A minimally destructive method for 2-dimensional soil and root mapping in row crops
摘要
Monitoring belowground soil–plant interactions in the field remains challenging and limits our ability to inform and improve agricultural management. Our primary objective was to develop two‑dimensional (2D) maps of soil and root properties using a minimally destructive, paired soil-root co‑sampling strategy in a long‑term, small‑plot experiment. Our secondary objective was to test two hypotheses: H1) soil and root properties mirror one another across the crop row, and H2) strip‑tillage and in‑row fertilization will cause localized effects relative to the interrow.
MethodsWe collected 90 soil and 90 root samples from three 6.86 × 6.10 m plots using a staggered, paired sampling design. Samples were reconstructed into 2D grids centered on the Zea mays (maize) row (76 × 30 cm). We measured bulk density (ρb), gravimetric water content (θg), pH, electrical conductivity (EC), ammonium (NH4⁺‑N), nitrate (NO3⁻‑N), salt‑extractable organic N, root biomass, root length density (RLD), and mean root diameter (MRD) to evaluate H1 and H2.
Results2D maps of soil and root properties were broadly consistent across the three plots, though optimal interpolation models varied. H1 was partially supported: 6 of 11 variables were correlated across sides of the row. Row management influenced 8 of 11 variables, supporting H2. The strongest in-row effects occurred for NH4⁺‑N > root biomass, RLD > NO3⁻‑N > EC > ρb.
ConclusionThis minimally destructive co‑sampling and mapping approach enables simultaneous characterization of soil and root distributions at the plant scale (0.05–1 m). We recommend its application in other agroecosystems to evaluate row-crop management practices.