Short-term effects of lime management in soybean no-tillage system implementation in Brazilian savannah.

The aim of this research was to assess the effect of lime management under no-till system implementation to evaluate the millet cover crop and soybean performance. This experiment was carried out during the years 2012 and 2013 in the municipality of Ponta Pora, state of Mato Grosso do Sul, Brazil. The experimental design in blocks with four replicates and three treatments (Treat-1; Lime surface application without incorporation; Treat-2; Lime surface application and incorporated with intermediate disk harrow followed by leveling disk harrow; Treat-3; Lime surface application and incorporated with chisel plow, followed by intermediate disk harrow and leveling disk harrow), the amount of lime was 2.7 tonnes ha-1. The crops evaluated were millet ('Pennisetum glaucum' cv. BRS-1501) and soybean ('Glycine max' cv. BMX-Potencia RR) in crop rotation. The millet was planted as cover crop to produce above-ground dry mass. The soybean was sowed under millet dry mass in no-till system. After 12 months from planting, the lime management promoted chemical and physical changes in soil properties through the profile. The Treat-2 and 3 resulted in better lime incorporation in the layer 10-20 cm and 20-30 cm. The highest dry mass of millet was obtained in Treat-2 (6,460 kg ha-1) and Treat-3 (6,690 kg ha-1). The highest soybean productivity (3,330 kg ha-1) was reached in Treat-3. The absence of lime incorporation into the soil caused decrease in millet and soybean production. Even if the soil chemical is adequate for a good performance for crops, the SPR may limit the root development. The Treat-2 and 3 reduced the SPR and increased the vegetable production of soybean and millet.