Soil microorganisms play critical roles in ecosystem function.  However, the relative impact of the potassium (K) fertilizer gradient on the microbial community in wheat‒maize double-cropping systems remains unclear.  In this long-term field experiment (2008–2019), we researched bacterial and fungal diversity, composition, and community assemblage in the soil along a K fertilizer gradient in the wheat season (K0, no K fertilizer; K1, 45 kg ha⁻¹ K₂O; K2, 90 kg ha⁻¹ K₂O; K3, 135 kg ha⁻¹ K₂O) and in the maize season (K0, no K fertilizer; K1, 150 kg ha⁻¹ K₂O; K2, 300 kg ha⁻¹ K₂O; K3, 450 kg ha⁻¹ K₂O) using bacterial 16S rRNA and fungal internally transcribed spacer (ITS) data.  We observed that environmental variables, such as mean annual soil temperature (MAT) and precipitation, available K, ammonium, nitrate, and organic matter, impacted the soil bacterial and fungal communities, and their impacts varied with fertilizer treatments and crop species.  Furthermore, the relative abundance of bacteria involved in soil nutrient transformation (phylum Actinobacteria and class Alphaproteobacteria) in the wheat season was significantly increased compared to the maize season, and the optimal K fertilizer dosage (K2 treatment) boosted the relative bacterial abundance of soil nutrient transformation (genus Lactobacillus) and soil denitrification (phylum Proteobacteria) bacteria in the wheat season.  The abundance of the soil bacterial community promoting root growth and nutrient absorption (genus Herbaspirillum) in the maize season was improved compared to the wheat season, and the K2 treatment enhanced the bacterial abundance of soil nutrient transformation (genus MND1) and soil nitrogen cycling (genus Nitrospira) genera in the maize season.  The results indicated that the bacterial and fungal communities in the double-cropping system exhibited variable sensitivities and assembly mechanisms along a K fertilizer gradient, and microhabitats explained the largest amount of the variation in crop yields, and improved wheat‒maize yields by 11.2–22.6 and 9.2–23.8% with K addition, respectively.  These modes are shaped contemporaneously by the different meteorological factors and soil nutrient changes in the K fertilizer gradients.

Despite China’s fast-growing e-commerce and its great achievement in promoting poverty alleviation through consumption, little is known about Chinese consumers’ online ethical consumption.  Using the payment card elicitation method, this paper designs a within-subject survey and a between-subject survey to investigate Chinese consumers’ quality perception and preference for apples from poverty-stricken areas.  The results show that before “information shock”, emphasizing that taste and safety attributes of apples from poverty-stricken areas are the same as the conventional ones, Chinese consumers on average are willing to pay a 31% premium for apples from poverty-stricken areas.  After “information shock”, both the within-subject and between-subject designs show a minimal drop of the premium, implying that the ethical attribute is the main motivation for buying apples from poverty-stricken areas.  The regression results show that quality perception of private attributes has significant effect on consumers’ willingness to pay (WTP) for apples from poverty-stricken areas, and trust in government supervision of e-commerce plays an essential role in motivating online ethical consumption.     

Most previous studies have investigated country-of-origin effect for agricultural products from the economically developed country, but few have focused on the impact of country-of-origin on agricultural products from economically developing countries.  Using a national online survey in France, we determine French consumers’ perceptions and preferences for fresh fruit from China.  Results of ordered logit models show that fresh fruit from China was perceived as low quality and unsafe.  Respondents who care about country-of-origin were less likely to purchase fresh fruit from China, while those who care about brand were more likely to buy Chinese fresh fruit.  Risk perception and quality perception both had a significant impact on the purchase of Chinese fresh fruit.  Results of latent class models obtained with key consumer demographics show that heterogeneous preferences exist among different consumer groups.  The results provide critical information to both China and other economically developing countries in their efforts to improve market penetration in economically developed countries.