جستجوی مقالات مرتبط با کلیدواژه "chemical fertilizer" در نشریات گروه "آبخیزداری، بیابان، محیط زیست، مرتع"

Improving physical structures and stimulating of soil micro-organisms through adding organic fertilizers has led to facilitating the release of nutrients and increasing plant growth. In order to investigate the effect of organic fertilizers (compost, cow and poultry) and urea on some morphological traits and yield components of corn plant, an experimental was carried out in split plot arrangement base on randomized complete block design with three replications in the Torogh station of Khorasan Razavi Agricultural Research and Education Center in 2019-2021. The main plots were urban waste compost organic fertilizer (16 and 32 t.ha-1), cow (24 and 48 t.ha-1) and poultry (9.5 and 19 t.ha-1), urea chemical fertilizer (225 and 450 kg.ha-1) and control (no use any fertilizer) and subplot were two corn cultivars (KSC704 and KSC260). The results showed that the use of organic fertilizers significantly (p≤0.01, p≤0.05) improved diameter and length of cob, dry and wet forage yield. The highest plant height (285 cm) was obtained from the impact of 24 t.ha-1 of cow manure in KSC704 cultivar. Also, the maximum wet and dry biomass (75 and 30.5 t.ha-1, respectively) and the maximum ear length (23.1 cm) was obtained from the effect of 32 t.ha-1 of compost in KSC704 cultivar. The lowest amount of dry matter yield was observed in KSC260 variety and using different levels of urea fertilizer and control treatments. In general, the use of organic fertilizers (compost, poultry and cow manure) showed better results in the KSC704 cultivar than of the KSC260 cultivar in the examined traits. There was a positive and significant correlation between dry forage and height (r = 0.54**), cob length (r = 0.57**) and stem diameter (r = 0.71**). In general, the consumption of maximum 32 tons of compost per hectare in commercial KSC704 cultivar has a significant advantage compared with other treatments.

Currently, the excessive application of chemical fertilizers in agriculture field is under debate due to environmental concerns. Therefore, it is important to find the alternative strategies to reduce harmful effects of farming practices. Aims of the research was to investigate the potential of rhizosphere and endophytic bacterial isolates isolated from the roots of wheat plant in terms of plant growth promoting (PGP) traits and study their effect on the wheat plant growth indices and decreased phosphorus (P) fertilizer use. To this end, the isolated bacteria were first screened for the production of indole-3-acetic acid (IAA) in the presence of tryptophan in the culture medium, and then the bacteria were tested for their ability to dissolve inorganic and organic phosphates. Then, the ability of these bacteria to improve wheat plant growth was conducted in a completely randomized design under greenhouse condition. Rhizospheric isolate R185 and endophyte isolate E240 produced 299.2 and 330.1 μg / ml P respectively and also produced 19.2 and 22 μg / ml IAA, respectively. 16S rRNA sequencing showed that these bacterial isolates were Pseudomonas. The results obtained from pot assay showed that the combined use of the strains caused a significant increase in wheat growth and nutritional indices (an increase of 55.6% in the amount of plant P) compared to their single application (35.6 and 36.4% increase in plant P content by R185 and E240, respectively). Among the cultivars evaluated, Roshan cultivar had a higher percentage of P (4.7%) and biomass (14.2%) than Marvdasht cultivar.

Extensive use of chemical fertilizers has caused various mounting problems for the environment including pollution of cultivated products, soil and water resources. Calcareous soils face issue of low solubility and availability of nutrient elements for plants which increases use of chemical fertilizers and its environmental consequences. Hence, methods capable of healing such deficiency and decreasing use of chemical fertilizers are vital. Although sulfur-bentonite granules as replacer of mass consuming chemical fertilizers have environmental priority improvement of their efficiency requires further research. Objective of this research is evaluating sulfur-bentonite granules enriched with iron as one of the plants' nutrient elements having broad insufficiency across farmlands in Iran. Therefore, sulfur-bentonite-iron granules compared to sulfur-bentonite alongside with iron powder dispersed into the soil mass throughout simulating real environment by soil columns inoculated with Thiobacillus thioparus were evaluated for 19 two-weeks leaching periods. The results revealed that application of sulfur-bentonite-iron has acceptable effect on iron availability while it brings efficient solubility of sulfate, nitrate and phosphate into calcareous soils.

In recent years, a major contribution of the nitrogen needed for agricultural production was supplied from urea chemical fertilizer in Iran; this issue would lead to the serious environmental impacts. The aim of this study was to investigate the environmental impacts of the use of this important agricultural input through Life Cycle Assessment (LCA) methodology during 2007-2012. LCA in four sections including "the goal and scope definition”, “inventory analysis (inputs and outputs of the system)”, “impact assessment, and interpretation of the impacts were calculated. Investigation was performed on three impact categories such as global warming, acidification and eutrophication for terrestrial ecosystems. The obtained data analysis showed that approximately of 1.5%, 8.6% and 42.8% of the environmental consequences of impact categories including global warming, acidification and eutrophication for terrestrial ecosystems in Iran were related to the this input consumption, respectively. The amounts of weighted indices during the period for these impact categories were calculated 1160785, 11330566 and 25384073, respectively. Urea fertilizer consumption had the highest environmental hazards in terms of eutrophication for terrestrial ecosystems impact category. Therefore, management of the urea fertilizer consumption to minimize its environmental impacts and its replacement by non-chemical nitrogen resources is vital in agriculture sector of Iran.