Effect and mechanism of the improvement of coastal silt soil by application of organic fertilizer and gravel combined with Sesbania cannabina cultivation

Abstract

Jiangsu Province of China has a large area of coastal silt soil (CSS) with poor permeability, high salinity, and poor nutrients, which brings great difficulties to the development and utilization of coastal zones, so that needs to be improved as a matter of urgency. In this study, river-sand, serpentine, and organic fertilizer were used as additives in CSS, and Sesbania cannabina, a salt-tolerant cash crop, was planted in these differently treated soils. Through high-throughput sequencing, analysis of soil physico-chemical properties, and detection of plant growth status, the rhizosphere bacterial diversity of S. cannabina growing in CSS under different treatments and their environmental impact factors were studied, while exploring the effect and mechanism of organic fertilizer combined with gravel as a CSS modifier. The results implied that single application of organic fertilizer could significantly increase the fertility levels of total nitrogen (TN), total organic carbon (TOC) and Avail. P in CSS; then, the application of organic fertilizer with river-sand significantly reduced salt content and alkalinity of soil; meanwhile, in the treatment of single application of organic fertilizer and application of organic fertilizer combined with river-sand, the rhizosphere of S. cannabina enriched the bacterial communities of organic matter degradation and utilization to varying degrees. The soil moisture content and indicators related to saline-alkali soil (including total salt, electrical conductivity (EC), exchangeable sodium percentage (ESP), Avail. Na and Avail. K, etc.) were further reduced significantly by the application of organic fertilizer combined with river-sand and serpentine. The method has greatly improved the growth conditions of S. cannabina and promoted the positive development of its rhizosphere bacterial community. Among them, in the treatment of organic fertilizer combined with river-sand and serpentine, a variety of plant growth-promoting rhizobacteria (PGPR, such as Sphingomonas, Ensifer, and Rhodobacter) and nitrogen-cycle-related bacteria (such as nitrate-reduction-related bacteria, nitrogen-fixing bacteria like Ensifer, and purple non-sulfur photosynthetic bacteria like Rhodobacter) were enriched in the rhizosphere of S. cannabina; moreover, the mutual association and robustness of bacterial co-occurrence networks have been significantly enhanced. The results provide a theoretical basis and reference model for the improvement of coastal saline-alkali silt soil.

Characterization of four digestates from different types of substrates used in biogas production in Northern Peru

“…One way to apply biols with high salt concentrations is to manage this salinity through different strategies, contributing to sustainable agriculture and reducing the risk of soil degradation. Some of the most common strategies are to favor soil leaching or to apply the biol in salinity-resistant crops (An et al, 2022).…”

Effects of Clipping an Invasive Plant Species on the Growth of Planted Plants of Two Co-Occurring Species in a Greenhouse Study

“…Interspecific variations in the suppression of exotic species using different native species have been observed [38,48], and selecting species with faster growth rates may enhance success in the initial stages of invaded ecosystem restoration [43,58]. Although S. cannabina is listed as an invasive species in China [59], it is a typical leguminous nitrogen-fixing species [60] and there is a long history of cultivation of S. cannabina as green manure to improve soil quality, especially that of saline or alkaline soil, by increasing soil organic matter and decreasing soil salinity and alkalinity [61,62], as forage for domesticated animals, and as a herbal medicine and a source of a food additive [63,64]. As S. cannabina serves as a multipurpose species in China currently, it can potentially be used in controlling S. canadensis.…”

Cropping system shifts enhanced nutrient yields under changing daily hydrological processes in a coastal watershed of Eastern China

“…Large amounts of N and P in coastal areas are reported to be primarily derived from agricultural activities (Huang et al, 2017; Lheureux et al, 2023; Li et al, 2019); it is therefore critical to identify the driving forces behind agricultural activities that affect nutrient losses from agricultural fields to the coast. Studies have suggested that the oversupply of chemical and organic fertilizers enhances nutrient runoff losses to coastal areas (An et al, 2022; Laurent et al, 2022). China is a large global fertilizer consumer, accounting for 25%–33% of global consumption between 1990 and 2010 (Lu & Tian, 2017).…”