Nitrogen Fertilizer Reduction on Way Apo Buru and Inpari 33 Rice Varieties

Urea fertilizer usage in farmers is mostly applied at a higher dose than the standard dose of recommendation. The excessive urea fertilizer usage decreased the plant productivity and quality, also polluting the soil. The experiment aimed to observe the growth, yield, and quality response of rice in low N supplements. The experimental design used a factorial randomized complete block design, i.e., urea doses (0%, 40%, 100% 250 kg ha-1) and rice varieties (Way Apo Buru and Inpari 33). The traits observed were plant height (cm), number of tillers, number of leaves, chlorophyll fluorescence (unit), grain content (%), number of panicles, content of dissolved protein (mg g-1), ascorbic acid (mg g-1), reducing sugar (mg g-1). The results showed that a reduction of 40% urea produced the same higher number of tillers compared to the standard dose (250 kg ha-1). The standard dose of urea resulted in the highest ascorbic acid content, value of chlorophyll fluorescence, and number of panicles. Inpari 33 produced higher plant height and grain content meanwhile Way Apo Buru produced a higher number of leaves. The reduction of 40% urea in Inpari 33 resulted in the highest dissolved protein content. Inpari 33 produced the lowest reducing sugar and could be used as an alternative food for diabetics. Keywords: chlorophyll content, dissolved protein, reducing sugar, vitamin CPemupukan urea di petani umumnya dilakukan dengan dosis yang lebih tinggi dari standar pemerintah. Penggunaan pupuk urea berlebih dapat menurunkan produksi, kualitas tanaman, serta pencemaran lingkungan. Tujuan percobaan ini adalah melihat respon pertumbuhan, hasil dan kualitas padi sawah pada media N rendah. Rancangan percobaan menggunakan rancangan acak kelompok faktorial, dosis pupuk urea (0%, 40%, dan 100% 250 kg ha-1) dan varietas padi (Way Apo Buru dan Inpari 33). Parameter yang diamati adalah tinggi tanaman (cm), jumlah anakan, jumlah daun, chlorophyl fluorescence (unit), gabah isi (%), jumlah malai, kandungan protein terlarut (mg g-1), vitamin C (mg g-1), dan gula reduksi (mg g-1). Hasil penelitian menunjukkan bahwa reduksi pupuk urea 40% menghasilkan jumlah anakan yang sama tinggi dengan dosis standar (250 kg ha-1). Pemupukan urea dosis standar menghasilkan kandungan vitamin C, nilai chlorophyl fluorescence dan jumlah malai yang tertinggi. Inpari 33 menghasilkan karakter tinggi dan persentase gabah isi yang lebih baik sementara Way Apo Buru menghasilkan jumlah daun yang lebih tinggi. Reduksi 40% dosis urea pada Inpari 33 menghasilkan kandungan protein terlarut tertinggi. Inpari 33 menghasilkan gula reduksi terendah sehingga dapat digunakan sebagai pangan alternatif bagi penderita diabetes. Kata kunci: gula reduksi, kandungan klorofil, protein terlarut, vitamin