RESPON TANAMAN RUMPUT PAKAN POLIPLOID YANG TOLERAN TANAH SALIN TERHADAP PEMUPUKAN NITROGEN BERDASARKAN SERAPAN NITROGEN, ANR, KANDUNGAN KLOROFIL DAN KUALITAS HIJAUAN

Abstract

This research was aimed to measure polyploid and diploid forage grass response as well as among polyploid forage grass which was tolerance against saline soil towards nitrogen fertilization based on nitrogen absorption, nitrate reductase activity, chlorophyl quantity and the green grass quality. The research was carried out during the time periods of January 2004 until Juli 2004 at The Forage Crop Laboratory, Department of Animal Food Science andNutrition, Faculty ofAnimal Husbandry, Diponegoro University, Semarang. The research used six kinds of grasses, namely R1 = Pennisetum purpuphoides diploid, R2 = Pennisetum purpuphoides polyploid, R3 = Panicum maximum diploid, R4 = Panicum maximum polyploid, R5 = Setaria splendida diploid, and R6 = Setaria splendida polyploid. The research design was series of experiments using The Completely Randomized Design. The six kinds of grass were experimented in series within four (0kg, 100 kg, 200 kg and 300 kg N/ha per acre) nitrogen fertilization dosages, in three replications. The observed parameters were : the nitrogen absorption, the urea fertilization efficiency, the nitrogen treatment efficiency, the nitrate reductase activity, the chlorophyl quantity, the crude protein quantity and the crude fiber quantity. The data obtained was analyzed through variance analyses. In order to measure the nitrogen fertilization response, then the data was further analyzed employing Orthogonal Polynomial Test's in order to get the regression equation. The research showed through variance analyses there were no interactions between kinds of grass with nitrogen fertilization dosages (P > 0,05) within all parameter. Based on Duncan's Test, it was indicated that the 100 kg dosage per acre of nitrogen fertilization was able to increase the highest nitrogen absorption, nitrate reductase activity, chlorophyl quantity and the green quality. The regression equation in general indicated that polyploid as well as diploid grass had the equal response toward nitrogen fertilization. The research conclusion was that, there were indications polyploid grass have more response towards the parameter within saline conditions. The findings were in succession as follows : 1) P. maximum, 2) S. splendida 3) P. purpuphoides, whereas these three kinds of forage grass were having of reponsiveness towards the nitrogen fertilization as follows : 1) S. splendida, 2) P. maximum, 3) P. purpuphoides. Penelitian ini bertujuan untuk mengetahui respon tanaman rumput pakan poliploid dan diploid serta diantara tanaman rumput pakan poliploid yang toleran tanah salin terhadap petnupukan nitrogen berdasarkan serapan nitrogen, aktivitas nitrat reduktase, kandungan klorofil dan kualitas hijauan. Penelitian dilaksanakan pada bulan Januari - Juli 2004 di Laboratorium Ilmu Tanaman Makanan Ternak, jurusan Nutrisi dan Makanan Ternak Fakultas Peternakan Universitas Diponegoro. Materi yang digunakan adalah Ri = Pennisetumpupuphoides diploid, R2 = Pennisetum purpuphoides poliploid, R3 = Panicum maximum diploid, R4 = Panicum maximum poliploid, R5 = Setaria splendida diploid, R6 = Setaria splendida poliploid. Penelitian ini menggunakan Series Eksperimen dengan Rancangan Acak Lengkap. Tanaman rumput sebanyak 6 jenis dicobakan secara series terhadap 4 perlakuan dosis pemupukan N (0, 100, 200 dan 300 kg N / ha) dengan 3 ulangan. Parameter yang diamati meliputi : serapan ham nitrogen, efisiensi pemupukan urea, efisiensi pemanfaatan nitrogen, aktivitas nitrat reduktase, kandungan klorofil, kandungan protein kasar dan kandungan serat kasar. Data yang diperoleh dianalisis menggunakan uji ragam, selanjutnya untuk mengetahui respon dari pemupukan nitrogen dilakukan uji lanjut dengan menggunalcan Uji Polinomial Ortogonal dan persamaan regresinya. Hasil penelitian menunjukkan bahwa berdasarkan analisis ragam tidak terlihat adanya interaksi antara j enis rumput dan dosis pupuk N (P > 0,05) terhadap seluruh parameter. Berrlasarkanuji Duncan pemupukan nitrogen dengan dosis 100 kg N /ha dapatmenghasilkan serapan nitrogen, aktivitas nitrat eduktase, kandunganklorofil dankualitas hijauantertinggi. Persamaan regresi secara umum memperlihatkan bahwa rumput poliploid dan diploid memiliki respon yang sama terhadap pemupukan nitrogen. Kesimpulan dari hasil penelitian ini adalah pemupukan nitrogen dosis 100 kg N / ha dapat meningkatkan serapan nitrogen, aktivitas nitrat reduktase kandungan klorofil dan kualitas hijauan. Rumput poliploid yang lebih responsif terhadap semua parameter pada kondisi salin adalah dengan urutan 1) P. maximum, 2)S. splendida 3)P purpuphoides, selanjutnya ke tiga rumput pakan tersebut memiliki responsibiltas terhadap pemupukan N, dengan urutan 1) S. splendida, 2) P. maximum, 3) P. purpuphoides.