Abstract:

By leaching soil column in the laboratory, vertical migration status and losses of nitrogen (N), phosphorus (P) and potassium (K) of paddy soil were studied by different amounts of fertilizer application in allusion to the fact that vegetables were fertilized too much and the nutrients lost easily in the North Beach Area of Fuxian Lake, Yunnan Province. The results showed that available N lost much mainly by vertical migration with water and the loss amount was related most positively significantly to N application amount and under no N application, N lost 381 kg per hectare from sandy loam and 85 kg per hectare from loam clay. Effective P migrated with water down shortly and with few loss, which was absorbed mainly in the fertilized soil layer (0-20 cm depth) and sediment amount in the upper soil was related most positively significantly to P application, P loss was not significantly related to P application amount and P lost 0.007-0.014 kg per hectare from sandy loam or loam clay. Vertical migration distance and amount of available K with water was related positively to K application amount and available K lost very few with 12.00-23.02 kg and 4.81-7.91 kg loss per hectare for sandy loam and loam clay, indicating that most K was absorbed by soil.