Huan Dong

Degradation of crop straw in natural environment has been a bottleneck. There has been a recent increase in the exploration of cold-adapted microorganisms as they can solve the problem of corn straw degradation under low temperatures and offer new alternatives for the sustainable development of agriculture. The study was conducted in low-temperature (10°C) and high-efficiency cellulose-degrading bacteria were screened using carboxymethyl cellulose (CMC) selection medium and subjected to genome sequencing by the third-generation Pacbio Sequl and the second-generation Illumina Novaseq platform, and their cellulase activity was detected by 3,5-dinitrosalicylic acid (DNS) method. The results showed that the low-temperature (10°C) and high-efficiency cellulose-degrading bacterium Bacillus subtilis K1 was 4,060,823 bp in genome size, containing 4,213 genes, with 3,665, 3,656, 2,755, 3,240, 1,261, 3,336 and 4,003 genes annotated in the non-redundant protein sequence database (NR), Pfam, clusters of orthologous groups of proteins (COGs), Genome Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Annotation databases, respectively. In addition, a large number of lignocellulose degradation-related genes were annotated in the genome. The cellulose activity of B. subtilis K1 was higher, exhibiting the highest activity of endo-β-glucanase (24.69 U/ml), exo-β-glucanase (1.72 U/ml) and β-glucosaccharase (1.14 U/ml). It was found that through adding cold-adapted cellulose-degrading bacteriaK1 in the corn straw composting under 6°C (ambient temperature), the average temperature of straw composting was 58.7°C, and higher 86.7% as compared to control. The HA/FA was higher 94.02% than the control and the lignocellulose degradation rate was lower 18.01–41.39% than the control. The results provide a theoretical basis for clarifying the degradation potential of cold-adapted cellulose-degrading bacteria and improving the cellulose degradation efficiency.

Nowadays, consumers have become increasingly aware of their local food system as a result of concerning about health and nutrition, food safety and sustainability, and local economic development. This transitional shift from global to direct-to-consumer farm operations has increased the demand for locally produced foods. As an alternative, community supported agriculture (CSA), a direct and sustainable food channel, has gained tremendous popularity in the US. Despite the interest garnered by local agriculture and CSA, relatively few studies have empirically tested the determinants of why this marketing phenomenon has grown so rapidly. The purpose of this study is to explore the factors that drive producers to market their products through CSA by using a county-level data set from the US. Results using a Tobit model indicate that specific operator characteristics, such as young and female operators and those engaged in farming as primary occupation, play a strongly positive role in the likelihood of marketing through CSA; farms with small size, rented land, and engagement in growing vegetables, melons, fruits and tree nut crops are more interested in marketing via CSA; households with higher income and females significantly increase the share of farms marketing through CSA; presence of children and seniors and being married are negatively related to the demand for CSA foods. Moreover, counties with higher density of population, establishments-supermarket and other grocery stores, and legislation or active programs that encourage local food consumption tend to encourage more farms marketing through CSA.

The purpose of this study is to reveal the characteristics and driving factors of cropland change in Sichuan Province. This study summarizes the current status of coordination among croplands, ecosystem protection, and urban expansion in the region and provides suggestions for the rational use and conservation of arable land resources. The research methods include ArcGis spatial analysis and the PLUS model. The results show that: (1) The cropland area in Sichuan Province has been continuously decreasing over the past 21 years, but arable land protection policies have effectively mitigated this situation. (2) With the exception of Chengdu, the reduction of arable land in each city in Sichuan province has gradually balanced out, safeguarding the development of major and lagging cities. (3) “Dual suitability” refers to the conflict between urban development and planting. Moreover, due to the Matthew effect, urban development further promoted the expansion of construction lands, leaving croplands in a weak position in the competition with construction lands. (4) Sichuan Province showed the characteristics of alternating leadership between urbanization of land and population urbanization during the process of urban development occupying cropland. In conclusion, the decreasing trend of croplands in Sichuan Province has gradually improved, and the coordination between cropland, ecosystem, and urban space has been achieved.