with four levels of irrigation water (I1, I2, I3 and I4 equivalent to 40%, 60%, 80%, and 100% crop water requirement) and three levels of potassium (K1, K2 and K3 equivalent 50%, 75%, and 100% potassium requirement) as sub-plot. At the end of experiment, quantitative parameters of plant including height, weight and number of capsules, dry yield, and water use efficiency were measured. Also, qualitative parameters including anthocyanin, protein, and carbohydrate content were measured to investigate the effects of water stress and fertilizer on Roselle quality. The results showed that the simple effects of irrigation water and potassium fertilizer were significant (P <0.01) on all measured parameters. The highest yield was obtained from 100% potassium fertilizer treatments and 80% water requirement. The highest water use efficiency was obtained in 60% water requirement plus 100% potassium fertilizer application, but no significant difference was found between 60% and 80% water requirement. The anthocyanin, protein, and carbohydrate contents increased with decreasing irrigation water depth to 60% of plant water requirement and decreasing potassium fertilizer application. However, there was no significant difference between 50% and 75% K fertilizer application. Therefore, due to the water status of the region and the reduction in water resources, application of 80% water requirement reduces water consumption and 75% potassium fertilizer increases quality and mitigates effect of drought stress in Roselle.

In the recent decades, the industrial revolution resulted in contamination of the biosphere by heavy metals and mycorrhizal fungi could affect the metals uptake by the plant. This research was carried out using Zea mays with three levels of soil Cd cotamination (0, 50 mg kg-1 using Polymer (Poly-hydroxybutanamide) – Cd, and 50 mg kg-1 using Cd-nitrate) and two levels of mycorrhizal (inoculanted with Glomus Caledonium and non-inoculanted) with three replications in a factorial experiment as a completely randomized design in greenhouse conditions. Cadmium pollution caused a significant reduction (P≥0.05) in shoot dry weight (from 31.05 to 26.34 and 27.10 g pot-1), shoot phosphorus concentration (from 0.37 to 0.36 and 0.36 g kg-1), soil carbohydrate (from 12.67 to 10.40 and 9.81 mg g-1) and also resulted an increases in soil glomalin (from 458.56 to 600.37 and 635 µg g-1) from control to polymer-Cd and nitrate-Cd respectively. Inoculation with mycorrhizal fungi reduced Cd uptake by the Zea mays, increased the soil glomalin content and improved the soil biological parameters. The results of this study showed that glomalin is an important protein in response to stress condition of Cd contamination. Poly-hydroxybutanamide polymer (a non-toxic compound) increased Cd availability and Cd uptake by plant (34.91 mg kg-1) compared to nitrate-Cd (19.83 mg kg-1) and it could be recommended to improve phytoremediation.

Satureja hortensis plant is a medicinal, annual, Herbaceous belonging to the family Lamiaceae, which is used as a medicinal plant and spice, as well as fresh vegetable. Various plant species show a wide range of resistance to drought due to their physiological, morphological and biochemical adaptations. The use of various organic fertilizers, including humic acid, has been widely used to improve the quality and quantity of crops and gardens without harmful environmental effects. Hormonal effects and enhancement of the absorption of nutrients to enhance performance, especially under stress conditions, are the effects of humic acid is derived from humus and other natural sources and Growth stimulating bacteria. Considering the dry and semi-dry nature of a large area of Iran, it is necessary to save water; on the other hand, nutrition is important in the yield and quality of the effective materials of medicinal plants. Therefore, the purpose of this study was to investigate the effects of drought stress and humic acid on morphological and physiological characteristics of Satureja hortensis. The experiment was a factorial based on a completely randomized design with four replications in greenhouse conditions in 2017. Four levels of irrigation water regulations 40, 60, 80 and 100% of field capacity and foliar application of humic acid in concentrations of 0, 150, 300 and 450 mg/L were applied. In the 6 to 8 leaves stage, Drought treatments were applied to the pots. Humic acid was applied in two stages in the desired concentrations. The first stage of spraying was when the plants were in the 4 to 6 leaves stage and the second stage was done two weeks after the first spraying. About 7 weeks after application of drought treatments, traits such as plant height, number of branches, number of leaves, leaf length, plant dry weight, proline, chlorophyll a, b and total, carotenoid and carbohydrates were measured. The results showed that the highest plant height, leaf number, number of branches and plant dry weight were obtained under irrigation conditions at 100% FC and spraying with 450 mg/l humic acid; While the highest leaf length, chlorophyll a, b and total, carotenoid and carbohydrate were obtained from irrigation treatment at 100% FC and 300 mg / l humic acid. Also, the highest proline content was obtained from irrigation treatments at 40% FC without humic acid application. Satureja hortensis plant is susceptible to drought stress and with increasing stress and reaching 40% of FC, decrease in the amount of physiological and morphological traits of Satureja hortensis. Meanwhile humic acid had a positive and significant effect on these traits. Finally, by improving the absorption of nutrients and the development of Vegetative and reproductive parts, the physiological and morphological traits increased. The highest effect of humic acid treatment on drought stress of Satureja hortensis was in the treatment of 450 mg/l. The highest salinity production was obtained in irrigation treatment with 100% FC and 450 mg/l humic acid.

The combined effects of biochemical composition and amount of plant residues returned to soils affect stability of aggregation and the rate of aggregate turnover. To investigate the influence of vegetation type on aggregate size distribution, five vegetation types including rainfed wheat (RW), grasses (G), Astragallus–Bromus (A-B), Astragallus–Lactuca (A-L) and Astragallus–Artemisia (A-A) were studied under similar environmental conditions in terms of parent material and slope aspect in Gonbad watershed, Hamadan. Total organic carbon (TOC), soil carbohydrates (Ch), mean weighted diameter (MWD), size distribution of water-stable aggregates (AS) and aggregate carbon (AC) were measured in surface (0-15 cm) soils. The amounts of TOC, Ch, MWD and AC (present in all aggregate size fractions) were significantly greater in soils under A-B and A-A than the soils of other vegetation covers, while the lowest values were observed in soils under RW and G. The highest AS>2 mm and lowest AS 2 mm were lower in soils under A-L, G and RW compared to other aggregate sizes. A-B and A-A vegetation types had greater canopy, annual production, plant diversity and litter content compared to other vegetation types.Frequent soil ploughing in RW site andlow plant diversity and canopy cover in A-L and G sites contributed to reduced soil aggregation and lower content of coarse aggregates;AS in 0.5-0.053 (mm) fraction in soils of aforementioned vegetation types was greater than other aggregate sizes. It was concluded that Ch and 0.5-0.053 (mm) aggregate size fraction might be reliable soil quality indicators that reflected land use and vegetation type changes.

Soil organic matter is influenced strongly by vegetation cover and management, therefore it is proposed as the main indicator of soil quality and health. The changes in soil organic matter status occur much more rapidly in the labile pools than in organic C. Thus, labile pools can be used as early indicators of changes in total organic matter that will become more obvious in the longer term here. In addition, the labile fraction has a disproportionately large effect on nutrient-supplying capacity and structural stability of soils. Land management as well as soil and environmental conditions lead to the deployment of different plant communities in rangeland ecosystems, which in turn may have different effects on soil quality indicators. The main objective of this research was to investigate the influence of different vegetation covers on the quantity and quality of soil organic carbon fractions in Gonbad experimental watershed, Hamadan. Moreover, the seasonal changes of selected soil carbon fractions were investigated.
Paired Gonbad watershed in Hamedan consists of two sub-basins: in control sub-basin no grazing management is applied, while in protected sub-basin, grazing has been restricted to a very short period in late autumn since 2002. Average annual precipitation and average annual temperature in the area are 304.4 mm and 9.5 °C, respectively (5). The soil cover of the watershed consists of TypicCalcixerepts, TypicHaploxerepts and Lithic Xerorthents (9). Five different vegetation typesof which, grasses (G), Astragalus-Bromus (A-B), Astragalus-Artemisia (A-A), Astragalus-Lactuca (A-L) in protected sub-basin, and Astragalus-Euphorbia (A-E) in control sub-basin, were selected. In addition, a formerly cultivated hilly land outside the watershed, now under rainfed wheat farming (RW) was selected as a non-pasture vegetation type. All of the six vegetation types were similar in terms of soil parent materials and slope aspect.. Soil and plant sampling were conducted in mid-autumn 2012 (a), and late spring 2013 (s). Three plots (1*1 m2) were studied in each vegetation type. Total organic carbon (TOC), carbon stock (CS), carbon stock normalized with sand(CS/Sa), active carbon (AC), normalized active carbon (AC/TOC), soil carbohydrates (Ch), normalized carbohydrates (Ch/TOC), basal respiration (BR) and normalized basal respiration (BR/TOC) were measured in surface soils (0-15 cm). A factorial experimental design with two factors, vegetation type (6 levels) and time (2 levels), was conducted. Prior to statistical analysis, data were normalized, if required.
TOC and CS contentswere significantly different between vegetation types. A-B and A-A had highest canopy cover, litter cover and species diversity. Species diversity in the rangeland ecosystems has direct effect on fodder production and soil organic carbon content. A-E site, despite its low TOC content, hadhigher CS/Sa (51.9 Mg/ha) due to higher amount of clay content, compared to A-A (43.1Mg/ha) with higher TOC content. The amount of AC andAC/TOC in different vegetation types is proportional to the amount of TOC, CS, total canopy, and the canopy and production of herbaceous species. AC content was significantly highest in A-B (711.7 mg/kg), and lowest in RW site(262.6 mg/kg). A-B site is rich in grass species with high amounts of readily decomposable root residues and exudates. The variation of carbohydrate contents in different vegetation types wasvery similar to that of total organic carbon, in that A-B and A-A exhibited the highest (5843 and 5258 mg/kg, respectively) and RW showed the lowest (1937 mg/kg) carbohydrate contents. The woody, not easily decomposible litters in A-A explainedthe high content of Ch/TOC (38.12%) in this site; low rate of humification entails increased soil carbohydrates. Ch/TOC was significantly lower in A-E than other covers. The highest BR andBR/TOC, were observed in A-B and A-A sites, mainly due to the high canopy cover, species richness,and soil organic matter. The lowest BR andBR/TOC were observed in A-E.Thesoil texture in this site was clay.The recirculation of organic matter in fine-textured soils is low because of organic materials protection from microbial decomposition. Total organic matter and labile organic carbon inputs werelower in A-L, A-E and G sites; this may explain the reduction of microbial activity in these vegetation types. Except for AC/TOC, Ch, and BR, seasonal changes of all other indicators were significant. Unlike other indicators, the content of Ch/TOC was significantly higher in autumn than spring.
Vegetation types had significant effects on selected soil quality indicators, so that A-A and A-B sites exhibited the highest soil quality, mainly because of higher vegetation cover, litter, and plant diversity. RW, followed by A-E site, demonstrated the lowest soil quality due to the tillage practices and low plant residue inputs in the first case, and overgrazing of vegetation cover and litter in the second. Total soil organic carbon and active carbon were significantly higher in spring compared to autumn. Seasonal changes of basal microbial respiration and carbohydrates were not statistically significant.

