The significant spatial heterogeneity among river basin ecosystems makes it difficult for local governments to carry out comprehensive governance for different river basins in a special administrative region spanning multi-river basins. However, there are few studies on the construction of a comprehensive governance mechanism for multi-river basins at the provincial level. To fill this gap, this paper took Henan Province of China, which straddles four river basins, as the study region. The chord diagram, overlay analysis, and carbon emission models were applied to the remote sensing data of land use to analyze the temporal and spatial patterns of carbon storage caused by land-use changes in Henan Province from 1990 to 2018 to reflect the heterogeneity of the contribution of the four basins to human activities and economic development. The results revealed that food security land in the four basins decreased, while production and living land increased. Ecological conservation land was increased over time in the Yangtze River Basin. In addition, the conversion from food security land to production and living land was the common characteristic for the four basins. Carbon emission in Henan increased from 134.46 million tons in 1990 to 553.58 million tons in 2018, while its carbon absorption was relatively stable (1.67–1.69 million tons between 1990 and 2018). The carbon emitted in the Huai River Basin was the main contributor to Henan Province’s total carbon emission. The carbon absorption in Yellow River Basin and Yangtze River Basin had an obvious spatial agglomeration effect. Finally, considering the current need of land spatial planning in China and the goal of carbon neutrality by 2060 set by the Chinese government, we suggested that carbon sequestration capacity should be further strengthened in Yellow River Basin and Yangtze River Basin based on their respective ecological resource advantages. For future development in Hai River Basin and Huai River Basin, coordinating the spatial allocation of urban scale and urban green space to build an ecological city is a key direction to embark upon.

Enhancing the rate and efficiency of crop residue utilization is critical for sustainable agriculture and cleaner production. However, differentiated utilization patterns, influencing factors, and economic efficiency among smallholder farmers remain largely unknown. This study explored the barriers, motivations, influencing factors, as well as economic inputs and outputs of crop residue utilization among 382 respondents (267 in plains and 115 in hilly areas) in China’s main grain-producing regions. The results indicate that fertilizer (49.76% of respondents) and livestock feed (19.18%) were the most prevalent ways of crop residue utilization, followed by crop residue selling (9.29%), crop residue used for domestic fuel (2.94%), and raw materials (1.41%). The collectable crop residue yield (7759.24 kg), utilization rate (87.17%), total economic input (79.70 USD/ha), and output (164.84 USD/ha) among farmers in plain areas were higher than those in hilly areas (3812.04 kg, 71.07%, 66.79 USD/ha, and 144.55 USD/ha, respectively). The return on investment (ROI) was significantly higher in plains (113.92%) than in hilly areas (98.54%). Environmental protection and crop residue recycling were identified as the main motivations for the high rate of crop residue utilization, while additional inputs for crop residue utilization and labor shortages were significant barriers in plain and hilly areas, while farmers in plain areas are most constrained by the additional funds and labor input they need, while those in mountainous areas face more severe challenges related to a lack of knowledge, equipment and market access. The use of crop residue for livestock feed, fertilizer, and sales was positively influenced by agricultural income, planting area, and available crop residue yield. Factors affecting crop residue utilization for raw materials and domestic fuel varied across terrains. In plain areas, crop residue used for raw materials was affected by gender, while in hilly areas, crop residue used for domestic fuel was affected by age, market availability, and awareness of crop residue resources. These findings suggest that differentiated strategies are required: implementing targeted Farmer Field Schools (FFS) to improve technical skills and residue management; providing financial incentives to offset machinery and sales costs; promoting land consolidation and mechanized, large-scale residue collection; and developing regional residue markets with centralized collection networks and on-site processing facilities, particularly in hilly areas.