Influence of different irrigation methods on the alfalfa rhizosphere soil fungal communities in an arid region

Abstract

Xinjiang is the largest arid and saline agricultural region in China. The common irrigation methods in this area are traditional flood irrigation and drip irrigation. In this study, we investigated the effects of these two irrigation methods on the fungal diversity, community structures, and functions in alfalfa rhizosphere soil as well as the associated environmental factors in northern Tianshan Mountain (Xinjiang, China). Soil enzyme activities (urease and neutral phosphatase) were significantly higher in the drip-irrigated alfalfa rhizosphere soil than in the flood-irrigated alfalfa rhizosphere soil, whereas the fungal alpha diversity in the drip-irrigated alfalfa rhizosphere soil was significantly lower than that in the flood-irrigated alfalfa rhizosphere soil. Six dominant fungal phyla were identified (>0.1%), with Ascomycota being the most abundant in all soils, followed by Basidiomycota (5.47%), Mortierellomycota (1.07%), Glomeromycota (0.55%), Rozellomycota (0.27%), and Chytridiomycota (0.14%). Ascomycota and Glomeromycota species were significantly less abundant in drip-irrigated alfalfa rhizosphere soil than in flood-irrigated alfalfa rhizosphere soil. A LEFSe analysis identified Cladosporiaceae (20.8%) species as the most abundant marker fungi in drip-irrigated alfalfa rhizosphere soil. Of the 13 fungal functional groups identified on the basis of the functional annotation using the FUNGuild database, Ectomycorrhizal (22.29%) was the primary functional group. Compared with flood irrigation, drip irrigation significantly decreased the relative abundance of Ectomycorrhizal and Arbuscular_Mycorrhizal, while increasing the relative abundance of Plant_Pathogen, although not significantly (P = 0.19). Available potassium was revealed to be the main environmental factor influencing soil enzyme activities, fungal alpha diversity, fungal community structures, and fungal functions in response to the different irrigation methods. In conclusion, drip irrigation may be more appropriate than flood irrigation in the Tianshan dryland agricultural area for enhancing soil enzyme activities, but it may also increase the abundance of plant pathogenic fungi in the soil.

Impact of alternate partial root-zone irrigation on the rhizosphere microbiota of alfalfa plants inoculated with rhizobia

“…In the present study, the dominant fungus in the rhizosphere soil under each treatment was the phylum Ascomycota, which is consistent with the findings of previous studies on rhizosphere microbes in the Legaceae ( Deng et al, 2022 ; Liu G. et al, 2023 ). Compared with bacteria, fungi have unique mycelial structures and more stable collinearity networks and are generally less affected by drought ( Bapiri et al, 2010 ; de Vries et al, 2018 ).…”

Effects of different management practices on the growth and yield of corn

“…In this research, the effect of mycorrhiza application on furrow irrigation was not well expressed. This was shown by the farmer's practices (furrow irrigation) + mycorrhiza treatment, which was not significantly different from the farmer's (Deng et al, 2022). The harvest index is the ratio of the economic yield to the total dry weight of plants, which shows the level of efficiency of plants in the process of using photosynthates.…”

“…Application of mycorrhiza in furrow irrigation did not have a significant effect due to the possibility that mycorrhiza was leached with irrigation water so its effect was not expressed in the plant height of corn. According to the results of research by Deng et al (2022), the application of mycorrhiza in furrow irrigation did not enhance soil enzyme activities and nutrient content (total Nitrogen, total Potassium, total Kalium, and soil organic matter). Lack of water resources, high water consumption, and inadequate flood irrigation have significantly reduced yield and quality.…”

Climate-smart agricultural practices influence the fungal communities and soil properties under major agri-food systems

“…Wang et al ( 2017 ) concluded that tillage influenced the distribution of fungal communities with more stable communities under ZT conditions. Irrigation management and soil moisture had a great impact on fungal communities in arid and semi-arid areas where water availability is limited (Vargas-Gastélum et al, 2015 ; Deng et al, 2022 ). But in our study, irrigation was given to all the scenarios based on the tensiometer to maintain the soil moisture as per crop requirement to minimize the effect of irrigation management on fungal community composition.…”