Water stress and salinity are among the problems of agricultural production in many parts of the world. In this study, the effect of salinity (2, 5 and 8 dS/m), different irrigation levels (120%, 100%, 75%, and 50% of water requirement) and three harvesting times (cuttings) were investigated on some qualitative and quantitative parameters of sorghum silage in the Sistan region. The study was carried out using a factorial split plot design with 12 treatments and 3 replications. The results showed that increasing salinity and irrigation water depth decreased fresh and dry matter yield. However, no significant difference was observed between 100% and 75% crop water requirement treatments. Also, treatments with 2 and 5 dS/m salinity were not significantly different in feed production. Furthermore, the fresh and dry forage yields were higher in the second cutting than in the first and third harvesting. Decrease in irrigation water and increase in salinity decreased protein but increased carbohydrate and proline. The highest amount of protein (16.79 percent) was obtained in the second harvesting and at the salinity of 2 dS/m, while the highest amount of carbohydrates (10.79 mg/gFW) and proline (0.42 mg/gFW) belonged to the third harvesting with salinity of 8 dS/m. By increasing salinity in irrigation water and with the passage of time during the growing season, soil salinity increased and distribution of salinity in the soil profile was more uniform in the treatments that had no water stress. Thus, according to the results, 25% of the plant water consumption can be saved and irrigation with 75% of water requirement and salinity of 5 dS/m would have no significant effect on the amount of forage produced. The best forage quality for livestock consumption was obtained in the second harvesting. However, this experiment was done in one growing season and in the long time reduction in the amount of water and the use of salt water can cause soil salinization and accumulation of salts in the soil. Therefore, it is recommended that the experiment be repeated in the future, before making a final decision about reducing irrigation water.

Arbuscular mycorrhizal fungi (AMF) are widespread endosymbionts in terrestrial ecosystems and their exudates have important effects on soil properties. A greenhouse experiment was conducted with six AMF treatments including four exotic species inoculums (Funneliformis mosseae، Claroideoglomus claroideum and Rhizophagus irregularis and a mixed isolate of three species)، one mixed native AMF species treatment and a sterilized soil (control) with four salinity levels (1، 5، 10 and 15 dS m-1). AMF increased the soil (EEG) and total (TG) extractable glomalin، and also the hot water (HWC) and diluted acid (DAC) extractable carbohydrates compared to control treatment in all salinity levels. The native AMF species had the greatest effects on EEG، TG، HWC and DAC at 10 and 15 dS m-1. Soil EEG and TG concentrations were higher in the mixed exotic AMF treatment than in each AMF species. The greatest glomalin concentration was related to F. mosseae at 1، 5 and 15 dS m-1 but at 10 dS m-1 the greatest glomalin concentration was related to C. claroideum. The greatest carbohydrate concentration was related to F. mosseae at 1 and 5 dS m-1 but at 15 dS m-1 significant differences were observed among the three AMF species. Our results showed that there is an interaction between salinity and different AMF species، and a combination of them determines the function of AMF.

