Judul: Development of fertilization recommendation for Nitrogen, Phosphorus, and Pottasium on pineapple (Ananas comosus (L) Merr.) smooth cayenne be based on soil nutrient status
Abstrak: Nitrogen (N), phosphorus (P), and pottasium (K) are needed in a large amounts foe plant growth and production of pineapple, however, exceed application may decrease the growth and production of pineapple. Therefore, the fertilization application must be based on soil nutrient status and plant requirements. Minus one test was conducted to prove the potential of N, P, and K nutrients as limiting factor for pineapple plant growth in Inceptisol-Darmaga, Inceptisol-Ciawi, Ultisol-Jasinga, and Andisol-Ciapus on pineapple.
Keyword: Minus one test, Nutrient status, Extraction method, Optimum dosage, Critical level, Kalibrasi uji tanah, Korelasi uji tanah, Tanah inceptisol, Tanah ultisol, Tanah andisol

Judul: The Effectiveness of Biofertilizer Dosage on the Growth of Pineapple Plants (Ananas Comosus L.Merr) in the Vegetative Phase
Abstrak: Tanaman nanas merupakan komoditas unggulan di Indonesia, produksi tertinggi berada di Provinsi Lampung. Penggunaan pupuk anorganik di Lampung sangat tinggi hal ini disebabkan karena tingkat kesuburan tanah yang rendah. Penggunaan pupuk anorganik dapat memberikan dampak buruk pada kesehatan tanah. Pupuk hayati memiliki kandungan mikroorganisme yang dapat memperbaiki kesuburan serta kesehatan tanah. Penelitian bertujuan mengetahui efektivitas dosis pupuk hayati dengan mengurangi dosis pupuk anorganik dan mengetahui pertumbuhan vegetatif tanaman nanas. Pengambilan tanah dilakukan dengan metode komposit pada sub anakan dengan tiga ulangan. Desain penelitian menggunakan RAL (Rancangan Acak Lengkap) uji lanjut DMRT 5% (software R- Studio), dan uji korelasi (Microsoft Excel 2019) dengan sembilan taraf perlakuan tiga ulangan. Sembilan taraf perlakuan tersebut adalah Sembilan taraf perlakuan tersebut adalah P0 (Pupuk kandang - kontrol), P1 (NPK 100% - standar GGP), P2 (Pupuk hayati Provibio 100% + NPK 100%), P3 (Pupuk hayati Provibio 100% + NPK 50%), P4 (Mikoriza 100% + NPK 100%), P5 (Mikoriza 100% + NPK 50%), P6 (Pupuk hayati Provibio 100% + Mikoriza 100% + NPK 50%), P7 (Pupuk hayati Provibio 75% + Mikoriza 75% + NPK 50%), P8 (Pupuk hayati Provibio 50% + Mikoriza 50% + NPK 50%). Hasil penelitian menunjukkan bahwa pemberian pupuk hayati mempengaruhi peningkatan pH, N-total, c-organik, C/N rasio, dan K- total. Total populasi mikrob terbaik pada perlakuan P5 (Mikoriza 100% + NPK 50%) dan P6 (Provibio 100% + Mikoriza 100% + NPK 50%). Sedangkan pada parameter pertumbuhan tanaman nanas, bobot basah, dan bobot kering tidak memberikan pengaruh nyata pada seluruh parameter. Pada parameter kesehatan akar termasuk dalam kategori agak sehat sampai ke sehat. Nilai korelasi tinggi didapatkan antara pH dengan total mikrob sebesar 0,649. Pemberian pupuk hayati pada penelitian ini memberikan hasil yang positif di beberapa perlakuan. Perlakuan dengan dosis pupuk hayati terbaik yang menyerupai hasil dosis standar pemupukan antara lain P5 (Mikoriza 100% + NPK 50%) dan P8 (Pupuk hayati Provibio 50% + Mikoriza 50% + NPK 50%)., Pineapple is a leading commodity in Indonesia, with the highest production in Lampung Province. The use of inorganic fertilizers in Lampung is very high, mainly due to the low fertility level of the soil. The use of inorganic fertilizers can have a negative impact on soil health. Biofertilizers contain microorganisms that can improve soil fertility and health. The research aimed to determine the effectiveness of fertilizer doses and vegetative growth of pineapple plants. Soil samples were taken using composite methods on three seedlings with three replications. The research design used a Completely Randomized Design (CRD) with ANOVA test, DMRT 5% test (R-Studio software), and correlation test (Microsoft Excel 2019) with nine levels treatment of three. Ninth levels treatment are P0 (Pupuk kandang - kontrol), P1 (NPK 100% - standar GGP), P2 (Pupuk hayati Provibio 100% + NPK 100%), P3 (Pupuk hayati Provibio 100% + NPK 50%), P4 (Mikoriza 100% + NPK 100%), P5 (Mikoriza 100% + NPK 50%), P6 (Pupuk hayati Provibio 100% + Mikoriza 100% + NPK 50%), P7 (Pupuk hayati Provibio 75% + Mikoriza 75% + NPK 50%), P8 (Pupuk hayati Provibio 50% + Mikoriza 50% + NPK 50%). The research results show that the application
Keyword: Soil fertility, Soil health, Microorganisms, PH

Judul: Pemodelan Harga Saham Menggunakan Model Lévy dan Model Black-Scholes
Abstrak: Stock may produce high profits. However, it has a high risk as well, because the stock prices fluctuate over time. Therefore, a model is required to estimate the future stock prices accurately. In this paper, Lévy model is compared to Black-Scholes model in estimating the stock price at Bank of America Corporation. As a result, it is concluded that the Black-Scholes model is more accurate than Lévy model.
Keyword: