Effects of green-manure and tillage management on soil microbial community composition, nutrients and tree growth in a walnut orchard

Abstract

This study characterized the effect of green manures (February orchid, hairy vetch, rattail fescue and a no-green-manure control) and the termination method (flail or disk) on nutrient contents, enzyme activities, microbial biomass, microbial community structure of rhizosphere soil and vegetative growth of walnut tree. All three selected green manures significantly enhanced the water content, organic C, total N and available P. The rattail fescue significantly decreased the mineral N. Total organic C, total N, mineral N and available P were significantly greater under flail than under disk. Hairy vetch and February orchid significantly improved levels of soil β-glucosidase, N-acetyl-glucosaminidase and acid phosphatase activity, whereas rattail fescue improved only β-glucosidase activity. All of the green manures significantly decreased phenoloxidase activity. β-glucosidase, N-acetyl-glucosaminidase and acid phosphatase activities were significantly greater under flail relative to disk. The termination method had no significant effect on phenoloxidase activity. The different types of green manures and termination methods significantly altered the soil microbial biomass and microbial community structure. The green-manure treatments were characterized by a significantly greater abundance of Gram-positive (Gram +) bacteria, total bacteria and saprophytic fungi compared to the control. Hairy vetch significantly decreased the abundance of arbuscular mycorrhizal fungi (AMF) while February orchid and rattail fescue increased their abundance compared to the no-green-manure treatment. The abundance rates of Gram+ bacteria, actinomycetes, saprophytic fungi and AMF were significantly greater in soils under flail than under disk. In terms of vegetative growth of walnut tree, hairy vetch showed the greatest positive effects. The growth of walnut tree was significantly greater under flail relative to disk. Our results indicate that green-manure application benefits the rhizosphere soil micro-ecology, rhizosphere soil nutrient contents and tree growth. Overall, the hairy vetch and flail combined treatment is recommended for walnut orchards in northern China.

Germplasm Screening of Green Manure Rapeseed through the Effects of Short-Term Decomposition on Soil Nutrients and Microorganisms

“…The decomposition of green manure will affect the soil nutrients, and the latter will affect the structural diversity and abundance of the soil microbial community [5,6,18]. Microorganisms are the main driving force of the soil nutrient material cycle, and the microbial communities in the soil are vulnerable to the influence of the external environment; thus, they react to the soil environment [37,38].…”

“…In parallel with the rapid development of modern industry, the unreasonable application of chemical fertilizer has caused a series of environmental and safety problems [1][2][3], which deters the realization of the target for sustainable development [3]. Planting green fertilizer can reduce the use of chemical fertilizers and pesticides [4], and the use of green manure can increase the contents of soil nutrients and improve the soil fertility and structure of soil microbial community among others [5,6]. It is of substantial significance to cultivate high-quality green manure varieties and develop the green manure industry for the ecological environment and agricultural green sustainable development.…”

Combined effects of water retaining agent and green manure on trace elements concentration in tobacco farming purple soils

“…On the other hand, Asagi and Ueno (2009) found that T. repens L. and Vicia villosa Roth were the most efficient N sources for rice yield. It was previously reported that the benefits associated with weed control, water holding capacity, rhizosphere soil ecology, and soil conservation might be attributed to V. villosa (Dong et al, 2021;Choi and Daimon, 2008;Hartwig and Ammon, 2002). Thus, the green manure improves soil conditions, nutrient availability and cycling, and soil physical properties (Ma et al, 2021;Karkanis et al, 2007).…”

Effects of green manure planting mode on the quality of Korla fragrant pears (Pyrus sinkiangensis Yu)

“…Using green cover crops as plant fertility is an effective environmental protection measure to improve fruit quality and decrease fertiliser consumption ( Srivastava et al., 2007 ; Chen et al., 2014 ; Dong et al., 2021 ). Meanwhile, some scholars have studied the effects of green manures on pear orchards.…”