Judul: Optimization of Fertilizer Doses for Yard Long Bean  Cultivation Using Fertigation Through Drip Irrigation
Abstrak: Pemupukan harus diberikan dengan dosis yang tepat sesuai kebutuhan tanaman dan keadaan lahan yang digunakan. Pemupukan dosis yang optimum dengan penggunaan irigasi tetes diterapkan untuk meningkatkan efisiensi produksi kacang panjang. Penelitian ini bertujuan mendapatkan dosis rekomendasi pemupukan optimum bagi budidaya kacang panjang varietas Parade Tavi berdasarkan hasil analisis tanah. Penelitian dilakukan pada tanah latosol dengan kandungan hara P-tersedia 29 ppm (sedang), K-tersedia 39 ppm (sedang), 2,2% C- Organik (sedang), serta pH 5,82 (agak masam) di Kebun Percobaan Cikarawang, Institut Pertanian Bogor pada bulan Juli hingga Oktober 2022. Penelitian menggunakan rancangan kelompok lengkap teracak dengan 5 dosis pemupukan, yaitu 0%, 50%, 100%, 150%, 200% dari rekomendasi pemupukan Ferads (164,25 kg N ha-1 ; 56,16 kg P2O5 ha-1 ; dan 56,4 kg K2O ha-1 ) dan dilakukan pengulangan sebanyak 5 kali. Hasil penelitian menunjukkan tidak adanya pengaruh nyata variasi dosis pemupukan terhadap setiap parameter pengamatan. Lahan direkomendasikan untuk tidak dipupuk sama sekali dengan capaian bobot panen hingga 17,4 ton ha-1 pada periode panen 33 hari., Fertilizers must be given at the right doses according to the needs of the plants and the conditions of the land used. Optimum fertilization doses with the use of drip irrigation can be applied to increase the efficiency of yard long bean production. This study aims to obtain the optimum fertilizer recommendation doses for yard long bean var. Parade Tavi cultivation based on the results of soil analysis. This research was conducted on latosol soil with available content of available P 29 ppm (moderate), available K 39 ppm (moderate), 2.2% C-Organic (moderate), and pH 5.82 (slightly acidic) at Cikarawang Field Station, IPB University from July to October 2022. The research used a randomized complete block design with 5 doses of fertilization, 0%, 50%, 100%, 150%, 200% of Ferads fertilization recommendation (164,25 kg N ha-1 ; 56,16 kg P2O5 ha-1 ; and 56,4 kg K2O ha-1 ) and replicated 5 times. The results showed no significant effect of variations in fertilizer doses on each observation parameter. The Field was recommended not to be fertilized at all with a yield up to 17.4 ton ha-1 at 33 harvest days.
Keyword: dosis pemupukan, Ferads, irigasi tetes, Parade Tavi

Judul: Optimization of Fertilization Dose in Eggplant Cultivation using Fertigation through Drip Irrigation
Abstrak: Terung banyak dibudidayakan di Indonesia namun masih memiliki angka produktivitas nasional yang cukup rendah. Peningkatan produktivitas dapat dilakukan dengan menyediakan unsur hara secara tepat melalui analisis tanah dan irigasi tetes. Penelitian bertujuan mendapatkan dosis optimum rekomendasi pemupukan tanaman terung berdasarkan uji analisis tanah Mehlich 1. Penelitian dilakukan di lahan terbuka Kebun Percobaan Cikarawang, Institut Pertanian Bogor selama bulan Juni sampai November 2022. Penelitian ini menggunakan rancangan kelompok lengkap teracak (RKLT) dengan satu faktor yaitu perlakuan 5 dosis pemupukan (0% X, 50% X, 100% X, 150% X, dan 200% X di mana X merupakan rekomendasi dosis pupuk Ferads) dengan 5 ulangan. Pemberian pupuk N, P, dan K melalui irigasi tetes mampu meningkatkan tinggi tanaman, diameter batang, jumlah buah, dan bobot buah, serta mempercepat waktu antesis, waktu buah masak, dan growing heat summation. Dosis optimum pemupukan untuk tanaman terung varietas Yuvita F1 di tanah latosol tercapai pada taraf 137,74% dosis pada taraf P-tersedia sangat rendah (Mehlich 1) dan K-tersedia sedang (Mehlich 1). Dosis pupuk rekomendasi Ferads 100% dapat digunakan karena peningkatan dosis pupuk optimasi tidak meningkatkan produksi secara signifikan., Eggplant is widely cultivated in Indonesia but still has a relatively low national productivity. Productivity can be increased by providing the right nutrients amount through soil analysis and drip irrigation. The objective of this study was to find optimum fertilization recommendation dose for eggplant based on Mehlich 1 soil analysis test. The study was conducted on open field at Cikarawang, Experimental Farm, Bogor Agricultural University from June to November 2022. This study used a randomized complete block design (RCBD) with one factor that consisted of 5 doses of fertilization (0% X, 50% X, 100% X, 150% X, and 200% X where X is the recommended fertilizer dose from Ferads) with 5 replications. Application of N, P, and K fertilizers through drip irrigation can increased plant height, stem diameter, number of fruits, and fruit weight, as well as speed up anthesis time, fruit ripening time, and growing heat summation. The optimum dose of fertilizer for eggplant variety Yuvita F1 on latosol soil was reached at the level of 137.74% from recommended dose at very low available P (Mehlich 1) and medium available K (Mehlich 1). 100% Ferads fertilizer recommendation dose can be used because increased fertilizer optimum dose does not significantly produce higher yield.
Keyword: dosis optimum, growing heat summation, Mehlich 1, optimum rate

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