Wheat Growth as Affected by Combinations of Phosphate Dose and Patch Size

Abstract

Core Ideas We investigated response of wheat growth to different combinations of P‐patch size and dose.Heterogeneous supply of P outperformed its homogeneous supply in terms of yield.Optimal combinations of P‐patch size and dose realized highest wheat yield. Heterogeneous supply of P generally confers a distinct advantage to crops. However, this advantage depends closely on the size of the heterogeneous patch and the dose of nutrients. This study investigated the combined effect of patch size and P dose on the growth of wheat (Triticum aestivum L.). A pot experiment was conducted with five P‐rich patches by adding one P dose (P1, 100 mg) to varying fractions of soil volume [100% (V100), 20% (V20), 10% (V10), 5% (V5), no soil (V0)], and an additional three doses of P [P2 (300 mg); P3 (500 mg); P4 (1000 mg)] were added to the first two patch sizes. A heterogeneous supply of P outperformed a homogeneous supply in terms of yield in patch sizes V0 to V20 with the same dose of P (p < 0.05). Compared with V100, however, significant less dry matter was still observed in the early stages of crop growth when P fertilizer was mixed with V0. In heterogeneous P‐supply environments, wheat yield increased markedly with patch size up to V10 and then decreased by 11% in V20 at the P1 dose (p < 0.05). Increases in P doses to P4 in V20 consistently improved wheat yield and shoot P uptake compared with V10/P1. This may be mainly attributed to improved root length and mass density inside P‐rich patches. Hence, a suitable match between P‐rich patch size and the dose of P contributes to more efficient use of P and helps to realize greater yield.