The rising demand for food has resulted in efforts to increase grain yield by using intensive
management practices, including increased application of water and N fertilizer[1]. However, according a
reported[2], the rise of N fertilizer input from 1950 to 1991 was about 4.3 times whereas the average yield
of cereals could only be improved by 2.7 times. Excessive irrigation and N fertilizer application rate may
result in low utilization efficiency of applied resources and lead to more soil nitrate accumulation and
leaching, therefore, cause a groundwater nitrate contamination[3].