## 1 Introduction  
Forage rape (_Brassica napus_), also known as rapeseed, oilseed rape, or canola, is the second largest oil-producing crop grown worldwide [1]. In addition to oil production, the utilization of forage rape in biofuel or livestock production will help to combat energy crises and feed shortages. Forage rape has a high nutritional value and very high biomass yield (\(>\)40 tons fresh matter/hm\({}^{2}\)), according to [PERSON] et al. [2], which could be used to support the growth of ruminants [3, 4]. In China, there is a long-term shortage of high-quality forage, especially in southern China, which challenges the development of ruminant breeding [5]. The high-humidity climatic conditions and acidic soil conditions in southern China are extremely detrimental to the growth of alfalfa, but it is conducive to the growth of forage rape [2]. Therefore, the efficient utilization of forage rape in ruminant production is one of the important solutions to alleviate the shortage of high-quality forage [6].  
Ensiling is a traditional technology for preserving green forage, which can extend storage time, improve palatability, and supply year-round availability of moist forage. During ensiling, epiphytic lactic acid bacteria (LAB) ferment water-soluble carbohydrates (WSC) to lactic acid, resulting in a drop in pH and an inhibition of spoilage microorganisms in the ensiled material [7, 8]. However, forage rape is difficult to ensile due to its high moisture content (\(>\)800 g/kg fresh matter) and high buffer capacity [9]. The pH value of high-moisture silage tends to drop slowly, and it often bears a high risk of clostridial fermentation, resulting in high production of undesirable butyric acid and poor fermentation quality [10; 11].  
Given the moist and rainy weather during forage rape harvest, it is not practical to reduce moisture content by field wilting. The use of absorbent during ensiling has been suggested as an alternative to wilting and has been reported to improve the quality of silage [12]. According to previous reports, sugar beet pulp, dried barley, and distillers' dried grains were promising absorbents as they were found to prevent excessive effluent loss and decreased the pH value of ensiled crops with low DM content [12; 13]. Konjac flour (KF) is processed from the root of konjac tuber (_Amorphophilus konjac_), which mainly contains konjac glucomanan (KGM) and displays a very high water-holding capacity [14]. Hence, adding KF could be a possible way to achieve high-quality forage rape silage by inhibiting the water activity. Currently, KF or KGM is generally used as a food additive or dietary supplement because of its considerable potential for enhancing human and animal health [15]. However, little is known about the effectiveness of KF as a silage additive.  
Apart from absorbent, inoculating silage with LAB has been proposed as an efficient way to overcome the difficulty in natural ensiling [8; 16]. _Lacitplantibilucillus plantarum_ (LP) is a homoformentative LAB, which has been widely used in the ensiling of corn, alfalfa, etc., to enhance silage quality by converting WSC to lactic acid and lowering pH [17; 18].  
Accordingly, it is speculated that adding KF or LP would improve the fermentation quality of high-moisture forage rape, and their combination might show a potential synergistic effect. Nevertheless, there is no information available on the effect of KF or LP on the ensiling of forage rape. Therefore, the present study was conducted to investigate the effect of KF and LP on fermentation quality, chemical composition, aerobic stability, and microbial community of high-moisture forage rape silage.