Seasonal Change in Microbial Diversity and Its Relationship with Soil Chemical Properties in an Orchard

Abstract

This study aimed to determine the microbial diversity at different soil depths (0–5 and 5–20 cm) in a subtropical orchard during different seasons (i.e., spring, summer and autumn) to advance knowledge of the roles of microbes in orchard ecosystem balance. In tracking experiments conducted in an orchard (established in 1996), the phospholipid fatty acid (PLFA) biomarker method was employed to determine the soil microbial system. The total PLFA concentration did not vary significantly between soil depths but changed between seasons. It peaked in the summer at 258.97 ± 23.48 μg g soil-1 from 0–5 cm and at 270.99 ± 58.94 μg g soil-1 from 5–20 cm. A total of 33 microbial fatty acid biomarkers were observed and identified in the sampled soil. The quantities of PLFAs for 29 microbial groups varied significantly between seasons, except for 15:0 iso 3OH, 15:1 iso G, 16:0 2OH, and 17:0 iso 3OH. The bacterial PLFAs and fungal and actinomycetic PLFAs in the orchard soil collected in summer were significantly more abundant than those collected in the spring or autumn (P < 0.01). The number of soil microorganism species (richness) and the Simpson and Shannon-Wiener indexes were all highest in summer. The total PLFAs, bacterial PLFAs, fungal PLFAs, actinomycetic PLFAs, richness, and Simpson and Shannon-Wiener indexes were all significantly negatively correlated with soil pH, total organic carbon (TOC), total nitrogen (TN) and the cation exchange capacity (CEC) (P < 0.05).

Seasonal Changes in Soil Microbial Community and Co-Occurrence Network of Species of the Genus Corylus

“…Therefore, fungi are more susceptible to precipitation and temperature changes caused by seasonal changes than bacterial communities; hence fungi and bacteria have different adaptability to environmental changes [20,38]. The change trend of fungal Shannon diversity in the current study was similar to that of He et al [20], and the change trend of bacterial diversity was also similar to previous studies [49,51]. The increase in soil moisture caused by summer precipitation may be one reason for the increase in microbial richness [37,40].…”

Biocontrol of Melolontha spp. Grubs in Organic Strawberry Plantations by Entomopathogenic Fungi as Affected by Environmental and Metabolic Factors and the Interaction with Soil Microbial Biodiversity

“…Different reasons could be hypothesized to explain the observed changes. The inoculative effect may be a consequence of the seasonal variations [ 78 ] or modification of the trophic populations of nematodes [ 79 ] that are inducing fluctuations in the community structure without a disturbance that alters the overall soil biodiversity. This effect could even promote potential synergistic interaction within soil microbial community [ 80 ].…”

Land use and season drive changes in soil microbial communities and related functions in agricultural soils

“…Soil moisture influences microbial structure by driving changes in soil temperature, pH, nutrient distribution, microbes’ cell metabolism, and bacterial movements (Wang et al, 2014). Luo et al (2019) conducted research on the effect of seasonal changes (summer, spring and autumn) on soil microbial diversity in agricultural soils. Based on their results, due to higher rainfall, summer recorded higher diversity compared with spring in agreement with our findings.…”

“…Chemical soil disturbances are usually related to fertilizer application (Ogundijo et al, 2015). Additionally, soil disturbances can also occur naturally by shifts in rainfall and temperature, caused by seasonal changes (Luo et al, 2019). Although there are many other factors that can cause soil disturbance within the agricultural environment, site visits identified land use, fertilizer application, and seasonality as some of the main factors in the study region.…”