FLUKTUASI FOSPOR DAN KEMASAMAN PADA AGREGAT TANAH DI PERKEBUNAN TEH YANG BERUMUR 36 TAHUN DI KECAMATAN GUNUNG TALANG, KABUPATEN SOLOK

Soil acidity is the dominant factor in the phosphate amount, distribution of nutrients in the aggregate is important to supporting nutrient requirement and cycling. Furthermore, Al-P and Fe-P or Ca-P bonds trapped in soil minerals, also physically protected from loss due to associate with aggregates. Thus, the factual limitation of phosphorus becomes a topic, including various aggregate fractions changes and their effect on the slope. Soil samples were taken from 36 years old plantations consisting of 45 points with two depths (0 - 20 cm and 20 - 40 cm) on a various slope, soil samples fractionated into several aggregate fractions, namely micro (<250 µm), meso (250-2000 µm) and macro-aggregates (2,000-5,000 µm). For chemical analysis, soil pH was measured by pH meter, aluminium with the volumetric method, and P-available with Bray method. Based on the analysis, it is known that the P content in the meso aggregate is higher than P content in the macro aggregate ± 0.055 g m-2 for 0 - 20 cm ± 2.136 g m-2 for 20-40 cm depth, and ± 1.058 g m-2 for slope of 0-8% at 0-20 cm depth. In total, phosphate in the tea plantation area is very low.