Potato Production with Various Types and Dosages of Organic Fertilizers

Large amounts of dairy cow manure are produced in the Pangalengan dairy farming center in West Java; however, it remains underutilized because farmers lack the time to process it into organic fertilizer. As a result, farmers prefer to use chicken manure, which is readily available and easier to obtain from the market. The objective of this study was to determine the most effective type and application rate of organic fertilizer for improving potato yield. The research was carried out from November 2014 to February 2015 in Pangalengan Village, Pangalengan District, West Java. A randomized block design with two factors and three replications was employed. The first factor was the type of organic fertilizer, including cow manure, chicken manure, vermicompost, a 1:1 (v/v) mixture of cow and chicken manure, wet biogas residue, and dry biogas residue. The second factor was the fertilizer application rate, set at 10 and 15 t/ha. Each organic fertilizer treatment was analyzed for pH, moisture content, organic carbon, total nitrogen, and phosphorus and potassium levels. Before the experiment, soil samples were analyzed for macro- and micronutrient content, pH, and texture. Observations on plant growth and yield included plant height, numbers of large and medium tubers, total tuber count, tuber weight per plant, and average tuber weight. The data were analyzed using an F-test, and when significant differences were detected, a Duncan’s Multiple Range Test (DMRT) at the 5% significance level was applied. The results indicated that there was no interaction between the type and application rate of organic fertilizer for any of the observed variables. The dry biogas waste treatment produced the highest numbers of medium and large tubers, as well as the greatest tuber weight per plant and per tuber, which was attributed to its low C/N ratio (12) and low moisture content (14.9%). The treatment with 15 t/ha organic fertilizer has a higher number of large tubers (20%) than the 10 t/treatment.