Judul: Soil Aggregate Stability of Regosol dan Latoso as Measured by Different Sieve Types under Bamboo Stands
Abstrak: Bambu memiliki fungsi yang baik bagi tanah. Bentuk perakaran bambu yang menyebar ke segala arah serta akar halus yang berbentuk serabut, mampu menahan erosi dengan mengikat partikel-partikel tanah menjadi agregat. Erosi merupakan salah satu bentuk degradasi lahan yang sangat erat kaitannya dengan agregat tanah. Peran agregat tanah terhadap ketahanan erosi dapat diketahui melalui pendekatan analisis agregat tanah menggunakan metode ayakan kering dan basah dengan jenis ayakan berbeda diameter dan urutan ayakan berbeda mesh. Penelitian ini bertujuan mengetahui distribusi diameter dan stabilitas agregat Regosol dan Latosol pada jenis ayakan berbeda diameter di bawah tegakan bambu serta kaitannya dengan sifat fisik tanah. Diameter masa rataan (DMR) tanah hasil ayakan A nyata lebih besar dibanding DMR ayakan B pada dua kedalaman tanah. Regosol memiliki DMR yang lebih tinggi daripada Latosol yang berbeda nyata pada kedalaman 20-40 cm dan tidak berbeda nyata pada kedalaman 0-20 cm. Jarak yang berbeda dari rumpun bambu tidak menunjukkan DMR yang berbeda nyata pada kedua kedalaman tanah. Penggunaan ayakan 25 cm menunjukkan pola distribusi diameter agregat yang berbeda pada kedua jenis tanah, sedangkan pada ayakan 15 cm relatif sama. Stabilitas agregat tanah hasil ayakan 15 cm memiliki nilai yang jauh lebih tinggi daripada hasil ayakan 25 cm. Indeks stabilitas agregat (ISA) Regosol lebih tinggi daripada Latosol. Secara keseluruhan, ISA pada kedalaman 0- 20 cm lebih tinggi daripada kedalaman 20-40 cm., Bamboo has a good function for soil ecosystem. The shape of bamboo roots that spread all directions and their fine roots system, are able to resist soil erosion by binding soil particles into aggregates. Erosion is a form of land degradation that is closely related to soil aggregates. The role of soil aggregates on soil erosion resistance might be approached by analyzing soil aggregate using 25 cm and 15 cm sieve diameter of dry and wet sieve methods with different meshes configuration. This study aims to determine soil aggregate diameter distribution and aggregate stability of Regosol and Latosol based on different type of sieve under the bamboo stand and its relation to the physical properties of the soil. The mean mass diameter (DMR) of the soil from sieve A was significantly larger than the DMR of sieve B at two soil depths. Regosol had a higher DMR than Latosol which was significantly different at a depth of 20-40 cm and not significantly different at a depth of 0-20 cm. Different distances from bamboo clumps did not show significantly different DMR at the two soil depths. The use of sieve diameter of 25 cm showed a different pattern of aggregate diameter distribution in the two types of soil, while the use of sieve diameter of 15 cm produced relatively similar pattern. Soil aggregate stability measured using sieve diameter of 15 cm has a much higher value than that measured using sieve diameter of 25 cm. The aggregate stability index (ISA) of Regosol is higher than that of Latosol. Overall, the ISA at a depth of 0-20 cm was higher than at a depth of 20-40 cm.
Keyword: ayakan basah, distribusi agregat, stabilitas agregat, aggregate distribution, aggregate stability, wet sieve