KEMAMPUAN RETENSI AIR DAN KETAHANAN PENETRASI TANAH PADA SISTEM OLAH TANAH INTENSIF DAN OLAH TANAH KONSERVASI

A research to study a long term influence of soil management systems on water availability-related soil properties has been carried out in Darmaga Bogor. The experiment was conducted in area with conventional intensive tillage system (OTI) and conservation tillage systems (OTK) in dry-farming agriculture in the clay soils (Oxic Dystrudepts) with seasonal crops rotation. The two tillage systems have been practice in the area for more than 12 years. Water retention characteristics and penetrability of soil from the two tillage system were compared. Conventional intensive tillage system appreciably reduced soil organic matter content as compared to conservation tillage. Similar tendency is also found for water retention characteristics. Field capacity, available water capacity, and field water contents are lower in OTI than in OTK, whereas soil penetrability is higher in OTI than that in OTK. A relatively high differences of soil penetrability in the soil profile under intensive tillage system has been observed, possibly due to the compaction of the sub soil.