Sustainable strategies for the management of iron deficiency in agriculture are warranted because of the low use efficiency of commercial iron fertilizer, which confounds global food security and induces negative environmental consequences. The impact of foliar application of differently sized γ-Fe2O3 nanomaterials (NMs, 4–15, 8–30, and 40–215 nm) on the growth and physiology of soybean seedlings was investigated at different concentrations (10–100 mg/L). Importantly, the beneficial effects on soybean were size- and concentration-dependent. Foliar application with the smallest size γ-Fe2O3 NMs (S-Fe2O3 NMs, 4–15 nm, 30 mg/L) yielded the greatest growth promotion, significantly increasing the shoot and nodule biomass by 55.4 and 99.0%, respectively, which is 2.0- and 2.6-fold greater than the commercially available iron fertilizer (EDTA-Fe) with equivalent molar Fe. In addition, S-Fe2O3 NMs significantly enhanced soybean nitrogen fixation by 13.2% beyond that of EDTA-Fe. Mechanistically, transcriptomic and metabolomic analyses revealed that (1) S-Fe2O3 NMs increased carbon assimilation in nodules to supply more energy for nitrogen fixation; (2) S-Fe2O3 NMs activated the antioxidative system in nodules, with subsequent elimination of excess reactive oxygen species; (3) S-Fe2O3 NMs up-regulated the synthesis of cytokinin and down-regulated ethylene and jasmonic acid content in nodules, promoting nodule development and delaying nodule senescence. S-Fe2O3 NMs also improved 13.7% of the soybean yield and promoted the nutritional quality (e.g., free amino acid content) of the seeds as compared with EDTA-Fe with an equivalent Fe dose. Our findings demonstrate the significant potential of γ-Fe2O3 NMs as a high-efficiency and sustainable crop fertilizer strategy.

Purpose The selection of marketing channels by vegetable producers directly affects the income of producers and is important for the maintenance of a stable supply of vegetables and food control. The purpose of this paper is threefold: to investigate the cooperative selection of vegetable marketing channels; to identify the factors that influence the selection of marketing channels by professional vegetable cooperatives by comparing emerging and traditional circulation modes; and to solve the problems related to vegetable circulation channels in Beijing. Design/methodology/approach A total of 187 valid questionnaires were collected from seven main vegetable production districts in Beijing urban areas from September to December 2017, with a response rate of 89 percent. Binary logistic regression was used for analysis in this study. Findings Results revealed that the cooperatives mainly selected large wholesalers, wholesale markets, supermarkets and electronic commerce as their marketing channels for their vegetables. Estimation results showed that among the 18 influencing factors in the four categories, the educational level of the person in charge and some other factors significantly influence the selection of these four distribution channels by the cooperatives. Research limitations/implications Due to the lack of time and energy, this paper does not analyze the factors influencing a cooperative’s choice of different e-commerce platforms. If this problem can be solved, it will definitely promote the development of e-commerce in rural areas. Originality/value The results obtained in the present study and their implications could help policy makers establish a science-based and reasonable policy to encourage vegetable producers to participate in the new circulation modes of vegetables in Beijing and ensure their income in the vegetable supply chain. This study suggests methods to improve the vegetable sector in other cities facing similar issues.

The prevailing framework for matching multimodal inputs is based on a two-stage process: 1) detecting proposals with an object detector and 2) matching text queries with proposals. Existing two-stage solutions mostly focus on the matching step. In this paper, we argue that these methods overlook an obvious mismatch between the roles of proposals in the two stages: they generate proposals solely based on the detection confidence ( i . e ., query-agnostic), hoping that the proposals contain all instances mentioned in the text query ( i . e ., query-aware). Due to this mismatch, chances are that proposals relevant to the text query are suppressed during the filtering process, which in turn bounds the matching performance. To this end, we propose VL-NMS, which is the first method to yield query-aware proposals at the first stage. VL-NMS regards all mentioned instances as critical objects, and introduces a lightweight module to predict a score for aligning each proposal with a critical object. These scores can guide the NMS operation to filter out proposals irrelevant to the text query, increasing the recall of critical objects, and resulting in a significantly improved matching performance. Since VL-NMS is agnostic to the matching step, it can be easily integrated into any state-of-the-art two-stage matching method. We validate the effectiveness of VL-NMS on three multimodal matching tasks, namely referring expression grounding, phrase grounding, and image-text matching. Extensive ablation studies on several baselines and benchmarks consistently demonstrate the superiority of VL-NMS.

As the coupling of photovoltaic (PV) and agriculture, PV agriculture can effectively promote the development of the PV industry and modern agriculture. PV agriculture has attracted numerous countries, prompting the emergence of a growing number of PV farms. As the largest polysilicon producer with large agricultural production area and abundant solar energy resources, China is selected as a case study. This paper identifies indicate that the weakness-threat (WT) strategy should be adopted to promote the development of PV agriculture in China by establishing a unified support policy, encouraging the participation of market capital, and promoting the development of related technology. Similarly, the Chinese scenario might provide a useful reference for other developing countries.