PENINGKATAN PRODUKTIVITAS BEBERAPA VARIETAS LOKAL UBI JALAR (Ipomoea batatas L.) DENGAN PENGUNAAN PUPUK ORGANIK ALAMI DAN PUPUK BUATAN (N, P DAN K)

Abstrak

The emergence of food crises that strike down the world today requires us to develop foodstuffs alternative. One important alternative food ingredient in diversification program is the sweet potato. Currently the productivity of sweet potato in Indonesia is still very low at between 8.5 to 10 ton / ha while the potential harvest could reach between 25-35 tons / ha. The low yield is due to the cultivation techniques applied in the farm level which is still not good, especially in the use of varieties and crop fertilization. One effort that can make it increase the productivity through fertilization is with the use of organic fertilizer by utilizing residual rice harvest and also fertilizers (N, P and K). This study aims are to determine: (1) The varieties of local sweet potato  which has high productivity, (2) The optimum dose of organic and artificial fertilizer (N, P, K) which provide the most production of sweet potato. The experiment was conducted at Kebun Percobaan Badan Pengkajian Teknologi Pertanian (BPTP), West Kalimantan Province at Desa Pal  IX of Kubu Raya Regency The study was conducted from July 2013 to November 2013. The research using a randomized block design (RAK) with factorial pattern (Factorial Design). The first factor in the form of local varieties which consists of three levels, namely: v1: ubi jalar keribang varieties, v2: ubi jalar edan varieties and v3: ubi jalar telor varieties. The second factor dose combination of organic fertilizer and artificial fertilizer (N, P, and K), which consists of four levels, namely: p1: 72 g of urea, 20 g SP36, 85 g of KCl, p2: 54 g of urea, 15 g SP36, 64 g KCl and 4.500 grams of composted straw, p3: 36 g of urea, 10 g SP36, 42.5 g KCl and 4,500 g straw compost, p4: 18 g of urea, 5 g SP36, 21.25 g of KCl and 4,500 g straw compost. The   results revealed that the growth and the best sweet potato production is obtained using ubi jalar telor  varieties  in accordance with the recommendation without the use of organic fertilizer. Composting straw doses of 20 ton / ha has not been able to increase the growth and production of sweet potato significantly.