P-Available Enhancement Mechanism through Combinations of Organic Matters and Incubation Period in Psammentic Paleudults Soil

Understanding the mechanisms underlying the availability of phosphorus (P) is important for improving soil productivity Psammentic Paleudults. This research aimed to determine the mechanism for increasing phosphorus availability due to the application of various organic matters and incubation period in the Psammentic Paleudults soil from Labuhan Batu Selatan District, Sumatera Utara Province. This research was conducted at the Research Laboratory of Faculty of Agriculture, Universitas Sumatera Utara, using Factorial Completely Random Design with 2 treatment factors and 3 replications. Factor 1 was organic matters (20 tons/ha) consisting of Control, Tithonia diversifolia Compost, Durian Skin Compost, Empty Fruit Bunches Compost, Chicken Manure, Tithonia diversifolia Compost + Chicken Manure, Durian Skin Compost + Chicken Manure and Empty Fruit Bunches + Chicken Manure. Factor 2 was the incubation period consisting of 1 week incubation, 2 weeks incubation, 3 weeks incubation and 4 weeks incubation. The results showed that the combination of Tithonia diversifolia compost with chicken manure was able to increase P-available soil higher and reduce Al-P and Fe-P content.Organic matters incubation for 3 weeks reduced soil Al-P and Fe-P content. The interaction of compost Tithonia diversifolia+ chicken manure with 3 weeks incubation was the best treatment increasing soil P-available and reducing Al-P and Fe-P content in Psammentic Paleudults soil.