High rates of nitrogen fixation of Ulex species in the understory of maritime pine stands and the potential effect of phosphorus fertilization

2005 ◽  
Vol 35 (5) ◽  
pp. 1183-1192 ◽  
Author(s):  
L Augusto ◽  
N Crampon ◽  
E Saur ◽  
M R Bakker ◽  
S Pellerin ◽  
...  
Keyword(s):  
Potential Effect ◽  
Maritime Pine ◽  
Phosphorus Fertilization ◽  
P Fertilization ◽  
Fixation Rate ◽  
Ulex Europaeus ◽  
Growing Seasons ◽  
Annual Biomass ◽  
Pine Stands ◽  
Very High

Nitrogen (N2) fixation by Ulex species was studied in a range of mature maritime pine (Pinus pinaster Ait.) stands as well as in a phosphorus (P) fertilization trial in a young (6-year-old) open pine stand. The biomass was estimated by allometric relationships, and the percentage of N derived from atmosphere was calculated according to the natural 15N abundance method. Ulex stand biomass was lower in the mature pine stand than in the young open pine stand. In the latter pine stand, Ulex mean annual biomass increment ranged from 1 to 5 Mg·ha–1·year–1, increasing with P fertilization dose, as did the Ulex stand biomass, ranging from 5.4 to 31.1 Mg·ha–1 after six growing seasons in the most highly fertilized treatment. For the sites where the natural 15N abundance method was applicable, the calculated percentage of N in the Ulex europaeus L. tissues derived from atmosphere was very high (mean = 82%; range = 59%–100%). At the other sites, the N2 fixation was probably also very important but could not be calculated with confidence. Here, the mean fixation rate of the former sites was used to calculate the N2 fixation flux. The estimated annual N2 fixation flux ranged from 0.5 to 5.1 kg N·ha–1·year–1 in the mature pine stands. In the young open pine stand, the Ulex understory fixation ranged from 8.1 to 57.4 kg N·ha–1·year–1, increasing with P fertilization dose. Considering the low levels of N fluxes in theses ecosystems, these figures are very high.

Cyanolichens: a link between the phosphorus and nitrogen cycles in a Hawaiian montane forest

2011 ◽  
Vol 28 (1) ◽  
pp. 73-81 ◽  
Author(s):  
Jon W. Benner ◽  
Peter M. Vitousek
Keyword(s):  
Nitrogen Fixation ◽  
Community Composition ◽  
Ground Level ◽  
Montane Forest ◽  
P Fertilization ◽  
Fixation Rate ◽  
Low Phosphorus ◽  
Very High ◽  
P Supply ◽  
Individual Fixation

Abstract:Low phosphorus (P) supply frequently has been shown to limit the abundance and activity of nitrogen (N)-fixing organisms, potentially constraining N inputs to ecosystems. Previous research in a montane Hawaiian forest has shown that ground-level P-fertilization led to significant increases in the population size of epiphytic N-fixing lichens (cyanolichens), as well as a shift in community composition from crustose to leafy species. In this study, we ask whether these changes in the cyanolichen community have resulted in increased N inputs to the forest, and also whether the very high levels of P in the canopy of P-fertilized forest stimulate individual lichen fixation rates over those of lichens from a nearby unfertilized reference forest. We used acetylene reduction (AR) assays to measure the fixation rates of 14 cyanolichen species from P-fertilized forest, and calibrated these rates by measuring15N2fixation incorporation in four species. We found that the ratio of acetylene reduced to N fixed ranged from 2.4 ± 0.4 inPseudocyphellaria crocatato 9.3 ± 2.4 inLeptogium denticulatum. Nitrogen fixation rates in the P-fertilized forest ranged from 0.64 ± 0.05 nmol N cm−2h−1inNephroma helveticumto 3.97 ± 1.48 nmol N cm−2h−1inParmeliella nigrocincta. Fixation rates did not vary greatly among species from P-fertilized forest. We compared these P-fertilized rates to those of 10 species from the reference forest, and found that mass-based fixation rates of P-fertilized lichens were not greater than those of lichens from the unfertilized forest. Using the measured AR rates, we estimate that the P additions increase cyanolichen N inputs to the forest 30-fold, from ~0.3 kg N ha−1y−1to ~9 kg N ha−1y−1. These results suggest that P additions to this ecosystem increase N inputs primarily by increasing the abundance of cyanolichens, and that shifts in cyanolichen community composition and changes in individual fixation rate were of lesser importance in determining ecosystem N inputs.

scholarly journals Field effect of P fertilization on N2 fixation rate of Ulex europaeus

