Pengaruh bobot isi tanah terhadap sifat fisik tanah dan perkecambahan benih kacang tanah dan kedelai

Abstract

Soil physical properties can affect to seed germination and plant growth. Soil compaction will degrade soil physical properties which in term will affect to root penetration and development in the soil. The improvements of soil physical properties is required to ensure seed germination and plant growth such treatment to maintain soil bulk density is quite low. The purpose of this research is to study the influence of soil compaction (soil bulk density) to soil physical characteristics and seed germination of peanuts and soybean.This research used Jasinga Podsolik Soil, conducted at Soil Physical Laboratory, Department of Soil Science and Land Resources, Faculty of Agriculture IPB, and Greenhouse of Center of Biological Resources and Biotechnology, Research and Community Services Agency, IPB(March-November 2009). Completed random design was used as experimental design and Duncan's Multiple Range Test (DMRT) was used to identify the effect of treatment. The bulk density results of the research showed that the increasing of soil bulk density (soil compaction) had significantly affect on pF curves, permeability rate, and soil resistance before or after planting. For peanut, soil compaction significantly affect to plant height and root length. Soil compaction did not significantly affect on stem diameter, number of leaves, canopy or root biomass.For soybean, the influence of soil compaction had significantly affect just only on plant height. Stem diameter, number of leaves, root length or root and canopy biomasses were not affected by soil compaction.

Sifat fisik tanah yang kurang baik akan menyebabkan perkembangan benih terganggu, sehingga penentuan bobot isi tanah sebagai indikator kepadatan tanah perlu dilakukan. Tujuan dari penelitian ini, diharapkan dapat melihat pengaruh kepadatan tanah yang dinyatakan dalam perbedaan bobot isi tanah dan mengetahui bobot isi yang paling baik untuk mendukung perkecambahan benih kacang tanah dan kedelai. Pengambilan sampel tanah podsolik Jasinga dilakukan pada bulan Maret 2009. Penentuan sifat fisik tanah dilakukan di Laboratorium Fisika Tanah, Departemen Ilmu Tanah dan Sumberdaya Lahan FAPERTA, IPB pada Bulan Agustus-Oktober 2009. Penanaman dilaksanakan pada bulan November 2009 di Rumah Kaca Pusat Penelitian Sumberdaya Hayati dan Bioteknologi, LPPM IPB. Rancangan percobaan yang digunakan :Rancangan Acak Lengkap (RAL) yang selanjutnya dilakukan uji lanjut Duncan Multiple Range Test (DMRT) pada taraf 5 % dan dibuat persamaan regresi. Hasil penelitian menunjukan: bahwa pada.perlakuan tanpa tanaman, peningkatan kepadatan berpengaruh sangat nyata terhadap kurva pF, permeabilitas, dan resistensi, baik sebelum maupun setelah ditanami. Pada kacang tanah, peningkatan kepadatan berpengaruh nyata terhadap tinggi tanaman dan panjang akar. Bobot isi tidak berpengaruh nyata terhadap diameter batang, jumlah daun, dan biomassa baik tajuk ataupun akar. Pada kedelai, pengaruh bobot isi berpengaruh nyata pada tinggi tanaman dan tidak berpengaruh nyata pada diameter batang, jumlah daun, panjang akar ataupun biomasa akar serta tidak berpengaruh nyata terhadap biomassa tajuk.