Karakteristik dan Klasifikasi Tanah pada Satuan Lahan Volkan Tua di Sumatera Utara
ABSTRAK
Penelitian survei yang mengkaji karakteristik tanah pada satuan lahan
volkan tua. Penelitian dilakukan pada dua areal lahan, yaitu kaki lereng Gunung
Sipiso-piso dan kaki lereng Gunung Simbolon. Analisis tanah di Laboratorium
Riset dan Teknologi, Fakultas Pertanian, Universitas Sumatera Utara. Pada
masing-masing areal dibuat profil pewakil kemudian diamati morfologi dan
karakteristik serta diklasifikasikan menurut klasifikasi taksonomi tanah dan
klasifikasi nasional. Analisis tanah meliputi Bulk densiti, tekstur, pH H2O, pH
KCl, pH NaF, ZPC, KTK, KB, Basa-basa tukar, C-organik, P-tersedia, Retensi P,
P-total, Al Fe Si ekstrak oksalat, Al dan Fe ekstrak pirofosfat. Hasil penelitian
menunjukkan bahwa satuan lahan volkan tua yang berada di kaki lereng Gunung
Sipiso-piso memiliki BD < 0.90 gcm-3, muatan tanah permanen negatif, retensi P
sedang, kadar P tersedia sangat rendah, pH NaF ≥ 9.2, nilai KTK sedang dan ZPC
tidak terdeteksi. Lahan ini masih mempunyai sifat tanah andik dan
diklasifikasikan menurut taksonomi tanah (Ultic Hapludand) dan klasifikasi
nasional (Andosol Distrik). Sedangkan lahan volkan tua yang terdapat di kaki
lereng Gunung Simbolon memiliki BD < 0.90 gcm-3, muatan tanah permanen
negatif, retensi P rendah, kadar P tersedia sedang, pH ≥NaF
9.2, nilai KTK
rendah, dan ZPC tidak terdeteksi. Klasifikasi tanah pada areal ini berdasarkan
taksonomi tanah (Andic Dystrudept) dan klasifikasi nasional (Kambisol Kromik).
Volkan tua memiliki perbedaan dengan tanah di lahan volkan muda dalam hal
muatan tanah, ZPC, retensi P dan KTK tanah.
Kata kunci : karakteristik tanah, klasifikasi tanah, lahan volkan tua
Universitas Sumatera Utara
ABSTRACT
The survey research was aimed to review the character of soil on old
volcan land units. This study was conducted in two area, i.e the Mt.Sipiso-piso
and Mt.Simbolon footslope. Soil analysis was held in Research and Technology
Laboratory, Agriculture Faculty, University of North Sumatera. The
representative pedon in each area was observed morphologcally and the
properties as well, then classified according to soil taxonomy and national
classification. Soil properties measured were bulkdensity, soil texture, pH H2O,
pH KCl, pH NaF, ZPC (Zero Point of Charge), Cation Exchange Capacity (CEC),
Base saturation, C-Organic content, P-available (Bray II), P-retention, Aloxsalate extracted (Alo) Fe-oxsalate extracted (Feo), Al-pyrophosphate extracted
(Alp) and Fe-pyrophosphate extracted (Fep). The result showed that the footslope
Mt.Sipiso-piso old volcan land unit has BD < 0.90 gcm-3, negative permanent
charge, moderate P-retention, low P-available (Bray II), pH NaF ≥ 9.2, moderate
CEC and ZPC was undetected. This land had andic soil features and classified
into Ultic Hapludand (according to Soil Taxonomy) and Andosol Distrik
(according to national classification). Meanwhile, the footslope Mt.Simbolon old
volcan land unit has BD < 0.90 gcm-3, negative permanent charge, low Pretention, moderate P-available (Bray II), pH NaF≥ 9.2, low CEC and ZPC was
undetected. This land was classified into Andic Dystrudept (according to Soil
Taxonomy) and Kambisol Kromik (according to national classification). Old and
young volcan soil have the differentiation in term of soil charge, ZPC, P-retention
and CEC.
