Abstract:

Residue after evaporation (RAE) is a byproduct generated during the industrial production of vitamin C through two-step fermentation, while Bacillus mucilaginosus is a potassium-solubilizing bacterium. Both play a crucial role in enhancing soil quality, fertility, and plant growth. In this study, a mixed fertilizer (RB) was prepared using a combination of RAE and Bacillus mucilaginosus. Three RB treatments with mass fractions of 0% (CK), 0.5%, and 1.0% were applied, along with straw-mat mulched and non-mulched treatments, to conduct field plot experiments. In this field experiment, the growth, physiological indicators, soil nutrient indices, and their correlations of both Medicago sativa and Elymus dahuricus were analyzed. The results demonstrated that RB significantly improved the growth and physiological indexes of forage crops, with higher concentrations of RB showing greater enhancements. In the 1.0% RB treatment, the aboveground biomass of Medicago sativa increased by 112%, while Elymus dahuricus showed an increase of 80.1%. With the same amount of RB applied, germination rates, germination potential, plant height, aboveground biomass, and root development were all significantly higher in mulched treatments compared with non-mulched treatments. The germination rates of Medicago sativa and Elymus dahuricus increased by an average of 164% and 194%, respectively, while the aboveground biomass increased by an average of 64.3% and 24.9%, respectively. Soil organic carbon and nutrient content were effectively increased with the application of RB treatment, particularly with 1.0% RB leading to a 33.1% increase in soil organic carbon and a 105% increase in quick potassium. At the same RB application amount, the mulched treatments could increase the organic carbon content of the soil by an average of 2.75% compared to the non-mulched treatments. Two-way ANOVA revealed significant interaction effects between RB and grass mat mulching on forage growth, physiological indexes, and soil nutrient content. Redundancy analysis and Pearson correlation analysis identified organic carbon, ammonium nitrogen, effective phosphorus, and quick-acting potassium as key factors influencing the growth and physiological indexes of pasture grasses. Based on the findings, it is recommended to use 1.0% RB and grass mat mulching to improve soil quality in arid regions of Xinjiang, facilitating the growth of pasture grasses. This study provides a scientific foundation for the utilization of residue after evaporation, Bacillus mucilaginosus resources, and land development in dry regions like Xinjiang.

Key words: residue after evaporation, Bacillus mucilaginosus, straw mat covering, Medicago sativa, Elymus dahuricus Turcz., soil nutrient content

摘要：

古龙酸母液（RAE）是工业上通过二步发酵法生产维生素C过程中产生的废液，胶质芽胞杆菌（Bacillus mucilaginosus）是解钾细菌，二者在改善土壤质量、提升土壤肥力和促进植物生长方面具有重要意义。使用RAE与胶质芽胞杆菌的混合液作为古龙酸母液混制肥（RB），设RB施加量为0%（CK）、0.5%、1.0%的3个处理，并设置草席覆盖和未覆盖处理，开展田间小区试验，对紫花苜蓿（Medicago sativa）和披碱草（Elymus dahuricus）的生长、生理指标、土壤养分指标及相关关系进行分析。结果表明，相同覆盖处理下，RB总体上显著提高了牧草的生长和生理指标，表现为1.0%>0.5%>CK，在1.0% RB处理下，紫花苜蓿的地上生物量平均提高了112%，披碱草平均提高了80.1%。相同RB施加量处理，覆盖处理的牧草总体上发芽率、发芽势、株高、地上生物量和根系发育显著高于未覆盖处理，紫花苜蓿和披碱草发芽率平均提高164%和194%，地上生物量平均提高64.3%和24.9%。相同覆盖处理下，土壤有机碳和速效养分含量均随RB处理有效提高，1.0%RB将土壤有机碳和速效钾分别显著提高了33.1%和105%。相同RB施加量下，覆盖处理能提高土壤的有机碳含量，平均提高了2.75%。双因素方差分析表明RB和草席覆盖措施对牧草的生长、生理指标和土壤养分含量具有显著的交互影响。冗余分析和Pearson相关性分析表明影响牧草生长生理指标的环境因子主要为有机碳、铵态氮、有效磷、速效钾，建议采用1.0% RB与草席覆盖联用来改良新疆旱区土壤促进牧草生长。研究结果为古龙酸母液、胶质芽胞杆菌资源化利用和新疆旱区土地资源开发提供了科学依据。

关键词: 古龙酸母液, 胶质芽胞杆菌, 草席覆盖, 紫花苜蓿, 披碱草, 土壤养分含量