Yulnafatmawita Yulnafatmawita
Soil Department, Faculty of Agriculture, University of Andalas, Padang, 25163, Indonesia

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Dynamics of Physical Properties of Ultisol under Corn Cultivation in Wet Tropical Area Yulnafatmawita, Yulnafatmawita; Detafiano, Dendy; Afner, Prakarsa; Adrinal, Adrinal
International Journal on Advanced Science, Engineering and Information Technology Vol 4, No 5 (2014)
Publisher : International Journal on Advanced Science, Engineering and Information Technology

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Abstract

Cultivation will change some of soil physical properties which determine the susceptibility to erosion.  Therefore, the properties must be paid much attention in cultivating soil for annual crop farming, such as for corn.  A research about dynamics of physical properties of Ultisol was conducted during corn cultivation in Ultisol Limau Manis, a wet tropical area.  The objective of the research was to determine the changing of the soil physical properties during corn cultivation.    The soil was sampled before cultivation, 1, 2, and 3 months of corn age, and 3 weeks after harvesting.  Parameters analyzed were soil texture, bulk density, total pore, aggregate stability, soil moisture, organic C, permeability.  The result showed that there was a short term effect of corn growth on some physical properties such as bulk density, total pore, aggregate stability, permeability, and organic matter content of the Ultisol.  The properties tended to improve during corn age 2 and 3 months, and then get down again after harvesting.  
Spatial and Temporal Analysis of Land Use Change for 11 years (2004-2014) in Sub-Watershed Sumpur Singkarak Edwin, Edwin; Saidi, Amrizal; Aprisal, Aprisal; Yulnafatmawita, Yulnafatmawita; Carolita, Ita
International Journal on Advanced Science, Engineering and Information Technology Vol 5, No 5 (2015)
Publisher : International Journal on Advanced Science, Engineering and Information Technology

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Abstract

The pressure of population growth and the economy has an impact on changes in land use in Sub-watershed Sumpur Singkarak West Sumatra, Indonesia. Changes in land use are analyzed spatially and temporally using satellite imagery Landsat TM 7 and 8 (resolution 30 m) that has been in the interpretation of 2004 to 2014. The analysis is done by comparing the changes in land use in the area of forest, farming and settlement. From the analysis it can be concluded that there has been a decline in forest area of 128 ha (1.6%), an increase in mixed-farming area of 146 ha (16.1%), an increase in settlement area of 143 ha (26%) for 11 years in Sub-watershed. In 2011, a change of 3125 ha of rice-paddy which have been changed become dry land an area of 2645 ha. This is due to the farming community, prefer to plant horticulture and crop plant from the rice plant.In the protected forest area has been used for settlement area of 1.37 ha and for dry land area of 11.41 ha. In the tourist nature reserve forest areas have been used for rice paddy area of 0:33 ha and for dry land area of 42.91 ha. 
DYNAMICS OF SOIL ORGANIC CARBON FRACTIONS UNDER DIFFERENT LAND MANAGEMENT IN WET TROPICAL AREAS Ermadani, Ermadani; Hermansah, Hermansah; Yulnafatmawita, Yulnafatmawita; Syarif, Auzar
Jurnal Solum Vol 15, No 1 (2018): JURNAL SOLUM
Publisher : Jurusan Tanah Fakultas Pertanian Universitas Andalas

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Abstract

Karbon (C) organik tanah yang merupakan bagian utama dari bahan organik tanah mengalami penurunan sebagai akibat perubahan-perubahan penggunaan lahan dari kondisi alami menjadi lahan-lahan pertanian. Penurunan C organik tanah menjadi semakin besar karena masukan bahan organik yang rendah dan bila penurunan ini. berlangsung terus menerus  maka pada akhirnya menyebabkan degradasi tanah. Artikel ini membahas peranan, dekomposisi dan struktur dari bahan organik tanah dalam hubungannya dengan dinamika fraksi C organik tanah pada pengelolaan lahan yang berbeda di daerah tropis basah. Perubahan penggunaan dan pengelolaan lahan menyebabkan terjadinya perubahan C organik total dan fraksi-fraksi C organik labil dan stabil tanah. Beberapa penelitian telah menunjukkan bahwa fraksi C organik labil seperti C organik partikulat lebih responsif terhadap perubahan-perubahan dari pengelolaan tanah dan merupakan suatu indikator yang sensitif dari kualitas tanah. Disamping itu fraksi C organik stabil seperti asam humat yang mengalami perubahan karena praktek-praktek  pengelolaan tanah dapat digunakan untuk menilai kapasitas potensial tanah sebagai penyimpan karbon. Perubahan-perubahan penggunaan lahan dan pengelolaan tanah mempunyai pengaruh negatif dan positif terhadap C organik total, fraksi C organik labil (C organik partikulat) dan fraksi C organik stabil (asam humat). Praktek-praktek pengelolaan yang dapat mempertahankan dan memperbaiki fraksi-fraksi C organik tanah  meliputi sistem agroforestri,  aplikasi pupuk organik, mulsa dan pengembalian sisa tanaman ke dalam tanah. Fraksi C organik partikulat dan asam humat menunjukkan perubahan-perubahan yang lebih besar dibandingkan C organik total akibat perubahan-perubahan penggunaan lahan dan praktek-praktek pengelolaan tanah di daerah tropis basah.Key words : Fraksi C organik, penggunaan lahan, tropis basah
KLASIFIKASI BEBERAPA SUMBER BAHAN ORGANIK DAN OPTIMALISASI PEMANFAATANNYA SEBAGAI BIOCHAR Sismiyanti, Sismiyanti; Hermansah, Hermansah; Yulnafatmawita, Yulnafatmawita
Jurnal Solum Vol 15, No 1 (2018): JURNAL SOLUM
Publisher : Jurusan Tanah Fakultas Pertanian Universitas Andalas

