Effects of sole and combined addition of biochar and compost on improving soil quality and crop productivity
Abstract
Soil organic matter is a critical component of productive soils. It has vital role in maintaining
important soil functions. Consequently, using biochar and date palm waste compost as
soil amendments is considered one of the agricultural practices for improving productivity and
soil fertility in the dryland soils. The aim of this work was to compare the application of compost
sole and its mixture with biochar on soil quality and barley growth performance. A field
experiment in blocks was conducted in the south of Tunisia. Triplicates of 4m2 (2×2 m) were
performed for each treatment which were: control, 56 t.ha-1 compost (C), 10 t.ha-1 biochar + 56
t.ha-1 compost (BC+C), 10 t.ha-1 biochar + inorganic fertilizer (BC+F) and inorganic fertilizer
only (F). Soil samples were characterized chemically for pH, electrical conductivity (EC), soil
organic carbon content (OC), total nitrogen content (N), phosphorus content (P) during the
crop season. In addition, plots were planted with barley and studied traits (plant height, dry
weigh biomass and yield) were measured.
Results showed that date palm waste compost increased OC by 50% and total N by 21% at
harvest time. Nevertheless, a significant increase in P was observed when inorganic fertilizer
only and biochar+ compost were applied. Positive effects of compost and biochar-compost addition
also were observed on (plant height, dry weigh biomass and grain yield). Indeed, C and
(BC+C) significantly increased the plant height by 15% and 13%, respectively as compared to
control soil. Furthermore, compost increased dry weigh biomass by 22%. Also, C and (BC+C)
had a positive impact on the grain yield and minerals nutrition.
Overall, our results highlight that in a soil poor in nutrients, the combination of compost and
biochar could be effectively used to enhance and sustain soil fertility and improve crop productivity
over time.