Efektivitas pemupukan N, P, K dan Mg atas estimasi kebutuhan unsur hara makro untuk tanaman sawi hijau akuaponik

Abstract

Brassica juncea L. was know as mustard vegetable that has higher an economic value. However, it was a cultivation depend on the estimation of fertilizer application to increase to crop production. This study determine to nutrients obtained the optimal production results. Furthermore, the method used a survey method or qualitative research. Whereas, the conventional planting experimental design with a spacing of 20 × 20 cm per plant in 1 hectare. The percentage of N was calculated using the Kjeldahl method. Then, the compound of P, K, and Mg used a spectrophotometry. The data was analyzed using Microsoft Excel 2019. For parameters observed i.e: the wet weight (gr) and dry weight (gr), dry basis or Md (%), percentage from N, P, K, and Mg. Needed for total fertilizer to 10 tons/ha until 40 tons/ha. The results showed that fertilizer N was found in 3.86%, P was calculate in 0.72%, K was obtain in 3.83% and Mg was found in 0.37%. Furthermore, it was the average weight of Brassica juncea L. was 91.01 gr, wherein the dry weight was found in 6.72 gr. The dry basis Md was 12.54%. Finally, the fertilizer recommendations for Brassica juncea L. plants to optimal results up to 40 tons/ha using the fertilizer 5.45 grams. In this case, to the total urea in fertilization was 2.5 grams, and SP-36 fertilizer was 0.6 grams. Then, the KCl fertilizer was 1.8 grams, and dolomite of 0.6 grams with a recommended planting doses to aquaphonic system.