3.1.1. Lint Yields

The soil, landscape, and weather factors associated with lint yields in the estimated mean difference regressions were silt soil texture (Pr ≤ 0.01), loam soil texture (Pr ≤ 0.05), elevation (Pr ≤ 0.01), organic matter (Pr ≤ 0.01), soil depth (Pr ≤ 0.01), soil erosion index (Pr ≤ 0.01), and growing degree days (GDD) (Pr ≤ 0.01) (Table 4). Soils classified as having a silty or loamy texture relative to sand (the intercept term) were negative in relation to VRN yields when compared to FP. Higher temperatures, as measured by seasonal GDD, or field sites at higher elevations also had a negative association with

VRN yields compared to FP. Therefore, soils with coarser textures, fields at higher elevations, or fields in locations with warmer temperatures were negatively related with VRN yields when compared to FP, all other factors equal. Thus, VRN managemen<sup>t</sup> may not increase lint yields on fields with these conditions when compared to the FP. By contrast, soils with higher organic matter content, deeper profiles, or subject to more erosion were positively associated with VRN yields relative to FP, all else equal. Soils with more organic matter may have more natural N available to the plant [45]. Soils with a higher erosion index had a positive association with lint yields, potentially because more N was applied in areas of the field that were more eroded.


**Table 4.** Estimated average landscape, soil, and weather effects on lint yield, fertilizer nitrogen (N) rate, N efficiency (lint yield/fertilizer N rate), and net return.

Note: Standard errors are in parentheses. \* Significant at the 0.10 probability level, \*\* significant at the 0.05 probability level, \*\*\* significant at the 0.01 probability level. a Variable names are defined in Table 3. b Intercept contains sand soil texture. c Soil texture coefficients scaled by 10%. d WHC coefficients scaled by 100. e SOM coefficients scaled by 100%.
