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With global climate change, the agricultural light-temperature potential productivity in the agro-pastoral ecotone has increased. This offers a good opportunity to develop agriculture in the agro-pastoral ecotone. However, the agro-pastoral ecotone is also an ecologically fragile area in which land degradation challenges agricultural development. As population grows and the need for food increases, the land carrying capacity of the agro-pastoral ecotone becomes insufficient, and the human–land relationship is not harmonious. Such conditions have limited the agricultural and rural development in the ecotone. The paper demonstrates how land engineering may improve land quality and support agricultural development in the ecotone based on studies at a research station established in 2015 in Yulin, Shaanxi Province, China. The studies target three factors: soil improvement, crop selection, and field management. The results show that: (1) The highest yield of crops planted on improved land is close to or even higher than that achieved under previous crop growth conditions. For instance, the corn yields can exceed 25%. (2) The potatoes grown on the improved land yield the highest gross income, reaching 67,200 yuan/ha. By way of land engineering, input costs can be balanced in 3–5 years. (3) As a result of land engineering, some villages in Yulin City have realized sustainable agricultural and even rural development, and promotion of this model will support the sustainable development of agriculture in the agro-pastoral ecotone.

Rural residential land is the main space of a farmer’s life, rural culture, and social relations. Prior research of rural residential land has focused more on its evolvement in plain and traditional agricultural areas. Yet, there is no clear picture of rural residential land expansion, especially in ecologically fragile areas. This study analyzed the characteristics of rural residential land expansion based on 30 m spatial resolution land-use datasets of the Baota District of Yan’an City, Shannxi Province, and further explored the influencing factors and mechanisms of rural residential land expansion through binary logistic regression (BLR) modeling. Our findings indicated that the area of rural residential land in the Baota District increased by 116.16% during 1990–2015. More than 75% of the residential land expansion came from the occupation of cropland. Moreover, rural residential land expansion was heterogeneous in the rural regional system. The expansion scale, speed, and mode diversity of rural residential land decreased with the increased distance to urban built-up areas. Geographical conditions and resource endowments are the primary internal driving factors, urbanization and policy implementation are two major external driving forces. The authors suggest that the realization of regional sustainable development in ecologically fragile areas should strengthen urban–rural integration, focus on constructing central towns, and ensure ecological protection measures.

Climate warming and its corresponding impacts on agriculture system increasingly attach great attentions. Earlier studies more concerned the impacts of the cultivated area expansion under climate change. Yet limited knowledge is about the impacts of climate warming on the cropping index change with the shifts of cropping system border. In this study, we used climatic data (1961-2015) to firstly investigate impacts of warming temperature on potential cropping system border expansion of China, and further used agricultural statistical data and satellite-based land use data to analyze the response of current land system to potential cropping system border expansion. Results of this study indicated that obviously advanced SDT10 and prolonged EDT10 contributed to the 88.4% regions of increased AAT10 at the past half century. Moreover, the northward expansion of the suitable cultivated areas in different cropping systems provided advantages for potential multiple cropping index (PMCI) improvement. Unfortunately, this study found that a significantly declined multiple cropping index (MCI) was observed in the peri-urban regions and the provinces with large out-migration of agriculture labor. The evidently increased MCI was only greatly observed in Xinjiang province. Besides, the potential increment of multiple cropping index (PIMCI) for different cropping system border expansion regions presented a rising trend and reached 53.6% in 2015 due to warming climate. Particularly, the significantly increased PIMCI was observed in the Loess Plateau, the Inner Mongolia, the Middle-lower Yangtze Plain, Northeast China Plain, Southern China and Beijing-Tianjin-Hebei Metropolitan Region. However, the response of current land system to the changes of PMCI and PIMCI was not timely. Based on the findings of our study, some potential agriculture development strategies were suggested by comprehensively considering regional natural conditions, agricultural production conditions and socioeconomic conditions. We hope these findings of this study could provide some valuable information for agricultural development policy decision-making.

Land use change and its impacts on eco-environment attract great attentions. Earlier studies shed light on the impacts of urban build-up land and agriculture land. Yet, knowledge about the impacts of rural residential land on eco-environment, especially from different expansion patterns perspective, is relatively limited. Taking Baota District, a typical city in loess hilly and gully region during the period of 1990–2015 as a case study, this paper analyzed rural residential land and habitat quality changes based on land-use data (30-m spatial resolution), and further used direct/indirect measurement model to explore the impacts of different expansion patterns of rural residential land on eco-environment. Results showed that the growth rate of rural residential land decreased first and then increased during study period, and the pattern of edge expansion has the largest scale among the newly added residential land. Moreover, the eco-environment in northern area of Baota District had been significantly improved, especially the habitat quality of shrubs and grasslands. Unfortunately, this study found that the eco-environment around cities and townships deteriorated dramatically. Environment policy, land engineering projects and residential land changes were important driving factors on eco-environment changes. Furthermore, this study verified the difference in indirect impacts of rural residential land expansion patterns on eco-environment (infilling pattern