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Abstract

Optimalisasi pemanfaatan bahan organik akan dapat dilakukan dengan mengetahui kualitas bahan organik tersebut. Kualitas bahan organik tidak hanya ditentukan oleh kandungan hara, namun juga kecepatan pelapukannya yang dilihat dari kandungan lignin, nisbah C/N, C/P, dan C/S.  Pengujian terhadap 24 jenis sumber bahan organik di Kota Padang ini telah dilakukan pada bulan November 2016-April 2017 di laboratorium kimia tanah Fakultas Pertanian Universitas Andalas. Penelitian ini bertujuan untuk mengelompokkan bahan organik berdasarkan kandungan haranya, menentukan bahan organik yang dapat dimanfaatkan sebagai sumber biochar, dan mengkaji karakteristik dari biochar yang dihasilkan.  Parameter analisis bahan organik meliputi kadar air, C-total, N-total, P-total, K-total, C/N, C/S, C/P, dan kadar lignin.  Parameter analisis biochar meliputi kadar air,  kandungan N-total, C-total, P-total, K-total, S-total C/N, dan kadar abu. Dua puluh empat (24) sumber bahan organik yang tersedia, dapat disimpulkan bahwa berdasarkan kandungan haranya bahan organik  ini diklasifikasikan menjadi 2 yaitu : a)  bahan organik berkualitas tinggi, yang terdiri dari:  tithonia, krinyuh, gamal, kiambang, widelia, paku resam, azola, enceng gondok, alang-alang, jerami kacang tanah, jerami kedele, jerami jagung, kulit kakao, pupuk kandang ayam, pupuk kandang sapi, dan kulit jengkol, dan b) bahan organik berkualitas rendah yang dinyatakan berdasarkan kadar lignin, C/N, C/P dan C/S  yang tinggi, yang terdiri dari : jerami padi, sekam padi, pelepah kelapa sawit, tongkol jagung, tandan kosong kelapa sawit, ampas tebu, ampas kelapa sawit, dan serbuk gergaji. Bahan organik berkualitas rendah yang dioptimalkan untuk dimanfaatkan sebagai bahan biochar adalah jerami padi, sekam padi, dan tandan kosong kelapa sawit, dengan karakteristik kimia biochar yang dihasilkan memiliki C-total (28,86%), N-total (1,27%), P-total (0,28%), K-total (0,76%), S-total (0,21%), kadar abu (25,42%), C/N (22,72), C/P (103,07), dan C/S (137,43).Kata kunci : bahan organik, biochar.
Characteristics and Stocks of Soil Nutrient under Various Land Use Types in a Super Wet Tropical Rain Forest Padang, West Sumatra Hermansah, Hermansah; Sendi, Nofrita; Yulnafatmawita, Yulnafatmawita; Matsunaga, Tsugiyuki; Wakatsuki, Toshiyuki; Wakatsuki, Toshiyuki
Journal of Tropical Soils Vol 15, No 1: January 2010
Publisher : UNIVERSITY OF LAMPUNG

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Abstract

In order to clarify the characteristics and stocks of soil nutrient under various land use types in a super wet tropical rain forest in Padang, West Sumatera. We investigated the nutrient characteristics of the several samples of soils under different land use such as cacao plantation (CP), cinnamon plantation (CMP), mixed garden (MG), and primary forest (PF) in Gadut Mountain, Padang, West Sumatra. The soil nutrient characteristics varied among the different land use types. The range of nutrient characteristics under four land use type were 4.60 – 7.01% and 0.4 – 0.60 % for total carbon and total nitrogen and were 9.80 – 24.59, 0.68 – 2.07 and 0.30 – 0.8 mol (+) kg-1 for Ca, Mg and K, respectively. The highest content of soil nutrient status was found under MG, while the lowest soil nutrient status found at PF. This result indicated that the MG with various vegetation types might contribute in enriching the organic matter in soil. The soil nutrient content such as TN, exchangeable Ca, Mg and K tended to decrease with soil depth of each land use type. However, the sodium (Na) content in soil tended to increase within the soil depth. These were presumably due to evaporation of Na at surface soil within the study area was low. These study results showed that spatially the nutrient properties of soil were closely related to the land use type and management practices. It was suggested that the nutrient characteristics of soils under various land use types in a super wet tropical rain forest region, in Gadut Mountain, Padang West Sumatra were significantly affected by the land use types and land coverage.