Application of Soil Amendment and N, P, K Fertilizers on the Growth and Production of Corn (<i>Zea mays</i> L.) In Ultisol Soils of Lampung, Indonesia

Abstract This study aimed to investigate the effects of soil amendment and NPK fertilizers on corn production in Ultisol soils of Lampung, Indonesia. This research was carried out in February-August 2023 at the Integrated Field Laboratory, University of Lampung at coordinates 5°22′10″ S and 105°14′38″ E. A randomized block design with two factors (soil amendment and NPK fertilizer levels) was employed. The first factor was soil amendment (cow dung manure, 5 ton ha −1 , and biochar 5 ton ha −1 (B), namely: without soil amendment (control, B 0 ), a combination of cow dung manure and rice husk biochar (B 1 ), a combination of cow dung manure and corn cob biochar (B 2 ), a combination of cow dung and cassava stem biochar (B 3 ). The second factor was the N, P, K fertilizer dose (P), which consists of: without fertilizer (control, P 0 ), a half dose of standard base fertilizer (P 1 ), and recommended basal dose fertilizer (P 2 ). The results showed that applying soil amendment (cow dung manure +biochar) increased the growth and production of corn more than without soil amendment. Still, there were no significant differences effect between the various types of soil amendment. The recommended basal dose fertilizer (P 2 ) had the highest corn production than (P 1 ) and (P 0 ).