Understanding the preference of a crop for forms nitrogen (N) is important to ensure efficient use N-sources in agriculture. A study was conducted assess nutrient uptake and dry matter yield six vegetable crops under different ratios ammonium- N (NH4+-N) nitrate-N (NO3–-N) growth medium. Seedlings cabbage, carrot, capsicum, knolkhol, lettuce, tomato, were supplied with five N-treatments (NH4+-N...

The presence of energetic materials (used as explosives and propellants) at contaminated sites is a growing international issue, particularly with respect to military base closures and demilitarization policies. Improved understanding of the ecotoxicological effects of these materials is needed in order to accurately assess the potential exposure risks and impacts on the environment and its eco...

The diets of four diurnal fish species (Creagrutus bolivari, Knodus deuterodonoides, Knodus sp. and Poecilia reticulata) were examined during a year in the Orituco stream at northern Venezuela. The fishes were sampled monthly from February 1991 to March 1992 (except October 1991 and February 1992) in the stream main channel with a beach seine and a cast net. Diet is reported as frequency of occ...

in order to study the effect of intensity and exposure duration magnetic field on wheat (triticum aestivum l.) seed germination an experiment was conducted in laboratory of ferdowsi university of mashhad, iran. the experiment was including 11 treatments as three level of magnetic field intensities (pretreatment of seeds with 50, 100 and 150 mt magnetic field) and three exposure durations (10, 2...

iron is an essential microelement for plant growth. low content of organic matter and excess application of phosphate fertilizer in soils can be affected on availability of iron. in this study the effect of iron, phosphorus and organic matter on growth and iron uptake of mays was evaluated. a greenhouse experiment was conducted with two levels of cattle manure (0 and 1 %), three levels of phosp...

in order to investigate the effects of salicylic acid on some growth and stomatal characteristics of calendula plant, a factorial experiment was conducted based on completely randomized design with five replications in the research greenhouse of shahid bahonar university of kerman in 2013. salt stress levels including 1, 3, 5, 7 and 9 mmhos/cm were applied to the soil and salicylic acid solutio...

To elucidate the effects of seasonal variation of precipitation on the distribution of polychlorinated biphenyls (PCBs) in estuarine sediments and benthic feeders, PCB concentrations of river surface sediments and mullet fish (Liza macrolepis) were investigated in the estuary of Er-Jen River near former PCB contamination sites before and after each wet season from 2002 to 2004. Analyses of grai...

Pasture biomass is an important quantity globally in livestock industries, carbon balances, and bushfire management. Quantitative estimates of pasture biomass or total standing dry matter (TSDM) at the field scale are much desired by land managers for land-resource management, forage budgeting, and conservation purposes. Estimates from optical satellite imagery alone tend to saturate in the cov...