Soil chemical properties and nutrients in maize fertilized with urban waste compost1

ABSTRACT Urban waste compost has a potential to be used as an organic fertilizer in agriculture, but field studies are required to define the recommendable rates for crops. This study aimed at evaluating the effect of fertilization with urban waste compost on the soil chemical properties, yield, nutrient and heavy metal contents, in maize leaves and grains. The field experiment was carried out in a randomized complete block design, with seven treatments and four replications. The treatments consisted of six urban waste compost doses (0 Mg ha-1, 5 Mg ha-1, 10 Mg ha-1, 20 Mg ha-1, 30 Mg ha-1 and 40 Mg ha-1), applied in the planting furrow, plus an additional control treatment, with NPK mineral fertilization and no waste compost application. Fertilization with up to 40 Mg ha-1 of urban waste compost improves soil fertility. Fertilization with urban waste compost increases grain yield and the N, P and K contents in leaf tissue and maize grains, without inducing plant contamination with heavy metals. The application of 30 Mg ha-1 of urban waste compost can replace mineral fertilization in maize cultivation.