PENGARUH PUPUK KANDANG SAPI TERHADAP KETERSEDIAAN KALIUM DAN PRODUKTIVITAS BAWANG MERAH (Allium cepa L.) PADA INCEPTISOL DI KABUPATEN BREBES, JAWA TENGAH

Abstract

Status hara kalium (K) pada tanah-tanah di Brebes berdasarkan hasil penelitian terdahulu berstatus tinggi sampai sangat tinggi. Penelitian ini bertujuan menguji efektivitas pupuk kandang sapi terhadap ketersediaan hara K tanah, pertumbuhan, serapan hara, dan produktivitas bawang merah pada Inceptisol. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan faktor tunggal yaitu dosis pupuk kandang sapi. Dosis pupuk kandang sapi yang diberikan adalah Kontrol (0 t/ha), B1 (5 t/ha), B2 (10 t/ha), B3 (15 t/ha), B4 (20 t/ha), B5 (25 t/ha), B6 (30 t/ha), dan B7 (35 t/ha). Bobot tanah yang digunakan dalam percobaan ini 7 kg berat kering mutlak yang ditempatkan dalam polybag. Setiap perlakuan diulang sebanyak 3 kali sehingga terdapat 24 satuan percobaan. Setelah itu, polybag-polybag percobaan diinkubasi selama 2 minggu dan kemudian ditanami bawang merah hingga panen. Analisis K-larut air dan K-dapat ditukar (K-dd) tanah dilakukan setelah akhir masa inkubasi dan setelah panen. Hasil menunjukkan bahwa pupuk kandang cenderung meningkatkan kadar K-larut air dan K-dd tanah setelah 2 minggu masa inkubasi dan setelah panen. Pertumbuhan vegetatif umumnya tidak berbeda nyata antar perlakuan akan tetapi bobot umbi segar dan kering eskip menunjukkan peningkatan secara nyata pada dosis 20 t/ha dan dosis 35 t/ha dibandingkan perlakuan kontrol. Serapan N, P, dan K pada umbi juga meningkat secara nyata pada dosis 20 t/ha dan 35 t/ha. Penelitian ini merekomendasikan bahwa pupuk kandang sapi efektif meningkatkan ketersediaan K tanah, serapan hara N, P dan K, dan produktivitas umbi bawang merah di Inceptisols Brebes.

The status of available potassium (K) in soils of Brebes based on previous research reports is high to very high. This study aimed to evaluate the effectiveness of cow manure on K availability, growth, nutrient absorption, and productivity of shallots in Inceptisol. This study used a Complete Random Design (CRD) with a single factor of the dose of cattle manure. The doses of cow manure given were Control (0 t/ha), B1 (5 t/ha), B2 (10 t/ha), B3 (15 t/ha), B4 (20 t/ha), B5 (25 t/ha), B6 (30 t/ha), and B7 (35 t/ha). The weight of the soil used in this experiment was 7 kg of oven-dry weight placed in a polybag. Each treatment was repeated 3 times so that there were 24 experimental units. After that, the experimental polybags were incubated for 2 weeks and then planted with shallots until harvest. Analysis of water-soluble K and exchangeable K (exch. K) soils was performed after the end of the incubation period and after harvest. Results showed that manure significantly increased water-soluble K levels and soil exch. K after 2 weeks of incubation and after harvest. Vegetative growth generally did not differ significantly between treatments, but the weight of fresh and dried tubers showed a marked improvement at a dose of 20 t/ha and a dose of 35 t/ha compared to the control treatment. The absorption of N, P, and K in the tubers also increased markedly at doses of 20 t/ha and 35 t/ha. This study recommended that cow manure fertilizer was effective in increasing soil K availability, nutrient absorption of N, P and K, and productivity of shallot tubers in Inceptisols Brebes.