Judul: APPLICATION OF BROMELAIN EXTRACTION WASTE AND CHOPPED BAMBOO TO IMPROVE SOIL CHEMICAL PROPERTIES AND PINEAPPLE VEGETATIVE GROWTH IN ULTISOL OF CENTRAL LAMPUNG
Abstrak: Pengelolaan secara intensif, terus-menerus, dan dalam jangka waktu lama pada lahan perkebunan nanas (Ananas comosus L. Merr) PT. Great Giant Pineapple, Lampung Tengah telah menyebabkan degradasi kesuburan tanah. Ameliorasi menggunakan berbagai jenis limbah organik telah dilakukan, namun kadar bahan organik tanah belum meningkat secara signifikan karena waktu dekomposisi atau residence time bahan amelioran yang diberikan lebih cepat daripada umur pertanaman nanas. Penelitian ini bertujuan mengevaluasi pengaruh dan menentukan dosis rekomendasi aplikasi limbah ekstraksi bromelin atau bambu cacah terhadap perbaikan sifat kimia tanah dan pertumbuhan vegetatif nanas pada umur tanaman 13 bulan setelah tanam (BST). Penelitian ini merupakan lanjutan dari penelitian sebelumnya dengan peubah pengamatan yang sama tetapi dilakukan pada umur tanaman 6 BST (Azhar 2023). Percobaan dilakukan dengan Rancangan Acak Kelompok (RAK) satu faktor 10 perlakuan, yaitu aplikasi limbah ekstraksi bromelin (LEB) atau bambu cacah masing-masing dengan dosis 0, 20, 40, 60, dan 80 ton ha-1 dengan 4 ulangan. Hasil penelitian menunjukkan aplikasi 20 ton ha-1 LEB efektif menurunkan kejenuhan Al, Al-dd dan H-dd, 40 ton ha-1 secara nyata menghasilkan pertumbuhan vegetatif tanaman tertinggi, dan 80 ton ha-1 efektif meningkatkan pH, Ca-dd dan Mg-dd, sedangkan peningkatan tertinggi kadar C-organik dan N-total tanah diperoleh dari aplikasi 80 ton ha-1 bambu cacah., Intensive land management practiced continuously for a long-term in the pineapple (Ananas comosus L. Merr.) plantation of PT. Great Giant Pineapple, Central Lampung has caused soil fertility degradation. Amelioration using diverse organic wastes has been done, but soil organic matter content has not been improved significantly because residence time of the ameliorant was faster than the pineapple growing age. This study aimed to evaluate the effects of and determine the recommended dose of bromelain extraction waste or chopped bamboo application on soil chemical properties and pineapple vegetative growth at 13 Month After Plant (MAP). This research was a continuation of the previous one with the same observational variables but conducted at 6 MAP (Azhar 2023). The experiment applied an RBD 1 factor with 10 treatments, namely bromelain extraction waste (BEW) or chopped bamboo application of respectively 0, 20, 40, 60, and 80 ton ha-1 with 4 replications. Application of BEW at 20 ton ha-1 significantly decreased soil Al-saturation, exch.Al, and exch.H; 40 ton ha-1 resulted in the highest crop vegetative growth; and 80 ton ha-1 increased soil pH, exch.Ca, and exch.Mg. The highest increase in soil organic-C and total N were obtained at 80 ton ha-1 chopped bamboo application.
Keyword: ameliration, Ananas comosus, organic waste, recidence time

Judul: Improvement of Soil Chemical Properties and Pineapple Plant Growth by Ultilizing Bromelain Waste Fiber and Chopped Bamboo
Abstrak: Permasalahan yang dihadapi oleh PT Great Giant Pineapple pada lahan 88C2 dalam budidaya nanas adalah terjadinya pemadatan tanah (soil compaction) dan rendahnya sifat kimia tanah. Limbah ekstraksi bromelain dan cacahan bambu merupakan bahan organik yang mengandung lignin tinggi sehingga diharapkan akan mempunyai residence time yang lebih panjang. Bahan ini diharapkan dapat memberikan pengaruh terhadap kimia tanah di lapangan sehingga dapat meningkatkan pertumbuhan akar nanas yang selanjutnya dapat meningkatkan produksi nanas. Penelitian ini merupakan percobaan faktorial dua faktor (petak utama) yang ditempatkan dalam rancangan petak terpisah (split plot). Faktor pertama jenis bahan organik organik terdiri dari dua taraf: limbah ekstraksi ekstraksi bromelain dan bambu cacah, merupakan petak utama, faktor kedua dosis bahan organik terdiri dari lima taraf: 0, 20, 40, 60, dan 80 ton ha-1 dan merupakan anak petak. Data diolah dengan menggunakan aplikasi minitab dan parameter yang berpengaruh nyata diolah lebih lanjut dengan Duncan Multiple Range Test (DMRT.) Parameter yang diamati adalah sifat kimia tanah, kadar hara tanaman, dan pertumbuhan vegetatif tanaman. Hasil percobaan menunjukkan bahwa kondisi kesuburan tanah awal rendah. Setelah aplikasi, bahan organik berpengaruh nyata terhadap pH H2O, C-Organik, Fe tersedia, Zn tersedia, Al-dd dan KTK, sedangkan dosis bahan organik berpengaruh nyata terhadap P tersedia. Bahan organik berpengaruh nyata terhadap kadar hara P, namun tingkat kecukupan hara N dan Ca masih rendah. Jenis bahan organik berpengaruh nyata terhadap lebar daun dan indeks tanaman. Dosis bahan organik berpengaruh nyata terhadap lebar daun dan indeks tanaman., The problem faced by PT Great Giant Pineapple's in 88C2 land in pineapple cultivation is soil compaction and low soil chemical properties. Bromelain extraction waste and chopped bamboo are organic materials that contain high lignin so they are expected to have a longer residence time. This material is expected to have an influence on improving the chemical properties of the soil in the field so that it can increase the growth of pineapple root which can further increase pineapple production. This study is a two-factor factorial experiment (main plot) placed in a split plot design. The first factor of the type of organic organic matter consists of two levels: bromelain extraction waste fiber and chopped bamboo, is the main plot, the second factor is the dose of organic matter consists of five levels: 0, 20, 40, 60, and 80 tons of ha-1 and is a child plot. The data was processed with variance analysis and the parameters of real effect were further processed with the Duncan Multiple Range Test (DMRT.) The observed parameters are the chemical properties of the soil, the nutrient content of plants, and the vegetative growth of plants. The results of the experiment showed that the conditions of early soil fertility were low. After application, organic matter has a marked effect on pH H2O, C-Organic, Fe available, Zn available, exchangeable Al and KTK, while the dose of organic matter has a noticeable effect on P available. Organic matter has a significant effect on P nutrient levels, but the level of adequacy of N and Ca nutrients is still low. This type of organic matter has a noticeable effect on the width of the
Keyword: Pineapple, Bromelain, Bamboo

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.
Keyword: