Mulching is a widely employed soil management practice. The mulches used have variable effects on the soil properties and plant growth. In China, mulches are used to cover bare soil at a few places in landscapes, where most of the soil is uncovered, especially in tree pits. As to improve our understanding on the effect of various mulches on soil properties and tree growth after two years of the treatment justifying its implication in soil fertility and tree growth. A comparison study was conducted to determine the effects of inorganic (cobblestone—CB; water permeable brick—WPB), organic (pine bark—PB; green waste compost—GWC), and living (turf grass—TG) mulches on soil physical and chemical properties at three different depths (0–10 cm, 10–20 cm, and 20–40cm), and on tree growth (Sophora japonica) in urban tree pits. Soil moisture was measured once a month in 2015.The soil samples were collected from the tree pits two years after mulching and used to evaluate the physical and chemical properties. Further, trunk diameter and tree height were determined once a year. During the most months, all types of mulches significantly affected the moisture content of the soil at all the depths analyzed. In July and August, however, the moisture content of PB and TG treated soil decreased when compared with that of unmulched bare soil. Two years after mulching, the bulk density of the soil treated with PB, GWC, and TG was significantly affected at10–20 cm, with GWC exhibiting a relatively better effect. The treatments with PB, GWC, and TG also improved the total porosity, macroporosity, and microporosity of the soil at lower depths. Further, WPB worsened the bulk density and porosity of the soil, elevating the pH at lower depths. The organic matter, total N, mineral N, available P, and available K contents of the soil at lower depths increased when mulched with organic material. Turf grass significantly increased only the total N and available K at 0–10 and 10–20 cm. There was no significant difference in the soil properties among the treatments at 20–40 cm. Furthermore, the trunk diameter and tree height were not affected by the mulches two years after mulching. In conclusion, organic mulches especially GWC, not only increased soil fertility significantly but improved soil physical characters (0–10 cm depth) comparing to other mulches, are suitable to cover bare soil in urban tree pits.

Belowground nitrogen (N) transfer from legumes to non-legumes provides an important N source for crop yield and N utilization. However, whether root contact facilitates N transfer and the extent to which N transfer contributes to crop productivity and N utilization have not been clarified. In our study, two-year rain shelter experiments were conducted to quantify the effect of root contact on N transfer in a maize/alfalfa intercropping system. N transfer occurred mainly one direction from alfalfa to maize during the growth period. Following the N0 treatment, the amount of N transfer from alfalfa to maize was 204.56 mg pot−1 with no root barrier and 165.13 mg pot−1 with a nylon net barrier, accounting for 4.72% and 4.48% of the total N accumulated in maize, respectively. Following the N1 treatment, the amount of N transfer from alfalfa to maize was 197.70 mg pot−1 with no root barrier and 139.04 mg pot−1 with a nylon net barrier, accounting for 3.64% and 2.36% of the total N accumulated in the maize, respectively. Furthermore, the amount of N transfer without no root barrier was 1.24–1.42 times higher than that with a nylon net barrier regardless of the level of N addition. Our results highlight the importance and the relevance of root contact for the enhancement of N transfer in a maize/alfalfa intercropping system.

As a major public health emergency, the COVID-19 pandemic has had a huge impact on economies all over the world. The experience of post-COVID-19 economic recovery is of great significance for achieving sustainable and high-quality economic development. Taking the economic development of China as an example, based on the theory of resilient economy and related measurement methods, this article selects five major indicators that are generally recognized as closely connected with economic resilience to construct a system of economic resilience indicators. In addition, the autoregressive integrated moving average (ARIMA) model is used to predict gross domestic product (GDP) under the scenario of no epidemic. The actual value of China's GDP is compared with the predicted value in the absence of the epidemic, verifying that strong economic resilience plays an important role in the country's economic response to major shocks. Based on the results, policy recommendations are made for countries to strengthen their economic resilience in the postepidemic era.

Root competition is a key factor determining plant performance, community structure and ecosystem productivity. To adequately estimate the extent of root proliferation of plants in response to neighbours independently of nutrient availability, one should use a setup that can simultaneously control for both nutrient concentration and soil volume at plant individual level. With a mesh-divider design, which was suggested as a promising solution for this problem, we conducted two intraspecific root competition experiments one with soybean (Glycine max) and the other with sunflower (Helianthus annuus). We found no response of root growth or biomass allocation to intraspecific neighbours, i.e. an ‘ideal free distribution’ (IDF) norm, in soybean; and even a reduced growth as a negative response in sunflower. These responses are all inconsistent with the hypothesis that plants should produce more roots even at the expense of reduced fitness in response to neighbours, i.e. root over-proliferation. Our results suggest that neighbour-induced root over-proliferation is not a ubiquitous feature in plants. By integrating the findings with results from other soybean studies, we conclude that for some species this response could be a genotype-dependent response as a result of natural or artificial selection, or a context-dependent response so that plants can switch from root over-proliferation to IDF depending on the environment of competition. We also critically discuss whether the mesh-driver design is the ideal solution for root competition experiments.

The effects of adding the biosurfactant rhamnolipid, the lignolytic and cellulolytic fungus Phanerochete chrysosporium, and the free-living nitrogen-fixing bacterium Azotobacter chrococcum on vermicomposting of green waste with Eisenia fetida was investigated. The addition of rhamnolipid and/or either microorganism alone or in all combinations significantly increased E. fetida growth rate, the number of E. fetida juveniles and cocoons, the population densities of cellulolytic fungi and Azotobacter bacteria, and cellulase and urease activities in the vermicomposts. The quality of the final vermicompost (in terms of electrical conductivity, nutrient content, C/N ratio, humic acid content, lignin and cellulose contents, and phytotoxicity to germinating seeds) was enhanced by addition of rhamnolipid and/or microorganisms. The physical characteristics of vermicomposts produced with rhamnolipid and/or microorganisms were acceptable for agricultural application. The best quality vermicompost was obtained with the combined addition of P. chrysosporium, A. chrococcum, and rhamnolipid.