Organic Carbon, Texture, and Quantitative Color Measurement Relationships for Cultivated Soils in North Central Iowa

Abstract

The quantification of soil organic C (SOC) concentrations is becoming increasingly more desirable because of environmental and economic concerns regarding the reactivity of SOC with pesticides, fertilizers, and waste materials. The objectives of this study were to quantify soil color organic C relationships and to quantify soil particle‐size organic C relationships for Ap horizons in north central Iowa. All of the 130 soils examined developed in glacigenic diamicton or local hillslope sediment derived from glacigenic diamicton. A Minolta CR‐310 chroma meter was used to quantify the percentage of reflectance, and Munsell value and chroma for both air‐dry and moist soils. Organic C concentration of the sample set ranged from 4.4 to 70.8 g kg−1 Significant relationships were observed between organic C concentration and percentage of reflectance (r2 = 0.77 moist, r2 = 0.74 air‐dry), Munsell value (r2 = 0.77 moist, r2 = 0.74 air‐dry), Munsell chroma (r2 = 0.68 moist, r2 = 0.77 air‐dry), the percentage of sand (r2 = 0.74), the percentage of clay (r2 = 0.71), and geometric mean particle diameter (GMPD) (r2 = 0.74). Logarithmic relationships existed for reflectance, Munsell value and chroma, and GMPD while linear relationships were observed for sand and clay contents. Chroma meter soil color measurements and particle‐size data are useful predictors of organic C concentrations for Ap horizons in north central Iowa. Evidence from this study and the literature suggest that unique relationships exist for different soil landscapes.

Significance of Soil Lightness Versus Physicochemical Soil Properties in Semiarid Areas

“…In the bivariate linear correlations we found that despite the low contents of these two chromogen components, the relationships were statistically significant. Finally, in relation to SOC effects on lightness, we obtained the same relationship found by others authors (Konen et al 2003;Lindbo et al 1998), but its significance was lower (P<0.05).…”

“…In this regard, some authors have conducted experiments on wide areas with considerable variation in soil characteristics (Ibarra-F et al 1995;Konen et al 2003).…”

Organic Matter Modeling at the Landscape Scale Based on Multitemporal Soil Pattern Analysis Using RapidEye Data

“…Further, the characteristics of the improved OM prediction model based on MSPA, such as the best percentile threshold for eliminating temporal effects, the number of sampling points used for the prediction model generation, model-quality and model-robustness criteria (R 2 and RMSE), and the results of the OM prediction model, expressed as the extremes of the modeled OM values are demonstrated in Table 4b. [48] found a similar non-linear correlation between OM and soil lightness resp. soil color (Munsell value, chroma, and reflectance).…”

Spatial Variation in Surface Soil Total Carbon and Its Relationship with Soil Color in a River Floodplain Ecosystem of Northern Ghana

“…For example, L* ranged from 33.2 to 58.5 in our study, while Moritsuka et al (2014) showed that L* of agricultural soils collected throughout Japan ranged from 32.1 to 68.6. Previous reports suggested an empirical rule that the lightness value (L*) has a strong negative relationship with SOC or soil TC content, and would be the best indicator for the estimation of SOC or soil TC content (Konen et al 2003, Viscarra Rossel et al 2006, Moritsuka et al 2014. Schulze et al (1993) reported that the humic acid fraction was responsible for the dark color of the soil.…”

“…Soil color is one of the best options to estimate soil TC content (Konen et al 2003, Viscarra Rossel et al 2006, Moritsuka et al 2014). However, no study has been conducted in a river floodplain in West Africa to investigate the spatial variability of soil color parameters and their relationship with soil TC content.…”