scholarly journals Nitrogen Pools in Tropical Plantations of N2-Fixing and Non-N2-Fixing Legume Trees under Different Tree Stand Densities

Nitrogen ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 86-98
Author(s):  
Kelly Nery Bighi ◽  
Ranieri Ribeiro Paula ◽  
Marcos Vinícius Winckler Caldeira ◽  
Diego Lang Burak ◽  
Eduardo de Sá Mendonça ◽  
...  

We investigated the nitrogen pools in monocultures of legume species widely used in reforestation in Brazil that have contrasting growth and nitrogen acquisition strategies. The plantations were established with the slow-growing and N2-fixing tree Anadenanthera peregrina var. peregrina, and the fast-growing and non-fixing tree Schizolobium parahyba var. amazonicum. The measurements of N pools in the tree biomass and the soil followed standard methods and were carried out on 54 experimental plots. The N2 fixation pools were evaluated by abundance natural of 15N and the N accretion methods. The soil N content was of similar magnitude between species and stand densities. The species showed similar amounts of N in the biomass, but divergent patterns of N accumulation, as well as the 15N signature on the leaves. S. parahyba accumulated most N in the stem, while A. peregrina accumulated N in the roots and leaves. However, the N accumulation in biomass of A. peregrina stand was less constrained by environment than in S. parahyba stands. The percentage of N derived from N2 fixation in A. peregrina stands decreased with the increase of stand density. The biological N2 fixation estimates depended on the method and the response of tree species to environment.

2010 ◽  
Vol 34 (4) ◽  
pp. 1093-1101 ◽  
Author(s):  
Eduardo Chagas ◽  
Adelson Paulo Araújo ◽  
Bruno José Rodrigues Alves ◽  
Marcelo Grandi Teixeira

Seeds with a high concentration of P or Mo can improve the growth and N accumulation of the common bean (Phaseolus vulgaris L.), but the effect of enriched seeds on biological N2 fixation has not been established yet. This study aimed to evaluate the effect of seeds enriched with P and Mo on growth and biological N2 fixation of the common bean by the 15N isotope dilution technique. An experiment was carried out in pots in a 2 x 3 x 2 x 2 factorial design in randomized blocks with four replications, comprising two levels of soil applied P (0 and 80 mg kg-1), three N sources (without N, inoculated with rhizobia, and mineral N), two seed P concentrations (low and high), and two seed Mo concentrations (low and high). Non-nodulating bean and sorghum were used as non-fixing crops. The substrate was 5.0 kg of a Red Latosol (Oxisol) previously enriched with 15N and mixed with 5.0 kg of sand. Plants were harvested 41 days after emergence. Seeds with high P concentration increased the growth and N in shoots, particularly in inoculated plants at lower applied P levels. Inoculated plants raised from high P seeds showed improved nodulation at both soil P levels. Higher soil P levels increased the percentage of N derived from the atmosphere (%Ndfa) in bean leaves. Inoculation with the selected strains increased the %Ndfa. High seed P increased the %Ndfa in inoculated plants at lower soil P levels. High seed Mo increased the %Ndfa at lower soil P levels in plants that did not receive inoculation or mineral N. It is concluded that high seed P concentration increases the growth, N accumulation and the contribution of the biological N2 fixation in the common bean, particularly in inoculated plants grown at lower soil P availability.


AMBIO ◽  
2002 ◽  
Vol 31 (7) ◽  
pp. 612-613 ◽  
Author(s):  
Charles Lugomela ◽  
Birgitta Bergman

2000 ◽  
Vol 35 (4) ◽  
pp. 809-817 ◽  
Author(s):  
ADELSON PAULO ARAÚJO ◽  
MARCELO GRANDI TEIXEIRA ◽  
DEJAIR LOPES DE ALMEIDA

The genotypic differences on growth and yield of common bean (Phaseolus vulgaris L.) in response to P supply were evaluated in a field experiment under biological N2 fixation. Eight cultivars were grown at two levels of applied P (12 and 50 kg ha-1 of P -- P1 and P2 respectively), in randomized block design in factorial arrangement. Vegetative biomass was sampled at three ontogenetic stages. The effects of genotype and phosphorus were significant for most traits, but not the genotype ´ phosphorus interaction. The cultivars presented different patterns of biomass production and nutrient accumulation, particularly on root system. At P1, P accumulation persisted after the beginning of pod filling, and P translocation from roots to shoots was lower. The nodule senescence observed after flowering might have reduced N2 fixation during pod filling. The responses of vegetative growth to the higher P supply did not reflect with the same magnitude on yield, which increased only 6% at P2; hence the harvest index was lower at P2. The cultivars with highest yields also presented lower grain P concentrations. A sub-optimal supply of N could have limited the expression of the yield potential of cultivars, reducing the genotypic variability of responses to P levels.


2017 ◽  
Vol 4 ◽  
Author(s):  
Víctor Moreira-Coello ◽  
Beatriz Mouriño-Carballido ◽  
Emilio Marañón ◽  
Ana Fernández-Carrera ◽  
Antonio Bode ◽  
...  

2000 ◽  
Vol 48 (1) ◽  
pp. 47-59 ◽  
Author(s):  
K. Hairiah ◽  
M. Van Noordwijk ◽  
G. Cadisch

1996 ◽  
Vol 36 (6) ◽  
pp. 701 ◽  
Author(s):  
CP Horn ◽  
RC Dalal ◽  
CJ Birch ◽  
JA Doughton

Following long-term studies at Warra, on the western Darling Downs, chckpea (Cicer anetinum) was selected as a useful grain legume cash crop with potential for improvement of its nitrogen (N) fixing ability through management. This 2-year study examined the effect of sowing time and tillage practice on dry matter yield, grain yield (Horn et al. 1996), N accumulation, N2 fixation, and the subsequent soil N balance. Generally, greater N accumulation resulted from sowing in late autumn-early winter (89-117 kg N/ha) than sowing in late winter (76-90 kg N/ha). The amount of N2 fixed was low in both years (15-32 kg N/ha), and was not significantly affected by sowing time or tillage. The potential for N2 fixation was reduced in both years due to high initial soil nitrate levels and low total biomass of chickpea because of low rainfall. Nitrogen accumulation by grain was higher under zero tillage (ZT) than conventional tillage (CT) for all sowing times, and this affected the level of grain N export. The consequence of low N2 fixation and high N export in chickpea grain was a net loss of total soil N, (2-48 kg N/ha under CT and 22-59 kg N/ha under ZT). Management practices to ensure larger biomass production and lower soil nitrate-N levels may result in increased N2 fixation by chickpea and thus a positive soil N balance.


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