FACTORES QUE AFECTAN LA FIJACIÓN DE NITRÓGENO EN EL SISTEMA Inga spp. -RIZOBIOS EN CAFETALES DE SOMBRA

Abstract

<p><strong>Background</strong>. The results of a review on the factors that affect nitrogen fixation in the Inga-café system are presented. The nitrogen contribution that the <em>Inga</em> Miller tree genus provides to shade coffee plantations and the factors that affect its stability in biological nitrogen fixation are scarcely recognized. This work delves into the ecological factors and glyphosate herbicides that can affect the symbiosis of Inga spp. with diazotrophic bacteria in their roots (rhizobia), which form nodules and carry out biological nitrogen fixation. <strong>Methodology</strong>. Different information sources such as EBSCO, Scopus and Google Schoolar were reviewed, with logical or Boolean data search. 183 papers were used to address the factors that affect the symbiosis between trees of the <em>Inga</em> genus and rhizobia. The findings were organized in: <em>Inga</em> Miller taxonomy, shade coffee plantations with Inga spp., symbiosis between Inga spp. and <em>Bradyrhizobium</em> spp., ecological factors that affect the functioning of the <em>Inga</em> spp.-rhizobia symbiosis and the agrochemical factor: glyphosate herbicide. <strong>Results.</strong> The genus Inga is recognized as a clade Mimosoideae nested in the subfamily Caesalpinioideae. Shade coffee plantations with Inga are established below 23º N and 30º S, up to 3,100 m.a.s.l. and the symbiont genus is predominantly <em>Bradyrhizobium</em> spp. whose ecological limits of <em>Inga</em> spp-rhizobia were: altitude [988.7-1,381.5 m.a.s.l.], annual precipitation [2,048.4-2,064.36 mm], temperature [20.39-21.93 ºC] and soil pH [4.88-5.42 pH]. Glyphosated herbicides, as an external stimulus, can reduce the benefit of biological nitrogen fixation and erode the soil by keeping it devoid of vegetation. Additionally, some <em>Bradyrhizobium</em> spp. (thiO gene), which oxidizes glyphosate to aminomethylphosphonic acid (AMPA), could be a potential glyphosate degrader in the soil. <strong>Implications</strong>. Shade coffee plantations with 205-250 trees per hectare of <em>Inga</em> spp. allow fixing around 45 kg of N ha<sup>-1</sup> year<sup>-1</sup>. This review may allow the adoption of new observational or experimental studies of the <em>Inga</em> spp.-rhizobia symbiosis, to approach the performance that favors the biological fixation of nitrogen in shade coffee plantations. <strong>Conclusions</strong>. The review indicates that there is a specific association between <em>Inga</em> spp. and <em>Bradyrhizobium</em> spp., that ecological factors, including the agronomic management with glyphosated herbicides can decrease nitrogen fixation performance during the symbiosis between <em>Inga</em> spp. and rhizobia. No systematic studies of the symbiosis-environment-agrochemical interaction in shade coffee plantations were found.</p>

Análise fitossociologia e valor de importância em carbono de áreas em restauração florestal na Serra da Mantiqueira, Minas Gerais, Brasil

“…( gênero Inga são reconhecidas por sua eficácia na fixação de nitrogênio devido à sua simbiose com bactérias que colonizam nódulos radiculares, denominadas rizóbios (Rhem et al, 2021;Arévalo-Granda et al, 2023;Velasco-Trejo et al, 2023). I. vera e P. dubium são consideradas espécies-chave em processos de recuperação de áreas degradadas, pois apresentam crescimento rápido, adaptabilidade às diferentes condições de solo e potencial para estocagem de carbono na biomassa, contribuindo para a mitigação das mudanças climáticas (Balestrin et al, 2021, Albuquerque et al 2022Silva et al, 2023).…”