The influence of pulse crops on phosphorus supply to a subsequent wheat crop

Abstract

Field experiments were carried out at Central Butte and Swift Current, Saskatchewan, to determine the influence of a previous pulse crop on phosphorus supply to a following wheat crop. It was hypothesized that a portion of the non-nitrogen benefit from a pulse crop in rotation is related to an effect on phosphorus availability. Wheat was planted on pea stubble and fallow at Central Butte; and pea, lentil, chickpea, wheat stubble and fallow at Swift Current. Differences in above and below ground residue effects were measured at Central Butte by removing above ground residue from part of the pea plot and placing it on an equal area of the fallow plot. Soil phosphorus supply rates were measured at various times during early growth using PRSm anion exchange probes. Yields and phosphorus uptake by the treatments were measured as indicators of effect of the previous crop on P supplied to the next crop.