Judul: Analisis Skenario Tanam dan Pemetaan Lahan Kedelai Berdasarkan Ketersediaan Air Tanah di Kabupaten Tanjung Jabung Barat
Abstrak: Availability of soil water affect the growth, development, and productivity of soybean plants. The purpose of this study were to analyze the soil water availability in Tanjung Jabung Barat Regency using SWAT, mapping suitable land, and to analyze soybean planting scenario. Soil water availability was calculated by SWAT model, and land mapping was conducted based on crop water requirement of soybean. The result of SWAT simulation showed that the soil water availability in field capacity on 155 subbasin were 5 - 352.3 mm, with the planting period 90 days. Water deficits months were August and September. Water requirement for soybean was 250-317 mm per planting scenarios. Land mapping for soybean produced 12 planting scenarios with the area of sufficient and unsufficient soil water availability. The area with sufficient soil water availability had a small surface and located in West side of Tanjung Jabung Barat Regency. The best planting scenario was scenario 11 (November – January) with the minimum water requirement of 249.7 mm.
Keyword: crop water requirement, planting scenario, soil water, soybean, SWAT

Judul: Evaluasi Skenario Waktu Tanam Kedelai dengan Metode Growing Degree Days dan Suhu Optimal di Kabupaten Tanjung Jabung Barat, Jambi
Abstrak: Tanaman kedelai ialah tanaman multiguna karena bisa digunakan sebagai pangan, pakan maupun bahan baku berbagai industri manufaktur dan olahan. Growing degree days atau hari derajat tumbuh adalah cara menghitung nilai panas setiap hari. Tujuan penelitian ini adalah untuk menentukan wilayah pertanian kedelai dan mengevaluasi skenario waktu tanam kedelai yang baik berdasarkan growing degree days dan suhu optimum. Lokasi objek penelitian yaitu di Provinsi Jambi. Prosedur analisis data yang dilakukan yaitu penentuan suhu rata-rata harian, penentuan nilai GDD akumulasi serta penentuan musim tanam. Penelitian ini menggunakan musim tanam kedelai selama 120 hari. Waktu tanam yang digunakan, yaitu Februari-Mei, Maret-Juni, dan April-Juli. Nilai akumulasi GDD yang ideal untuk tanaman kedelai yaitu 1680-1800. Daerah yang paling optimal untuk pertumbuhan kedelai adalah pada wilayah barat Kabupaten Tanjung Jabung Barat. Waktu tanam yang optimal April-Juli. Suhu rata-rata harian di Kabupaten Tanjung Jabung Barat yaitu berkisar antara 25-27⁰C.
Keyword: growing degree day, kedelai, suhu optimal, waktu tanam

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology