Abstract: Under the framework of production water footprint theory, based on CROPWAT 8.0 and GIS software, we quantitatively analyzed the water footprint structure and its dynamics during the processes of maize, rice and wheat production in Liaoning Province from 1980 to 2016 and illustrated the spatial evolution of water footprint of main grain crops production in 14 cities in Liaoning Province using the data of 2000, 2005, 2010 and 2015. The results are as follows: (1) During the study period, the annual water footprint of maize, rice and wheat in Liaoning Province was about 132.00×10⁸ m³. The overall trend was fluctuating and rising, among which the green water footprint occupied a dominant position. The proportion and total water footprint of the same grain crop were obviously different in different cities, being the highest in Shenyang and the lowest in Benxi. (2) According to the characteristics of annual variation, the production water footprint of maize and rice showed a steady upward trend, while that of wheat showed a trend of inverted “U” shape. In terms of water footprint structure, the proportion of green water footprint was higher than that of blue water footprint and grey water footprint. (3) From the evolution characteristics of spatial pattern, as a whole, the water footprint of main grain crops was higher in the north than in the south, and higher in the south than in the middle, showing a decreasing trend from northeast to southwest. Therefore, the rational layout of crop planting structure can effectively improve water use efficiency and the situation of water pollution. The rational use of green water resources is the key for sustainable use of water resources.

Key words: mechanically harvested cotton, water and nitrogen regulation, seed cotton yield, fiber quality, water use efficiency, nitrogen partial factor productivity.