Pengaruh Sistem Olah Tanah dan Residu N Tahun ke–29 pada Beberapa Sifat Kimia Tanah dengan Tanaman Indikator Leguminosa

Land degradation due to intensive soil tillage can decrease agricultural production. This research aims to obtain the effect of soil tillage system, to obtain the effect of various rate of N on soil chemical properties, and to gain interaction between soil systems and N residues on soil chemical properties of the 29th year using leguminosae plant indicator. The research was conducted at State Polytechnic of Lampung from May 2016 to November 2016. The research use randomized block design with two factors. The first factor is the various of tillage soil systems consisting of intensive soil tillage (IST), minimum tillage (MT), and no-tillage (NT). The second factor is the residue of nitrogen fertilizer (Urea) from the previous plant with three levels i.e. 0 kg N/ha (N 0 ), 100 kg N/ha (N 1 ), and 200 kg N/ha (N 2 ). The experiment was repeated 4 times. Observational variables were pH, organic carbon, total Nitrogen, available phosphorus (H 2 O), total Potassium, and weight of shoot. Data were analysed using Anova and  followed  by LSD-test at α = 0,05. The Result showed that no interaction effect between soil tillage system and N fertilizer residue. No-tillage resulting the highest  available phosphorus (10,713). Nitrogen fertilizer residue at the rate of 200 kg/ha resulting the lowest soil pH value (5,980).