Wheat Root Growth and Phosphorus Uptake Affected By Fertilizer Source and Rate.

Plants can adjust the root system growth to improve water and nutrient uptake. The objective of this study was to assess the effect of phosphorus (P) fertilizer source and rate on winter wheat’s (Triticum aestivum L.) root system growth and P uptake. A greenhouse study was carried out at Kansas State University, Manhattan, Kansas, during the 2016-17 winter season under controlled environment. The experimental design was a completely randomized design with four replications. Treatments consisted of three P fertilizer sources: (1) monoammonium phosphate (MAP), (2) MicroEssentials (MESZ), and (3) MAP + ammonium sulfate (AS) + ZnSO_4. Phosphorus fertilizer sources were applied at 3 rates: (1) 34, (2) 67, and (3) 101 kg P₂O₅ ha^-1. There was an additional treatment with 0 kg P₂O₅ ha^-1 (control). The wheat response parameters assessed were plant shoot dry weight, as well as root length and diameter through scanned images, estimated using the software WinRHIZO Pro. The increase in P fertilizer rates from 34 to 101 kg ha^-1 promoted an increase in root length growth of 94 and 119% for MAP and MESZ fertilizer sources, respectively. There was no effect of P fertilizer sources and rates on plant shoot dry weight and root diameter in the greenhouse. However, is possible that changes in root growth due to P fertilizer source and rate can may affect plant growth and yield particularly under conditions of water stress in the field.