Judul: The Effect of Actinobacteria Consortium, Carrier Materials, and NPK Fertilizers on the Growth of Rice Plants
Abstrak: Kebutuhan akan beras mengalami peningkatan seiring dengan kenaikan jumlah penduduk, sehingga perlu dilakukan peningkatan produksi untuk menjamin ketersediaannya. Peningkatan produktivitas padi dapat dilakukan melalui pemupukan yang tepat dan berimbang. Bio-inokulan aktinobakteri yang diformulasikan dengan bahan pembawa dapat meningkatkan pertumbuhan dan perkembangan tanaman karena kemampuannya sebagai bakteri pemacu pertumbuhan tanaman. Penelitian ini bertujuan menganalisis pengaruh penggunaan bio-inokulan aktinobakteri yang diformulasi dengan bahan pembawa gambut atau zeolit, serta pupuk NPK pada pertumbuhan tanaman padi. Penelitian ini berdasarkan pada Rancangan Acak Kelompok yang terdiri dari 18 perlakuan dan tiga ulangan, yaitu berupa kombinasi antara pemberian konsorsium aktinobakteri (dilakukan dan tidak dilakukan penambahan), jenis carrier (zeolit, gambut, dan kombinasi) dan dosis pupuk NPK (0 g/pot, 0,375 g/pot, dan 0,75 g/pot). Perlakuan penambahan konsorsium aktinobakteri, kombinasi gambut-zeolit 1:3, dan pupuk NPK dosis 0,75 g/pot (A2C3P3) memberikan hasil yang konsisten dalam meningkatkan hasil rata-rata parameter vegetatif dan reproduktif tanaman padi yang diamati di rumah kaca. Perlakuan A2C3P3 memberikan pengaruh nyata pada jumlah anakan, lebar daun bendera, bobot kering akar dan tajuk padi yang diamati pada umur 10 MST dibandingkan dengan kombinasi perlakuan lainnya., The high demand for rice is due to the increasing population. Therefore it is necessary to increase rice production to ensure its availability, through proper and balanced fertilization. Actinobacterial bioinoculum formulated with carriers can enhance plant growth and development due to their ability as plant growth promoting bacteria. This study aims to analyze the effect of using actinobacterial bio-inoculants formulated with peat or zeolite carrier materials, as well as NPK fertilizer on the growth of rice plants. This study was based on a randomized block design consisting of 18 treatments and three replications, namely in the form of a combination of actinobacterial consortium administration (added and not added), type of carrier (zeolite, peat, and combination) and doses of NPK fertilizer (0 g/ pot, 0.375 g/pot, and 0.75 g/pot). The addition of actinobacteria consortium, peat-zeolite combination 1:3, and NPK fertilizer at a dose of 0.75 g/pot (A2C3P3) gave consistent results in increasing the average yield of rice vegetative and reproductive parameters observed in the greenhouse. The A2C3P3 treatment had a significant effect on the number of tillers, width of flag leaf, dry weight of roots and shoots of rice observed at 10 WAP compared to other treatment combinations.
Keyword: actinobacteria, in planta, NPK, peat, zeolite

Judul: Increased Rice Yield (Oryza sativa L.) with Application of Organic Fertilizer Enriched with Microbes
Abstrak: Produktivitas padi Indonesia beberapa tahun terakhir mengalami penurunan. Pemupukan yang sesuai dengan kondisi tanah dan kebutuhan tanaman mampu meningkatkan produksi tanaman. Aplikasi pupuk organik diperkaya dapat meningkatkan kesuburan tanah. Mikroba yang hidup di perakaran tanaman atau PGPR dalam pupuk dapat meningkatkan ketersediaan hara dalam tanah dan mensintesis hormon pertumbuhan tanaman melalui aktivitas biologisnya. Penelitian ini bertujuan untuk mempelajari pengaruh aplikasi pupuk organik diperkaya terhadap peningkatan hasil padi sawah dan pengurangan dosis pupuk anorganik. Rancangan yang digunakan adalah rancangan kelompok lengkap teracak satu faktor yaitu dosis pupuk dengan 4 ulangan. Penelitian dilaksanakan di Kebun Pendidikan Sawah Baru IPB. Analisis tanah dan analisis kandungan pupuk dilaksanakan di Laboratorium Kimia dan Kesuburan Tanah, Departemen Ilmu Tanah dan Sumber Daya Lahan, Laboratorium Pengujian Departemen Agronomi dan Hortikultura, serta Laboratorium Tanah, Tanaman, Pupuk, Air, Balai Penelitian dan Pengembangan Pertanian. Pelaksanaan penelitian dimulai pada November 2020 hingga April 2021. Pengamatan dilakukan terhadap pertumbuhan, hasil, dan komponen hasil padi sawah. Hasil penelitian ini menunjukkan aplikasi pupuk organik diperkaya secara umum tidak meningkatkan pertumbuhan dan hasil per tanaman maupun hasil per hektar padi sawah. Aplikasi pupuk organik diperkaya dapat mengurangi 25% penggunaan pupuk anorganik dengan nilai efektivitas agronomi relatif sebesar 108,8%., Rice productivity in Indonesia has decreased in recent years. Fertilization that is suitable for soil conditions and plant needs can increase crop yield. The application of bioorganic fertilizer would be able to increase soil fertility. Microbes that live in plant roots could increase the availability of nutrients in the soil and synthesize plant growth hormones through their biological activities. The research aims to study the effect of the application of organic fertilizer enriched with microbes on increasing growth, yield, and yield components of lowland rice and the reduction of the dose of inorganic fertilizer. The experimental design used was a randomized complete group design with one factor, namely the dose of fertilizer with 4 replications. The research was carried out at the Sawah Baru Teaching Farm, IPB. Soil analysis and analysis of fertilizer content were carried out at the Laboratory of Chemistry and Soil Fertility, Department of Soil Science and Land Resources, Testing Laboratory of the Department of Agronomy and Horticulture, and the Laboratory of Soil, Plants, Fertilizer, Water, Agricultural Research and Development Center. The experiment was conducted from November 2020 until April 2021. The observations made were observations of vegetative and generative characters, as well as yields. Results shows, the application of enriched organic fertilizers did not increase growth and yield per plant or yield per hectare of lowland rice. Application of enriched organic fertilizers, however, could reduce 25% of inorganic fertilizers usage with a relative agronomic effectiveness value of 108.8%.
Keyword: effectiveness, organic fertilizer, PGPR, rice, yield

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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