COMBINED EFFECTS OF SUBSURFACE DRAINAGE AND ORGANIC FERTILIZER APPLICATION ON THE NUTRIENT LOSS IN COASTAL SALINE SOIL

摘要

Subsurface drainage is an effective measure to improve the soil and promote the agricultural production in coastal areas. To reveal the combined effects of subsurface drainage and organic fertilizer application on the nutrient change of the coastal saline soil, a 3-year (from 2011 to 2014) field experiment was conducted in eastern China. The treatments included the subsurface drainage combined with organic fertilization (S-OF), the subsurface drainage with inorganic fertilization (S-IF) and the control with no drainage but inorganic fertilization (CK). Results showed that S-IF significantly (^<0.05) decreased the contents of soil nutrients (total N, P, K and available N, P，K) in comparison to CK. However, compared with S-IF, S-OF signifi-cantly(^ 0.05) increased the contents of total P and K. Moreover, S-OF was detected to sharply decrease the loss rate of available N, P and K. Significant (^<0.05) increase (by 18.6%) of organic matter content was found for S-OF relative to S-IF in the last experimental year. We concluded that subsurface drainage combined with inorganic fertilization resulted in quantities of nutrient loss (total N, P, K and available N, P, K) during the 3 years, while organic instead of inorganic fertilization would contribute to a dramatic increase in total N content, and a decrease in the loss rate of available nutrients (N,PandK).