Agriculture is one of the largest consumers of water and energy. This paper evaluated the agricultural sustainability of the Chenmengquan irrigation district of China based on the water–energy–food nexus. One objective weighting method and one subjective weighting method were integrated, based on game theory, and a matter–element model was constructed to evaluate agricultural sustainability for the research region. The sensitivity of each index to the evaluation class was also analyzed. The results showed that agricultural sustainability was moderate in 2006–2012 and high in 2012–2015. The indexes, which represent water-use efficiency and yield per unit area of crops, had higher sensitivities in the context of the present case study. The results also indicated that agricultural sustainability had a comparatively positive trend between 2012 and 2015, and that pesticide utilization was the most important issue for agricultural sustainability. The approach of using the combination of a weighting method, based upon game theory, and the use of the matter–element model provides a guide for the evaluation of agricultural sustainability.

Comprehensive land improvement causes strong disturbances of land use patterns in the short term, resulting in changes in landscape structure and function. This study adopts the moving window method and semi-variation function to explore the spatial scale effect of landscape pattern metrics in the comprehensive land consolidation project area of Baimahu Farm, and the spatial variability and homologous ecological processes. The results showed that: (1) patch density, largest patch index, area-weighted average shape index, contagion, and division index all showed obvious scale effects, and the suitable first and second scale domains in the study area are 5–7 m and 35–40 m, respectively, and 5 m is the most suitable grain size for the study of landscape pattern change. (2) The block basis ratio of the semi-variogram of the six landscape level indices begins to stabilize at the window radius of 210 m. This scale can reflect the spatial variability of the landscape pattern in the study area and is the most suitable analysis range. (3) The fragmentation degree of paddy fields as landscape matrix decreased and the landscape dominance degree increased in the comprehensive land improvement; the degree of fragmentation of irrigated land and agricultural land for facilities increased, the aggregation of land for construction increased, the dominance degree of the pond surface decreased, and the overall landscape diversity of each mosaic decreased; the landscape heterogeneity of ditches, rural roads, forest and grassland corridors was weakened, and the ecosystem service function was weakened. (4) The trend of increased fragmentation, simplification of landscape types, and decreased diversity presented by the landscape pattern clearly indicates that the landscape pattern of the study area has been seriously damaged to some extent under the influence of human activities. This damage not only has a direct negative impact on the local ecological environment, but also poses a potential threat to the sustainable development of the region.

Soil salinization and water scarcity pose critical threats to agricultural sustainability. Therefore, investigating the impacts of tillage practices and brackish water irrigation on the dynamic changes in soil water and salt is of great significance. To investigate the effects of fenlong-ridging deep tillage (FL) on soil water and salt distribution under brackish water irrigation, indoor soil column experiments were conducted comparing FL and conventional tillage (CT) across three irrigation water salinity conditions (0, 3, and 5 g·L⁻¹). The dynamic changes in soil moisture content and electrical conductivity (EC) were measured. The HYDRUS-2D model was used to simulate transport processes under varying FL depths (40/60/80/100 cm). Results indicated that compared with CT, FL can promote water infiltration. Furthermore, FL obviously reduced EC in the 0–50 cm layer compared to CT. Simulations confirmed that increasing FL depth enhanced desalination. Notably, irrigation with 3 g·L⁻¹ brackish water yielded higher EC reduction rates (26.04–30.12%) than 5 g·L⁻¹ water. The combination of 3 g·L⁻¹ salinity and 60 cm FL depth proved most effective; the soil electrical conductivity decreased by 28.28%. This study offers a feasible technical solution for the sustainable utilization of brackish water resources and the amelioration of saline soils.