Influence of biogas-digester effluent on crop growth and soil biochemical properties under rotational cropping

摘要

Abstract A 6-year study investigated the suitability of effluent from an anaerobic biogas digester as a fertiliser for supporting crop growth and maintaining soil biochemical levels under rotational cropping. The soil at the experimental area was predominantly a Fluvaquentic Eutrochrept. Comparisons were made with an inorganic fertiliser and a water-only treatment, using three crops (maize, oats, and kale) grown over a 2-year rotation. Dry matter yields were not consistently influenced by any of the treatments, apparently because of high soil-nutrient reserves. Thus the effectiveness of the effluent as a fertiliser could not be assessed. However, plant nitrogen concentrations were usually higher in the effluent and fertiliser treatments than in the water-only treatment for the last 3 years of the study. Soil organic C content for each treatment remained unchanged over the 6-year period. In contrast, microbial biomass, urease activity, and net mineral-N production (0–28 days) declined significantly in all ...