SUPPLEMENTARY FERTILIZATION MANAGEMENT AND TWO SOIL IMPROVEMENT EFFECT IN CORN

Abstract

Fifteen trials were established in Azuero Region on the second sowing season (August-January), to determine some alternatives for corn supplementary fertilization management and to measure grain yield increase by soil bio-stimulant utilization. It was used a complete randomized block design with four replicates. The treatments consisted in two factors in a 3 x 3 factorial arrangement. The first factor (Supplementation Type) comprised in different supplementary fertilization managements at 21 and 37 days after seeding (dap) with urea (46-0-0) and nitrogen fertilizer (27-6-3-2-4). The second factor was the use of soil bio-stimulant algas extract and humus, the third level of this factor was a tester (plots without bio-stimulant application), for nine treatments. The soil bio-stimulants were applied at seeding, along with the herbicides. According to the obtained results during the three years of this experiment, grain yield increase was not significant, as a result of the bio-stimulant application. The rainfall at some crop development stage affected urea substitution by other types of supplements. During the years with lack or uneven rainfall, the treatments with N-Fertilizer can be an alternative to urea substitution for using at the first spread at 21 dap. The economic analysis indicated that application of double N-Fertilizer without bio-stimulant succeeded the other treatments. On the other hand, the stability analysis indicated that N-Fertilizer-Urea without bio-stimulant was the most stable treatment.