Optimasi Hasil dan Mutu Nilam (Pogostemon cablin, Benth) Melalui Pemulsaan dan Pengelolaan Pemupukan di Aceh Utara

Abstract

Nilam merupakan tanaman penghasil minyak atsiri yang dibudidayakan pada lahan kering dengan mengandalkan air dari curah hujan saja. Kekurangan air merupakan penyebab turunnya produksi nilam, apalagi jika diikuti oleh kekurangan unsur hara dan pemberiannya tidak tepat. Penanggulangan kekurangan air dan pengelolaan budidaya melalui pemupukan yang sesuai kebutuhan diharapkan dapat meningkatkan pertumbuhan dan produksi nilam. Penelitian dilakukan dua tahap, percobaan pertama bertujuan untuk mempelajari respon tiga varietas nilam unggulan nasional terhadap cekaman kekeringan dengan berbagai dosis pemupukan. Dilaksanakan di rumah plastik dari bulan Juli sampai Desember 2015. Penelitian dilakukan dengan menggunakan Rancangan Acak Lengkap Faktorial dua kali ulangan. Faktor pertama adalah pemberian air kapasitas lapang (pemberian air 100%, 75%, 50% dan 25%, faktor kedua adalah varietas nilam (Lhokseumawe, Tapaktuan dan Sidikalang) dan faktor ketiga adalah dosis pemberian pupuk, 128,8 kg N/ha + 25 kg P2O5/ha + 84 kg K2O/ha + 42kg MgO/ha ; 233 kg N/ha + 196 kg P2O5 /ha + 120 kg K2O/ha + 135 kg MgO/ha dan 311 kg N/ha + 35 kg P2O5/ha + 394 kg K2O/ha + 63 kg MgO/ha. Hasil penelitian menunjukkan bahwa, semakin rendah kadar pemberian air semakin menurunkan pertumbuhan nilam, kandungan klorofil, kadar patchouli alkohol, produksi minyak dan rendemen minyak serta meningkatkan kadar prolin. Varietas Tapaktuan memiliki respon pertumbuhan dan hasil yang adaptif pada kadar air kapasitas lapang yang rendah, ditandai dengan menghasilkan tinggi tanaman, kandungan prolin, berat minyak dan rendemen minyak yang lebih tinggi. Dosis pemupukan anjuran 128,8 kg N/ha + 25 kg P2O5/ha + 84 kg K2O/ha + 42kg MgO/ha menghasilkan pertumbuhan vegetatif dan produksi terna yang lebih baik dibandingkan dosis pupuk lainnya. Terdapat interaksi yang nyata antara perlakuan kadar air kapasitas lapang, varietas nilam dan dosis pupuk terhadap tinggi tanaman, luas daun, bobot basah tanaman, bobot basah tajuk dan kandungan prolin. Penelitian kedua bertujuan untuk mempelajari pengaruh penggunaan mulsa dan cara pemberian pupuk pada nilam untuk mengurangi dampak cekaman kekeringan. Penelitian dilaksanakan dari bulan Juli – Desember 2016, dilakukan di kebun percobaan menggunakan Rancangan Petak Terpisah dalam Rancangan Acak Kelompok dengan tiga ulangan. Faktor pertama yaitu pemulsaan (tanpa mulsa , mulsa jerami padi dan mulsa plastik hitam perak). Faktor kedua yaitu cara pemberian pupuk (satu kali, dua kali dan tiga kali). Hasil penelitian menunjukkan bahwa penggunaan mulsa jerami padi menghasilkan pertumbuhan vegetatif, produksi terna dan kandungan patchouli alkohol nilam lebih tinggi, menghasilkan kandungan prolin, produksi minyak, rendemen minyak. Dosis pemupukan 128,8 kg N/ha + 25 kg P2O5/ha + 84 kg K2O/ha + 42kg MgO/ha dengan dua kali pemberian meningkatkan pertumbuhan vegetatif, produksi terna, produksi minyak dan rendemen minyak nilam, namun menghasilkan patchouli alkohol yang lebih rendah. Tidak terdapat interaksi yang nyata antara perlakuan mulsa dan cara pemberian pupuk terhadap pertumbuhan dan produksi minyak nilam.

Patchouli has been identified as one such essential oil bearing aromatic plant. This plant can be cultivated on dry land relying on water from rainfall only. Lack of water is a contributing factor to the decline in production of cultivated plants, especially if it is followed by nutrient deficiency and improper application of nutrients. Mitigation of water shortages and cultivation management through fertilization according to the needs of patchouli plants is expected to increase growth and production of patchouli plants. The study was conducted in two experiments. The first experiment aimed at studying the response of three different varieties of local superior patchouli to drought stress at various doses of fertilization. This experiment was conducted in a plastic house from July to December 2015, using Completely Randomized Design (CRD) with two replications. The first factor was the application of water under different field capacities : water-holding capacity 100%, 75%, 50% and 25%. The second factor was patchouli varieties : Lhokseumawe, Tapaktuan and Sidikalang, and the third factor was doses fertilizer, 128,8 kg N/ha + 25 kg P2O5/ha + 84 kg K2O/ha + 42kg MgO/ha ; 233 kg N/ha + 196 kg P2O5 /ha + 120 kg K2O/ha +135 kg MgO/ha, and 311 kg N/ha +35 kg P2O5/ha + 394 kg K2O/ha + 63 kg MgO/ha. The results revealed that decreasing water of supply tended to decrease vegetative growth, chlorophyll content, levels of alcohol, oil production and oil yield, but increased the levels of proline. Tapaktuan variety had better growth response and yield under low field capacities of water by higher results of plant height, proline content, oil weight and oil yield. The proper doses of fertilizer recommended 128,8 kg N/ha + 25 kg P2O5/ha + 84 kg K2O/ha + 42kg MgO/ha resulted in better vegetative growth and stem/branch production compared to other fertilizer doses. There were significant interactions between treatments applied to its plant height, leaf area, plant wet weight, crown wet weight and proline content. The second experiment aimed at evaluating the effect the application of mulch and how fertilizer is applied to patchouli in an effort to reduce the effects due to drought stress. The study was conducted in an Experimental Garden from July to December 2016 using Split Plot Design in Completely Randomized Block Design (CRBD) with three replications. The first factor was mulching (no mulch, rice straw and silver black plastic). The second factor was the application of fertilizer at different frequencies (once, twice and three times). The results showed that the application of rice straw mulch has increased the vegetative growth, stem/branch production and also it generated patchouli alcohol contents, but it decreased proline content, oil production, oil yield. Fertilizing dose 128.8 kg N/ha + 25 kg P2O5/ha + 84 kg K2O / ha + 42kg MgO / ha with application of fertilizer twice increased vegetative growth, stem/branch production, oil production and yield of patchouli oil, but produced lower level of alcohol. There was no significant interaction between mulch application and frequency of fertilizer application to the growth and production of patchouli oil.