Pengolahan Tanah Optimum Pada Budidaya Tebu

ii
ABSTRAK
GATOT PRAMUHADI. Pengolahan Tanah Optimum pada Budidaya Tebu
Lahan Kering. Dibimbing oleh EDUARD NAMAKEN SEMBIRING, RADITE
PRAEKO AGUS SETIAWAN, dan MUHAMMAD ACHMAD CHOZIN.
Penelitian ini bertujuan untuk mempelajari hubungan antara jenis dan
intensitas pengolahan tanah dengan densitas dan tahanan penetrasi tanah, dan
dengan pertumbuhan dan produksi tebu, menentukan kisaran densitas dan tahanan
penetrasi tanah optimum, dan menentukan metode pengolahan tanah optimum
(efektif dan efisien) pada budidaya tebu lahan kering.
Penelitian dilaksanakan di areal kebun tebu lahan kering PT Gula Putih
Mataram, Lampung Tengah mulai dari awal September 2002 hingga akhir Januari
2004. Enam metode pengolahan tanah diaplikasikan, dan dilakukan pengukuran
kondisi sifat fisik-mekanik tanah, unjuk kerja alat dan mesin pengolahan tanah,
serta secara periodik diukur dan diamati pertumbuhan tebu hingga saat panen, dan
dilanjutkan hingga ratoon 6 bulan.
Hasil penelitian menunjukkan bahwa aplikasi metode pengolahan tanah
dengan intensitas semakin tinggi menghasilkan produktivitas tebu dan gula
sampling yang semakin rendah, dan biaya konsumsi bahan bakar yang semakin
tinggi, sehingga menyebabkan hasil pengolahan tanahnya semakin tidak efektif
dan semakin tidak efisien.
Metode pengolahan tanah dengan intensitas
pengolahan tanah minimum menghasilkan densitas dan tahanan penetrasi tanah
optimum yang menyebabkan produktivitas tebu dan gula sampling mencapai
maksimum, tetapi pertumbuhan gulma dan biaya konsumsi bahan bakarnya
minimum, sehingga menghasilkan pengolahan tanah paling efektif dan efisien.
Kisaran densitas dan tahanan penetrasi tanah optimum untuk pertumbuhan
dan produksi tebu maksimum, serta untuk pertumbuhan gulma minimum, adalah
sebesar 1.20-1.30 g/cc dan 6.00-14.00 kgf/cm2, yang diperoleh dengan cara
mengaplikasikan metode pengolahan tanah minimum untuk tebu, yaitu metode
“subsoiling – plowing – harrowing – furrowing”.
Metode pengolahan tanah “subsoiling – moldboard plowing – disk
harrowing – furrowing” merupakan metode pengolahan tanah paling optimum
pada budidaya tebu lahan kering di PT Gula Putih Mataram, Lampung Tengah.
iii
ABSTRACT
GATOT PRAMUHADI. Optimum Soil Tillage on Dry Land Sugarcane
Cultivation. Under the direction of EDUARD NAMAKEN SEMBIRING,
RADITE PRAEKO AGUS SETIAWAN, and MUHAMMAD ACHMAD
CHOZIN.
The objectives of the research were to study the relationship between soil
tillage kind and intensities and soil density and penetration resistance, and
sugarcane growth and productivity, to determine the range of optimum soil
density and penetration resistance, and to determine optimum soil tillage method
on dry land sugarcane cultivation.
The research was conducted on dry land sugarcane field at Gula Putih
Mataram Company, Central Lampung. It was conducted at the beginning of
September 2002 until the ending of January 2004. Six soil tillage methods were
applied, and soil physical-mechanical properties and tractor and implement
performance were measured and calculated. Sugarcane growth was monitored
periodically until the harvesting time and it was continued until six month after
harvest.
The results showed that the increasing of soil tillage intensities would
increase fuel consumption cost, but it decreased the sampling average of
sugarcane and sugar productivities, so it caused ineffective and in efficiency soil
tillage method. The application of soil tillage method with minimum intensities
would result in optimum soil density and penetration resistance that caused
maximum sugarcane growth and production, but it caused minimum weeds
growth and fuel consumption cost, so it produced the most optimum soil tillage
method.
The ranges of optimum soil density and penetration resistance for resulting
maximum sugarcane and sugar productivities and minimum weeds growth were
1.20-1.30 g/cc and 6.00-14.00 kgf/cm2. It was obtained by applying the soil
tillage method of “subsoiling-plowing-harrowing -furrowing” on dry land
sugarcane cultivation.
The soil tillage method of “subsoiling -moldboard plowing-disk harrowingfurrowing” was the most optimum soil tillage method on dry land sugarcane
cultivation at Gula Putih Mataram Company, Central Lampung.