Maize was harvested in late September and early October, and winter wheat has been planted at the end of the monitoring period. According to the crop condition development graph based on NDVI, crops were gradually ripening from August to early September, after which they were harvested from mid-September to the end of the monitoring period. The temperature (TEMP, -0.2℃) was slightly below average while radiation was above average (RADPAR, +4%).  Shortage of precipitation (RAIN -8%) resulted in potential biomass production (BIOMSS) to be below average (-24%). In most of the area, the analyses based on spatial NDVI clusters and profiles are consistent with VCIx. The most favorable conditions occurred mainly in the southern part of Ningxia, the eastern part of Gansu, the north central part of Shaanxi and some regions in western Shanxi from July to October, due to favorable agroclimatic conditions. On the contrary—and mostly because of drought during the monitoring period (as confirmed by the maps of potential biomass)—crops were in unpromising condition (compared to the five-year average) in south central Gansu and southern Shanxi. Moreover, the cropped arable land fraction (CALF) increased by 10% compared with recent years, resulting in a relatively promising crop production outlook for the region, which is also confirmed by figure 4.3. 

Figure 4.9. Crop condition China Loess region, July-October 2018

(a) Crop condition development graph based on NDVI

(b) Spatial NDVI patterns compared to 5YA                 (c) NDVI profiles

(d) Maximum VCI                                                (e) Biomass