Judul: Optimization of Liquid Organic Fertilizer from Animal Manure with Indigofera for Hydroponic Lettuce Productivity
Abstrak: Tanaman selada (Lactuca sativa L.) adalah sayuran hijau yang memiliki kandungan gizi cukup tinggi. Usaha peningkatan produksi selada dilakukan dengan sistem hidroponik. Harga yang tinggi pada pupuk anorganik dapat diatasi dengan penggunaan alternatif nutrisi pupuk organik. Peningkatan pupuk organik cair yang terbuat dari kotoran ayam petelur, kotoran sapi perah, dan Indigofera zollingeriana dalam penelitian ini merupakan salah satu penentu kualitas pupuk organik. Tujuan dari penelitian ini menganalisis respon pertumbuhan tanaman selada (Lactuca sativa L.) terhadap pemberian kombinasi pupuk organik cair dan mengkaji beberapa kandungan kombinasi pupuk organik cair. Analisis penelitian menggunakan rancangan acak lengkap yang terdiri dari 5 percobaan dan 3 ulangan, AB Mix 100% (A100C0), AB Mix 75% + 25% POC (A75C25), AB Mix 50% + 50% POC (A50C50), AB Mix 25% + 75% POC (A25C75), dan 100% POC (A0C100). Hasil penelitian menunjukkan bahwa perlakuan yang diberi nutrisi AB Mix dengan konsentrasi yang lebih tinggi atau sama dengan pupuk organik cair dapat mendukung pertumbuhan tanaman selada secara optimal. Kandungan unsur hara pupuk organik cair yang telah memenuhi standar yaitu nitrogen (N) dan fosfor (P). Pemberian kombinasi nutrisi A75C25 dan A50C50 rata-rata memberikan hasil yang terbaik pada seluruh parameter pertumbuhan tanaman selada. Kombinasi nutrisi pupuk organik cair memiliki unsur hara makro dan hara mikro yang lengkap, namun tergolong rendah sehingga diperlukan penambahan AB Mix sebagai pelengkap nutrisi., Lettuce (Lactuca sativa L.) Lettuce is a green vegetable with high nutritional content. Despite its low production growth, efforts to increase lettuce production are being made through hydroponic systems. The high cost of inorganic fertilizers can be mitigated by using alternative organic fertilizer nutrients. Enhancing the quality of liquid organic fertilizers made from layer chicken manure, dairy cow manure, and Indigofera zollingeriana is crucial for formulating effective organic fertilizers. This study aims to analyze the growth response of lettuce (Lactuca sativa L.) to the application of various combinations of liquid organic fertilizers and to evaluate the nutrient content of these combinations. The research design employed was a Completely Randomized Design (CRD) consisting of five treatments and three replications: 100% AB Mix (A100C0), 75% AB Mix + 25% POC (A75C25), 50% AB Mix + 50% POC (A50C50), 25% AB Mix + 75% POC (A25C75), and 100% POC (A0C100). The results showed that treatments with higher or equal concentrations of AB Mix compared to liquid organic fertilizers could optimally support lettuce growth. The nutrient content of the liquid organic fertilizers met the standards for nitrogen (N), phosphorus (P), and potassium (K). The combination of liquid organic fertilizers provided complete macro and micro nutrients, though generally in lower amounts, necessitating the addition of AB Mix to supplement the nutrients. The combinations of A75C25 (75% AB Mix + 25% POC) and A50C50 (50% AB Mix + 50% POC) yielded the best results on average across all growth parameters of lettuce.
Keyword: indigofera zollingeriana, liquid organic fertilizer, chicken manure, dairy cow manure, lettuce growth

Judul: Pemanfaatan Limbah Ternak Sebagai Pupuk Cair Organik Untuk Meningkatkan Pertumbuhan Dan Produksi Selada (Lactuca Sativa Var. Crispa)
Abstrak: The research are to determine the effect of organic liquid fertilizer derived from manure and urine of cattle, urine of sheep, urine of rabbits and combination between of manure and urine on growth, production, physical quality and freshness of lettuce (Lactuca sativa var. crispa) and to find the best organic liquid fertilizer. The experiment was conducted in the Vegetable Garden, University Farm Cikabayan Bogor Agricultural University, Dramaga, Bogor (processing of organic liquid fertilizer and planting) in December 2010 until February 2011 and Postharvest treatment in the Laboratory of Production, Department of Agronomy and Horticulture, Faculty of Agriculture, Bogor Agricultural University in March 2011. The Method of this research is Randomize Complete Block Design with one factor. The treatment are kinds of organic liquid fertilizer with three replicates. The treatments are treatment without liquid fertilizer application (just water), liquid fertilizer from urine of cattle, liquid fertilizer from urine of sheep, liquid fertilizer urine of rabbit, liquid fertilizer from manure of cattle, liquid fertilizer from combination between manure and urine of cattle, liquid fertilizer from combination between manure of cattle and urine of sheep, liquid fertilizer from combination between manure of cattle and urine of rabbit. The results indicate that the liquid fertilizer does not significantly affect the growth, production, physical quality and freshness of lettuce. This means that, each treatment gives the same effect for all parameters.
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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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