Judul: Effectiveness Test of Mycorrhizzal Biofertilizer on Akasia (Acacia mangium Willd.) in Nursery
Abstrak: Akasia (Acacia mangium Willd.) merupakan salah satu jenis tanaman yang memiliki prioritas unggul dalam pengembangan hutan tanaman indsustri (HTI) di Indonesia, salah satunya dalam kegiatan reboisasi pada potensi kawasan hutan kurang produktif. Pemberian pupuk hayati dapat menjadi salah satu alternatif dalam memperbaiki, meningkatkan, dan mempertahankan kualitas tanah sehingga mampu menunjang pertumbuhan, hasil, serta kualitas berbagai tanaman. Penelitian ini bertujuan mengetahui pengaruh pupuk hayati mikoriza terhadap pertumbuhan tanaman akasia di nursery, menganalisis infeksi akar dan jenis spora disebabkan mikoriza, serta mengkaji pengaruh pemberian pupuk hayati mikoriza terhadap sifat kimia dan biologi tanah. Penelitian ini menggunakan rancangan acak lengkap (RAL) faktor tunggal dengan enam taraf perlakuan dan dua belas ulangan, sehingga satuan percobaan adalah 72 polybag. Perlakuan pengujian pupuk hayati berdasarkan Peraturan Menteri No. 1 Tahun 2019 antara lain kontrol (tanpa pupuk NPK dan pupuk hayati); 1 NPK; 1 pupuk hayati; 1 NPK standar + 1 pupuk hayati; 3/4 NPK + 1 pupuk hayati; serta 1/2 NPK + 1 pupuk hayati. Perlakuan kombinasi 1 NPK standar + 1 pupuk hayati memberikan hasil pertumbuhan paling baik pada parameter tinggi, jumlah daun, dan berat kering tajuk (BKT), sedangkan kombinasi 1/2 NPK + 1 pupuk hayati paling baik pada parameter diameter batang dan berat kering akar (BKA). Nilai Relative Agronomic Effectiveness (RAE) pada perlakuan 1 NPK + 1 pupuk hayati menunjukkan hasil yang paling efektif secara agronomi. Pemberian mikoriza mampu membentuk kolonisasi akar sebesar 60% dan jenis spora yang paling banyak ditemukan berasal dari jenis Acaulospora sp. dan Glomus sp. Total populasi mikroba dan respirasi tanah tertinggi terdapat pada perlakuan 1 NPK + 1 pupuk hayati. Pemberian mikoriza pada tanaman akasia menunjukkan adanya peningkatan ketersediaan fosfor tersedia dan fosfor total dalam tanah., Acacia (Acacia mangium Willd.) is one of the plant species that has a high priority in the development of industrial plantations in Indonesia. High priority in the development of industrial plantation forests in Indonesia, one of which is in reforestation activities on potential underdeveloped productive forest areas. The application of biological fertilizers can be an alternative in improving, improve and maintain soil quality so that it can support growth, yield, and quality of various plants. This study aims to determine the effect of mycorrhizal biofertilizer on acacia plant growth in the nursery, analyze root infection and spore types caused by mycorrhiza in acacia plants in the nursery, and examine the effect of mycorrhizal biofertilizers on the chemical and biological properties of soil. This study used a single-factor completely randomized design (CRD) with six levels of treatments and twelve replications, so the experimental unit was 72 polybags. Biological fertilizer testing treatment is based on Ministerial Regulation no. 1 of 2019, including control; 1 standard NPK (15-15-15); 1 biofertilizer; 1 standard NPK + 1 biofertilizer; 3/4 NPK + 1 biofertilizer; and 1/2 NPK + 1 biological fertilizer. The combination treatment of 1 standard NPK + 1 biological fertilizer gave the best growth results in the parameters of height, number of leaves, and shoot dry weight (BKT), while the combination of 1/2 NPK + 1 biological fertilizer was the best in the parameters of stem diameter and root
Keyword: root infection, microbes, relative agronomic, Regosol

