Relationship between soil organic matter and nematodes in sugarcane fields

Abstract

Sugarcane plays an important socio-economic role in northeastern Brazil. However, the low yield in this region is associated with several factors (e.g. frequent occurrence of plant-parasitic nematodes). In order to observe the influence of soil organic matter on the nematodes, this study aimed to characterize the spatial nematode distribution in a sugarcane field. The study was carried out in Goiana -Pernambuco State (Brazil), fifty days after sugarcane cutting (10 days after vinasse application). The sampling scheme consisted of a regular 60 × 50-m grid, 10 m spaced, through 0 to 0.2 m depth. Spatial distribution was evaluated by semivariograms fit and performed by ordinary kriging interpolation for mapping. Exponential and spherical models promoted the best fit to semivariograms, resulting in ranges from 16 to 19 m. There was a strong negative correlation between soil organic matter and plantparasitic nematode population density. Free-living nematodes had a similar distribution pattern as soil organic matter content. These results indicated that soil organic matter had important effects on spatial distribution of both plant-parasitic and free-living nematodes. Key words: Soil microfauna. Semivariogram. Spatial variability. Vinasse. ResumoA cana-de-açúcar desempenha importante papel socioeconômico para o Nordeste Brasileiro. Por outro lado, a baixa produtividade nesta região está associada a diversos fatores, dentre estes, a relevante presença de nematoides fitoparasitas. A fim de verificar a influência da matéria orgânica sobre os nematoides, o objetivo deste estudo foi caracterizar a distribuição espacial da matéria orgânica e da nematofauna em área cultivada com cana-de-açúcar fertirrigada com vinhaça. O estudo foi realizado no município de Goiana, Zona da Mata Norte de Pernambuco, 50 dias após corte da cana (10 dias após aplicação da vinhaça). Utilizou-se um sistema de amostragem em malha regular de 60 × 50 m, com espaçamento de 10 m, na profundidade de 0-0,2 m. A distribuição espacial foi avaliada por meio de ajustes de semivariogramas e realizada interpolação por krigagem ordinária para mapeamento. O modelo esférico e o exponencial proporcionaram melhor ajuste aos semivariogramas, com alcances de 16 a 19 m. A matéria orgânica correlacionou-se negativamente com a população dos nematoides fitoparasitas. O mapeamento permitiu observar padrões de distribuição espacial similares entre as comunidades de nematoides de vida livre e a matéria orgânica. Esses resultados indicam que a matéria orgânica tem um papel importante na distribuição espacial dos nematoides fitoparasitas e de vida livre. Palavras-chave: Microfauna do solo. Semivariograma. Variabilidade espacial. Vinhaça.

Biodiversity of Nematode Communities Associated with Wheat (Triticum aestivum L.) in Southern Morocco and Their Contribution as Soil Health Bioindicators

“…It is known that organic matter accumulation in soils could cause a decline in nematode diversity [90,91]. Contrarily, soil organic matter contents could be positively linked with soil nematodes [92], probably due to the presence of microbial communities (bacteria and fungi), which could significantly promote nematode occurrence and influence plant growth and development [93,94]. The carbon to nitrogen ratio C/N, which monitors the input of carbon and nitrogen in agricultural soils, was moderately linked to nematode patterns.…”

Diversity and Management Strategies of Plant Parasitic Nematodes in Moroccan Organic Farming and Their Relationship with Soil Physico-Chemical Properties

“…Organic matter accumulation in soils causes a significant decrease in nematode abundance [105,106]. Alternatively, soil organic matter contents were positively correlated with free-living nematodes [107], probably due to microbial community (bacteria and fungi) influence, which could increase significantly these nematode population abundances and contribute to plant growth [108,109]. The ratio C/N, which monitors the contribution of carbon and nitrogen in agricultural soils, was positively related to our identified PPNs.…”

Employing Plant Parasitic Nematodes as an Indicator for Assessing Advancements in Landfill Remediation

“…The accumulation of organic matter in soils leads to a notable reduction in nematode abundance [43,44]. Alternatively, soil organic matter contents were positively correlated with free-living nematodes [45], probably due to microbial community (bacteria and fungi) influence, which could significantly increase these nematode population abundances and contribute to plant growth [46,47]. Oteifa [48] showed that the input of nitrogen to the soil had drastically decreased the population of M. incognito.…”