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. ...

The NAC (nitrogen assimilation control) protein from Klebsiella aerogenes is a LysR-like regulator for transcription of several operons involved in nitrogen metabolism, and couples the transcription of these sigma 70-dependent operons to regulation by the sigma 54-dependent NTR system. NAC activates expression of operons (e.g. histidine utilization, hut), allowing use of poor nitrogen sources, ...

The objective of the current study was to investigate the effect of N-carbamoylglutamate (NCG) supplementation on milk production and nitrogen (N) utilization in Chinese Holstein dairy cows. Sixty multiparous cows (78±17.3 d in milk, 635±61.00kg of body weight, and 41.9±7.9kg/d milk yield; mean ± SD) were blocked by parity, days in milk, and milk yield and randomly allocated to 1 of 4 groups, e...

Cheviot wethers were defaunated by using dioctyl sodium sulfosuccinate and were constantly infused with urea to provide 2.87% of the daily N intake. Defaunation resulted in higher rumen dry matter and lower rumen pH. The molar per cent propionate was higher in defaunated sheep, whereas the molar per cent butyrate and acetate was lower. Apparent nitrogen digestibility, nitrogen utilization, and ...

A series of experiments was conducted to determine the effects of limit-feeding high-concentrate (LFHC) diets on dietary CP requirements of steer calves. When steer calves were fed 80% concentrate diets at 78 g/kg of BW.75, increasing dietary CP resulted in increased ADG (P less than .001). Average daily gain was increased in steers as daily monensin dosage increased from 120 to 180 mg (P less ...

the effect of concentration and time of supplementary nitrogen fertilizer spray application on grain yield and nitrogen use efficiency in rapeseed (hyola401) as a second crop in paddy fields were evaluated in a field experiment conducted in randomized complete block design with 3 replications at rice research institute of iran (rasht) in 2008. in this experiment two factors, concentration of so...

Prochlorococcus is the most abundant phytoplankter throughout the photic zone in stratified marine waters and experiences distinct gradients of light and nitrogen nutrition. Physiologically and genetically distinct Prochlorococcus ecotypes partition the water column: high-B/A (low-light adapted) ecotypes are generally restricted to the deep euphotic zone near or at the nitracline. Low-B/A (high...

Urea is one of the dominant organic nitrogenous compounds in the oligotrophic oceans. Compared to the knowledge of nitrogen transformation of nitrogen fixation, ammonia oxidization, nitrate and nitrite reduction mediated by sponge-associated microbes, our knowledge of urea utilization in sponges and the phylogenetic diversity of sponge-associated microbes with urea utilization potential is very...