Genetic improvement is the fundamental basis for improving nitrogen-use efficiency. A better understanding of genetic factors controlling nitrogen uptake and utilization is required for crop genetic improvement. In this study, we identified the quantitative trait loci (QTLs) associated with traits of nitrogen uptake and utilization by using the single-sequence repeat marker method and a recombi...

crop rotation affect on crop nitrogen uptake and nitrogen use efficiency (nue). crop rotations with high nue decrease energy use and increase level of sustainability in agro ecosystems. the objectives of this research were to determine the suitable double cropping system for enhancing nue and evaluate the effects of crop rotation, n fertilizer rate and return of crop residue on nue. this study ...

A basic tenet of nitrogen utilization in phytoplankton is that ammoniuln inhibits nitrate uptake. Consequently, it is generally believed that little or no nitrate uptake occurs at ammonium concentrations above ca 1 yM. A thorough review of field studies shows that the reduction of nitrate uptake rate in the presence of ammonium is rarely so severe, and that it is a highly variable phenomenon. T...

This study was designed to assess the importance of dissolved free amino acids (DFAA) as a nitrogen source for the scleractinian coral Stylophora pistillata. For this purpose, experiments were performed using (15)N-enriched DFAAs, and %(15)N enrichment was measured both in animal tissue and zooxanthellae at different DFAA concentrations, incubation time and light levels. As previously observed ...

Kinetin-induced expansion of lettuce (Lactuca sativa) cotyledons and inhibition of root are accompanied by parallel changes in protein nitrogen. However, during its inhibition of the longitudinal growth and water uptake of hypocotyl and pea (Pisum sativum) epicotyl sections kinetin markedly stimulates protein synthesis. Kinetin seems to separate auxin induced effects on protein synthesis and wa...

BACKGROUND Industrial fermentation typically uses complex nitrogen substrates which consist of mixture of amino acids. The uptake of amino acids is known to be mediated by several amino acid transporters with certain preferences. However, models to predict this preferential uptake are not available. We present the stoichiometry for the utilization of amino acids as a sole carbon and nitrogen su...

Dissolved organic nitrogen (DON) makes up a large fraction of the total dissolved nitrogen pool in coastal waters, but is often ignored as a potential nitrogen source for primary producers. In laboratory experiments, we measured the uptake of small, labile DON compounds, urea and a variety of different amino acids, by the common estuarine macroalgae Ulva lactuca and Gracilaria vermiculophylla. ...

Intensive forest management led to elevated losses of nitrogen from a recently harvested loblolly pine plantation in North Carolina. Measurements of nitrogen-15 retention in the field demonstrated that microbial uptake of nitrogen during the decomposition of residual organic material was the most important process retaining nitrogen. Management practices that remove this material cause increase...

introduction between oil seeds, from the quality, quantity and nutrition index point of view, canola has the top level . because of the solubility of n fertilizers, the time of urea application, is very important and one of the main reasons of the reduction in n application efficiency is utilization of urea in an inappropriate time. by precisely foliar application of nitrogen, the efficiency of...

Standard nutritional advice for irrigated sugarcane in South Africa and Swaziland is based on soil sample analysis and threshold values that have been determined experimentally over many years with surface-applied fertilisers. Fertilisers are normally applied in solid form during the early stages of crop development and watered in by the next irrigation cycle. The increasing popularity of subsu...