Observed Climatic Variations in the Growing Season of Field Crops in Northeast China from 1992 to 2012

To determine the potential effects of climate change on crop phenological development and productivity, an integrated analysis was conducted based on the observed climatic and phenological records of Northeast China from 1992 to 2012. A set of quality assurance procedures, including repeated record checks, agro-meteorological station selection, internal consistency checks, temporal outlier checks, spatial outlier checks, and interpolation of missing data, were designed and applied to the phenology datasets of spring maize and paddy rice. Our results indicated that almost all phenological dates of spring maize and paddy rice became increasingly delayed from 1992 to 2012. The duration of the growing season was prolonged, particularly for the grain-filling stage (GS3). The prolonged growing season was beneficial to productivity. For spring maize, the average precipitation during GS3 decreased at a rate of 27.46 mm/decade, and the annual accumulated temperature over 10°C increased at a rate of 31.07°C/decade. Farmers initiatively adjusted crop cultivars and selected drought-resistant crops to cope with the challenges of drought.