Uso de dejeto líquido de suínos permite reduzir a adubação mineral na cultura do milho?

Abstract

The costs of mineral fertilizers have increased considerably in the last decades, in this scenario organic fertilization can be an alternative to reduce costs and maintain and/or increase the productivity of grain crops. The objective of study was to evaluate the use of liquid swine manure (LSM) associated to different combinations of mineral fertilization in maize crop development, as well as the economic aspect. The treatments tested were T1: NPK 09-33-12 + Urea; T2: NPK 0-20-20 + DLS; T3: DLS only; T4: NPK 9-33-12 + DLS; T5: DLS + Urea. Morphological, yield and economics analysis components were evaluated in two seasons. For the morphological components, only stem diameter and number of grains per row were influenced significantly, where the treatments that involved greater nitrogen addition guaranteed the increase of these variables. The combined use of mineral and organic fertilizer allowed the reduction of costs and the maintenance of high yields, being superior to the mineral control in the 2014/15 season. The exclusive use of organic fertilization with LSM was not as efficient. The combination of 50 m³ of LSM + urea under topdressing was the best option for LSM management in maize.