Judul: Penggunaan pupuk cair hayati  berbahan dasar sawi putih dan keong untuk meningkatkan produksi sawi putih (Brassica pekinensis (lour))
Abstrak: This research to study the eefect of Bio Fertilizer (PCH) on the productivity of chicovy (Brassica Pekiwensis (Lour). The experiment was conducted in gedepangrango Village, Kadudampit Subdirict, Sukabumi is located at an altitude of 950 m above sea level, from January to May 2011.
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Judul: Pengayaan pupuk organik dengan pupuk hayati untuk meningkatkan efisiensi penggunaan hara, pertumbuhan, dan produksi tanaman cabai, The Enrichment of Organic Fertilizer with Biofertilizer to Improve Nutrient Use Efficiency, Growth, and Yield of Red Chili).
Abstrak: Red chili production in Indonesia is low due to low soil productivity. Soil productivity can be increased by using biofertilizer. Biofertilizer can improve plant growth, yield, and soil quality. The aim of this study was to study influence of enriched compost and ordinary compost to increase nutrient use efficiency, growth, and yield of red chili. This study used biofertilizer which consisted of Bacillus subtilis (strain HU48), Pseudomonas beteli (strain ATCC1986IT), Azotobacter sp. (strain HY1141), and Azospirillum sp. (strain NS01). The experiment was conducted in the field using randomized block design (RBD) with two factors and three replications. The first factor was organic fertilizer that consisted of ordinary compost (O1), enriched compost (O2), and compost added biofertilizer when planted (O3). The second factor was inorganic fertilizer that consisted of 50% dosage of NPK and 100% dosage of NPK. The plants were grown on plots of 3 m x 3 m with a plant distance about 50 cm x 60 cm. The observed parameters were nutrient use efficiency, plant growth, and yield. The results showed that biofertilizer increased plant nutrient uttilization efficiency, plant growth, and yield by 65 %, 59%, and 126%, respectively. The combination of enriched compost and 50% dosage of NPK (O2A1) had the highest plant nutrient uttilization efficiency, plant growth, and yield than the other treatment.
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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