Judul: Uji Efektivitas  Pupuk Hayati Fungi Mikoriza Arbuskula (FMA) pada Bibit Kelapa Sawit (Elaeis guineensis Jacq.) di Nursery
Abstrak: Kelapa sawit (Elaeis quineensis Jacq.) merupakan salah satu tanaman perkebunan penghasil minyak nabati yang menjadi komoditas unggulan di Indonesia. Pemberian pupuk hayati menjadi salah satu alternatif untuk membantu meningkatkan pertumbuhan bibit kelapa sawit. Penelitian ini bertujuan menganalisis pengaruh penggunaan pupuk hayati mikoriza terhadap pertumbuhan tanaman kelapa sawit di Nursery, menganalisis infeksi akar dan jenis spora oleh mikoriza serta mengkaji pengaruh pemberian pupuk hayati terhadap sifat biologi tanah dan kimia tanah. Penelitian menggunakan rancangan acak lengkap (RAL) faktor tunggal dengan 6 taraf perlakuan dan 10 ulangan, sehingga total satuan percobaan adalah 60 polibag. Perlakuan pengujian pupuk hayati berdasarkan Peraturan Menteri No.1 Tahun 2019 yaitu kontrol; pupuk NPK standar (15-15-15) 2,5 g; 20 g pupuk hayati; NPK standar + 20 g pupuk hayati; 3/4 NPK standar + 20 g pupuk hayati; dan 1/2 NPK standar + 20 g pupuk hayati. Perlakuan kombinasi 3/4 NPK standar + 20 g pupuk hayati memberikan hasil pertumbuhan bibit kelapa sawit paling baik pada parameter tinggi, diameter, dan jumlah daun. Nilai Relative Agronomic Effectiveness (RAE) pada perlakuan 3/4 NPK + 20 g pupuk hayati mikoriza menunjukkan hasil yang paling efektif secara agronomi dan ekonomi. Perlakuan mikoriza mampu membentuk kolonisasi pada akar sebesar 100% dan jenis spora yang paling banyak ditemukan berasal dari jenis Acaulospora dan Glomus. Pemberian pupuk hayati mikoriza berpengaruh nyata dalam meningkatkan populasin total mikrob tanah, respirasi tanah, serta adanya peningkatan ketersediaan fosfor dalam tanah., Oil palm (Elaeis quineensis Jacq.) is one of the vegetable oil-producing plantation crops that is a leading commodity in Indonesia. The application of biological fertilizers is an alternative to help improve the growth of oil palm seedlings. This study aims to analyze the effect of the use of mycorrhizal biofertilizers on the growth of oil palm plants in the Nursery, analyze root infection and spore types by mycorrhiza and examine the effect of biofertilizers on soil biological and soil chemical properties. The study used a single-factor Completely Randomized Design (CRD) with 6 treatment levels and 10 replications, so that the total experimental units were 60 polybags. Biofertilizer test treatments based on Ministerial Regulation No.1 of 2019 are control; standard NPK fertilizer (15-1515) 2,5 g; 20 g biofertilizer; standard NPK+20 g biofertilizer; 3/4 standard NPK+20 g biofertilizer; and 1/2 standard NPK+20 g biofertilizer. The combination treatment of 3/4 standard NPK+20 g biofertilizer gave the best growth results of oil palm seedlings in the parameters of height, diameter, and number of leaves. The Relative Agronomic Effectiveness (RAE) value in the 3/4 NPK+20 g mycorrhizal biofertilizer treatment showed the most effective results agronomically and economically. The mycorrhiza treatment was able to form colonization on the roots by 100% and the types of spores found were mostly from the Acaulospora and Glomus. The application of mycorrhizal biofertilizer has a significant effect in increasing the total population of soil microbes, soil respiration, and an increase in the availability of phosphorus in the soil.
Keyword: mycorrhiza, oil palm, relative agronomic, regosol

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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