ChinaCropPhen1km: Phenological Observations for Every Crop Across China's Agricultural Belt

From above, the North China Plain looks like a quilt stitched by giants — wheat fields stretching to the horizon in golden squares, punctuated by the dark green of irrigated maize. But what no single farmer can see from the ground, a constellation of satellites has been watching for fifteen years: the slow, uneven transformation of Chinese agriculture. This dataset captures that transformation at a resolution of one square kilometer, tracking how crop yields and water productivity shifted across the world's most populous nation from 2001 to 2015.

The numbers reveal a story of unevenness. While wheat yields in the northern plains climbed steadily — driven by improved seed varieties and precision irrigation — rice paddies in the humid south told a different tale. Water productivity gains were concentrated in regions that adopted drip irrigation, leaving vast swaths of traditional flood-irrigated land behind. The dataset exposes a geographic fault line in Chinese agriculture: modernization spreading outward from infrastructure hubs while remote provinces remained locked in older patterns.

What makes this work remarkable is not just its spatial precision but its temporal depth. Fifteen years of continuous monitoring at 1km resolution creates a living atlas of agricultural change — one that captures drought years, policy shifts, and the creeping effects of urbanization swallowing farmland at the edges of megacities. For researchers studying food security in a warming world, this is not just data. It is the ground truth against which every future projection will be measured.