PERTUMBUHAN TANAMAN DAN KADAR KALSIUM HIJAUAN SORGUM MANIS (Sorghum bicolor (L).Moench) DENGAN PEMUPUKAN FOSFAT DAN ORGANIK (Plant Growth and Calsium Content of Sweet Sorghum Forage (Sorghum bicolor (L). Moench) with Phosphate and Organic Fertilization)

Abstract

ABSTRAK

Penelitian bertujuan mengkaji pengaruh pemupukan fosfat dan organik terhadap pertumbuhan dan kadar kalsium (Ca) hijauan sorgum. Materi dalam penelitian adalah benih sorgum manis, pupuk kandang (pukan), pukan ‘plus’ (pukan + BP yang didekomposisikan bersama), arang, pupuk batuan phosphate (BP) 27% P₂O₅ dan triple super phosphate (TSP) 46% P₂O₅ serta amonium sulfat (AS) 21% N dan KCl 50%K₂O sebagai pupuk dasar. Penelitian dilaksanakan dalam percobaan Rancangan Acak Kelompok (RAK) dengan 8 perlakuan dan 3 ulangan. Perlakuan pemupukan pada penelitian adalah T0 = Kontrol,  T1 = Pukan,  T2 = Pukan + BP,  T3 = Pukan + TSP,  T4 = Pukan ‘plus’, T5 = Pukan+ BP + arang, T6  = Pukan + TSP + arang,  T7 =  Pukan ‘plus’ + arang.Parameter pengamatan yaitu tinggi tanaman, kadar protein kasar (PK) dan kadar Ca hijauan pada pemotongan I (40 hari) dan pemotongan II (40 hari setelah potong pertama). Data dianalisis ragam kemudian dilanjutkan dengan uji jarak berganda Duncan. Hasil penelitian menunjukkan bahwa pukan ‘plus’ menghasilkan kadar Ca pemotongan I nyata lebih tinggi dibanding pukan + BP, pukan dan kontrol. Pukan ‘plus’ menghasilkan tinggi tanaman dan kadar Ca pemotongan I serta kadar Ca pemotongan II setara dengan pukan + TSP. Pukan ‘plus’ + arang menghasilkan tinggi tanaman pemotongan II setara dengan pukan + TSP + arang.Simpulan penelitian ini adalah perlakuan pemupukan organik + pupuk P baik dengan maupun tanpa arang meningkatkan tinggi tanaman sorgum pada pemotongan II. Perlakuan pupuk kandang + TSP + arang menghasilkan kadar Ca hijauan sorgum tertinggi pada pemotongan I.

Kata Kunci: sorgum manis; pertumbuhan;kadar kalsium; fosfat;organik.

ABSTRACT

The aim of this study was to examine the effect of phosphate and organic fertilization on the growth and calsium (Ca) content of sorghum forage. The materials in this study were sweet sorghum seeds, manure, manure 'plus' (manure + rock phosphate were decomposed together), charcoal, rock phosphate 27% P₂O₅ and triple super phosphate(TSP) 46% P₂O₅ as well as the sulphate ammonium (AS) 21% N and KCl 50%K₂O as a basic fertilizer.The experiment was conducted in a Randomized Complete Block Design (RCBD) with 8 treatments and 3 replications. Fertilizing treatments of this research was T0 = Control, T1 = Manure, T2 = Manure + rock phosphate, T3 = Manure + TSP, T4 = Manure ‘plus’, T5 = Manure + rock phosphate + charcoal, T6 = Manure + TSP + charcoal, T7 = Manure ‘plus’ + charcoal. The parameters were plant height, crude protein (CP) content and Ca content of sorghum forage at the first cutting (40 days)and second cutting (40 days after the first cutting). The data were analyzed using ANOVA, then followed by Duncan's multiple range test (DMRT).The results showed that manure 'plus' resulted Ca content of first cuttingthat was significantly higher than that of manure + rock phosphate, manure and control. Manure 'plus' resulted in plant height and Ca content on both cutting (first and second cutting) similar to manure + TSP. Manure 'plus' + charcoal resultedin plant height of second cuttingsimilarto manure + TSP + charcoal.The conclusionof thisresearchisorganic+P fertilizationtreatment either used or without used charcoal was able to increase height ofsorghumplant on second cutting. Treatmentof manure+TSP+charcoalresultthe highestCacontent of sorghumforage onfirst cutting.

Keywords : sweet sorghum; growth;calsium content; phosphate; organic.