Abstract
Living cover is an important management measure for orchards in China, and has certain influences on soil properties, microorganisms, and the micro-ecological environment. However, there are few studies on the effects of living cover on the soil changes in hazelnut orchards. In this study, we compared the soils of living cover treatments with Vulpia myuros and the soils of no cover treatments, and analyzed the observed changes in soil properties, microorganisms, and microbial functions by using high-throughput ITS rDNA and 16S rRNA gene Illumina sequencing. The results demonstrated that the total organic carbon content in the 20–40 cm deep soils under the living cover treatments increased by 32.87 and 14.82% in May and July, respectively, compared with those under the no cover treatments. The living cover treatment with V. myuros also significantly increased the contents of total phosphorus (TP), total nitrogen (TN), available phosphorus (AP), and available potassium (AK) in the soil samples. Moreover, the influence of seasons was not as significant as that of soil depth. The living cover treatment also significantly improved the soil enzyme activity levels. The results demonstrated that Ascomycota, Mortierellomycota and Basidiomycota were the dominant fungal phyla in all samples, while Proteobacteria, Actinobacteria, Acidobacteria, Firmicutes, and Chloroflexi were the dominant bacterial phyla, but the different treatments impacted the compositions of fungal and bacterial communities. Principal component analysis (PCA) showed that living cover with V. myuros significantly changed the soil fungal community structures whereas the bacterial community structures may be more sensitive to seasonal changes. At the microbial functional level, the living cover treatment increased the fungal operational taxonomic units (OTUs) of symbiotrophs and decreased that of pathotrophs. According to this study, we believe that the application of a living cover with V. myuros has a favorable regulating influence on soil properties, microbial communities and microbial function. This treatment can also reduce the use of herbicides, reduce the cost of orchard management, and store more carbon underground to achieve sustainable intensification of production in hazelnut orchards, so it can be considered as a management measure for hazelnut orchards.
Highlights
Hazelnut, a shrub or small tree belonging to Corylus L. in Betulaceae, is one of the four largest nuts in the world, together with the walnut, almond and cashew
The soil TOC content under the living cover treatment was higher than before (11.37 g/kg), but no significant (p > 0.05) effect was observed under the no cover treatment
Some living covers compete with fruit trees for water, which adversely affects the growth of fruit trees (Unger, 1998; Zhao and Li, 2006; Wang et al, 2009)
Summary
A shrub or small tree belonging to Corylus L. in Betulaceae, is one of the four largest nuts in the world, together with the walnut, almond and cashew. Previous studies tried to use Trifolium repens and Lolium perenne as interplanting grasses in orchards; these species can effectively inhibit soil and water loss. Due to their growing periods being close to those of deciduous fruit trees, the interplanting of these species will inevitably lead to water and fertilizer competition (Qi et al, 2005; Liu et al, 2014; Rong et al, 2014; Wang et al, 2014). V. myuros, a perennial grass with a plant height of ∼50 cm and dense growth, functions as conservation grass in deciduous orchards This species germinates in September every year, falls naturally when it grows to ∼50 cm and dies in June. In this study, we used V. myuros as the living cover material
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
