We examined the effects of a forest fertilizer (urea) on newly metamorphosed terrestrial amphibians (Western toads, Bufo boreas; Cascades frogs, Rana cascadae; long-toed salamanders, Ambystoma macrodactylum; and roughskin newts, Taricha granulosa). We examined avoidance behavior of Western toads and Cascades frogs on both paper towel and soil substrates dosed with urea (control and 100 kg N/ha ...

Urea is the most commonly used nitrogen fertilizer worldwide. The overused urea in agricultural fields may affect the soil organisms especially, the earthworms which are known well for their role in soil fertility. Earthworms are typically inferred as soil indicators without which soil fertility cannot be measured directly. An acute toxicity test of urea to earthworm (Eisenia fetida) was perfor...

in order to evaluate different sources and rates of nitrogen on dry matter yield, concentration and uptake of primary macronutrients (nitrogen, phosphorous and potassium) in forage sorghum (hybrid of speedfeed), three levels of nitrogen (80, 160 and 240 kg n ha-1) from three n sources (urea fertilizer, cattle manure and equal combination of urea fertilizer + cattle manure) and the control (no f...

the high yield depends on high dry matter production per unit area. azotobacter bio-fertilizer experiment to investigate the effect on the index, total dry matter accumulation and pishtaz and chamran wheat cultivars in 2005 was conducted in the faculty of agriculture, lorestan university. experiment, a split-plot randomized complete blocks design with four replicates were tested. treatments con...

BACKGROUND: Fertilizer management plays an important role for obtaining satisfactory yields and to increase crop productivity. Nitrogen is generally a limiting nutrient in crop production, and especially in sorghum, as it has been said to be the most responsive nutrient for its production. OBJECTIVES: Current study was conducted to assessment effect of urea fe...

Slow-release fertilizers are gaining acceptance to increase fertilizer use efficiency and reduce environmental impact. The release of nitrogen from methylene urea, a common slow release N fertilizer, is controlled by microbial decomposition. An enzyme hydrolyzing slowrelease nitrogen fertilizer, methylene urea, was purified from Rhizobium radiobacter (Agrobacterium tumefaciens) to homogeneity u...

one of the important aspects of the medicinal plants production is using less chemical inputs. it could be effective for increasing of production and environmental purposes. in order to investigate the effects of application time of integrated chemical fertilizer with cattle manure on growth, yield and yield components of black cumin (nigella sativa l.), an experiment was conducted based on a r...

in this study, the effect of irrigation regimes and plant nutrition were evaluated as split plot arrangment based on randomized complete block design with three replications in 2010. treatments consisted of irrigation regimes at three levels: well-irrigation, irrigation disruption at vegetative growth stage, and irrigation disruption at reproductive growth stage as main plots and combination of...

High N fertilizer and irrigation amounts applied to potato (Solanum tuberosum L.) on coarse-textured soils often result in nitrate (NO3) leaching and low recovery of applied fertilizer N. This 3-yr study compared the effects of two rates (140 and 280 kg N ha(-1)) of a single polyolefin-coated urea (PCU) application versus split applications of urea on 'Russet Burbank' potato yield and on NO3 le...