The leaf nitrogen content is generally accepted as an indicator of food quality and as a factor affecting host selection by phytophagous insects. The alate pea aphids (Acyrthosiphon pisum Harris, Aphididae) were given a choice among non-nodulated pea plants (Pisum sativum L.) supplied with one of four nitrate-N levels (0, 3, 15 and 30 mM). When whole plants were exposed to aphids for 7 days, th...

Scientific Events: Scientific Apparatus and Laboratory Methods: Grants for War Research to the University of Cincinnati; The Supply of Technical Men to the A Rapid Method for the Determination of Nitrogen Armed Forces and to Industry; Bare Chemicals; in Plant Tissue: DR. R. C. LINDNER and C. P. The Inter-American Program of the American HARLEY..... 565 Standards Association; Fellowships in the ...

The effect of water supply during grain growth on grain nitrogen concentration (GNC) and grain nitrogen yield (GNY) of winter wheat (Triticum aestivum L.) was studied in the field experiment on fertile loamy-clay soil in years 2004–2007. The water regime was differentiated using mobile rain shelter (water shortage, treatment S) and drip irrigation (ample water supply, treatment W); rain-fed cro...

Whole-plant and leaf nitrogen isotope composition are determined by the isotope ratio of the external nitrogen source and physiological mechanisms within the plant. Whole-plant isotope composition can reflect that of the nitrogen source when plant demand exceeds nitrogen supply. Uptake by mycorrhizae can cause the isotope ratio of the plant to deviate from the source. Intra-plant variation in i...

The input of new nitrogen into the euphotic zone constrains the export of organic carbon to the deep ocean and thereby the biologically mediated long-term CO2 exchange between the ocean and atmosphere. In low-latitude open-ocean regions, turbulence-driven nitrate diffusion from the ocean's interior and biological fixation of atmospheric N2 are the main sources of new nitrogen for phytoplankton ...

Nitrogen absorption from the large intestine, largely as ammonia and possibly as amino acids (AAs), is generally thought to be of little nutritional value to nonruminant animals and humans. Ammonia-nitrogen absorbed from the large intestine, however, may be recycled into the small intestine as urea and incorporated into microbial AAs, whichmay then be used by the host. A cecal infusion study wa...

Objective: Soil organic carbon has been the most important soil quality measurement factors and has intense relation with soil physical, chemical and biological characteristics. Organic matter and its components are important factors of soil aggregates constitution and stability and play significant role in its structure. So, this research has been done for achieving this purpose. Methods: This...

Nitrogen absorption from the large intestine, largely as ammonia and possibly as amino acids (AAs), is generally thought to be of little nutritional value to nonruminant animals and humans. Ammonia-nitrogen absorbed from the large intestine, however, may be recycled into the small intestine as urea and incorporated into microbial AAs, which may then be used by the host. A cecal infusion study w...

Soil organic carbon has been the most important soil quality measurement factors and has intense relation with soil physical, chemical and biological characteristics. Organic matter and its components are important factors of soil aggregates constitution and stability and play significant role in its structure.So, this research has been done for achieving this purpose. This area is arounding sa...