Keyword : Soil characteristic, soil classification, an old volcan land
Universitas Sumatera Utara
Penelitian survei yang mengkaji karakteristik tanah pada satuan lahan
volkan tua. Penelitian dilakukan pada dua areal lahan, yaitu kaki lereng Gunung
Sipiso-piso dan kaki lereng Gunung Simbolon. Analisis tanah di Laboratorium
Riset dan Teknologi, Fakultas Pertanian, Universitas Sumatera Utara. Pada
masing-masing areal dibuat profil pewakil kemudian diamati morfologi dan
karakteristik serta diklasifikasikan menurut klasifikasi taksonomi tanah dan
klasifikasi nasional. Analisis tanah meliputi Bulk densiti, tekstur, pH H2O, pH
KCl, pH NaF, ZPC, KTK, KB, Basa-basa tukar, C-organik, P-tersedia, Retensi P,
P-total, Al Fe Si ekstrak oksalat, Al dan Fe ekstrak pirofosfat. Hasil penelitian
menunjukkan bahwa satuan lahan volkan tua yang berada di kaki lereng Gunung
Sipiso-piso memiliki BD < 0.90 gcm-3, muatan tanah permanen negatif, retensi P
sedang, kadar P tersedia sangat rendah, pH NaF ≥ 9.2, nilai KTK sedang dan ZPC
tidak terdeteksi. Lahan ini masih mempunyai sifat tanah andik dan
diklasifikasikan menurut taksonomi tanah (Ultic Hapludand) dan klasifikasi
nasional (Andosol Distrik). Sedangkan lahan volkan tua yang terdapat di kaki
lereng Gunung Simbolon memiliki BD < 0.90 gcm-3, muatan tanah permanen
negatif, retensi P rendah, kadar P tersedia sedang, pH ≥NaF
9.2, nilai KTK
rendah, dan ZPC tidak terdeteksi. Klasifikasi tanah pada areal ini berdasarkan
taksonomi tanah (Andic Dystrudept) dan klasifikasi nasional (Kambisol Kromik).
Volkan tua memiliki perbedaan dengan tanah di lahan volkan muda dalam hal
muatan tanah, ZPC, retensi P dan KTK tanah.
Kata kunci : karakteristik tanah, klasifikasi tanah, lahan volkan tua
Universitas Sumatera Utara
ABSTRACT
The survey research was aimed to review the character of soil on old
volcan land units. This study was conducted in two area, i.e the Mt.Sipiso-piso
and Mt.Simbolon footslope. Soil analysis was held in Research and Technology
Laboratory, Agriculture Faculty, University of North Sumatera. The
representative pedon in each area was observed morphologcally and the
properties as well, then classified according to soil taxonomy and national
classification. Soil properties measured were bulkdensity, soil texture, pH H2O,
pH KCl, pH NaF, ZPC (Zero Point of Charge), Cation Exchange Capacity (CEC),
Base saturation, C-Organic content, P-available (Bray II), P-retention, Aloxsalate extracted (Alo) Fe-oxsalate extracted (Feo), Al-pyrophosphate extracted
(Alp) and Fe-pyrophosphate extracted (Fep). The result showed that the footslope
Mt.Sipiso-piso old volcan land unit has BD < 0.90 gcm-3, negative permanent
charge, moderate P-retention, low P-available (Bray II), pH NaF ≥ 9.2, moderate
CEC and ZPC was undetected. This land had andic soil features and classified
into Ultic Hapludand (according to Soil Taxonomy) and Andosol Distrik
(according to national classification). Meanwhile, the footslope Mt.Simbolon old
volcan land unit has BD < 0.90 gcm-3, negative permanent charge, low Pretention, moderate P-available (Bray II), pH NaF≥ 9.2, low CEC and ZPC was
undetected. This land was classified into Andic Dystrudept (according to Soil
Taxonomy) and Kambisol Kromik (according to national classification). Old and
young volcan soil have the differentiation in term of soil charge, ZPC, P-retention
and CEC.
Keyword : Soil characteristic, soil classification, an old volcan land
Universitas Sumatera Utara