15 research outputs found
Soil physical and mechanical properties, erosion and seedling emergence as affected byn soil bulk density in two indonesian soils
No full text
Klasifikasi Tanah dan Klasifikasi Kemampuan Tanah Lokasi Pemukiman Transmigrasi Terusan Tengah Kalimantan Tengah
No full textKlasifikasi Tanah dan Sifat-Sifat Fisika, Kimia Tanah Daerah Kurik Kumbe, Irian Jaya
No full textI. Keadaan Umum
Letak geografis
Kawasan survei semi detail Kurik Kumbe termasuk dalam
Kalurahan Kurik dan Izabadbekay, Kecamatan Merauke dan merupakan bagian dari daerah administratif Kabupaten Merauke, Propinsi Irian Jaya. Kawasan ini meliputi areal seluas 25.000 ha, terbagi dalam dua daerah, yaitu daerah A, terletak di kelurahan Izabadbekay seluas ll.350 ha dan daerah B, terletak di kelurahan Kurik seluas 13.650 ha.
Secara geografis dibatasi oleh garis 140°15' Bujur Timur
(Br) di sebelah Barat dan garis 140°271' Bujur Timur (Bt) dibagian timurnya. Di bagian utara dibatasi oleh garis 8°03' Lintang Selatan (LS) dan di sebelah selatan oleh garis 8°27' Ls.
II. Keadaan Tanah
1. Genesa
Genesa daerah A dan B kelihatan agak berbeda. Daerah A merupakan daerah endapan dari laut, terutama Yang dekat dengan pantai. Daerah B merupakan daerah endapan bahan-bahan dari pegunungan Jaya Wijaya. Perkembangan pembentukan tanahnya masih belum begitu lanjut, yaitu
belum terbentuknya horison penciri (diagnostika} dalam profil tanah.
2. Klasifikasi Tanah
Menurut sistem klasifikasi tanah Soil Taxonomy oleh USDA,
di daerah ini hanya dapat dijumpai dua ordo tanah yang penting, yaitu Inceptisol seluas 9.361 ha atau 82,6% di daerah A dan seluas 11.635 atau 85,2% di daerah B. Ordo Entisol seluas 1.979 ha atau 17,4% di daerah A dan seluas 2.015 ha a tau 14,8% di daerah B. Di daerah survei ini sangat langka dijumpai adanya gambut. Banyak dijumpai adanya bekas-bekas bakaran pada lapis permukaan tanah.
Kapasitasnya mungkin meningkat dengan kehadiran Limin, pemupukan dan pengukuran sejenis lainnya. Hasil analisis lanjutan menunjukkan kandungan bahan organik rendah hingga menengah dengan nilai lebih tinggi dari topsoil daripada lapisan Subsurface. Adany sisa-sisa debu dan material tumbuhan sering ditemui di lapisan permukaan, mengindikasikan bawa kebakaran sering terjadi di area pengamatan tersebut. Kandungan Nitrogen yang sangat rendah teramati bahkan pada tanah yang kaya akan bahan organik
Erosi Catchment Area Waduk Wadaslintang
No full textTanah-tanah di daerah tropika, mudah menjadi mangsa
erosi air, disebabkan karena curah hujan dan temperatur yang tinggi. Pencegahan erosi di daerah ini merupakan suatu masalah yang serius. Akibat kerusakan tanah di bagian hulu tidak saja menimbulkan masalah pendangkalan sungai, waduk dan saluran irigasi, tetapi bersama itu menimbulkan banjir, oleh karena kapasitas. sungai telah berkurang dan air dari hulu sekaligus masuk ke sungai.
Dalam penelitian ini besarnya kehilangan tanah (erosi)
dihitung dengan persamaan Wischmeier yang akhirnya dikenal sebagai. Universal Soil Loss Equation (USLE) yang dinyatakan sebagai berikut:
A= R.K.LS.C.P.
yang diartikan sebagai:
A = rata-rata kehilangan tanah (ton/ha)
R = faktor erosifitas hujan (1/ha)<
K = faktor erodib.ilitas tanah (ton/I)
LS= faktor panjang dan kemiringan lereng
C = £aktor tanaman
P = faktor tindakan pengawetan tanah
Dari basil penelitian didapatkan hasil sebagai berikut:
1. Faktor erosifitas hujan di daerah penelitian cukup besar.
Hal ini disebabkan curah hujan yang tinggi di daerah penelitian.
Faktor ini adalah faktor alam yang sukar.
2. Faktor erodibilitas tanah di daerah penelitian-agak tahan terhadap erosi. Hal ini disebabkan karena pada umumnya tanah di daerah penelitian ialah Latosol (Ultisol). Tanah tersebut ialah tanah yang telah mengalami perkembangan lanjut, mempunyai tekstur lempung sampai geluh, struktur remah sampai gumpal lemah, konsistensi gembur, permeabilitas sedang.
3. Faktor panjang lereng (L) dan k.e. miringan (S) di daerah penelitian cukup besar. Hal ini disebabkan karena daerah penelitian mempunyai fisiografi bergelombang.
