Wollastonite powder application increases rice yield and CO2 sequestration in a paddy field in Northeast China

ABSTRACT:

Background and aims
Enhanced silicate rock weathering (ERW) on cropland soils can increase crop yield and promote carbon dioxide (CO2) sequestration. Applying silicate rock powder to flooded rice paddies can promote weathering, but the effects of ERW on rice production and CO2 removal rates in the field remain unclear.

Methods
We investigated the effects of adding wollastonite (CaSiO3) powder (5 t ha−1) to rice paddy plots on soil properties, rice yield, rice grain quality, grain arsenic, grain cadmium, and soil CO2 sequestration in Liaoning Province, Northeast China.

Results
Wollastonite application increased soil pH, soil available silicon (Si) content, and Si uptake by rice. Wollastonite application increased grain number by 10% per panicle (15 ± 2), total grain number by 15%, and rice yield by 12% (1.4 ± 0.1 t ha−1). After five months of rice growth, soil inorganic carbon (SIC) content in the surface soil increased by 1.20 ± 0.03 t CO2 ha−1 in wollastonite treatments. We estimated a net profit of $300 (U.S.) ha−1 from yield increase and carbon trade with wollastonite application to this paddy field.

Conclusions
Wollastonite application to paddy fields in Northeast China promoted rice yield and CO2 sequestration in the surface soil. This soil CO2 sequestration triples that from the control soil and is comparable to prior pot trials. Although field trials are needed on the limits to CO2 sequestration and rice yield increases with wollastonite application, such applications promise to increase soil CO2 sequestration and profits for a key crop.

https://doi.org/10.1007/s11104-024-06570-5