Judul: Growth and Yield Response of Kangkong (Ipomoea reptans Poir) to the Aplications of Kascing, Bioboost, and Their Residues, Growth and Yield Response of Kangkong (Ipomoea reptans Poir) to the Aplications of Kascing, Bioboost, and Their Residues
Abstrak: Penelitian ini bertujuan untuk mengetahui respon pertumbuhan dan hasil kangkung terhadap pemupukan kascing dan bioboost beserta residu keduanya. Penelitian ini menggunakan Rancangan Kelompok Lengkap Teracak Faktorial. Faktor pertama adalah pemupukan kascing (K) dan residunya (RK), yaitu tanpa kascing (K0 dan RK0), kascing 300 g per lubang tanam (K1 dan RK1), dan kascing 450 g per lubang tanam (K2 dan RK2). Faktor kedua adalah pemupukan bioboost (B) dan residunya (RB), yaitu tanpa bioboost (B0 dan RB0), 2 l /ha (B1 dan RB1), 4 l/ha (B2 dan RB2), dan 6l/ha (B3 dan RB3). Kedua faktor diuji terhadap kontrol negatif (tanpa pemupukan) dan kontrol positif (pemupukan anorganik susulan) setiap perlakuan diulang sebanyak tiga kali sehingga seluruhnya terdapat 39 satuan percobaan dengan luas masing-masing petakan 1,5 m2. Penanaman dilakukan sebanyak dua kali. Penanaman kedua dimaksudkan untuk mengamati residual effect kedua faktor. Hasil penelitian ini menunjukkan kangkung terbaik terdapat pada interaksi 450 g kascing per lubang tanam dan 6 liter bioboost per hektar dengan potensi hasil mencapai 23,67 ton per hektar pada penanaman pertama dan 17,73 ton per hektar pada penanaman kedua yang memanfaatkan residu pemberian kascing dan bioboost sehingga tidak perlu melakukan pemupukan pada penanaman kedua., This study aims to determine the growth response and yield of kangkong to vermicompost and bioboost fertilization and their residues. This study used a Factorial Randomized Complete Group Design. The first factor was fertilization with vermicompost (K) and its residue (RK), ie without vermicompost (K0 and RK0), 300 g vermicompost per planting hole (K1 and RK1), and 450 g vermicompost per planting hole (K2 and RK2). The second factor was fertilization with bioboost (B) and residue (RB), namely without bioboost (B0 and RB0), 2 l/ha (B1 and RB1), 4 l/ha (B2 and RB2), and 6 l/ha (B3 and RB2). RB3). Both factors were tested against negative control (without fertilization) and positive control (follow-up inorganic fertilization). Each treatment was repeated three times so that in total there were 39 experimental units with an area of 1,5 m2 each. Planting was carried out twice. The second planting is intended to observe the residual effect of the two factors. The results of this study showed that the best kangkong was found in the interaction of 450 g of vermicompost per planting hole and 6 liters of bioboost per hectare with a potential yield of 23, 67 tonnes per hectare in the first planting and 17,73 tonnes per hectare in the second planting using residues of vermicompost and bioboost so there is no need to fertilize the second planting.
Keyword: dose, inorganic, mandailing natal, organic, yield potential, anorganik, dosis, mandailing natal, organik, potensi hasil

Judul: Growth and Yield Response of Lettuce Plants (Lactuca sativa L.) to the Application of Vermicompost Fertilizer and Rabbit Biourine with Different Concentrations
Abstrak: Penggunaan pupuk anorganik pada tanaman selada memiliki banyak kekurangan salah satunya dapat merusak tanah. Oleh karenanya, diperlukan pengurangan pupuk anorganik yang disubtitusi dengan pupuk organik namun tetap memberikan hasil terbaik. Penelitian ini bertujuan mengetahui respon pemberian pupuk organik yaitu kascing dan biourin kelinci terhadap pertumbuhan dan hasil tanaman selada. Penelitian menggunakan Rancangan Kelompok Teracak (RKLT) faktorial. Faktor pertama adalah pupuk kascing (K), yaitu tanpa kascing (K0) dan dengan kascing (K1). Faktor kedua adalah konsentrasi biourin kelinci, yaitu 0% (U0), 6% (U1), 9% (U2) dan 12% (U3). Kedua faktor diuji dengan dua kontrol, yaitu tanpa pupuk susulan (kontrol-) dan dengan pupuk anorganik (kontrol+). Hasilnya menunjukkan perlakuan kascing berpengaruh nyata terhadap seluruh peubah kecuali kadar air, perlakuan biourin kelinci hanya bepengaruh nyata pada bobot akar, dan interaksi antara kascing dan biourin berpengaruh nyata pada tinggi tanaman 2 MST dan kadar air., Inorganic fertilizer has deficiency that can damage soil so that solution is needed to reduce the use inorganic fertilizers with organic fertilizers. This study aims to see the response organic fertilizers, namely vermicompost and rabbit biourine to the growth and yield of lettuce. The study used factorial Randomized Complete Block Design (RCBD). The first factor is treatment of vermicompost (K), namely without kascing (K0) and with kascing (K1). The second factor is concentrations rabbit biourin, namely 0% (U0), 6% (U1), 9% (U2) and 12% (U3). Both factors were tested with two controls, namely without fertilizer (control -) and with NPK inorganic fertilizer (control+). The results showed that treatment of vermicompost was significantly different from all variable except moisture content, while treatment of biourine rabbits was significantly different only on the weight of roots. The interaction between vermicompost and rabbit biourin was significantly different on height 2 WAP and root weight of lettuce.
Keyword: inorganic, lettuce, organic, rabbit biourine, vermicompost

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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