2007 ◽  
Vol 64 (8) ◽  
pp. 875-881 ◽  
Author(s):  
Xavier Cavard ◽  
Laurent Augusto ◽  
Etienne Saur ◽  
Pierre Trichet
Keyword(s):  
N2 Fixation ◽  
Field Effect ◽  
P Fertilization ◽  
Fixation Rate ◽  
Ulex Europaeus

scholarly journals Yield and Nutritional Quality of Cabbage as Affected by Nitrogen and Phosphorus Fertilization

1970 ◽  
Vol 41 (1) ◽  
pp. 41-46
Author(s):  
KMF Haque ◽  
AA Jahangir ◽  
ME Haque ◽  
RK Mondal ◽  
MAA Jahan ◽  
...  
Keyword(s):  
Block Design ◽  
Growth Yield ◽  
Nutrient Content ◽  
Phosphorus Fertilization ◽  
Fertilizer Treatment ◽  
P Fertilization ◽  
Nitrogen And Phosphorus ◽  
Titrable Acidity ◽  
Nitrogen Phosphorus

An experiment was conducted in field condition to study the effect of nitrogen-phosphorus fertilization on growth, yield and nutrient content of cabbage. The experiment was laid out in randomize block design with three replications. The yield and yield components were maximized by N3P2 fertilizer treatment. Nutrient content of cabbage varied with fertilizer treatment. The maximum amount of reducing sugar, ascorbic acid, phosphorus were found at the highest rate of N - P fertilization whereas accumulation of titrable acidity, iron, calcium were maximum at the rate of N2P2 treatment. However pH, ash content were more or less same throughout the experiment. Bangladesh J. Sci. Ind. Res. 41(1-2), 41-46, 2006

scholarly journals Origin identification of maritime pine stands in France using chloroplast simple-sequence repeats

2002 ◽  
Vol 59 (1) ◽  
pp. 53-62 ◽  
Author(s):  
Maria Margarida Ribeiro ◽  
Gr�goire LeProvost ◽  
Sophie Gerber ◽  
Giovanni Guiseppe Vendramin ◽  
Maria Anzidei ◽  
...  
Keyword(s):  
Simple Sequence Repeats ◽  
Maritime Pine ◽  
Pine Stands ◽  
Origin Identification ◽  
Simple Sequence

Whole-Tree Harvesting Affects Pine Regeneration and Hardwood Competition

1985 ◽  
Vol 9 (2) ◽  
pp. 81-84 ◽  
Author(s):  
James W. McMinn
Keyword(s):  
Growing Seasons ◽  
Pine Regeneration ◽  
Pine Stands ◽  
Whole Tree Harvesting ◽  
Whole Tree ◽  
Tree Harvesting

Abstract Mixed upland hardwood-pine stands of low quality in the Upper Piedmont of Georgia were whole-tree harvested to 1-inch and 4-inch diameter limits in both winter and summer. Natural pine regeneration and hardwood sprouting were observed two growing seasons after harvesting. Early pine establishment was generally successful after winter harvesting but not after summer harvesting. Pine regeneration was excellent following the 1-inch winter harvest and acceptable following the 4-inch winter harvest. The treatment resulting in the best pine regeneration also produced the greatest coverage of hardwood sprouts.1

scholarly journals Growth Response of Herbaceous Ornamentals to Phosphorus Fertilization

HortScience ◽  
2017 ◽  
Vol 52 (10) ◽  
pp. 1362-1367 ◽  
Author(s):  
Josh B. Henry ◽  
Ingram McCall ◽  
Brian Jackson ◽  
Brian E. Whipker
Keyword(s):  
Plant Growth ◽  
Growth Response ◽  
Phosphorus Fertilization ◽  
P Fertilization ◽  
P Deficiency ◽  
Bedding Plants ◽  
Deficiency Symptoms ◽  
Series Of Experiments ◽  
Impatiens Hawkeri ◽  
New Guinea Impatiens

A series of experiments investigated the effects of increasing phosphate–phosphorus (P) concentrations on the growth and development of four horticultural species. In experiment 1, petunia [Petunia atkinsiana (Sweet) D. Don ex W.H. Baxter] plants were grown using eight P concentrations, and we found that the upper bound for plant growth was at 8.72–9.08 mg·L−1 P, whereas concentrations ≤2.5 mg·L−1 P caused P deficiency symptoms. Experiment 2 investigated P growth response in two cultivars each of New Guinea impatiens (Impatiens hawkeri W. Bull) and vinca [Catharanthus roseus (L.) G. Don]. Growth for these plants was maximized with 6.43–12.42 mg·L−1 P. In experiment 3, ornamental peppers (Capsicum annuum L. ‘Tango Red’) were given an initial concentration of P for 6 weeks and then switched to 0 mg·L−1 P to observe whether plants could be supplied with sufficient levels of P, and finished without P to keep them compact. Plants switched to restricted P began developing P deficiency symptoms within 3 weeks; however, restricting P successfully limited plant growth. These experiments indicated that current P fertilization regimens exceed the P requirements of these bedding plants, and depending on species, concentrations of 5–15 mg·L−1 P maximize growth.

