Application of Earthworm Manure (EWM) and NPK Fertilizer to Improve the Quality of Acid Sulphate Soil (ASS) as a Sweet Corn (Zea mays L) Cultivation Land in North Sumatra, Indonesia

A field trial has been carried out in order to study the use of Earthworm Manure (EWM) and NPK fertilizer improve quality Acid Sulphate Soil (ASS) as a sweet corn (Zea mays L) cultivation land North Sumatra. The experiment was Factorial Randomized Block Design. Factors studied were fertilizer. EWM treatment arranged 4 doses consisting of: Control (0 kg / plot), 0.4 plot; 0.8 1.2 EWM/plot. given control plot); 5 g 10 15 plot. material applied by mixing with topsoil ASS at depth about cm evenly each plot when it 1 week before plant planted. While between rows plants are 2 weeks old. Each size 100 x repeated 3 times. spacing set 60 70 cm, distance replications 50 plots 30 cm. Variables observed include some soil properties, growth crop yields. properties measured pH (H2O), total N (Kjeldahl), P (Bray II), Exchangeable-K (K-ex) (NH4OAc 7.0). Growth yield also determined including: height, stem diameter, yield. results obtained showed that application could shown increase content, available P, exchangeable-K, based on diameter growth. increases K-ex, but does not number leaves, Application pH, whereas no effect pH. effects interact positively content where content; better improving chemical (N, K, pH) compared application. can be used partially or completely substitute so save Therefore, potential an alternative agrobiotechnology product opportunity overcome problem agricultural land.