Influence of drought and dry-wet alternation on nitrogen transformation and low abundance microorganisms in tea garden soil

Abstract

Aim: The soil water availability seriously limits the growth and development of tea plants, and soil microorganisms are an important medium to regulate soil nutrient cycling. In this study, the effects of water supply mode on soil nitrogen nutrition and soil microbes in tea gardens were investigated. Methodology: This experiment set up consisted two water supply modes (consecutive drought and dry-wet alternation) by using the soil microcosm incubation experiment, and four treatments were set: 20% water holding capacity for 21day (D21); 20% water holding capacity for 1-7 days and 60% water holding capacity for 8-21 days (D7W14); 20% water holding capacity for 1-14 day and 60% water holding capacity for 15-21 days (D14W7); 20% water holding capacity for 1-7 days, 60% water holding capacity for 8-14 days, 20% water holding capacity for 15-21 days (D7W7D7). Destructive sampling was carried out to determine soil NH4+-N, NO3--N, soil enzyme activities. 16S rRNA sequencing technique was used to determine the change in soil microbial diversity. Results: The results showed that the consecutive drought reduced the content of soil NH4+-N to 13.97 mg kg-1, and the net nitrogen mineralization was negative (-2.75 mg kg-1) after 21 days of incubation. Dry-wet alternation promoted the increase in of soil net nitrogen mineralization quantity and net nitrification quantity, which rose to 3.48-26.41 mg kg-1 and 8.07-23.11 mg kg-1, respectively. Different water supply modes had no significant impact on the structure of dominant soil microbial community, and the effect mainly focused on relative abundance, especially dry-wet alternation mode. Compared with the continuous drought treatment, the relative abundance of Nitrospirae, Actinobacteria, Chloroflexi, Patescibacteria, Latescibacteria, Rokubacteria, Acidobacteria were significantly different in different dry-wet alternation treatments, while the relative abundance of Nitrospirae, Acidobacteria, Latescibacteria, Gemmatimonadetes, Patescibacteria and Chloroflexi also increased or decreased significantly among different dry-wet alternation treatments. Among the physical and chemical factors of tea garden soil, NO3- had the most significant effect on the structure of microbial community. Interpretation: Different water supply can significantly affect the transformation of soil nitrogen and the change in soil bacterial community in tea garden, which provided a theoretical basis for tea garden to cope with adverse weather changes and maintain the stability of tea garden soil ecosystem.

Effects of Water Supply Mode on Nitrogen Transformation and Ammonia Oxidation Microorganisms in a Tea Garden

“…There was an approximately linear relationship between soil water content and nitrogen mineralization. With the increase in water content, soil nitrogen mineralization increased [3]. However, past a certain point, increasing soil moisture could result in a rapid decrease in nitrogen mineralization [4].…”

“…The soil nitrogen transformation process and the microbial population driving nitrogen transformation were significantly different from other soil ecosystems. Although a large number of studies have been conducted on soil nitrogen transformation in tea gardens [1,3], the effects of water supply mode on soil nitrogen transformation and microbial communities in tea gardens had not been reported. In this study, the response of soil nitrogen transformation to different water supply modes was studied to better understand the mechanism of soil nitrogen transformation in Shandong tea gardens.…”

Response of soil microorganisms to soil fertility in the process of vegetation rehabilitation of degraded Pinus massoniana forest

“…Soil microorganisms are an important driving force for ecosystem restoration, and the biological characteristics of soil can respond quickly to changes in the internal and external environments (Zhao et al, 2022). Soil microorganisms not only participate in the decomposition of forest litter and the synthesis of humus but also actively influence the cycling of nutrients and energy conversion in the soil (Ma et al, 2023).…”