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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.

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.

Soil water overconsumption is threatening the sustainability of regional vegetation rehabilitation in the Loess Plateau of China. In this study, two typical natural and artificial grasslands under different precipitation regimes were selected and the spatial variations in and the factors that impact the soil water content were investigated to provide support for vegetation restoration and sustainability management in the Loess Plateau. Soil samples were collected in May and September. Medicago sativa L. and Stipa bungeana Trin. were selected as representatives of natural and artificial grasslands, respectively. Soil measurements were conducted at the beginning and end of the rainy seasons at soil depths of 0 to 3 m in 0.2-m increments, and 147 undisturbed and 2205 disturbed soil samples were collected at 27 sampling sites with different precipitation gradients across the Loess Plateau. The plant height, the field capacity, the saturated hydraulic conductivity, the bulk density, and the slope gradient were considered as impact factors. Statistic methods included one-way ANOVA, correlation tests, significance tests, and redundancy analyses. Spatial variation trends indicated that the mean soil water content increased as the multi-year mean precipitation increased, and the soil water content was higher in the natural grassland of Stipa bungeana Trin. than in the artificial grassland of Medicago sativa L. in the same precipitation gradient zone. Vertical spatial variation trends indicated that the soil water content was higher in most surface layers than in the deep layer and lower at the end of the rainy season than at the beginning of the rainy season, when the mean annual precipitation was less than 510 mm. The soil water content of the Stipa bungeana Trin. grassland was significantly correlated with precipitation and plant height, whereas the soil water content of the Medicago sativa L. grassland only exhibited a significant correlation with precipitation. Thus, grasses with fine palatability, good adaptability, and low water consumption should be cultivated in the Loess Plateau. The decreased soil water content is more obvious in the soil layers with active vegetation roots. In the areas with multi-year precipitation at 370–440 mm, natural grasslands are more suitable for restoration and these areas should be treated as key areas for vegetation restoration. With regard to the spatial distribution of vegetation restoration, the economic and ecological benefits must be balanced so that the ratio of artificial vegetation and natural restoration can be optimized to realize the continued sustainability of vegetation restorations.