Analisis Serapan Hara pada Tembakau Burley - A.S. Murdiyati (Buletin Tanaman Tembakau, Serat & Minyak Industri, 2010)
Penelitian ini dilakukan untuk mengetahui pola serapan hara dan tingkat efisiensi dosis pemupukan N pada tembakau burley. Penelitian ini terdiri atas dua unit percobaan, yaitu: (1) Percobaan di rumah kaca, meng-gunakan varietas Ky 17 ditanam pada 100 pot dengan dosis pemupukan standar. Pengamatan secara perio-dik meliputi kadar N, P, K, Mg, dan berat kering daun, batang, akar, dan total; (2) Percobaan lapangan dila-kukan di Lumajang pada tipe tanah Entisol, dengan rancangan acak kelompok dengan tiga ulangan. Perla-kuan adalah dosis pemupukan N, yaitu 0, 75, 150, 225, dan 300 kg N/ha. Pengamatan meliputi: akumulasi bahan kering, serapan N, P, K, dan Mg total; hasil kerosok, indeks mutu, dan indeks tanaman. Hasil peneliti-an menunjukkan bahwa tembakau burley mulai memasuki pertumbuhan cepat pada 5 minggu setelah ta-nam, sejalan dengan peningkatan akumulasi bahan kering, N, P, K, dan Mg. Semakin tinggi dosis N, efisiensi pemupukan semakin menurun. Efisiensi serapan N tertinggi (51,56%) diperoleh pada dosis 150 kg N/ha, yang memberikan hasil kerosok 1,77 ton/ha; indeks mutu 59,55; dan indeks tanaman 105,51. Serapan P to-tal 14,26 kg/ha; 36,56% dari pupuk yang diberikan. Serapan K total 140,98 kg K/ha, 53,00% berasal dari K tanah, dan serapan Mg total 54,43 kg Mg/ha. Two experiments were conducted to study nutrient absorption pattern and efficiency of nitrogen utilization of burley tobacco. The first was conducted in screen house. Burley tobacco variety Ky 17 was planted in 100 pots with based recommended fertilization. The data of N, P, K, and Mg concentration and dry matter accu-mulation of leaf, stalk, root, and total were periodically collected. The second experiment was conducted in Pasirian, Lumajang, on Entisol soil, using randomized block design with three replications. The rate of 0, 75, 150, 225, and 300 kg N/ha were applied. The observation parameters were total dry matter, N, P, K, and Mg accumulation; yield, grade index, and crops index. Results showed rapid growth rate of burley tobacco began on 5 weeks after transplanting, related to rapid nutrient accumulation rate. Higher N rate resulted in lower efficiency of N fertilization. The highest N fertilizer absorption efficiency (51.56%) was achieved at 150 kg N/ha that produced 1.77 ton/ha dried leaves, grade index 59.55, and crops index 105.51. Absorption of total P was 14.26 kg/ha or equivalent to 36.56% of P fertilization. Total K absorbed was 140.98 kg K/ha, 53% from the soil, and total Mg absorbed was 54.43 kg Mg/ha.