جستجوی مقالات مرتبط با کلیدواژه « خوابانیدن » در نشریات گروه « کشاورزی »

Soil and plant contamination with heavy elements due to industrial activities has adversely affected human health and has received much attention in recent decades. Heavy metals can endanger soil, plant and human health by entering the soil cycle and food products. In order to reduce the harmful effects of heavy metals on the soil ecosystem and food pollution, a factorial experiment was conducted in three replications in a completely randomized design in a greenhouse. The aim of this study was to investigate the effect of different amounts of natural biochar and poultry manure on the fertility of zinc and cadmium elements in a contaminated soil.

In order to conduct this research, first different levels of poultry manure (zero, 0.5, 1, 2, 4 and 8% by weight) and natural biochar (zero, 2, 4, 6, 8 and 10% Weight) were added separately to a contaminated soil. Then, 4 levels of incubation were applied to the moisture capacity of the farm (1, 2, 3 and 4 months). At the intervals mentioned from the pots, sub-samples were prepared and transferred to the laboratory. After drying in the oven at a temperature of 50-55 ºC was taken pH, EC, the total and absorbable amount of zinc and cadmium elements in them.

Comparison of mean effects of incubation and poultry manure and biochar levels showed that with increasing consumption level and incubation, soil pH decreased by 3.9% and 1.4%, respectively, and EC amount by 36.5 and 10.4 percent increased. There was a statistically significant difference between the control treatment of the control or the zero level of poultry manure and biochar with the treatment of 8% of poultry manure and biochar (statistically 5% probability level). With increasing incubation and levels of poultry manure and natural biochar, the adsorbent concentration of zinc and soil cadmium decreased significantly (P <0.05), which decreased in treatments containing poultry manure for zinc and cadmium, respectively, 19.9 and 29.5 percent, and in treatments containing natural biochar, zinc and cadmium were measured as 28.4 percent and 22.7 percent, respectively. In poultry manure treatments, the lowest zinc and cadmium concentrations extracted with DTPA extract in the fourth month and the consumption level of 8% were 304.7 and 10.9 mg/kg, respectively, and the highest amount was observed in the first month. Witness treatment (zero percent level) was observed to be 380.2 and 20.0 mg/kg, respectively. In treatments containing natural biochar, the lowest amount of zinc and cadmium extracted with DTPA extract in the fourth month and 10% consumption level were 272.4 and 12.9 mg / kg, respectively, and the highest amount was treated in the first month. The control (zero percent level) was observed to be 380.3 and 20.7 mg/kg, respectively.

According to the results of this study, the use of biochar and manure fertilizer caused a decrease in the concentration of absorbable heavy metals studied in the soil. Although treatments containing biochar and manure reduced the adsorption concentration of metals in the soil, the concentration of adsorbent metals in the soil decreased further with increasing levels of poultry manure and biochar and the incubation of the soil. In general, it can be stated that the application of poultry manure and natural biochar in the soil is an effective method to reduce the toxicity and absorbable concentration of heavy metals in the soil and also increase the yield and quality of agricultural products.

Soil is one of the factors influencing the balance of the ecosystem and countless biological and biochemical processes take place in it. In all of these processes, enzymes act as catalysts. Their presence in different cycles of soil nutrients causes the release of elements needed by plants. Therefore, the measurement of some of these enzymes can be an important indicator and criterion for evaluating soil bioavailability and consequently ecosystem measurement. Therefore, in order to investigate the extent and effect of mineral nitrogen (ammonium nitrate) and mineral phosphorus (triple superphosphate) in soils to which wheat plant residues have been added, on the enzymatic activities of urease, invertase, cellulase, alkaline and acid phosphatase were performed by a factorial experiment in a completely randomized design with three replications in the laboratory. The purpose of this study was to investigate the effect of different levels of N and P and their interactions on some enzymatic activities of soil containing plant residues of wheat.

For the purpose of this study, different levels of inorganic nitrogen were: control, 10, 25, 50 and 75 mg Nitrogen per kg soil (N, N10, N25, N50 and N75) and different levels of phosphorus including: control, 15, 30 and 45 mg phosphorous per kg soil (P, P15, P30 and P45) into a P and N poor soil. The soil was added to this soil by 5 wt.% Of crushed wheat residue, transferred to FC moisture and incubated at laboratory (relatively constant) temperature for 6 months. At the end of the incubated, the activities of urease, invertase, cellulase and alkaline and acid phosphatase were measured.

The interaction of different levels of phosphorus and inorganic nitrogen on some enzymatic activities showed that urease enzyme was highest in P30N25, P30N50, P15N25, P30N10, P30N75 and P45N10 and lowest in control treatment. Urease activity in these treatments was about 2.3 times that of the control. The highest activity of invertase was observed in P15N10, P15N25, P15N50 and lowest in P30N75. The activity of this enzyme was about 21% higher in the treatments containing phosphorus 15 and nitrogen 10 (mg/kg soil) than in the treatments containing phosphorus 30 and nitrogen 75 (mg/kg soil). The highest cellulase activity was observed in P15N10, P15N25 and the lowest activity in P45N25. Alkaline phosphatase had the highest activity in P30N10, P15N10, P30N25, P15N25 and P30N50 and lowest in phosphorus 45 and inorganic nitrogen 75 (mg/kg soil). The enzyme activity in these treatments was about 1.2 times that of P45N75. Acid phosphatase activity was highest in P15N50 and P15N25 and lowest in phosphorus 45 and inorganic nitrogen 10 (mg/kg soil) and in phosphorus 45 and mineral nitrogen 75 (mg/kg soil), respectively.

