Judul: Vegetative growth responses to the applications of compost from biomass of seasonal plants of the same and different species and in vitro test of self-DNA effects
Abstrak: Pengembalian biomassa tanaman ke dalam tanah yang dimaksudkan untuk mempertahankan status kesuburan tanah saat ini menghadapi tantangan terkait dampak negatif Self-DNA terkait dengan penerapan kompos yang dibuat dari biomassa dari spesies tanaman yang sama pada tahap kematangan kompos tertentu. Penelitian ini bertujuan untuk mengevaluasi pengaruh aplikasi kompos yang dibuat dari biomassa spesies tanaman pangan yang sama dan berbeda dengan periode pengomposan yang berbeda terhadap pertumbuhan vegetatif padi, jagung, dan kacang panjang dan ekstrak DNA dari kompos yang diterapkan pada perkecambahan biji oadi, jagung dan kacang panjang. Percobaan menggunakan RAL dengan 10 perlakuan [kontrol, k (bahan kompos): biomassa padi (P), jagung (J), dan kacang panjang (K), dan waktu pengomposan: 0, 30, dan 90 hari]. DNA diisolasi dengan metode CTAB yang dimodifikasi. Hasil penelitian menunjukkan bahwa aplikasi kompos matang mendukung pertumbuhan vegetatif tanaman uji, sedangkan perlakuan kP30 dan kJ30, masing-masing untuk aplikasi biomassa padi dan jagung kompos 30 hari, menunjukkan efek penghambatan terhadap pertumbuhan vegetatif spesies yang sama (kompos padi atau jagung yang diterapkan pada tanaman padi atau jagung). Namun, efek penghambatan Self-DNA secara in vitro tidak konsisten sehingga dianggap tidak terjadi dalam percobaan ini, Returning-back unharvested crop biomass into soil which is intended to maintain soil fertility status is now facing a challenge concerning self-DNA negative impacts related to the application of compost prepared from biomass of the same crop species at certain compost maturity stage. This study aimed at to evaluate the application effects of composts prepared from biomass of the same and different food crop species with different composting periods on the vegetative growth of rice, maize, and string beans and of DNA extracts from the applied composts on seed germination of the studied crops. The experiment applied CRD with 10 treatments [control, k (compost materials): rice (P), maize (J), and string beans (K) biomass, and composting periods: 0, 30, and 90 d]. DNA was isolated by the modified CTAB method. The results showed that application of mature compost supported the vegetative growth of the test crops, while kP30 and kJ30 treatments, stands respectively for the application of 30 days-composted rice and maize biomass, showed inhibitory effect to the vegetative growth of the same species (rice or maize compost applied to rice or maize cropping). However, in vitro self-DNA inhibition effect was inconsistent and therefore considered not occurred in this experiment.
Keyword: agronomic performance, growth inhibitory effect, in vitro seed germination, seasonal crops

Judul: Application of PGPR (Plant Growth Promoting Rhizobacteria) and Membrane Bionanomaterials on Rice Germination as Agroforestry Opportunities in Peatlands
Abstrak: Laju degradasi lahan gambut di Indonesia yang semakin tinggi mengakibatkan produktivitas lahan semakin menurun. Hal tersebut berdampak pada pentingnya upaya optimalisasi lahan, salah satunya melalui pengembangan sistem agroforestri, serta pemilihan jenis tanaman adaptif. Padi Dendang merupakan salah satu varietas padi adaptif di lahan gambut. Penelitian ini bertujuan menganalisis sifat tanah gambut yang dimanfaatkan untuk agroforestri, dan pengaruhnya terhadap perkecambahan padi Dendang dengan aplikasi PGPR serta membran bionanomaterials melalui uji in vitro dan in vivo. Analisis data yang digunakan adalah RAL faktorial dua faktor, yakni satu dosis PGPR, dan bionanomaterials (BNMs) yaitu tandan kosong kelapa sawit aktivasi (TA) dan non-aktivasi (TN), serta batang kelapa sawit non-aktivasi (BN) dan lignoselulosa (BL) dengan masing-masing 3 konsentrasi (1%, 3%, dan 5%). Hasil penelitian menunjukkan bahwa pH tanah gambut sangat masam (3,60). Aplikasi PGPR dan BNMs mampu meningkatkan pH, N, P, K, Na, Ca, Mg, dan menurunkan kandungan Al. Pada uji in vitro, aplikasi PGPR berpengaruh nyata terhadap persen hidup, sedangkan BNMs berpengaruh sangat nyata pada kecambah normal dan abnormal, persen hidup, serta tinggi kecambah. Pada uji in vivo PGPR berpengaruh sangat nyata terhadap persen hidup benih dan tinggi kecambah, sedangkan BNMs berpengaruh sangat nyata terhadap daya kecambah dan potensi tumbuh maksimum., The rate of peatland degradation in Indonesia is getting higher, resulting in lower land productivity. This has an impact on the importance of land optimization efforts, one of which is through the development of agroforestry systems, as well as the selection of adaptive plant species. Dendang rice is one of the adaptive rice varieties in peatlands. This study aims to analyze the properties of peat soil used for agroforestry, and its effect on the germination of Dendang rice with the application of PGPR and membrane bionanomaterials in vitro and in vivo tests. The data analysis used was two-factor factorial RAL, namely one dose of PGPR, and bionanomaterials (BNMs) of namely activated (TA) and non-activated (TN) oil palm empty bunches, and non-activated oil palm trunks (BN). and lignocellulose (BL) with 3 concentrations (1%, 3%, and 5%), respectively. The results showed that the pH of the peat soil was very acidic (3.60). The application of PGPR and BNMs was able to increase pH, N, P, K, Na, Ca, Mg, and decrease Al content. In the in vitro test, PGPR application had a significant effect on the survival rate, while BNMs had a very significant effect on normal and abnormal sprouts, percent survival, and sprout height. In the in vivo test, PGPR had a very significant effect on the percentage of seed survival and germination height, while BNMs had a very significant effect on germination and maximum growth potential.
Keyword: membrane bionanomaterials, peat soil, paddy Dendang, PGPR, germination

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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