abstract improving nitrogen use efficiency (nue) is an important objective of the agroecosystem management. a field experiment was conducted to study the effect of different competition patterns on nitrogen balance in the wheat agroecosystem. experimental design was split–plot based on randomized complete blocks with four replications. the main plots consisted of different nitrogen rates (i.e. ...

An approach is outlined for synthesising current understanding of nitrogen dynamics in natural grasslands and extensively managed grassland systems. The increasing complexity of models is illustrated from recent literature, first conceptualising and eventually process-simulating the dynamics of nitrogen, especially in the soil sub-systems of grasslands. Some comparisons are made between New Zea...

This instrumental method for total urinary nitrogen (TUN) is based on the principle of gas-phase chemiluminescence. Results correlate well with measurements of TUN by the Kjeldahl method, which has long provided the means to calculate nitrogen balances for nutritional management. In recent years, because of speed and convenience of measurement, determination of urinary urea nitrogen (UUN) has b...

l. Nutritional balances for calories, glucose, water, nitrogen, Na+, K+, Ca2+, and Mg2+ have been estimated for free-flying cedar waxwings feeding on Washington hawthorn fruits. 2. Birds assimilate 39.9 calories/fruit ( = 20.0% of available calories) and a net loss of 155 mg of water/fruit. 3. Reducing sugars account for 74.5% of assimilated calories ( = 66.0% assimilation efhciency). 4. While ...

Nitrogen (N) is essential for agricultural production, but excess quantities can be detrimental to both water and air quality. The increase in dairy cattle populations in the Magic Valley of southern Idaho has lead to concerns over the impact of N losses to the environment and the impact on both water and air in the region. This work examines the N flows and balances at the production facility,...

Three adult human subjects were maintained for 7 days (period I) on a protein-free formula diet containing the minimum daily requirements of the eight essential amino acids plus 40 g glycine. During the last 5 days of this period, the average daily nitrogen balances for the three subjects were +0.52, +0.71, and +0.30 g, respectively. During the next 7 days (period II), valine was withdrawn from...

Background: Although the protein catabolic effects of metabolic acidosis are well established, it is unclear whether the entire reference range of arterial pH (7.37–7.44) is equivalent for protein balance. Objective: We undertook this study to test the hypothesis that in patients undergoing automated peritoneal dialysis, an arterial pH of 7.43–7.45, as compared with a pH of 7.36–7.38, is associ...