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

Abstract

<span class="fontstyle0">Intercropping often results in increasing production than sole per unit land area, but the<br />underlying mechanisms are poorly understood. Plants showed different physiological<br />characteristics in intercropping and sole. However, less information was shown the relationships<br />between plant aboveground biomass (AB), phosphorus accumulation (PB) and remobilization<br />and the yield advantage. Here, field experiments were designed as split plot and carried out in<br />2012 and 2013 with three P levels (0, 40 and 80 kg P ha</span><span class="fontstyle0">-1</span><span class="fontstyle0">) in wheat (</span><span class="fontstyle2">Triticum aestivum </span><span class="fontstyle0">L.)/<br />maize (</span><span class="fontstyle2">Zea mays </span><span class="fontstyle0">L.) relay intercropping and sole. The study measured grain yield, AB and P<br />accumulation and remobilization of wheat. Averaged grain yield of intercropping wheat<br />increased 3.9 Mg ha</span><span class="fontstyle0">-1 </span><span class="fontstyle0">in 2012 and 2.7 Mg ha</span><span class="fontstyle0">-1 </span><span class="fontstyle0">in 2013 compared with that of the corresponding<br />sole and the grain yield of intercropping wheat changed with the border row (BR) > the inner<br />row (IR) > the sole wheat (SR), the grain yield in BR was contributed by 58.2% to intercropping<br />wheat. The PA was consistent with AB accumulation, which in intercropping was higher than<br />that in sole over the entire growing season. Close correlations between yield and AB<br />remobilization and P remobilization were observed. The yield of BR was higher from 39.3% to<br />88.0% than that of SR wheat, as mainly attributed to more AB and P accumulation across the<br />whole growing season and more remobilization from pre-anthesis to grain filling stage. More<br />than 40 kg P ha</span><span class="fontstyle0">-1 </span><span class="fontstyle0">did not result in any further increasing in yield and did not enhanced the<br />physiological processes associated with AB and P remobilization, indicating that P fertilizer and<br />agronomic management should be intensified synchronously in field to achieve high yield and<br />sustainability.</span>