Water consumption of the crops in the northwestern Shandong plain and comparisons of lysimeter and eddy covariance technique

Water consumption (WC) law of winter wheat and summer maize rotation system in the Northwestern Shandong plain is investigated on the base of 20 years' data from the weighing lysimeter in Yucheng comprehensive experimental station of the Chinese Academy of Sciences.The results indicate that the average WC of them are 457.6 and 411.7mm,respectively.For the winter wheat,the average daily WC and the maximum are 1.97 and 6mm/d,respectively.For the summer maize,the values are 3.18 and 4.8~6.0mm,respectively.The climate changes might contribute to the reduction of the WC by summer maize.Compared to the 2 years' synchronization data,the results determined by the ed by covariance(EC) technique can commendably reveal the WC law.However,the EC technique can bring about 20% decrease systemally,and the observation technique and unusual data processing methods are expected to produce preferable results after a further improvement.