Influence of pea cultivars on soil N balance and sequent crop production

Non-Peer ReviewedThree field experiments were conducted in northwestern Alberta to determine the influence of pea cultivars on the N economy and the performance of the sequent wheat crop: four pea cultivars were tested with barley as the check. All but one experimental year had below average growing season rainfall. Dinitrogen fixation decreased in the following order among the peacultivars: Grande > Carerra > Eiffel > Swing, the same order as net productivity. Only Grande pea resulted in balanced soil N; soil N deficit, in kg N ha-1, was 7-38 for Carrera, 20-37 for Swing, and 18-37 for Eiffel. Grain N uptake by the sequent wheat was well-correlated with N fixed by pea (r =0.843**). Even where the soil N balance was negative, wheat following pea mostly had higher seed protein content and yield than wheat following barley. The greater N availability after pea is attributed to higher net N mineralization from pea root and rhizodeposits than barley roots and rhizodeposits. It is concluded that selection of a high net productivity pea cultivar should typically result in greater N and yield benefits to the sequent cereal crop than a low net productivity cultivar