In order to fully explore the fertilizer use intensity and its potential threats to the ecological environment, this paper has studied the decomposition of fertilizer use intensity and its environmental risk in China’s grain production. Based on the statistical data collected from 10 provinces during 2004–2015 in China’s grain producing areas, this paper has analyzed the effect of fertilizer use intensity from a regional perspective. The environmental risk assessment model considers some factors such as the fertilizer application safety thresholds use efficiency, multiple cropping index, and environmental impact weight. The fertilizer application safety thresholds are calculated on the target output of local food crops. The results show that: (1) during 2004–2015, the fertilizer use intensity shows an increasing trend in China’s grain producing areas, and the intensity is significantly higher than the upper limit of the international safety fertilization; (2) the cumulative contribution rate of the increase of fertilizer use intensity caused by regional fertilizer use efficiency and grain planting structure adjustment are 57.03% and 1.81% respectively; (3) in 2015, China’s grain producing areas’ environmental risk index of phosphorus and potash was low, with the values in these two provinces being quite different and indicating the characteristics of aggregation and distribution. Therefore, the Chinese government should unswervingly encourage the application of some technology that could save fertilizer and increase efficiency, establish environmental risk monitoring and control systems, and improve relevant policies and regulations.
Increasing and intensifying the use of land represents a prominent sustainability challenge of particular importance in regions undergoing rapid change while at the same time exhibiting large natural and anthropocentrically induced variability. To reconcile the needs for both human prosperity and healthy ecosystems, a more integrated understanding of key biophysical and adaptation processes is paramount in such dynamic and deeply entangled social and environmental contexts. Interdisciplinary research utilizing a network perspective provides a novel methodological and theoretical approach to that end. We review and synthesize recent network-centric studies, and use this network perspective to show how rangeland managers in a dynamic pastoral region in the Qinghai Province of China form social relationships based on geographic proximity, social status and shared grazing areas. The results indicate that adaption to biophysical and socioeconomic changes is partly a social process in that rangeland managers develop their adaptive capacity jointly and in concert with others they trust and with whom they share grazing areas. Avenues for further development of this network perspective, in terms of how it might contribute important new insights about how to sustainably use land in dynamic landscapes undergoing rapid change, are suggested.
Several grassland conservation programs aiming to relieve grazing pressure have been implemented in Inner Mongolia since 2000 to reverse grassland degradation and protect local and regional environments. Previous studies on the effects of these programs usually used small-scale data generated from field experiments and household surveys, inhibiting the discovery of large-scale effects due to spatial heterogeneity. For a typical study region in Xilingol League, we used fixed-effects models and a panel dataset at the county level from 1998 to 2013 to examine the effects of two programs, namely, the Beijing–Tianjin Wind/Sand Source Control Program and the Ecological Subsidy and Award System and other drivers on vegetation rehabilitation. The modeling results suggested that the programs had a positive but delayed impact on grassland vegetation rehabilitation. Enrollment in the two programs in a specific year was predicted to increase the vegetation index value by amounts equivalent to 186 mm and 98 mm more annual precipitation after two years, respectively (p < 0.01). Fixed effects (including site factors and land use history) had a greater effect, hence the design and implementation of government conservation policies should be context-based.