Study of Several Soil Properties which Managed Conventionally and by Organic Systems in Naga Timbul Village, Bonatua Lunasi Sub-District of Toba Samosir District```

Abstract

The current agricultural system is generally carried out conventionally depending on the use of chemical fertilizers. But long-term use will have a negative impact because it can acidify the soil. This study's aim was to determine several physical and chemical of soil properties managed by conventional agriculture and organic systems in Naga Timbul Village, Bonatua Subdistrict, Toba Samosir District. The method used was purposive sampling which was carried out compositely on 4 sample points by the zigzag method, 2 points on conventional agricultural land, and 2 points on organic agricultural land, at a depth of 0-20 cm and 20-40 cm. The research started from June to November 2017. The parameters observed were soil physical properties (bulk density, total pore space, and water content) and soil chemical properties (soil pH, organic C, P-available, and P-total). The results showed that the newly managed organic farming system for 3 years had a bulk density value (1.37 g / cm3) 9.67% lower compared to conventional farming systems (1.52 g / cm3); total pore space (48.34%) 11.45% higher compared to conventional farming systems (42.81%); and water content (45.44%) 40.53% higher than conventional farming systems (27.02%). The pH value around (5.13) 3.71% higher compared to conventional agricultural land (4.94); C-Organic (0.55%) 31.25% lower compared to conventional farming systems (0.80%); P-available (25.83 ppm) 28.62% lower compared to the conventional system (36.19 ppm); and the P total value (135.09%) 44.44% lower compared to conventional farming systems (243.15%).