PERTUMBUHAN DAN HASIL JAGUNG MANIS (Zea mays Saccharata Stury) YANG DIPUPUK DENGAN PUPUK ORGANIK DAN ANORGANIK PADA SAAT YANG BERBEDA - Muhammad Martajaya (Department of Agronomy Faculty of Agriculture University of Mataram and Indonesian Society of Agronomy Branch NTB, 2009)
ABSTRAK Penelitian ini bertujuan untuk (1) membandingkan pertumbuhan dan hasil jagung manis yang dipupuk dengan pupuk organik dan anorganik pada saat yang berbeda, (2) mendapatkan hasil yang terbaik pada macam dan saat pemberian pupuk organik dan (3) mengetahui residu pupuk organik dan anorganik terhadap ameliorasi kesuburan tanah. Percobaaan menggunakan Rancangan Acak Kelompok dengan perlakuan: GO1=Glyricidia sepium diberikan seminggu sebelum tanam, GO2=Glyricidia sepium diberikan dua minggu sebelum tanam, TO1=Tithonia diversifolia diberikan seminggu sebelum tanam, TO2=Tithonia diversifolia diberikan dua minggu sebelum tanam, KO1= Kotoran sapi diberikan seminggu sebelum tanam, KO2= Kotoran sapi diberikan dua minggu sebelum tanam, dan A= pupuk anorganik. Hasil penelitian menunjukkan bahwa pertumbuhan dan hasil jagung manis yang dipupuk anorganik tidak berbeda nyata dengan pupuk organik (G.sepium, T.diversifolia, dan kotoran sapi). Hasil bobot segar tongkol secara berturut-turut adalah TO1 (8,5 ton ha-1), KO1 (8,2 ton ha-1), A (8,1 ton ha-1), TO2 (7,0 ton ha-1), KO2 (6,8 ton ha-1), GO2 (6,0 ton ha-1), dan GO1 (5.5 ton ha-1). Pupuk Organik memberikan simpanan terhadap ameliorasi kesuburan tanah yang lebih tinggi dibandinglan pupuk anorganik. Pupuk organik G. sepium, meskipun bobot segar tongkol lebih rendah, tetapi memberikan sumbangan residu pada tanah yang tertinggi. Hasil tertinggi berat berangkasan segar (sebagai pakan ternak) berturut-turut diperoleh pada perlakuan Tithonia diverisifolia, pupuk kotoran sapi yang diberikan seminggu sebelum tanam, serta pupuk anorganik masing-masing sebesar 11,4, 11,2, dan 10,0 ton ha-1. ABSTRACT The aims of this research were: (1) to compared growth and yield of sweet corn that was planted at kinds of organic fertilizers wich applied in different times against to inorganic fertilizer, (2) to obtain the best result at kind of organic fertilizer wich applied in different time, and (3) to know residual to the soil after harvesting from organic and anorganic fertilizer. The experimental method was Completely Randomized Block Design, ie. Glyricidia sepium applied in a week before planting (GO1), Glyricidia sepium applied in two weeks before planting ( GO2), Tithonia diversifolia applied in a week before planting ( TO1), Tithonia diversifolia applied in two weeks before planting (TO2), cow manure applied a week before planting (KO1), cow manure applied in two weeks before planting (KO2), and inorganic fertilizer (A). The results of the study indicated that there was no difference in growth and yield of sweet corn between inorganic with organic fertilizer ( G.sepium, T.diversifolia, and cow manure). While each of seven treatments yielding fresh weight of cobs as follows, from the highest : T. diverifolia, applied in a week before planting (8.5 Mg ha-1), cow manure applied in a week before planting (8.2 Mg ha-1), inorganic fertilizer (8.1 Mg ha-1), T. diversifolia.applied two weeks before planting (7.0 Mg ha-1), cow manure applied two weeks before planting (6.8 Mg ha-1), G.sepium applied two weeks before planting (6.0 Mg ha-1), and G.sepium applied a week before planting (5.5 Mg ha-1). G. sepium , though the corn yield is lower, but have high in contribution of residual soil amelioration. The highest total fresh weight was T. diversifolia and cow manure a week before planting applied, and from the inorganic fertilizer as 11.4, 11.2, and 10.0 Mg ha-1 respectively.