Farm Table says:
Biochar Improves Soil Aggregate Stability and Water Availability in a Mollisol after Three Years of Field Application
What is the problem?
Intensive, suboptimal agricultural practices have led to soil quality deterioration. In the top 30 cm of typical mollisols, the nitrogen content has declined by 61% and the soil organic matter by 50% over the past 40 years of continuous cultivation. Researchers from China investigated the effects of adding biochar to soil treatments overtime.
What did the research involve?
- Ma et al. (2016) carried out field experiments in the Jilin Province of China. The soils were predominantly mollisols and the climate is mainly temperate/monsoonal with hot and rainy summers and cold and dry winters.
- The experiments were carried over 2012-2014 and involved four different soil treatments; control/no fertilization, inorganic fertilizer (NPK), inorganic fertilizer with maize straw, inorganic fertilizer with biochar.
- Soil core samples were used to determine soil bulk density and an elemental analyser was used to determine soil organic carbon and total nitrogen content.
What were the key findings?
- Ma et al. (2016) reported that the chemical properties of soil changed significantly after three consecutive years of fertiliser and organic amendment treatments.
- Biochar amendment increased soil aggregate quality and significantly reduced bulk density in both the inorganic fertilizer with maize straw treatment and the inorganic fertilizer with biochar treated soils.
- NPK treatments and the inorganic fertilizer with biochar treated soils showed significant increases of plant available water.
- Furthermore, compared with the other three treatments, NPK treatment significantly reduced the soil organic carbon content.
Three consecutive years of amending soils with NPK fertilizers suplemented with biochar significantly improves soil organic carbon and increases plant accessible water content by decreasing bulk density while increasing the proportion of macro-aggregates and plant nutrient retention.
This paper was summarised by Luke Stafford (Bachelor of Biological Sciences with Honours – Botany and Genetics Majors (La Trobe University) and reviewed by Nickala Best (PhD Student (La Trobe University). Learn more about Luke and Nickala here.