Perennial Legume Seedling Growing After Additions of Biochar and Cow Manure in a Degraded Amazonian Oxisol.

Substrate to seedling production must to present physical and chemical characteristics that allow, respectively, water retention and also nutrients availability to supply the seedling requirement. The objective of this study was to investigate the effect of different levels of biochar and cow manure on perennial legume faveira (Enterolobium cyclocarpum (Jacq.) Griseb) seedling grown. Biochar was produced from woody material Lacre (Vismia guianenses Aubl. Pers.) from a 4-year old tree, at 600^oC in a pyrolysis furnace of refractory brick. The seedling was grown for three months in a greenhouse  pot trial (2,4 kg)  on a low fertility Amazonian oxisol amended with the biochar at application rates of 0,0%, 1,0%, 2,0%, 3,0% and 4,0% (w/w) (equivalent to 0,0; 20,0; 40,0; 60,0 and 80,0  t biochar ha^-1) and cow manure at application rates  of 0,0; 10,0; 20,0; 30,0 and 40,0 t cow manure ha^-1. Increased the rates of biochar did not increased the seedling grown; the higher level of cow manure in the absence of biochar showed the highest shoot dry matter production; the total amounts of nodules presented a linear response as increasing biochar rates in the absence of cow manure; the increase of cow manure rates affected negatively the nodules formation in the roots. The interaction biochar and cow manure was positively until 3,0% of biochar application, following by decreased. The P available and K exchangeable both presented the highest values with the combination of 40 t. ha-1 of cow manure and 40 t. ha-1 of biochar.

General program area: Soil fertility and plant nutrition