Qingjie Li

Replacement control technology is a sustainable strategy for the control of invasive weeds. Two consecutive years of field experiments were conducted in Xichang city to assess the ecological and economical possibility of replacement control of Eupatorium adenophorum (Spreng.) King & H.Rob. with maize. Four treatment groups were planted with maize at different densities after cutting E. adenophorum. Two reference groups were set by not treating and only cutting the aerial parts of E. adenophorum. All maize replacements in the “after tillage” treatments provided control effects of up to 100% and significantly reduced water and fertilizer use by E. adenophorum. Maize replacement provided a substantial economic benefit of up to 20,273.50 and 23,633.22 yuan/hm² in two consecutive years and increased incomes. Evaluated in terms of niche theory, the large leaves as well as high plant cover assisted in effectively occupying the available niche and reduced light interception, seed germination and growth of E. adenophorum. This study provided a scientific basis for the sustainable and eco-friendly control of weeds by ecological methods.

Soil fumigation is considered a method to control soil-borne diseases and solve crop continuous cropping obstacles. However, fumigant residues in the soil are detrimental to soil health. Though substrate cultivation is a cultivation mode that can promote plant growth, studies to date on whether substrate cultivation can replace soil fumigation for the control of soil pathogens are limited. In this study, the effects of chloropicrin fumigation (Pic) and substrate cultivation (SC) on yam growth, soil pathogens, soil nutrients, and microbial communities were demonstrated using a 2-year field experiment. The results showed that SC significantly increased the content of soil organic matter (SOM), available phosphorus, and available potassium compared with Pic. In addition, SC could effectively reduce the number of Fusarium spp. and Phytophthora spp., decrease the rate of diseased yam plants, and significantly increase the yam yield. Moreover, SC significantly increased the abundance of beneficial microorganisms such as Actinobacteriota, Acidobacteriota, and Bacillus in soil. Correlation analysis showed that yam yield exhibited a negative relation with the number of soil pathogens and a positive correlation with SOM. Our study suggests that substrate cultivation can be an alternative to soil fumigation to control soil pathogens and protect soil health.

Soil fumigation can kill soil pathogens and solve the problem of crop continuous cropping. However, soil fumigation also has negative effects on the soil environment. One way to mitigate the negative effects is to apply soil amendments, but there is limited evidence of the effects of combining soil fumigation and amendments. This study was a controlled environmental pot trial. We measured the effects of dazomet fumigation combined with soil amendments on soil-borne pathogens, soil nutrients, enzyme activities, and strawberry growth. The results showed that dazomet fumigation combined with soil amendments significantly increased the content of ammonium nitrogen, available phosphorus and organic matter and increased soil activities by varying degrees. We also found that the control effect of soil-borne pathogens Fusarium spp. and Phytophthora spp. was further enhanced, reaching 88.97–96.88%. Correlation analysis showed that the growth indices of strawberries such as plant height, stem diameter, chlorophyll content, and fresh weight were negatively correlated with Fusarium spp. (R = −0.75, R= −0.62, R = −0.71, R = −0.88; p < 0.01) and Phytophthora spp. (R = −0.72, R= −0.72, R = −0.78, R = −0.91; p ≤ 0.001), respectively. The effect of fumigation combined with soil amendments was better than that of fumigation alone, and silicon fertilizer had the best effect. Our study suggests that dazomet fumigation combined with soil amendments can improve soil nutrient supply, activate soil enzyme activities, enhance the control effect of soil-borne pathogens, and thus promote strawberry growth.

The use of antibiotics in the livestock and poultry industries has raised significant concern about environmental and health problems. In light of this, accurate knowledge of antibiotic residues in livestock and poultry manure is important for pollution management and strategic decision-making at the national level. This study aims to provide a comprehensive report on antibiotic residues in livestock and poultry manure in China using the published data of 3751 livestock and poultry feces in 29 provincial-level units over the past 20 years. In this study, the overall status of antibiotic residues in livestock and poultry feces was analyzed by mathematical statistics. Moreover, the spatio-temporal variation characteristics were analyzed by spatial statistics, and the differences among livestock and poultry species were evaluated by subgroup analysis. The finding indicated that tetracyclines (TCs), quinolones (QLs), sulfonamides (SAs), and macrolides (MLs) were the most abundant residues in livestock and poultry manure. The spatial and temporal variation revealed that the overall trend of antibiotic residues decreased gradually, and the spatial distribution was primarily concentrated in the southeast of Hu Line, exhibiting a “northeast-southwest” distribution. The distribution range also decreased slightly, with the residues of tetracyclines (TCs), quinolones (QLs), sulfonamides (SAs), and pleuromutilins (PMs) showing a significant spatial hot spot. The center of gravity of antibiotic residue shifted to the southwest between 2003 and 2021. In comparison to cow and sheep manure, the tetracyclines (TCs), sulfonamides (SAs), and macrolides (MLs) in pig and chicken manure were higher. The results can serve as a reference for the control and reduction of antibiotic pollution in livestock and poultry manure, as well as the wise utilization of those resources and achieving goals for clean agriculture.

Organic materials added to soil create anaerobic conditions that can reduce soil-borne pathogens that reduce the yield and quality of agricultural crops. Anaerobic soil disinfestation (ASD) requires relatively large quantities of readily available, inexpensive organic materials. We evaluated the impact of ASD with rice bran and biochar organic materials on changes to the soil’s physicochemical properties, microbial taxa, and strawberry fruit yield. We found that the organic materials applied at different dose rates significantly increased the control effect of the soil Fusarium spp. and Phytophthora spp. to 69–99% and 63–98%, respectively. In addition, ASD significantly increased soil organic matter and ammonium nitrogen contents. Strawberry yield also increased significantly after ASD treatment with biochar applied at 10 t/ha, which was positively correlated with increased soil nutrients and a significant reduction in pathogens. High-throughput gene sequencing showed that ASD significantly increased the abundance of some beneficial microorganisms such as Bacillus, Pseudomonas, and Mortierella, possibly due to changes in the soil’s physicochemical properties that favored their survival. We found for the first time that biochar applied at 10 t/ha could create anaerobic conditions that effectively reduced soil-borne pathogens and increased crop yield.