Elephant Grass Planting Plan at Eruption-affected Areas in Mount Merapi: Methods and Harvesting Time

Mount Merapi volcanic eruption in 2010 caused physical damages and left residences and hundreds of hectares of farm and plantation covered by volcanic ash. One of the immediate consequences was the inadequate supply of cattle fodder post-eruption. Elephant grass planting plan at eruption- affected areas was proposed to solve the problem. An experiment was arranged in a completely randomized design with two (2) factors and five (5) replications to assess the productivity and quality of elephant grass. The first factor comprised of the technique used to add volcanic ash to the soils: (1) Plowing or mixing method (volcanic ash mixed with soils), and (2) Planting the stolon at the beneath (volcanic ash at upper layer). The second factor consisted of three (3) harvesting periods i.e. harvesting time of 30, 45, and 60 days. The experiment revealed that volcanic ash exposure to the stolon during the planting time may suppress the grass growth, but the effects disappeared after 30-day growing time. This result indicates that elephant grass is suitable to be planted at the affected areas and it can be considered as an alternative for the dairy farmer even the soil surface has been transformed after the eruption. Sixty-day harvesting is the recommended time to produce high quality elephant grass. In this period, we found that volcanic ash offers some advantages as supplement to grow and develop. The elephant grass at the 60-day harvesting time will have the longest, widest, and greenest leaves, and also the tallest and biggest stem if exposed to volcanic ash only at the topsoil. Based on the observation, we can sugggest that the appropriate method to plant the stolon of elephant grass is to plant the stolon at the beneath without soil-mixing method.