Estimating topsoil texture fractions by digital soil mapping - a response to the long outdated soil map in the Philippines

Table 5 Cross validation of OK, SK, and UK applying exponential, Gaussian, and spherical variogram models applied to Clay texture fraction

Spatial Interpolation	Variogram model	MAE after kriging	RMSE	R²
OK
	exponential	0.130	0.186	0.8741
	Gaussian	0.234	0.312	0.5917
	spherical	0.134	0.191	0.8631
SK
	exponential	0.130	0.186	0.8732
	Gaussian	0.234	0.312	0.5903
	spherical	0.134	0.191	0.8625
UK – Stepwise
	exponential	0.128	0.182	0.8736
	Gaussian	0.223	0.296	0.6288
	spherical	0.133	0.187	0.8639
UK – Backward
	exponential	0.126	0.178	0.8780
	Gaussian	0.219	0.289	0.6463
	spherical	0.131	0.183	0.8690

ISSN: 2468-2039