Figures & data
Figure 1. Study area and soil series (LDD Citation2003).
Figure 2. Overall land management practice in the study area.
Table 1. Main management practices, rice yield, and SOC in irrigated areas (n = 24).
Table 2. Main management practices, rice yield, and SOC in rain-fed areas (n = 40).
Table 3. Comparison of the annual main management practices between irrigated and rain-fed areas (mean ± SD).
Table 4. Comparison of soil physical and chemical properties between irrigated and rain-fed areas for all soil depths (0–40 cm) (mean ± SD).
Table 5. Average values of soil physical and chemical properties at four different depths, 0–10, 10–20, 20–30, and 30–40 cm from all sites (mean ± SD).
Table 6. Correlation matrix of soil physical and chemical properties with SOC at all sites (n = 64).
Table 7. Comparison of rice yield and SOC between irrigated and rain-fed areas (mean ± SD).
Figure 3. Relationship between rice yield and SOC at all sites. The dashed line and solid line were fitted by simple linear regression for irrigated and rain-fed areas, respectively.
Figure 4. Relationship between rice yield and N, P, and K application rates: (A) irrigated areas; (B) rain-fed areas.
Figure 5. Relationship between rice yield and the period of manure application: every year, every other year, and without manure application for more than 5 years: (A) irrigated areas; (B) rain-fed areas.
Figure 6. Comparison of rice yield and SOC between irrigated and rain-fed areas under the period of manure application (men ± SD): (A) irrigated areas; (B) rain-fed areas.
Table 8. Multiple regression equations used to predict SOC and rice yield using manure (M), N fertilizer (N), P fertilizer (P), and K fertilizer (K).