Evaluasi Dosis Pupuk Jagung Manis Dengan Metode Deviation of Optimum Percetage (DOP)

Abstract

Jagung manis adalah salah satu komoditas pertanian yang banyak dibudidayakan di Indonesia, namun produktivitasnya belum bisa memenuhi permintaan industri pangan, oleh karena itu masih di impor. Salah satu cara meningkatkan hasil jagung manis adalah dengan memupuk sesuai dengan kebutuhan tanaman. Metode rekomendasi pupuk Deviation of Optimum Percentage (DOP) merupakan metode rekomendasi pupuk dengan pendekatan langsung, melalui perbandingan kadar hara tanaman dengan kadar hara referensi pada bagian jaringan dan umur tanaman yang sama. Percobaan dilakukan di Kebun Percobaan Cikabayan, IPB Darmaga Bogor. Rancangan Acak Kelompok dengan 10 perlakuan dan diulang 3 kali digunakan dalam percobaan ini. Perlakuan percobaan meliputi kombinasi pupuk hayati cair (PH) dengan pupuk mineral dengan dosis 1/3 dan 2/3 dari dosis pupuk standar. Dosis pupuk mineral standar untuk jagung manis adalah 300 kg/ha Urea, 200 kg/ha SP-36, dan 150 kg/ha KCl. Dosis standar PH dari formulator adalah 8 liter/ha dengan pengenceran 50 kali. Data hasil percobaan disidik ragam dan diuji lanjut dengan uji jarak berganda Duncan pada selang kepercayaan 5%. Analisis data yang lain meliputi perhitungan indeks hara DOP, dosis pupuk, dan analisis efektivitas agronomik relatif. Hasil percobaan menunjukkan perlakuan pupuk mineral, hayati dan kombinasinya berpengaruh nyata pada kadar N, P, K daun bendera jagung manis pada tingkat silking. Evaluasi kebutuhan hara berdasarkan metode DOP menunjukkan bahwa P adalah hara yang paling kekurangan disusul N yang saling bertukar urutan dengan K. Rekomendasi dosis pupuk jagung manis berdasarkan metode DOP di lahan percobaan sebesar 357 kg/ha Urea, 287 kg/ha SP-36, dan 203 kg/ha KCl. Perlakuan pupuk hayati cair pada dosis 8 dan 16 l/ha dapat menyamai peran 1/3 – 2/3 standar dosis pupuk mineral dalam memasok hara. Efektivitas pupuk tertinggi diperoleh pada perlakuan 2 UG+2/3 STD yang setara dengan 16 l/ha UG, 200 kg/ha Urea, 133.4 kg/ha SP36 dan 100 kg/ha KCl. Pupuk hayati dapat meningkatkan efisiensi penggunaan hara, namun peranannya sangat tergantung kondisi lingkungannya .

Sweet corn is one of the agricultural commodities that is widely cultivated in Indonesia, but its productivity has not been able to meet the demand for the food industry, therefore it is still imported. One way to increase the yield of sweet corn is fertilized according to the needs of the plant. The Deviation of Optimum Percentage (DOP) fertilizer recommendation method is a fertilizer recommendation method with a direct approach, by comparing plant nutrient levels with reference nutrient levels in the same tissue section and plant age. The trial was carried out at the Cikabayan Experimental Garden, IPB Darmaga Bogor. Randomized block design with 10 treatments and 3 repetitions was used in this trial. The trial treatment included a combination liquid biofertilizer (PH) with mineral fertilizers at a dose of 1/3 and 2/3 of the standard fertilizer dose. Standard mineral fertilizer dose for sweet corn are 300 kg/ha Urea , 200 kg/ha SP-36, and 150 kg/ha KCl. The standard dose of PH based on PH formulator is 8 liters/ha with 50 times dilution. The trial data were F-tested and Duncan's multiple range test at a 5% confidence interval. Other data analysis includes DOP nutrient index calculation, fertilizer dosage, and analysis of relative agronomic effectiveness. The trial results showed that the treatment of mineral and biofertilizers and their combinations had a significant effect on the N, P, K levels of sweet corn flag leaves at the silking stage. Evaluation of nutrient requirements based on the DOP method showed that P was the most deficient nutrient followed by N which exchanged order with K. The recommended dose of sweet corn fertilizer based on the DOP method in the field trial was 357 kg/ha Urea, 287 kg/ha SP-36, and 203 kg/ha KCl. PH fertilizer treatment at doses of 8 and 16 l/ha can match the role of 1/3 – 2/3 standard doses of mineral fertilizers in supplying nutrients. The highest fertilizer effectiveness was obtained in the 2 PH +2/3 STD treatment which was equivalent to 16 l/ha PH, 200 kg/ha Urea, 133.4kg/ha SP36 and 100 kg/ha KCl. Biofertilizers can increase the efficiency of nutrient use, but their role is highly dependent on environmental conditions.