Nitrogen, phosphorus, and rhizobial strain responses of lentil

Abstract

Non-Peer ReviewedThree field experiments were set out in 1987 to test the effect of nitrogen fertilizer, phosphorus fertilizer, and rhizobial strain on lentil yields and N2-fixation. The following treatments were laid out in a split-split-plot design: main plot treatments of uninoculated, Nitragin 'C' inoculated, and strain 99A1 inoculated lentil; sub-plot treatments of 0 and 30 kg P/ha, and sub-sub plot treatments of 0, 10, 20, 40, or 80 kg N/ha 15N-enriched fertilizer was applied to a 1.05 m2 micro-plot in each plot Barley was used as the non-N2-fixing reference crop. At all sites lentil inoculated with strain 99A1 had the greatest total dry matter yield, grain yield and N2 fixed. Uninoculated lentil had a strong N response at all sites, 'C' inoculated lentil had a starter N response at Kindersley and 99 A1 inoculated lentil had no N response at all. P responses were only observed at Foam Lake. Lentil receiving low amounts of N fertilizer obtained between 60 and 75 % of their N from the atmosphere at all sites. A good agreement was observed in estimating percent N derived from N2 using the 15N isotope dilution, A-value, or classical N-difference methods. The amount of fixed N in the seed ranged from 4 kg ha-1 under drought stressed conditions at Kindersley to 60 kg ha-1 under much better growing conditions at Foam Lake