The staking (elevating creeping vines above the ground with poles) of yam is practiced to optimize crop yield, but its effect on soil loss due to crop harvesting (SLCH-soil adhering to harvested tubers) and its associated carbon loss has not been investigated globally. A 3-year field experiment was conducted to study the yam (Dioscorea rotundata) staking effect on SLCH and to examine the environmental effect of soil carbon loss. Staking reduced soil loss due to crop harvesting by 55.6% and increased yam yield by 33.3% when compared to un-staking. Soil carbon loss and root hair weight per tuber yield decreased by 47.7 and 58.4%, respectively, under staking compared with un-staking practices. The un-staking with higher moisture (≃42%) exported two times more soil-available nutrients (N, P, K and Ca) than staking. SLCH was also linearly related to root hair weight (R² = 0.88–0.75; p < 0.05) and moisture content (R² = 0.79–0.63; p < 0.05). The lower ratio of root hair weight to tuber yield coupled with moderate mound moisture in staking neutralized its higher tuber yield effect on SLCH by reducing soil loss and its carbon loss. Thus, yam staking mitigates soil loss and its carbon loss which can increase the sequestration potential of soil carbon stock.

Soil loss from root crop harvesting is a significant erosion process contributing to soil degradation. While organic fertilization could promote soil structure and reduce soil loss, the variation in the effectiveness of different organic fertilizers vis-a-vis inorganic fertilization remains unclear. Such understanding is critical for adequate soil management for reducing harvest-related soil loss. A two-year field-based study was carried out to compare the effect of two commonly used organic amendments and inorganic fertilizer on carrot yield and harvest-related soil loss. Treatments included a control, inorganic fertilizer, pig manure, and poultry manure; with each manure applied at a rate to supply 60 kg K ha-1. Compared to the control where the average soil loss for the two years was 1.21 t-1 ha-1 harvest -1, inorganic fertilization induced a soil loss of 2.70 t-1 ha-1 harvest -1, while 1.94 t-1 ha-1 harvest -1 and 1.87 t-1 ha-1 harvest -1 of soil was lost under poultry manure and pig manure amendments, respectively. The higher soil loss in the fertilized treatments compared to the control was attributed to the higher crop yields. However, the reduced soil loss in organic amendments compared to the inorganic fertilizer was due to more improved soil aggregation. Also, higher nutrient uptake arising from the increased yield resulted in significant loss of soil nitrogen, phosphorus, potassium, and calcium in the second year. Higher carrot yield due to fertilization is associated with higher soil removal, especially under inorganic fertilization. It is suggested that cleaning carrot roots during harvesting will ensure minimal soil loss.