The Structure and Diversity of Nitrogen Functional Groups from Different Cropping Systems in Yellow River Delta

Abstract

The Yellow River Delta (YRD) region is an important production base in Shandong Province. It encompasses an array of diversified crop systems, including the corn–wheat rotation system (Wheat–Corn), soybean–corn rotation system (Soybean–Corn), fruits or vegetables system (Fruit), cotton system (Cotton) and rice system (Rice). In this study, the communities of ammonia oxidizer–, denitrifier– and nitrogen (N)–fixing bacteria in those cropping systems were investigated by Illumina Miseq sequencing. We found that Rice soil exhibited significantly higher diversity indices of investigated N–cycling microbial communities than other crop soils, possibly due to its high soil water content. Wheat–Corn soils had higher abundances of nitrification gene amoA and denitrification genes nirK and nirS, and exhibited higher soil potential nitrification rate (PNR), compared with Soybean–Corn, Cotton and Fruit soils. Consistently, redundancy analysis (RDA) showed that soil water content (SWC), electrical conductivity (EC), and total nitrogen (TN) were the most important influencing factors of the diversity and structure of the investigated N–cycling microbial.

Environmental Factors, More Than Spatial Distance, Explain Community Structure of Soil Ammonia-Oxidizers in Wetlands on the Qinghai–Tibetan Plateau

“…Both groups of taxa perform a similar function of ammonia monooxygenase enzymatic pathway; therefore, the amoA gene is commonly used as a functional marker for ecological assessment of these taxa [ 2 , 4 ]. However, many previous studies suggested that their relative abundances vary from fractional to several orders of magnitude, depending upon a variety of environmental factors—such as pH, salinity, organic carbon, temperature, ammonium and moisture content [ 5 , 6 , 7 , 8 , 9 , 10 ]. For instance, AOA dominates nitrification in low ammonium, low pH, and high temperature environments, while AOB dominates nitrification in high ammonium and low temperature environments [ 5 , 11 , 12 , 13 , 14 ].…”

Impacts of Rotation-Fallow Practices on Bacterial Community Structure in Paddy Fields

“…In addition, the relative abundance of anaerobic Acidobacteriota and Chloroflexi , which were the dominant phyla in treatment A, were considered higher compared to the other treatments. He et al ( 31 ) demonstrated that rice soils have high nitrogen cycle microbial diversity index than other rotational soils, which is might be attributed to the high-water content of rice soils. The significant effect on soil bacterial community structure during the period of rice field crop rotation-fallow pattern may be attributed to the inconsistent soil environment factor required by bacteria in paddy and dry land.…”

Soil Amendments Alter Ammonia-Oxidizing Archaea and Bacteria Communities in Rain-Fed Maize Field in Semi-Arid Loess Plateau

“…External factors can strongly influence the dynamics of microbial networks and ecosystem processes as a result of various environmental changes [22]. Based on the microbial diversity results, the network analysis in Figure 6A,B showed the highest number of edges within the AOA community, which could be attributed to the dominant OTUs with a relative abundance of 0.01 or more (Figure 6A) [21]. Nevertheless, the AOB modules were more strongly associated with abiotic and biotic variables than the AOA community.…”

“…In our dynamic global ecosystem, it has become essential to generate ideas that exist among diverse AOA and AOB taxonomies within their complex soil population [21]. The co-occurrence network can unravel the impact of environmental factors within ammonia oxidizers to mitigate dynamic microbe-to-microbe association within their taxonomies [22].…”