Consórcio de crotalária e milheto: produção de biomassa e características físicas do solo

Abstract

The inadequate use and management of soils, absence of crop diversification and crop rotation compromise long-term crop development, causing soil degradation and weed infestation. The notillage system emerged in Brazil in the 70 ’s and aims in soil sustainability and conservation. However, for the proper functioning of the system, it is necessary to cover the soil surface, using a variety of crops combination. Among the plants that can be used, legumes have the advantage of establishing symbiosis with bacteria - fixing nitrogen, helping in the development of crops grown later. However, grasses produce a straw with a high C/N ratio, presenting l ower decomposition and longer soil protection. Thus, the use of a consortium among cover crops of different species such as grasses and legumes has been an interesting alternative, given the variation in the decomposition speed and nutrients accumulation in the soil through the biomass provided by the species involved in the system. Millet is one of the main cover crops indicated for n o-tillage because it has high biomass production capacity, nutrient cycling and adaptability in different types of soil. Crotalaria spectabilis is a legume, which has great application as a cover plant for increasing the nitrogen content in soils and assisting to control nematodes. The use of the consortium has been widely used not only to improve the chemical and biological qualities of soil, but a lso to improve the physical quality of it. Thus, the association between millet and crotalaria presents great potential for straw formation, which may present an intermediate C/N ratio among the species, reducing the rate of decomposition of its residues and improving the nutrient contribution to the soil.