4. Faktor pengelolaan tanaman dan tanah (CP). Faktor ini
adalah satu-satunya faktor yang dapat dengan mudah untuk
diperbaiki, untuk bisa mengurangi besarnya erosi di daerah penelitian. Perbaikan CP yang dianjurkan untuk daerah penelitian antara lain:
a. Penghutanan daerah gundul/kritis
b. Pengelolaan hutan dengan baik, sehingga tajuk bisa lebat,menutupi seluruh permukaan tanah.
c. Pada daerah tegal dan kebun campuran supaya dikembangkan tanaman-tanaman perkebunan berumur panjang, sehingga sepanjang tahun bisa menutupi permukaan tanah
Effect of Humic Acid and Molybdate on Phosphate Adsorption in Typic Hapludult of Cigudeg, Bogor
No full textHumic acids containing carboxyl and hydroxyl groups that have the ability to cover the P adsorption site in Typic Hapludults. Molybdate has similarity behaviour with phosphate in theacid soils. Research aim was to study the effects of molybdate and humic acid to the kinetics of phosphate adsorption in Typic Hapludults of Cigudeg, Bogor. Important of kinetics is to get accuration of materials transport, to control influence on anion mobility, that the assessment is needed for the efficient application of Mo and P. Aplication humic acid and molybdate as competitor anion of phosphate was conducted with combination of humic acid and Mo concentration as double anions. Many models describe the kinetics for the adsorption of phosphate by soils i.e. zero order, first order, second order, and Elovich. As ststistically, there was not interaction of humic acid and molybdate on P adsorption. Application of humic acid with rate of 100 mg.L-1 was not effective decrease P adsorption in Typic Hapludults. It was due to the pH of the adsorption system that get near to its pKa of carboxyl gruop about 5. Meanwhile aplication 2 and 5 mmol.L-1 of molybdate significantly decrease of P adsorption. The second order kinetics models apropriate to the adsorptionof P in the Typic Hapludults of Cigudeg, with determination coefficients value (R2) of 0.999-1 and standard error value (SE) of 0.001–0.011.The results suggest that the molybdate as competitor anion affected the kinetics for the adsorption of phosphate due to the charge of molybdate
Penilaian hidrofobisitas gambut ombrogen Pontianak akibat variabilitas muka air tanah dan penggunaan lahan
No full textBuletin Agronomi Vol.30 No.3, Tahun 2002
No full textIn saturated soil culture the width of the be& were recommended between 1 m and 2 m, which require more labor to dig the furrows. An experiment was done to study the effect of the width of beds and to determine the optimal bed's width. The experiment was done on Regosol soil in Sleman Regency, Yogvakarta using Randomized Complete Blocked Design with three blocks. The treatments were Jood irrigation as control and saturated soil culture with 1, 2, 3 and 4 m wide of beds. Observations were done on soil moisture, physiological processes, growth and yield of soybean. The result of the experiment showed that saturated soil culture stabilized the soil moisture around field capacily, increased physiological processes, growth of the plant and increased the seed yield 81 %Ji.om 1.17 t ha-' up to 2.12 t ha-'. mere was no significant different on the effect of width of the beds, therefore 3-4 m bed's width was recommended
Infiltrasi, sifat fisik tanah dan erosi pada berbagai lereng tangkapan mikro sub das kali babon Kabupaten Semarang=Infiltration, Soil Physical Properties and Erosion on Micro Catchment with Various Slope in Sub Kali ...
No full textA research was done in Kedji, Ungaran District, Semarang Regency from November 2001 to April 2002, to study the infiltration rate, soil physical properties, and erosion rate of a small plot having different gradient scattered in microcatchment of sub Babon river watershed, Semarang Regency. Experimental design was Split Plot with three replicates, microcatchment of Tegalan and Rambutan as main plot, and slope: 15,25,40, and 60% as sub plot. Plot of 1 x 1 m2 size were made in levelled soil surface no tillage, on flat open spot free from gravels and shading from plant canopy or tree trunk in each respective designations. Soil texture, organic matter, soil aggregate stability, bulk density, permeability, pori distribution, and pH were taken from 0-10 cm soil depth were determined from samples. Rainfall, run off and soil loss were measured from daily rainfall. Volume of infiltration was calculated from effective rainfall minus run-off. Effective rainfall was calculated from rainfall ombro meter multiplied with slope degree. Infiltration capacity was measured using double ring infiltrometer method and calculated using Horton formula. Rainfall erosivity was determined using Bols and EI^ formula. Soil erodibility value was determined following USLE and using nomograph.
The results indicated that higher slope degree affected reduce volume, rate, and capacity of infiltration, and increased run-off and soil loss. However, increase of run-off occurred following exponential graph. In Tegalan and Rambutan microcatchments open space with no vegetation, during rainy season there would be reduction of organic matter, soil permeability, rapid drainage pores, and water available pores accompanied with an increase of bulk density. In Tegalan microcatchment, run-off, soil loss, and erodibility were higher. On the oher hand, in Rambutan microcatchment, infiltration, organic matter, and soil aggregate stability were higher, resulting in a more stable condition to erosion. Result also found that predicted soil erodibility value using USLE formula was lower than nomograph.
Keywords: infiltration -slope-micro catchment and erosio
