Hyperspectral remote sensing serves as an effective tool for estimating foliar nitrogen using a variety of techniques. Vegetation indices (VIs) are a simple means of retrieving foliar nitrogen. Despite their popularity, few studies have been conducted to examine the utility of VIs for mapping canopy foliar nitrogen in a mixed forest context. In this study, we assessed the performance of 32 vege...

anzali wetland on the south west of caspian sea is a unique ecosystem was registered as ramsar site at 1975. anzali wetland was deteriorated due to numerous disorder and poor water quality. the riverin input were strongly affective in the process of eutrophication where the eastern and central region was more degraded. the first survey on the eutrophication process was conducted at 1969, since ...

To investigate the feasibility of using salivary urea nitrogen as an index of renal glomerular filtration rate, we developed and applied a new analytical system consisting of a urease-containing test strip and an automatic reflectance spectrometer. The concentrations of urea nitrogen so determined correlate well (r = 0.93) with concentrations in serum. These preliminary data suggest that our me...

Benthic diatoms have been universally used as indicators to assess water quality in lotic ecosystems. However, most diatom-based indices developed in Europe have not been widely used or tested in other continents such as Asia or Oceania. This study compared the performance of 14 widely-applied diatom indices in assessing ecological conditions in subtropical streams in South East Queensland (SEQ...

.soil microorganisms are important agents in nutrient cycling and energy flow. they are extremely sensitive to environmental changes. soil microbial biomass has been proposed as an index of soil stress and disturbance. the objective of this study was to determine the effects of barley (hordeum vulgare l.) residue amounts, burning, nitrogen fertilizer levels and tillage management on organic car...

Leaf nitrogen and leaf surface area influence the exchange of gases between terrestrial ecosystems and the atmosphere, and play a significant role in the global cycles of carbon, nitrogen and water. The purpose of this study is to use field-based and satellite remote-sensing-based methods to assess leaf nitrogen pools in five diverse European agricultural landscapes located in Denmark, Scotland...

this research has been done for studying the effect of split application of nitrogen fertilizer on growth indexes and yield of three hybrids of grain corn in shahrood. a split plot experiment based on randomized complete block design with four replications was carried out in 2007. three hybrids of corn (double cross 370, single cross 447, single cross 499) were placed in main plots and split ap...

This study set out to investigate the effect of bio-fertilizers containing nitrogen-fixing bacteria and phosphorus on grain yield and yield components of Faba bean. To this end a factorial experiment on the basis of randomized complete block design with four replications was conducted in Behbahan region at South eastern part of Khuzestan Province of Iran. The experimental treatments included Ni...