Abstract:Under the rainfall from June to October, 2018, the standard runoff plots in garden land, forest land, grassland, farmland and bare land were taken as research object, with the bare land as the control. The soil moisture contents, total nitrogen, nitrate nitrogen and ammonium nitrogen contents in different soil depth and time were studied in garden land, forest land, grass land, farmland and bare land. Through statistical analysis of field test data, the effects of rainfall on soil water and nitrogen change characteristics under different land uses were proposed. The results showed that the rainfall increased soil moisture content in garden land, forest land, grassland, farmland and bare land and accelerated soil total nitrogen, nitrate nitrogen and ammonium nitrogen hydrolysis conversion of nitrification and denitrification rate, affected the soil moisture contents, total nitrogen, nitrate nitrogen and ammonium nitrogen contents. The rainfall had significant correlations (P<0.05) with soil moisture contents, total nitrogen, nitrate nitrogen, ammonium nitrogen. Under rainfall, soil moisture content increased with the soil depth in garden land, forest land, grassland, farmland and bare land. At soil depth of 100 cm, soil moisture content was the largest, which were 30.34%, 27.67%, 24.98%, 24.03% and 21.95%, respectively. Total nitrogen contents increased first and decreased then with the increasing soil depth, and at the soil depth of 60 cm, soil total nitrogen was the largest, which were 1.02, 0.99, 0.90, 0.86 and 0.75 g/kg, respectively. Nitrate nitrogen and ammonium nitrogen contents decreased with the increasing soil depth. The nitrate nitrogen and ammonium nitrogen contents at soil depth of 100 cm were the smallest, among which the nitrate nitrogen was 9.01, 7.89, 7.25, 6.10, 5.22 mg/kg, and the ammonium nitrogen was 9.41, 9.14, 6.40, 5.38, 4.37 mg/kg, respectively. With the time, soil moisture contents decreased first, then increased, and then decreased at last, showing a positively cosine changing trend. Soil moisture contents was the largest in August, which were 22.97%, 22.01%, 19.87%, 19.03% and 17.98% respectively. Total nitrogen first increased and then decreased with time, with the largest in August, which were 1.09, 1.01, 0.94, 0.84 and 0.76 g/kg, respectively. Nitrate nitrogen and ammonium nitrogen contents reduced gradually with time. Soil nitrate nitrogen and ammonium nitrogen contents were larger in June. Soil nitrate contents were 13.40, 12.37, 11.20, 10.39, 8.67 mg/kg, ammonium nitrogen 18.89, 17.02, 14.54, 12.02, 8.36 mg/kg, respectively. The relationships between average soil moisture contents, total nitrogen, nitrate nitrogen and ammonium nitrogen contents and soil depth and time in different land uses were following as:garden > woodland > grassland > sloping land > bare land. This study could provide theoretical and technical support for soil water and fertilizer loss control and nutrient utilization in farmland.