Karst areas in southwest China have experienced significant land cover and land use change (LUCC) due to utilization for human activity and a comprehensive rocky desertification control project (RDCP) since 2008. It is important to quantify the effect of LUCC on ecosystem productivity in this region for assessing the overall benefit of this ecological restoration project. In this study, we used using MODIS land cover and NPP products to investigate the relative contribution of LUCC to the change in net primary productivity (NPP) during 2008-2013 in Huanjiang County, one of first one hundred pilot counties to implement RDCP. Our results show that NPP increased in 95.53% of the county, and the average growth of NPP in non-rocky desertification area was higher than in rocky desertification or potential rocky desertification areas. LUCC has an important contribution (25.23%) to the NPP increase in the county, especially in the LUCC area (70.97%), which increased the average NPP by 3.9% and 10.5%, respectively. Across the six RDCP regions in the county, the average increase in NPP for the vegetation restoration measure of governed karst area is significantly greater than in the ungoverned karst area, and the positive change in NPP increased with the increasing implementation area of the vegetation restoration measure.
Land fragmentation is widely known to have an impact on farm performance. However, previous studies investigating this impact mainly focused on a single crop, and only limited data from China are available. This study considers multiple crops to identify the impact of land fragmentation (LF), as well as cropping system (CS), on farm productivity and the efficiency of grain producers in the North China Plain (NCP), using Cangxian County of Hebei Province as an example. Detailed household- and plot-level survey data are applied and four stochastic frontier and inefficiency models are developed. These models include different sets of key variables in either the production function or the inefficiency models, in order to investigate all possibilities of their influences on farm productivity and efficiency. The results show that LF plays a significant and detrimental role, affecting both productivity and efficiency. A positive effect is evident with respect to the CS variable, i.e., multiple cropping index (MCI), and the wheat-maize double CS, rather than the maize single CS, is usually associated with higher farm productivity and efficiency. In addition to LF and CS, four basic production input variables (labor, seed, pesticide and irrigation), also significantly affect farmers’ productivity, while the age of the household head and the ratio of the off-farm labor to total labor are significantly relevant to technical inefficiency. Policies geared toward the promotion of land transfer and the rational adjustment of cropping systems are recommended for boosting farm productivity and efficiency, and thus maintaining the food supply while mitigating the overexploitation of groundwater in the NCP.
Improving the level of intensive cultivated land use is an important measure to ensure food security and promote the sustainable development of the regional society and economy. Based on data from the statistical yearbook of Maoming City and its counties and districts from 2005 to 2018 and the land use change database of Maoming City for 2018, this study constructed an evaluation index system for four aspects: cultivated land use intensity, cultivated land use degree, cultivated land output benefit and cultivated land sustainable use status. The level of intensive use of cultivated land in Maoming City from 2004 to 2017 was evaluated by AHP, the range method and the comprehensive evaluation model, and its temporal and spatial characteristics were evaluated. The results revealed three major points. (1) The intensive use of cultivated land in Maoming City in the past 14 years was good, and its level showed an overall upward trend, with the intensive use degree of cultivated land rising from 0.4045 in 2004 to 1.3148 in 2017. (2) The levels of intensive use of cultivated land in each county and district of Maoming City were generally on the rise, with no significant differences between them. However, according to the regional distribution, the intensive use level of cultivated land was highest in Maonan District, while it was relatively low in Dianbai County. The largest increase in the level of cultivated land intensive use was in Gaozhou, and the smallest was in Dianbai County. (3) According to the existing problems of cultivated land utilization in Maoming City, combined with the current international and domestic measures to effectively improve the level of intensive use of cultivated land, four suggestions are put forward: to improve the efficiency of cultivated land utilization and effectively protect basic farmland; to improve the overall urban planning and rationally adjust the layout of construction land; to raise farmers’ awareness of the intensive use of cultivated land; and to increase agricultural investment and improve agricultural infrastructure.
After operating for four years, the fallow project in the groundwater funnel area of the North China Plain has produced an initial water-saving effect. However, groundwater funnel remediation is a long-term process, and grain price changes over time may affect farmers’ willingness to participate in fallow. Based on the estimation by the Cobb-Douglas production function, the relationship between farmers’ satisfaction with fallow compensation and planting income is analyzed based on survey data collected from farming households in Hebei, a typical province located in the groundwater funnel area. Using this data, the impact of wheat price changes on farmers’ willingness to participate in fallow is simulated. The results indicate wheat price changes affect farmers' expected planting income and consequently their willingness to fallow; 88% of farmers would be unwilling to participate in fallow with a 0.1 yuan per 500 g increase in the wheat price, whereas 71.4% of farmers would be willing to participate in fallow with a 0.2 yuan per 500 g decrease in the price. Finally, some policy implications are proposed, such as the recommendation that the fallow compensation should be adjusted according to the wheat price multiplied by the average wheat yield of the three years before fallow in the North China Plain.
