Relationships between maize yield and soil fertility and fertilization in farmers' plots in Wang Jia Catchment, Yunnan Province, Southwest China

摘要

This study was conducted from 1999 to 2002 in farmers' plots in Wang Jia Catchment, Yunnan Province, southwest China. Composite topsoil samples (0-20 cm depth) were collected and analyzed before the maize cropping seasons of 1999, 2000 and 2002. Maize yields were measured in the fields over four years (1999—2002). Correlation and linear regression analyses showed that soil sample data from 1999 and 2000 reasonably explain (R2 = 0.74, n = 20, P<0.05 and R2 = 0.33, n = 79, P < 0.001, respectively) differences in maize yields. Data from 2000 showed that soil pH, total and available N, available P and available K were significantly correlated with crop yield. Soil organic matter content was not significantly correlated. with yield, but was significantly correlated with pH, total and available N, available P and available K. Regression analysis of maize yield against manure, urea, compound fertilizer and superphosphate applications shows that only 2.4% of maize yield variance in 2001 can be related to manure and fertilizer applications, probably due to the destructive effects of a major hailstorm on 09 August 2001. However, 21.8% of maize yield variance in 2002 was coupled with variability in manure plus fertilizer applications (P < 0.001). Further regression of maize yield in 2002 with each single variable showed that 14.9% of maize yield variance was coupled with manure application rates (P < 0.001) and 10.7% with urea application (P < 0.001).