More aboveground biomass, phosphorus accumulation and remobilization contributed to high productivity of intercropping wheat

Intercropping often results in increasing production than sole per unit land area, but theunderlying mechanisms are poorly understood. Plants showed different physiologicalcharacteristics in intercropping and sole. However, less information was shown the relationshipsbetween plant aboveground biomass (AB), phosphorus accumulation (PB) and remobilizationand the yield advantage. Here, field experiments were designed as split plot and carried out in2012 and 2013 with three P levels (0, 40 and 80 kg P ha-1) in wheat (Triticum aestivum L.)/maize (Zea mays L.) relay intercropping and sole. The study measured grain yield, AB and Paccumulation and remobilization of wheat. Averaged grain yield of intercropping wheatincreased 3.9 Mg ha-1 in 2012 and 2.7 Mg ha-1 in 2013 compared with that of the correspondingsole and the grain yield of intercropping wheat changed with the border row (BR) > the innerrow (IR) > the sole wheat (SR), the grain yield in BR was contributed by 58.2% to intercroppingwheat. The PA was consistent with AB accumulation, which in intercropping was higher thanthat in sole over the entire growing season. Close correlations between yield and ABremobilization and P remobilization were observed. The yield of BR was higher from 39.3% to88.0% than that of SR wheat, as mainly attributed to more AB and P accumulation across thewhole growing season and more remobilization from pre-anthesis to grain filling stage. Morethan 40 kg P ha-1 did not result in any further increasing in yield and did not enhanced thephysiological processes associated with AB and P remobilization, indicating that P fertilizer andagronomic management should be intensified synchronously in field to achieve high yield andsustainability.