Early priority effects of occupying a nutrient patch do not influence final maize growth in intensive cropping systems

Abstract

Priority effects can be caused by an individual plant within a population that is the first to occupy and explore nutrient patches. However, the magnitude of priority effects of exploring a nutrient patch on plant growth during the ontogeny remains obscure. A 30-day rhizo-box experiment and a 2-year field trial with maize (Zea mays L) were conducted to examine the influence of priority effects arising from heterogeneous nutrient (nitrogen and phosphorus) supply on the root and shoot growth of maize under nutrient-limited and nutrient-rich environments. In the rhizo-box with limited soil resources, maize shoot biomass and nutrient content increased with the closeness to the nutrient patch, suggesting strong priority effects. In the field trial with high fertilizer input, priority effects arising from root proliferation within the nutrient patch also brought growth advantages for individual plants close to the patch in the first 45 days after sowing (DAS), but positive effects were weaker than in rhizo-box conditions. The growth advantage was not maintained after 60 DAS. The early priority effects did not promote grain yield. Our findings demonstrated that the growth advantage of early priority effects from exploring the nutrient patch was dependent on time and soil nutrient supply.