Nitrogen Metabolism of the Upper Three Leaf Blades of Wheat at Different Soil Nitrogen Levels. II. Protease Activity and Mobilization of Reduced Nitrogen to the Developing Grains

1978 ◽  
Vol 42 (3) ◽  
pp. 293-300 ◽  
Author(s):  
T. V. R. NAIR ◽  
H. L. GROVER ◽  
Y. P. ABROL
Keyword(s):  
Nitrogen Metabolism ◽  
Soil Nitrogen ◽  
Protease Activity ◽  
Nitrogen Levels ◽  
Reduced Nitrogen ◽  
Developing Grains

INORGANIC NITROGEN LEVELS AND NITRIFICATION POTENTIAL IN LOWBUSH BLUEBERRY SOILS

1988 ◽  
Vol 68 (1) ◽  
pp. 63-75 ◽  
Author(s):  
LEONARD J. EATON ◽  
DAVID G. PATRIQUIN
Keyword(s):  
Ammonium Nitrate ◽  
Ammonium Sulfate ◽  
Soil Nitrogen ◽  
Plant Uptake ◽  
Inorganic Nitrogen ◽  
Garden Soil ◽  
Laboratory Studies ◽  
Vaccinium Angustifolium ◽  
Nitrogen Levels ◽  
Lowbush Blueberry

Soil ammonium and nitrate in the top 15 cm of soil were monitored after application of ammonium nitrate and ammonium sulfate to plots at 14 PF (previously fertilized) and 12 NF (never fertilized) lowbush blueberry (Vaccinium angustifolium Ait.) stands representing a range of soil types and management histories. Overall, nitrate values in unfertilized and ammonium sulfate plots were higher at PF than at NF sites, suggesting greater nitrification at PF sites. In laboratory incubation studies, nitrification proceeded immediately in soil from a PF site, but only after a 4-wk lag in that from an adjacent NF site. Nitrification rates were low compared to that in a garden soil (pH 6.6). N-Serve inhibited nitrification in both soils. In ammonium nitrate plots, "excess" N values (N values in fertilized plots minus values in unfertilized plots) were higher for PF than for NF sites, suggesting greater immobilization, plant uptake or loss of N at NF sites. There was no evidence, in laboratory studies, of immobilization of added N by soil from either type of site. Rhizome N concentration increased significantly in response to fertilization at an NF site, but not at a PF site. Key words: Blueberry (lowbush), fertilizer and soil nitrogen

The effect of applied nitrogen on the growth and nutrient concentration of Kalonji (Nigella sativa)

2005 ◽  
Vol 45 (4) ◽  
pp. 459 ◽  
Author(s):  
M. Ashraf ◽  
Q. Ali ◽  
E. S. Rha
Keyword(s):  
Field Experiment ◽  
Seed Yield ◽  
Soil Nitrogen ◽  
Nutrient Concentration ◽  
Nigella Sativa ◽  
Negative Association ◽  
Plant Tissues ◽  
Nutrient Accumulation ◽  
Maximum Biomass ◽  
Nitrogen Levels

Growth and nutrient accumulation in Kalonji (Nigella sativa L.) under varying levels of nitrogen, were examined in a field experiment. Sixty-three-day-old plants were supplied with varying levels of nitrogen of 0, 30, 60 and 90 kg N/ha soil. Maximum biomass and seed yield were recorded at 30 and 60 kg N/ha. The soil nitrogen level, 90 kg/ha, proved to be ineffective in promoting growth of Kalonji. Accumulation of nitrogen, potassium and phosphorus in both shoots and roots of Kalonj increased consistently with increase in soil nitrogen. However, this pattern of increase in the levels of 3 nutrients in plant tissues had a negative association with the growth of the crop, particularly at the supra-optimal nitrogen levels (60 and 90 kg N/ha).

Exposure to aphids increases alder growth and nitrogen fixation

Botany ◽  
2011 ◽  
Vol 89 (4) ◽  
pp. 255-261 ◽  
Author(s):  
Corinthe Zekveld ◽  
John Markham
Keyword(s):  
Soil Nitrogen ◽  
Plant Nutrition ◽  
Soil Microbes ◽  
Nitrogen Fixing ◽  
Root:Shoot Ratio ◽  
Herbivore Damage ◽  
Resistance Response ◽  
Nitrogen Levels ◽  
Alnus Viridis ◽  
Low Nitrogen

Plants can respond to herbivore damage by mounting a resistance response or by compensating for lost fitness. Both plant nutrition and interactions with soil microbes can affect these responses. It has been shown that resistance responses can occur before plants have been attacked by herbivores. Here we show that a tolerance type of response can occur when plants are exposed to, but not fed on by, herbivores. Alnus viridis (Chaix) DC. spp. crispa (Ait.) Turrill were grown in sealed containers under positive air pressure with either 0.5 mmol·L–1 or 2.0 mmol·L–1 nitrate and either inoculated or not inoculated with Frankia , their nitrogen-fixing symbiont. Plants were then exposed to the genus-specific aphid Prociphilus tessallatus Fitch, which failed to establish feeding colonies. Exposure to aphids, formation of nitrogen-fixing nodules, and elevated soil nitrogen levels all significantly increased plant yield with no interaction among these factors. A combination of high soil nitrogen, nodulation, and exposure to aphids resulted in the lowest plant root:shoot ratio. Plants that were grown with low nitrogen and were exposed to aphids showed increased nitrogen-fixing activity within a day of being exposed. These results provide further evidence to support the observation that plants can respond to cues from other organisms prior to receiving herbivore damage.

Carbohydrate constituents of some nigerian maize varieties grown at three soil nitrogen levels

1982 ◽  
Vol 8 (3) ◽  
pp. 179-186 ◽  
Author(s):  
Oyebiodun G. Longe ◽  
B.L. Fetuga ◽  
M.E. Aken'ova
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen Levels ◽  
Maize Varieties
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