OPTIMASI DOSIS PEMUPUKAN PADI SAWAH (Oryza sativa L.) VARIETAS IPB 13S

Abstract

Peningkatan produktivitas padi memerlukan pengelolaan pemupukan yang sesuai dengan kebutuhan tanaman dan kondisi lingkungan. Penelitian ini bertujuan memperoleh dosis pemupukan optimum untuk pertumbuhan dan hasil padi sawah varietas IPB 13S sebagai dasar penyusunan rekomendasi pemupukan padi varietas IPB. Penelitian dilaksanakan pada September 2025–Januari 2026 di Kebun Pendidikan Sawah Baru IPB University, Bogor, menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) satu faktor dengan enam taraf perlakuan dan tiga ulangan, yaitu P0 (kontrol), P1 (50%), P2 (100%), P3 (150%), P4 (200%) dosis rekomendasi pupuk majemuk NPK 15-15-15 (175 kg ha-1) dan urea (250 kg ha-1), serta P5 (pupuk tunggal sesuai dosis rekomendasi yaitu urea 300 kg ha-1, SP-36 dan KCI 50 kg ha-1). Peubah yang diamati meliputi pertumbuhan, komponen hasil, dan hasil panen. Hasil penelitian menunjukkan bahwa perlakuan dosis pemupukan berpengaruh nyata terhadap tinggi tanaman umur 5 dan 6 MST, jumlah anakan umur 5 dan 8 MST, panjang daun bendera, panjang malai, dan jumlah gabah per malai, serta berpengaruh sangat nyata terhadap bobot 1000 butir, bobot gabah per petak, dan proyeksi produktivitas. Perlakuan P4 menghasilkan bobot gabah per petak tertinggi sebesar 4,40 kg dan proyeksi produktivitas sebesar 6,11 ton ha?¹. Namun, peningkatan dosis di atas dosis rekomendasi belum memberikan peningkatan hasil yang berbeda nyata dibandingkan P2, sehingga dosis rekomendasi telah mampu memberikan respons pertumbuhan dan hasil yang baik pada varietas IPB 13S dalam kondisi penelitian.

Increasing rice productivity requires fertilizer management that is appropriate to crop requirements and environmental conditions. This study aimed to obtain an optimum fertilizer rate for the growth and yield of lowland rice variety IPB 13S as a basis for developing fertilizer recommendations for IPB rice varieties. The experiment was conducted from September 2025 to January 2026 at the Sawah Baru Educational Field, IPB University, Bogor, using a randomized complete block design (RCBD) with one factor consisting of six treatment levels and three replications, namely P0 (control), P1 (50%), P2 (100%), P3 (150%), and P4 (200%) of the recommended rates of compound NPK 15-15-15 fertilizer (175 kg ha?¹) and urea (250 kg ha?¹), and P5 (single fertilizers at the recommended rates, namely urea 300 kg ha?¹, SP-36 and KCl 50 kg ha?¹). The observed variables included growth, yield components, and grain yield. The results showed that fertilizer rates significantly affected plant height at 5 and 6 weeks after transplanting (WAT), tiller number at 5 and 8 WAT, flag leaf length, panicle length, and grains per panicle, and highly significantly affected 1000-grain weight, grain yield per plot, and projected productivity. Treatment P4 produced the highest grain yield per plot of 4.40 kg and projected productivity of 6.11 t ha?¹. However, increasing the fertilizer rate above the recommended rate did not significantly increase yield compared with P2, indicating that the recommended fertilizer rate was sufficient to provide good growth and yield responses of IPB 13S rice under the conditions of this study.