Barley biomass and grain yield and canola seed yield response to land application of wood ash

Wood ash is considered a waste product that accumulates from the burning of wood waste for energy production. Field studies were conducted on acidic Boralf and Entrochrept soils and in the greenhouse using material from the surface of these soils in randomized complete block designs to evaluate the effectiveness of wood ash as a liming material for improving crop production. For the greenhouse study, soil was treated with the equivalent of 0 to 200 t ha(-1) (w/w) wood ash. Barley (Hordeum vulgare L.) yielded up to 50% more dry matter in this study. Based on these findings, a 3-yr field study was done to determine the effect of single applications of 6, 12.5, and 25 t ha(-1) wood ash to Boralf soils in central Alberta. Significant increases in barley dry matter and grain yield and oil seed yields of canola (Brassica rapa L.) were observed when soil was supplemented with 12.5 or 25 t ha(-1) along with N fertilizer. Increases of 72 and 50% in barley dry matter and grain yield were observed while canola oilseed yield increased 124% due to wood ash application. Applications up to 25 t ha(-1) did not have a deleterious effect on biomass or seed production in barley or canola crops. Results show that land application of wood ash increased pH and nutrient content of acid soils while having a beneficial effect on crop production. Land application of wood ash can provide timber companies with a viable alternative to landfill disposal.