Growth of four tree species managed as hedgerows in response to liming on an acid soil in West Sumatra, Indonesia.
A hedgerow intercropping (alley cropping) study was conducted for 7 years (1984-91) in West Sumatra on an acid and highly Al-saturated soil to determine growth and yield responses of tree hedgerows and upland rice and cowpea intercrops. Three tree species (Paraserianthes falcataria, Calliandra calothyrsus and Gliricidia sepium) and a no-tree control were planted at three lime rates with low annual fertilizer inputs of 20 kg P and 50 kg K ha-1. P. falcataria and C. calothyrsus grew vigorously, while G. sepium grew poorly and was replaced after four years with Flemingia macrophylla. After four years, P. falcataria yields declined due to tree mortality, probably due to intensive pruning. Prunings from all tree species were either incorporated into the soil (before cropping) or applied as mulch (during cropping). C. calothyrsus and F. macrophylla were well adapted to intensive pruning (4 to 6 times per year). G. sepium growth was especially limited by low soil Ca availability and high soil acid saturation. C. calothyrsus and F. macrophylla yields increased with liming only in the last several years of the study while P. falcataria did not respond to lime. The species can be tentatively ranked in response to lime as: G. sepium » C. calothyrsus > F. macrophylla > P. falcataria.