Below ground carbon inputs to soil via root biomass and rhizodeposition of field-grown maize and wheat at harvest are independent of net primary productivity

Summary

This field study investigated the relationship between above-ground net primary productivity and below-ground carbon allocation in two major cereals. The authors measured root biomass and rhizodeposition (soluble carbon exudates and root turnover) at harvest in maize and wheat, finding that below-ground carbon inputs were decoupled from above-ground productivity — a finding relevant to understanding soil carbon dynamics independent of yield. The results suggest that soil carbon sequestration potential in these crops cannot be reliably predicted from productivity metrics alone.

UK applicability

These findings are directly applicable to UK cereal production systems, where both maize and wheat are grown extensively. The decoupling of root carbon inputs from productivity has implications for soil health and carbon sequestration targets in UK arable farming, particularly for organic and regenerative agriculture policies.

Key measures

Root biomass, rhizodeposition, below-ground carbon inputs, net primary productivity in maize and wheat

Outcomes reported

The study quantified below-ground carbon inputs to soil via root biomass and rhizodeposition in field-grown maize and wheat at harvest. The research examined whether these carbon inputs varied independently of net primary productivity across growing conditions.

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