to evaluate the effect of gamma rays on the seeds and amounts of nitrogen on growth and yield of chamomile (chamomilla recutita synonym matricaria chamomilla), a factorial experiment was conducted based on randomized complete block design with three replications at the research farm of agriculture college of shahid-beheshti.-urmia in 2010. treatments were gamma rays from cobalt-60 on chamomile ...

Accidental, runaway veld fires cause enormous fodder flow problems in dry regions. It was the objective of this study to estimate the short-term (one year) impact of fire over 10 growing seasons (1995/96 – 2004/05) on the productivity (aboveground phytomass and litter) of a semi-arid grassland ecosystem. Fire caused a 41% decrease in basal cover over the first season following burning. On avera...

BACKGROUND Efforts to reduce emissions from deforestation and forest degradation in tropical Asia require accurate high-resolution mapping of forest carbon stocks and predictions of their likely future variation. Here we combine radar and LiDAR with field measurements to create a high-resolution aboveground forest carbon stock (AFCS) map and use spatial modeling to present probable future AFCS ...

Knowledge of the responses of soil nitrogen (N) availability, fine root mass, production and turnover rates to atmospheric N deposition is crucial for understanding fine root dynamics and functioning in forest ecosystems. Fine root biomass and necromass, production and turnover rates, and soil nitrate-N and ammonium-N in relation to N fertilization (50 kg N ha(-1) year(-1)) were investigated in...

The main aim of this study was to evaluate the effects of silicon (Si), ethanol (Et), ascorbic acid (AA) and citric acid (CA) on vase life of Narcissus tazetta L. cv. ‘Shahla’cut flowers. For this purpose, an experiment based on completely randomized design was conducted with Si (5, 10 and 20 mM), Et (2 and 4%), AA (100, 200 and 300 mg L-1), CA (100, 200 and 300 mg L-1) and control (distillated...

A closely spaced (1 x 1 m) cottonwood (Populus deltoides Bartr.) plantation was established to evaluate the effects of nutrient availability on fine root dynamics. Slow-release fertilizer (17:6:12 N,P,K plus micronutrients) was applied to 225-m(2) plots at 0, 50, 100 and 200 kg N ha(-1), and plots were monitored for two growing seasons. Fine root production, mortality, live root standing crop a...