In general, application of mineral fertilizers to soil containing wheat residues increased some of the enzymatic activities according to the results of experiments for maintaining soil fertility and also balance in the rate of decomposition and emission of greenhouse gases and enzyme activity. Inorganic fertilizers at low concentrations are recommended as the catalysts for the reaction. Therefore, farmers are advised not to remove plant residues from the soil after the end of the growing season, but to balance the residual decomposition rate by adding appropriate levels of mineral fertilizers to gradually improve plant nutrition and characteristics while gradually decomposing. Physically improve the soil as well.

Layering and hard wood cutting are known as apple rootstock propagation methods. In this research rooting ability of 1489 apple rootstock hybrid progenies obtained from different cross combinations or open pollination apple rootstock breeding program from 2004 to 2008 in Horticultural Sciences Research Intitute was studied. Screening was done in two separate experiments included: rooting ability of progenies in stool bed condition (the first screening) and rooting ability of elite's hardwood cutting in greenhouse condition (second screening). Results were showed 49 genotypes (3.2% of population) have good rooting ability in the stool bed layering. In the second screening 17 genotypes had hardwood rooting ability (above 40%) were selected as elites apple rootstocks. Progeny was resulted from combination Azayesh as the mother parent (native rootstock) with M9, M27, B9 as the father parents and azayesh open pollinated, with 11 easy rooting genotype, the most root number (2.05-12.3 root per cutting), deepest roots (1.75-4.25cm) and the most layer (8 layer per stool) has the best rooting ability among other combinations. Elite genotypes have more rooting ability than MM111 rootstock as easy rooting rootstock (control).

The effects of two different organic matters including compost and sewage sludge on the distribution of Cd, Pb and Ni in different fractions of two calcareous soils were investigated. The soil samples were treated with two levels of each organic material (0 and 2%). Heavy metals were added to soils at the rate of 10 mg kg-1 of Cd, 200 mg kg-1 of Ni and 400 mg kg-1 of Pb as nitrate salt. The samples were incubated for 12h, 20 and 40 days. After each incubation time, metals were fractionated by sequential extraction and analyzed for DTPA extractable form. Results showed that Pb and Ni were rapidly transformed from exchangeable to more stable fractions during the incubation intervals. In contrast, the amount of Cd in exchangeable fraction changed slightly and the considerable portion of Cd remained in this fraction. At the end of the experiment, the distribution percentage of Cd, Ni and Pb followed the order of carbonate>Fe-Mn oxide>exchangeable, Fe-Mn oxide>carbonate>organic matter, carbonate>Fe-Mn oxide>organic matter, respectively. There were almost no changes for the metals in the residual fraction. The effects of compost and sewage sludge on the distribution of studied metals in two soils were different. However, application of organic matter mainly resulted in the increased organic matter fraction and DTPA extractable forms of metals.

Introducing appropriate and applicable methods is an important step towards restoration of Zagros forests. In this study the possibility of rooting and propagation of sprouts of Manna oak was investigated by layering in soil. This study was conducted in Completely Random Design with four factors including soil type (forest soil and litter), super absorbent hydrogel (100 gr and 0 gr), IBA hormone (2000 ppm and 0 ppm) and pitcher irrigation (using earthen pot and disusing earthen pot). Overall, 16 treatments with three replications were prepared. The result of ANOVA test indicated that there are significant differences among treatments both in callus production and rooting. Callus production was observed in all of the treatments. In contrast, rooting was just observed in treatments treated by IBA. The highest proportion of callus production and rooting was observed in treatments with the best moisture conditions.

Because of the economic and medicinal importance of Rosa damascena Mill. the propagation of this plant was considered. In order to protect the selected genotypes, this experiment was performed by simple layering method during autumn and winter seasons 2007 on new growth twigs of Rosa damascena mature shrubs. The branches were laid in sand bed, soaked for 24 h by different concentrations of IBA and NAA hormones. The results showed that the rate of rooting was high in sand bedding material in autumn and winter. The highest rooting percentage was %100 with 50 mgl-1 concentration of IBA in autumn and winter seasons and the lowest of rooting percentage was %53.33 with 50 mgl-1 concentration of NAA in autumn season. The rooting branches were cut from the parent plants after 3 months and planted in pots containing soil: sand: peatmoss complex (1:1:1) in greenhouse conditions, survival percentage was 90%.

To determine the effect of mother stock vigor and auxin on callusing and rooting ability of walnut four trials were carried out in Kahriz Agricultural Research Station during 2006-2007. In cutting trials, the semi-hardwood or hardwood cuttings from each of three clusters of seedling vigor were collected in late September in 2006 and after treating with IBA were planted under mist and bottom heat condition or reversed silo. The mother stock vigor and hormone was only affected callus formation with no effect on rooting. Treating the base of callused cuttings with reduced concentration of IBA was not effective in stimulating of rooting on callus surface. In response to the modified stool layering with application of lanoline paste containing three auxins (IAA, IBA and NAA), average number of roots per layer and rooting score in low-vigor mother stocks were 7.8 and 4.2 (from 5), respectively and significantly improved compared to high-vigor ones. Improved rooting of low-vigor stocks imply on a substantial structural/and or hormonal differences among mother stocks with different vigor and provides the possibility of selection of easy to root clones in walnut.