Impact of Forage Fertilization with Urea and Composted Cattle Manure on Soil Fertility in Sandy Soils of South-Central Vietnam

Figure 1

Postexperiment pH least squares means for composted manure rates in the 0 to 15 cm ((a), ) and 15 to 25 cm strata ((b), ) and soil organic matter (OM) least square means for compost treatments in the 0 to 15 cm stratum ((c), ) and urea treatments in the 15 to 25 cm stratum ((d), ). pH models contained preexperiment soil pH and OM models contained preexperiment OM (Table 10). Error bars are ±1 SE of the mean. Bars connected by the same letter are not significantly different ( ≤ 0.05).

(a) 0 to 15 cm

(b) 15 to 25 cm

(c) 0 to 15 cm

(d) 15 to 25 cm