Biochar increases available phosphorous, prevents the nitrification of ammonium (i.e., keeps ammonium in plant available forms), improves crop root systems, raises soil organic carbon, reduces drought stresses, enhances soil microbial communities and benefits cation exchange capacity. These changes to the soil environment can limit environmental stresses to the crop and improve water use efficiency, which in turn improves productivity and yield.
How Does Biochar Improve Crop Productivity?
Nutrient Delivery
Biochar can directly deliver phosphorus and other nutrients to crop root zones. When combined with other fertilisers (organic or inorganic), biochar improves their improves their nutrient value through its sorbent properties. This means nutrients stay within biochar’s pores or stick to its surface, rather than being lost through emissions or leaching.
Crop Root Structure
Biochar increases nutrient concentration around roots while improving crop root structure. These work to improve the accessibility of soil nutrients to plants.
Nutrient Cycling
Soil nutrient cycles, particularly nitrogen and phosphorus, are altered, increasing available nutrients.
💡Using Biochar Effectively in Crop Productivity
The effect of biochar application on crop yield and productivity strongly depends on soil type, crop, application method, biochar type and dose rate. Biochar uses systems can be altered to improve efficacy and target specific factors which limit crop growth.
- Increases in yield and productivity are greatest in less fertile, acidic soils.
- Biochar is effective when applied in combination with other fertiliser or nutrient sources. Biochar must be used in combination with other nutrient sources.
- Application methods can improve biochar efficacy. Targeted application to increase biochar concentration near the crop root zone is recommended for low-dose applications.
Using high-quality biochar with known properties is necessary to quantify its fertilisation value and ensure adequate performance, so it can be used to reduce mineral fertiliser application.
Conclusion
The primary effect of biochar which leads to improved cropyield varies depending on many factors, such as soil type, biochar type,application method, and weather conditions. Over time, these effects such as:
- Enriched soil microbial and fungal communities,
- Increased nutrient retention and cycling,
- Enhanced root development,
- Increased adsorption and exchange of ammonium, and
- Improved soil structure, water and aerobicity,
work together to improve crop productivity and yield, and overall soil health.
Find out how biochar can be used to target specific benefits through the rest of our Biochar Basics series:
- Improving the nutrient value of organic fertiliser
- Enhancing soil water properties
- Increasing soil carbon
