Yang, XiaolinSui, PengChen, YuanquanGao, Wangsheng2014-09-042014-09-042014-09-03https://hdl.handle.net/1813/37320These data include measured precipitation, measured pan evaporation, planting and harvest dates and measured soil moisture contents of 0-180 cm soil profile at approximately 10-day intervals, annual groundwater table data from 2003 to 2013 by China Agricultural University in cooperation with Luancheng Agro-Ecosystem Experimental Station of Chinese Academy of Sciences.(Related journal paper prepared in cooperation with Cornell University, BEE Soil and Water Lab. Paper abstract follows.) Water tables are dropping by approximately one meter annually throughout the North China Plain mainly due to water withdrawals for irrigating winter wheat year after year. In order to examine whether the drawdown can be reduced we calculate the net water use for an 11 year field experiments from 2003 to 2013 where six irrigated crops (winter wheat, summer maize, cotton, peanuts, sweet potato, ryegrass) were grown in different crop rotations in the North China Plain. As part of this experiment moisture contents were measured each at 20 cm intervals in the top 1.8 m. Recharge and net water use were calculated based on these moisture measurement. Results showed that winter wheat and ryegrass had the least recharge with an average of 27mm/year and 39 mm/year, respectively; cotton had the most recharge with an average of 211 mm/year) followed by peanuts with 118 mm/year, sweet potato with 76 mm/year, and summer maize with 44 mm/year. Recharge depended on the amount of irrigation water pumped from the aquifer and therefore a poor indicators of future groundwater decline. Instead net water use (recharge minus irrigation) was found to be good indicator for the decline of the water table. The smallest amount of net (ground water) used was cotton with an average of 14 mm/year, followed by peanut with 32 mm/year, summer maize with 71 mm/year, sweet potato with 74 mm/year. Winter wheat and ryegrass had the greatest net water use with the average of 198 mm/year and 111 mm/year, respectively. Our calculations showed that any single crop would use less water than the prevalent winter maize summer wheat rotation. This growing one crop instead of two will reduce the decline of groundwater and in some rain rich years increase the ground water level, but will result in less income for the farmers.enrechargeevapotranspirationnet groundwater useNorth China Plaindataset