This study was conducted to investigate the impact of land use change on some of carbon components in Safashahr area, Fars province. Four land uses (destroyed rangeland, agricultural land, new and old apple orchard) were selected. Sampling was done randomly from two depths (0-20 and 20-50 cm) of each land use. Particulate organic matter (POM) and extractable carbohydrate by hot water were measured in both bulk soil and aggregate particles and mineral-associated organic matter and carbon pool were measured in bulk soil. Results showed that particulate organic matter, carbohydrate, and carbon pool in old apple orchard increased significantly. Results also showed that the particulate organic matter in old apple orchard, agricultural land and new apple orchard increased 333, 120 and 113%, respectively. As components of organic matter have been accumulated in the macro-aggregates and these aggregates have high sensitivity to soil degradation, it is expected that the factors which control the stability or degradation of these aggregates may control organic carbon pool of soils as well.

Plant growth promoting microorganisms enhance plant growth and yield by virtue of direct and indirect mechanisms. In this study the effects of plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) on plant height, yield, chlorophyll a, b, relative water content (RWC), carbohydrate and proline content of Hyoscyamus plant were evaluated. The soil was polluted with different concentrations of cadmium (0, 10, 30 and 100 mg kg-1 soil), and experiment was done in a factorial with randomized complete block design with three levels of microbial inoculation including fluorescent Pseudomonads as PGPR (P. putida, P. fluorescence and P. aeruginosa), fungal inoculation with Glomus species as AMF (G. mosseae, G. intraradices and G. fasciculatum) and control condition (no inoculation). The results indicated that the experiment treatments increased significantly (P≤ 0.05) plant height, shoot dry weight compared to control condition. Furthermore, as cadmium concentration raised in soil the contents of chlorophyll a, chlorophyll b, and relative water significantly decreased. However, plants inoculated with PGPR and AMF showed considerable amount of chlorophyll a, b as well as RWC. Under Cd contamination, the contents of soluble sugar and proline increased in inoculated plants in comparison to control plants. Cd addition also significantly decreased (73% compared to Cd0) mycorrhizal root colonization. It is concluded that at the presence of Cd, inoculation with PGPR and AMF could sustain and promote plant growth.

Eight hundred and fifty two multiparous Holstein cows in mid-lactation were used in a completely randomized and nested design with two treatments and three replications. Treatments were: 1) Isfahan and 2) Borkhar-Meymeh. Replications were: 1) class of one to five cows 2) class of six to ten cows and 3) class of eleven to twenty cows. Paired t-test was used for the comparison of nutrient consumption and requirement. The obtained results of one-year-old experiment indicated that township and different classes had no effect on consumption of dry matter intake (DMI), net energy lactating (NEL), metabolizable protein (MP), calcium (Ca), phosphorus (P), potassium (K), magnesium (Mg), sodium (Na), chlorine (Cl), sulphur (S), selenium (Se), zinc (Zn), copper (Cu), iodine (I), vitamin A, vitamin D, vitamin E, rumen degradable protein (RDP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and non-fiber carbohydrate (NFC). Township had a significant effect on consumption of rumen undegradable protein (RUP) (P<0/05). Township and different classes had no effect on nutrient requirements of dairy cattle. The difference between consumption and requirement for kg DMI, Mcal/d NEL, g Mp, (g absorbable) Ca, P, K, Mg, Na, Cl, S, mg per kg Se, Zn, Cu, I, Iu/d vitamin A, vitamin D, vitamin E, g/d RDP, RUP, percentage of dry matter NDF, ADF and NFC were -1/6, -2/5, -630/2, -21/8, -5, 40/6, 0, -3/3, 44/2, -7/4, -3/11, -38/7, -3/26, -4/45, -14834, -234, -342/5, -542/5, -886, 28/5, 17/5 and -10/4, respectively. The difference between consumption and requirement was not significant for P, Mg and Na. This difference had a significant effect on the rest of nutrients (P<0/05). The results of this study indicated that we can feed dairy cattle by using diets containing protein supplements and mineral-vitamin premix and improve milk yield and percentage of milk protein's rural areas of Holstein cows.