2021 Volume 65 Issue 2 Pages 59-67
This study aimed to develop sustainable practices for upland root crop production to resolve the issues of food security and environmental degradation in Palau. Studying the effects of slope and cropping design (taro on a horizontal ridge and sweet potato in a square-shaped bed) on soil erosion revealed that the square-shaped sweet potato bed significantly increased soil erosion when compared to taro planting on a horizontal ridge. A medium slope (9.0°–11.0°) significantly increased soil erosion compared to the low slope (6.5°–8.5°). Next, the effects of tillage (minimum tillage with auger or trencher versus conventional tiller [control]) and mulching (no mulch versus yard long beans/sweet potato living mulch versus betel nut leaf mulch) on soil erosion and upland taro production were investigated. Taro corm yield was significantly higher in auger and trencher with betel nut leaf mulch at 1.96 t ha-1 and 1.76 t ha-1, respectively, versus the control (0.55 t ha-1). The highest significant average single corm weight (256.35 g) was measured in the auger with betel nut leaf mulch. Eroded soil in minimum tillage was 5.1–11.3 times lower than that of the control. Considering the increased yield and reduced soil erosion, minimum tillage using a handy auger with betel nut leaf mulch can be recommended as a proper practice for upland taro production in Palau.