Belowground to aboveground biomass ratio and vertical root distribution responses of mature Pinus radiata stands to phosphorus fertilization at planting

2004 ◽  
Vol 34 (9) ◽  
pp. 1883-1894 ◽  
Author(s):  
Ayalsew Zerihun ◽  
Kelvin D Montagu
Keyword(s):  
Pinus Radiata ◽  
Aboveground Biomass ◽  
Root Distribution ◽  
Root Biomass ◽  
Phosphorus Fertilization ◽  
P Fertilization ◽  
Coarse Roots ◽  
Vertical Root Distribution ◽  
Allometric Relations ◽  
P Supply

We compared the belowground biomass (BGB)/aboveground biomass (AGB) ratio and the vertical root distribution of 40-year-old Pinus radiata D. Don fertilized with 0 or 90 kg P·ha–1 at planting. Root biomass was determined by a combination of coring (fine roots, ϕ < 2 mm; small roots, 2 ≤ ϕ < 15 mm) and excavation (coarse roots, ϕ ≥ 5 mm). Stand-level AGB and coarse root biomass (CRB) were estimated with the use of allometric relations. After 40 years, AGB and CRB of P-fertilized trees were 4.5 times those of unfertilized trees, indicating that CRB scaled isometrically with AGB independently of P supply. By contrast, P fertilization increased the fine and small root biomass (FSRB) pool by only 50%. As a result, the scaling of FSRB to AGB was dependent on P supply. The differential response of the FSRB to P fertilization caused the overall BGB/AGB ratio to decrease from 0.29 in control plots to 0.20 in P-fertilized plots. Phosphorus fertilization also altered the vertical distribution of fine root biomass (FRB). For example, the proportion of FRB in the top 15 cm increased from 41% to 52% with P fertilization. Collectively, the results showed that P added early in the growth phase had a persistent effect on the BGB/AGB ratio in P. radiata. This was primarily brought about by altered biomass partitioning to the nutrient-acquiring FSRB pool.

scholarly journals LONG-TERM EFFECTS OF TILLAGE, PHOSPHORUS FERTILIZATION AND CROP ROTATION ON PEARL MILLET–COWPEA PRODUCTIVITY IN THE WEST-AFRICAN SAHEL

2000 ◽  
Vol 36 (2) ◽  
pp. 243-264 ◽  
Author(s):  
G. V. SUBBARAO ◽  
C. RENARD ◽  
W. A. PAYNE ◽  
A. BATIONO
Keyword(s):  
Organic Matter ◽  
Grain Yield ◽  
Pennisetum Glaucum ◽  
Cropping Systems ◽  
Block Design ◽  
Phosphorus Fertilization ◽  
P Fertilization ◽  
Long Term Effects ◽  
Environmental Index ◽  
Traditional System

The millet (Pennisetum glaucum)-based cropping systems that dominate the Sudano–Sahelian Zone of West Africa cannot, as they are currently practised, meet the growing food needs of the region. They must therefore be intensified in a sustainable manner. The present study was initiated in 1986 and continued until 1996 to evaluate the effects of phosphorus (P) fertilization, tillage and rotation with sole cowpea (Vigna unguiculata) on an operational scale with two cropping systems, namely, sole millet and millet–cowpea intercropping. A randomized complete block design with four replications was used. The effects of P fertilization, ridging with animal traction and planting on ridges (AT), and rotation with sole cowpea increased the productivity of millet substantially in 10 of the 11 years. Based on the 11-year average, P fertilization alone improved grain yield by 52%, and AT with P fertilization improved grain yield by nearly 135%. Combining AT, P fertilization and the sole cowpea rotation resulted in a 200% increase in grain yield compared with the traditional system of production. Millet productivity did not show a significant decline when intercropped with cowpea. Stability and relative stability analysis showed that the traditional system was more stable than the various agronomic packages, but had the least yield. Conversely, the agronomic package with the highest yield advantage over the traditional system was the least stable. A major portion of the annual variation in the environmental index for grain yield and total dry matter was attributed to the seasonal variation in rainfall and organic matter depletion. Organic matter levels declined linearly with years of cultivation. Significant differences were found in the rate of depletion between the various agronomic treatments tested. After 11 years, nearly 60% of the organic matter was depleted irrespective of the agronomic treatments.

Sign in / Sign up

Export Citation Format

Share Document