I have the touch – evidence for considerable N transfer from peas to oats by rhizodeposition

The current study quantified the carbon (C) and nitrogen (N) transfer from peas to oats under field conditions to assess the effects of intercropping. The data obtained were compared with previously published pot and field experiments.

Pea (Pisum sativum L. cv. Santana) and oat (Avena sativa L. cv Dominik) plants were grown as intercrops for 105 days. Pea plants were labelled with a solution of 2% ¹³C glucose (99 atom%) and 0.5% ¹⁵N urea (95 atom%), using the cotton wick technique.

Pea rhizodeposits reached 540 kg C ha⁻¹ and 17 kg N ha⁻¹. CdfR (C derived from rhizodeposition) and NdfR corresponded to a proportion of 18.2 and 12.7%, respectively, of total pea biomass C and N. In the intercropped oat plants, only 0.6% of the total pea CdfR amount was found, but nearly 30% of the total pea NdfR amount.

CdfR and NdfR as proportion of total pea biomass C and N, respectively, were 2.5 times higher in peas intercropped with oat plants than in sole-cropped pea plants, comparing the current results with those from previously published pot and field experiments. Future studies on intercropping should consider root formation and rhizodeposition more often.