Fig. 1. (A) Nested design for the collection of soil samples. Samples were collected at the indicated distances in random directions within grid cells of 50 by 50 m. (B) Location of sampled sites and soil series present in Field A. Crosses indicate the location of samples collected for the determination of soybean cyst nematode population density; black circles indicate which of those samples were also used for soil particle size analysis. Soil series are (1) Newaygo sandy loam, (2) Conover loam, (3) Brookston loam, (4) Breckenridge sandy loam, and (5) Belding sandy loam. Soil series map was digitized from Threlkeld and Feenstra (1974). Spatial distribution of (C) sand, (D) clay, and (E) silt percentages in the soil as interpolated by ordinary kriging within the area sampled. The shadings in C, D, and E represent percentage ranges. (F) Soil type delineation determined based on the proportion of sand, silt, and clay. Soil types are (1) loamy sand, (2) sandy loam, (3) loam, and (4) sandy clay loam.