lactatingdairy cows (n=177) fed with grass and corn silage ad libitum kept in pasture, were randomly assigned to evaluate how urea nitrogen in plasma and milk can be related to their pregnancy rate. blood and milk samples were collected on the artificial insemination (ai) day to evaluate plasma urea nitrogen (pun) and milk urea nitrogen (mun) as well as progesterone levels, excluding cows with ...

a two year field experiment was carried out to evaluate the competitive effects of wild mustard densities growing with rapeseed (cultivar talaye) under different nitrogen rates. treatments were wild mustard densities (0, 10, 20, 30, and 40 plant m-2) and nitrogen (n) rates (0, 50, 100, 150, and 200 kg n ha-1). the factorial set of treatments was arranged into a randomized complete block design ...

abstract in this study different proportions of nh4+ and no3- in the growth medium on plant growth were investigated in hydroponic greenhouse experiments. the objectives of these studies were to investigate if ammonium (nh4+) stress in cucumber, a species sensitive to nh4+ toxicity, can be alleviated by matching the nitrogen supply rate to the plant nitrogen demand. ammonium was applied at a re...

the stoichiometric parameter namely “yield coefficient” associated with growth of certain organism can be determined by direct measurement and/or calculated indirectly. the focus of this paper was on the anoxic yield of heterotrophic organisms using ethanol as an external carbon source during the denitrification process. in the literature, it was observed that yield coefficients can vary for th...

the objectives of this study were to evaluate the effects of nitrogen fertigation frequency on lint yield, lint properties, chlorophyll content (spad readings), and the photosynthesis rate (pr) of cotton. this study was carried out in the southeastern anatolia region of turkey in 2011 and 2012 with drip-irrigated cotton. the maximum lint yield (1,856 kg ha-1) was obtained with one lateral for e...

to study the effects of plant density and nitrogen rates on the ability of canola (regent  cobra; an inbred variety) to compete with weeds, an experiment was conducted as a factorial complete block design with four replications. the treatments included four levels of plant density at 150, 190, 230, and 270 plants m-2, and four levels of nitrogen (n) fertil-izer at 0, 46, 92, and 138 kg ha–1. r...

Deficiency of nitrogen may lead to decrease in yield and yield potential of crop plants. An experiment was done under glasshouse conditions in order to investigate nitrogen levels and salicylic acid interaction on some physiologic traits of borage (Borago officinials L.). In this experiment various levels of nitrogen (including; 27.5, 55, 110, 220 and 330 mg/L from ammonium nitrate) and salicyl...

in the present study, the root vigor and kinetic characteristics of nitrogen absorption in potato cultivars was investigated through sand cultivation and pot tests with nutrient solution. four cultivars of potatoes, namely, feiwuruita, yunshu301, liangshu97, and chuanyu56 were grown in nutrient solution matrix cultures. the result showed that: (1) nitrogen uptake rates differed significantly am...