Judul: Optimasi Pupuk Nitrogen, Fosfor, dan Kalium pada Kelapa Sawit (Elaeis guineensis Jacq.) Belum Menghasilkan Umur Dua Tahun
Abstrak: Fertilization is the one of the important factors to increase the vegetative growth of the two years old of oil palm. Fertilization can increase the availability of nutrition that needed by the plant. The one type of fertilizer that can be used as an alternative to improve soil fertility is single anorganic fertilizer. The purposes of this research were (1) to study the effect of N, P, K fertilizer on two years old plant of oil palm and (2) to determine the optimum rate of N, P, K fertilizer on two years old plant of oil palm. The researchs were conducted at IPB-Cargill Teaching Farm of Oil Palm, Jonggol, Bogor from April 2014 to March 2015. This research consisted of three experiment namely: (1) optimization of nitrogen fertilizer rate, there were five levels of N fertilizer rate: 0, 316, 632, 948, 1 264 g plant-1 year-1 (2) optimization of phosphorus fertilizer rate, there were five levels of phosphorus fertilizer rate: 0, 226, 453, 679, 905 g P2O5 plant-1 year-1, and (3) optimization of pottasium fertilizer rate, there were five levels of pottasium fertilizer rate: 0, 384, 768, 1 152, 1 536 g K2O plant-1 year-1. Each experimentations consisted of single factor using randomized block design with three replications. The result showed that nitrogen fertilizer increased quadratically plant height, frond production, stem girth, and number of stomata, but nitrogen fertilizer increased linierly leaf nutrient content. The optimum rate of nitrogen was 879 g N plant-1 year-1 for two years old of oil palm. Phosphorus fertilizer increased quadratically frond production, stem girth, leaf area of 17th frond, leaf chlorophyll, number of stomata, and phosphorus fertilizer increased linierly leaf nutrient content. The optimum rate of phosphorus was 604 g P2O5 plant-1 year-1 for two years old of oil palm. Pottasium fertilizer increased quadratically frond production, stem girth, leaf area of 17th frond, and number of stomata. The optimum rate of pottasium fertilizer was 972 g K2O plant-1 year-1 for two years old of oil palm.
Keyword: nutrition, morphology, stomata, critical nutrient level

Judul: Respons Pertumbuhan Tanaman Kelapa Sawit (Elaeis guineensisJacq.) Belum Menghasilkan Umur Dua Tahun terhadap Pemupukan Kalsium.
Abstrak: Oil palm is an annual plant which can produce Fresh Fruit Bunch (FFB) economically up to age 25years, it does necessary to maintenance vegetative growth to support generative phase. Fertilizing will improve soil fertility by provides essential nutrients. The objective of this experiment was to study response of Ca fertilizer of immature oil palm in age two year. The experiment was conducted from March 2014 to February 2015 at IPB-Cargill Teaching Farm of Oil Palm, Jonggol, Bogor, West Java, Indonesia. The experiment was arranged in randomized complete block design with one factor and replicated three times. The treatments were four rates of fertilizer as followed: without Ca as a control (Ca0), 600 g Ca plant-1 (Ca1), 1 200 g Ca plant-1 (Ca2), 2 400 g Ca plant-1 (Ca3). The results showed that application of Ca fertilizer increased the growth rate of plant height, but not had significant affect on stem girth, fronds production,frond length, leaf area, and physiological parameters.
Keyword: growth rate, physiology, soil nutrient availibility

Judul: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix