No abstract

This study that was carried out in paddy fields next to Paguyangan main road in Paguyangan Village, Paguyangan District, Brebes Regency, was aimed to find out the effect of the road slope position, and the distance between main road and field toward the lead accumulation and rice productivity. The study was conducted using a survey method of purposive random sampling that consisted of two factors. The first factor was the slope position which was determined based on the three slope levels, i.e. T1/starting slope (3.4º of slope at 300 m above sea level (asl) altitude), T2/mid slope (15.84º of slope at 315 m asl altitude), and T3/end slope (8.7º of slope at 330 m asl altitude). The second factor was the distance of sampling points from the road, i.e. 25 m (J1), 50 m (J2) and 75 m (J3). The results showed that the difference in slope position and distance between the road toward plants did not significantly affect lead accumulation in rice, lead accumulation in the soil, and rice productivity on paddy fields alongside Paguyangan main road, Paguyangan Village, Brebes Regency, although the lead concentrations in rice and soil were above the specified threshold.

Food safety and soil degradation were the reasons to treat contaminated soil. Shallots are high-value commodities, so cultivation is carried out intensively. Continuous use of agrochemicals can cause heavy metal contamination. This study aimed to investigate chromium removal, physiological characters, and yield of shallot (<em>Allium ascalonicum</em> L.) on biochar and mycorrhizae application on chromium-contaminated soil. A pot experiment was conducted at the screen house ex-farm of the Faculty of Agriculture, Jenderal Soedirman University. The treatments tested consisted of two factors. The first factor was biochar dosage (B) consisting of 4 levels, i.e., B0 = without biochar, B1 = 1.2 g biochar kg^-1 of soil, B2 = 2.4 g biochar kg^-1 of soil, and B3 = 4.8 g biochar kg^-1 of soil. The second factor was mycorrhizae inoculation consisting of 3 levels, i.e., M0 = without mycorrhizae, M1 = 0.1 g mycorrhizae kg^-1of soil, M2= 0.2 g mycorrhizae kg^-1 of soil. The twelve treatments were arranged in a randomized block design with three replications. The results showed that the application of 1.2 g, 2.4 g, and 4.8 g biochar kg^-1 of soil had been able to increase plant height and the percentage of root infection. The application of mycorrhizae 0.1 g and 0.2 g mycorrhizae kg^-1of soil was able to increase plant height, percentage of root infection, and plant tissue P uptake. Both applications of biochar and mycorrhizae increased plant height and the percentage of root infection by mycorrhizae.