Short-term effects of organic amendments on soil properties and maize (Zea maize L.) growth

In recent years, the application of biochar as soil amendment has generated a huge interest for the preservation of soil fertility by improving the physicochemical and biological properties of soil, and for the reduction of the negative effects of greenhouse emissions (climate-change adaptation). In this study, we investigated the effect of three soil amendments, namely, biochars derived from wood (BC), solid digestate (SD), and biochar derived from solid digestate (BSD), on soil parameters and their influence in maize-growth performance. The experiment was conducted in a greenhouse where organic amendments were applied to the soil control (C) at different application rates: 0%, 1%, 2%, and 3% w/w (equivalent at 0, 10, 20, and 30 t ha−1, respectively). The results indicated that all applications of organic amendments significantly enhanced soil parameters such as pH and electrical conductivity, while only BSD and SD showed a significant increase in secondary macro-(i.e., Ca, Mg) and micronutrient-element content (i.e., Na, Fe, Mn and Zn). The best maize performance (i.e., plant height, stem diameter, biomass dry weight, seed number, and weight per ear) was observed while using BSD, while plant growth in BC had reduced results, probably due to the low presence of elemental content and the relatively high volatile-matter (VM) content, which may have altered nitrogen dynamics.