Faba Bean Organs Differed in Their Effects on Maize Seed Germination Rate and Soil Microbial Activities as well as Their Decomposition Patterns in a Regosol Soil

Abstract

This study was purposely designed to evaluate the potential of faba bean (Vicia faba) residues as green manure in a maize-faba bean rotation system. Seed germination test and pot experiments were conducted to measure the effects of aqueous extract on maize seed germination and the effects of residues on crop growth and soil microbial activities. Litterbag experiment was conducted to analyze the decomposition patterns of faba bean residues during maize growing season in a regosol soil. The faba bean was separated into roots, stems, leaves, aboveground parts, and whole plants. Seed germination and the lengths of radicle and plumule were lower than those of the control, particularly with 1% aqueous extract concentrations. Aboveground biomass of maize at heading stages was negatively reduced by whole plant, aboveground part, and stem, whereas positively increased by leaf. Faba bean residues varied in their influences on the contents of soil microbial nitrogen and carbon as well as enzyme activities, mainly attributing to their differences in nutrient quality and allelophathy. Faba bean residues showed a quick decomposition rate during the first 5 weeks and slightly decomposed thereafter. The amount of nitrogen (N) released into soil ranged from 3.74 kg N ha −1 in root to 34.67 kg N ha −1 from leaf in the first 5 weeks. Compared with other plant parts, there were more remaining residues in root and stem residues. These results suggest that different management strategies should be taken to balance their negative and positive effects when using faba bean residues as green manure.

Astragalus sinicus Incorporated as Green Manure for Weed Control in Corn

“…However, He et al (2020) found that corn seed germination and the lengths of radicle and plumule were lower than those of the control, particularly with 1% faba bean aqueous extract concentrations. Moreover, incorporating faba bean as green manure, the aboveground biomass of corn at the heading stages was negatively reduced by the whole plant, aboveground part, and stem (He et al, 2020). Milk vetch and spring corn rotation is an important tillage system.…”

“…Researchers based their findings on field tests that faba bean (Vicia faba L.) could exert weed control when used as green manure, and the weed inhibition ability was highest at the time of faba bean incorporation into the field (Álvarez-Iglesias et al, 2018). However, He et al (2020) found that corn seed germination and the lengths of radicle and plumule were lower than those of the control, particularly with 1% faba bean aqueous extract concentrations. Moreover, incorporating faba bean as green manure, the aboveground biomass of corn at the heading stages was negatively reduced by the whole plant, aboveground part, and stem (He et al, 2020).…”

Effects of p-Hydroxyphenylacetic Acid and p-Hydroxybenzoic Acid on Soil Bacterial and Fungal Communities

“…Soil microbes degraded phenolic acids and the released organic carbon was transformed into MBC. The progress was finished within a couple of days or 5 weeks according to the previous reports [4,36]. On the other hand, HPA/HBA addition caused some beneficial microbes to disappear such as Chaetomium, which could affect the biological nitrogen fixation and soil nutrient decrease.…”

The effects of allelochemicals from root exudates of Flaveria bidentis on two Bacillus species

“…Allelopathy directly influences the growth of surrounding plants ( Schalchli et al., 2012 ; He et al., 2019 ). Phenolics and their derivatives, terpenoids, and alkaloids are the main categories of plant allelochemicals ( Qu and Wang, 2008 ; Li et al., 2010 ; Lupini et al., 2018 ; Wang et al., 2018 ), which are released through different means, such as in root exudate, volatiles from leaves, and through decomposition products ( Li et al., 2016 ).…”