Quality of Shallot Waste Liquid Organic Fertilizer and Its Effect on Red Lettuce

Abstract

Abstract

Converting organic waste into liquid organic fertilizer (LOF) can reduce reliance on inorganic fertilizers and improve soil quality and the productivity of leafy vegetables, including red lettuce. The study aimed to 1) determine the chemical and microbiological properties of LOF from shallot waste (LOF-Shallot) and 2) analyze the growth and yield of red lettuce cv Arista after applying various concentrations of LOF-Shallot. The LOF-Shallot was produced using a fermentation method enriched with decomposer microbes. The field experiment was set up using a Randomized Block Design, with five LOF-Shallot concentrations (0, 30, 60, 90, and 120%), then applied 4 times every 7-day period. The research was conducted at the Chemistry Laboratory of UICM, Bandung City, and the experimental field in Cimenyan village, Bandung Regency, from June to September 2024 The results of the LOF-Shallot waste analysis contained total N 0.12%, P 0.16%, K 0.07%, Cu 3.14 ppm, Fe 151.77 ppm, and Zn 492.4 ppm. Beneficial soil microbes such as Azotobacter sp., Bacillus sp., and phosphate-solubilizing bacteria at 107–108 CFU mL-1 were detected in the LOF-Shallot waste. The total bacterial population in the LOF-Shallot was about 108 CFU mL-1, while the total fungal count was low, fewer than 102 CFU mL-1. The results of field experiments showed that the higher concentration of LOF-Shallot applied (up to 90%), the greater the effect on all observed variables. The application of 90% LOF-Shallot concentration had the best effect on shoot height, leaf count, and shoot fresh weight. Keywords: Beneficial soil microbes, Fertilizer quality, LOF-Shallot waste, Red lettuce. ABSTRAK Konversi limbah organik menjadi pupuk organik cair (POC) dapat mengurangi ketergantungan pada pupuk anorganik serta meningkatkan kualitas tanah dan produktivitas sayuran berdaun, termasuk selada merah. Penelitian ini bertujuan untuk 1) menkaji sifat kimia dan mikrobiologis POC Bawang Merah dan 2) menganalisis pertumbuhan serta hasil panen selada merah varietas Arista setelah pemberian berbagai konsentrasi POC-Bawang Merah. Pupuk organik cair dari limbah bawang merah diproduksi menggunakan metode fermentasi yang diperkaya dengan mikroba pengurai. Percobaan lapangan disusun menggunakan Rancangan Acak Kelompok, dengan lima konsentrasi POC-Bawang Merah (0, 30, 60, 90, dan 120%) yang diberikan empat kali setiap 7 hari, mulai hari ke 3 sampai dengan hari ke 24 setelah tanam. Penelitian telah dilaksanakan di Laboratorium Kimia UICM, Kota Bandung dan lahan percobaan di desa Cimenyan, Kabupaten Bandung dari Juni sampai September 2024 Hasil percobaan laboratorium menunjukkan bahwa POC-Bawang Merah mengandung 0,12% N total; 0,16% P; 0,07% K; 3,14 ppm Cu; 151,77 ppm Fe; dan 492,4 ppm Zn. POC ini mengandung bakteri potensial, yaitu Azotobacter sp. dan Bacillus sp., serta bakteri pelarut fosfat sebanyak 107–108 CFU mL-1. Total populasi bakteri dalam POC-Bawang Merah sekitar 108 CFU mL-1, sedangkan jumlah total jamur rendah, yaitu kurang dari 102 CFU mL-1. Hasil percobaan lapangan menunjukkan bahwa semakin tinggi konsentrasi POC-Bawang Merah yang diaplikasikan (hingga 90%), semakin besar pengaruhnya terhadap semua variabel yang diamati. Aplikasi konsentrasi POC-Bawang Merah 90% berpengaruh terbaik terhadap tinggi tajuk, jumlah daun, dan berat segar tajuk. Kata kunci: Bakteri penyubur tanah, Kualitas pupuk, Limbah Bawang merah, Pupuk Organik, Cair, Selada merah.