Carbono do solo e características do milho cultivado em sucessão a diferentes coberturas vegetais

Abstract

The use of vegetable coverings is capable of protecting the soil against various weather conditions, in addition to providing greater recycling and availability of nutrients for the plants and increasing the accumulation of organic matter in the soil. Thus, it is important to use indicators of soil quality, in addition to monitoring its production levels. Thus, the objective of this work was to evaluate the soil carbon, growth, production characteristics and grain yield of maize cultivated in succession to different vegetable coverings. The experimental design used was randomized blocks with nine treatments and three replications. The treatments consisted of sorghum (Sorghum bicolor), sunn hemp (Crotalaria spectabis), millet (Pennisetum americanum), brachiaria ruziziensis (Urochloa ruziziensis), brachiaria brizantha (U. brizantha) radish (Raphanus sativus L.), velvet bean (Raphanus sativus L.) (Mucuna pruriens), dwarf mucuna (M. pruriens) and the fallow. Soil organic carbon, growth characteristics, yield components and corn grain yield were evaluated. The highest plant height was verified using U. ruziziensis, with 2.68 m and the lowest height with fallow, 2.40 m. Larger stem diameter was achieved with U. ruziziensis, sorghum, millet and sunn hemp covers. The fallow provided the smallest mass of one thousand grains, with 261 g, with the highest values observed for U. ruziziensis, U. brizantha and millet. The highest grain yield was observed for U. ruziziensis, U. brizantha, radish and pearl millet, with 8992 kg ha-1, with the lowest yield reached by fallow, with 7202 kg ha-1, representing a gain of 24.8% for the covers. The organic carbon content of the soil was 5.3% lower in the fallow when compared to all coverings. It is concluded that the vegetative covers are favorable to increase the soil organic carbon content and the grain yield of the maize crop. Key words: Biomass carbon, soil management, organic matter, Zea mays.