DOI: http://dx.doi.org/10.25181/jppt.v21.i2.2094 Jurnal Penelitian Pertanian Terapan Vol. 21 (2): 158-166 Website: https://jurnal.polinela.ac.id/jppt pISSN 1410-5020 eISSN 2407-1781 Lisensi Ciptaan disebarluaskan di bawah Lisensi Creative Commons Atribusi-BerbagiSerupa 4.0 Internasional. Pengaruh Beberapa Campuran Kompos Cair Terhadap Pertumbuhan, Hasil Panen Dan Kandungan Vitamin C Tanaman Kale (Brassica oleracea var. acephala) Effect Of Mixed Liquid Compost on Growth, Yield, And Vitamin C Content Of Kale (Brassica oleracea var. acephala) Jose Natanael 1* , dan Dina Rotua Valentina Banjarnahor 1 1 Program Studi Agroteknologi, Fakultas Pertanian dan Bisnis, Universitas Kristen Satya Wacana * Email: dina.banjarnahor@uksw.edu ABSTRACT Minang Bangkit Merbabu farmers apply organic agriculture in form of administrating liquid compost with main materials that consist of rabbit urine, fresh cow milk, and chicken eggs as nutrient provider. This research’s main purpose is to know the effect of liquid compost toward growth, yield, and vitamin C content of organic kale. This research took place in Salaran Experimental Field, Faculty of Agriculture and Business, Satya Wacana Christian University, between March to May 2020. There are one control and four treatment mixtures of several liquid compost materials with codes CBK1, CBK2, CBK3, CBK4 which will be repeated six times and multiplied by two to test the yield and vitamin C content to obtain 60 experimental units. This research used a randomized block design, with vitamin C levels as a quality parameter, yield parameters in the form of wet and dry root and canopy weight, and growth parameters in the form of number of leaves, stem diameter, and crown diameter. Data were analyzed using variance test with Tukey follow-up test with α=5%. Based on the results of the variance test, the mixture of several compost materials had a significantly different effect on all parameters. The CBK4 treatment showed the best growth and yields including 15.17 leaf number, 0.97 cm stem diameter, 52.42 cm crown diameter, 10.01 g root crop and 101.37 g crown. The vitamin C content in kale showed significantly different results to the control, but not significantly different in treatment (CBK1, CBK2, CBK3, and CBK4) Keyword: Kale, liquid compost, fresh cow’s milk, chicken egg, rabbit urine Disubmit : 21 April 2021, Diterima: 20 Mei 2021, Disetujui : 16 Agustus 2021 PENDAHULUAN Kelompok Tani Minang Bangkit Merbabu yang berlokasi di Dusun Seloduwur, Desa Batur, Kecamatan Getasan menerapkan sistem pertanian organik untuk produksi sayur. Salah satu tanaman sayur yang dibudidayakan adalah kale (Brassica oleracea). Kale memiliki kandungan vitamin C antara 77 dan 133 mg/100 g (Korus, 2011). Nilai ini lebih tinggi daripada kandungan vitamin C pada jeruk dan lemon (Najwa & Azlan, 2017). Petani Minang Bangkit Merbabu menggunakan kompos cair berbahan urin kelinci, susu sapi, telur ayam kampung, gula aren, terasi udang, nanas, akar bambu, air kelapa dan jahe serta kunyit untuk menyediakan hara bagi semua tanaman termasuk kale. Bahan utama kompos cair tersebut adalah urin kelinci, susu sapi, dan telur