Biological response of Digitaria eriantha cultivars to soil amendment with earthworm humus

Abstract

The beneficial effects of earthworms on soils are widely proved as they increase the microflora and nutrients and encourage plants growth and crop production. The objective of this study was to assess the effect of different concentrations of worm compost from goat manure on production, growth and biomass of Digitaria eriantha cvs. Sudafricana and Mejorada INTA. Dissimilar concentrations of worm compost combined with sandy soil were used with the following rates: 1- 0:100, 2-10:90, 3-20:80, 4-30:70, 5-40:60, 6-50:50, 7-100:0 (worm compost: soil). The terrines with 100 g soil and absence of worm compost were considered control. Seeds from both cultivars were sown and on the third week the biological parameters were measured: germination, leaf-root length and dry weight. There were significant differences among treatments and cultivars and the cv. Mejorada INTA was more susceptible to biological and nutritional substratum changes. Worm compost and soil mixtures proved to be beneficial to all the assessed physiological parameters. The cv. Mejorada INTA responded favorably to worm compost concentrations from 10 to 100% while the cv. Sudafricana only displayed increases with more enriched substrata (40-100%). There existed a direct correlation between worm compost and biological response, being mixture 7 (100%) the best option for both cultivars.