Use of Airborne Hyperspectral Imagery to Map Soil Properties in Tilled Agricultural Fields

Table 2

Partial least squares (PLS) prediction model goodness of fit (𝑅²) associated with each of 15 math treatments, for the 13 analytes that predicted with 𝑅²>0.5, calculated using data from all 315 soil sampling locations¹. The first derivative gap two (1Dg2, depicted in bold) was selected as the overall most successful model although it was occasionally outperformed (italic). See Section 2 for analyte descriptions.

Derivative	Gap	C	Sand	Silt	Clay	pH	OM	K	Ca	Mg	Mn	Zn	Fe	Al	average
		𝑅^2	𝑅^2	𝑅^2	𝑅^2	𝑅^2	𝑅^2	𝑅^2	𝑅^2	𝑅^2	𝑅^2	𝑅^2	𝑅^2	𝑅^2	𝑅^2
NON	0	0.578	0.762	0.763	0.585	0.442	0.685	0.555	0.669	0.692	0.642	0.670	0.754	0.777	0.659
1ST	1	0.555	0.770	0.761	0.565	0.517	0.706	0.522	0.654	0.719	0.624	0.606	0.707	0.799	0.654
1ST	2	0.591	0.763	0.763	0.617	0.549	0.717	0.514	0.676	0.708	0.638	0.647	0.740	0.782	0.670
1ST	4	0.595	0.754	0.740	0.596	0.451	0.692	0.513	0.630	0.616	0.565	0.675	0.703	0.773	0.639
1ST	8	0.584	0.748	0.739	0.600	0.413	0.668	0.578	0.635	0.642	0.580	0.636	0.637	0.727	0.630
1ST	16	0.588	0.740	0.744	0.550	0.442	0.672	0.547	0.610	0.619	0.567	0.591	0.666	0.725	0.620
1ST	32	0.525	0.730	0.722	0.554	0.381	0.640	0.520	0.648	0.619	0.542	0.580	0.669	0.765	0.607
1ST	64	0.338	0.623	0.619	0.470	0.317	0.537	0.413	0.519	0.580	0.488	0.568	0.636	0.669	0.521
2ND	1	0.542	0.585	0.597	0.424	0.361	0.526	0.484	0.708	0.705	0.529	0.599	0.665	0.729	0.573
2ND	2	0.507	0.681	0.682	0.372	0.499	0.566	0.493	0.665	0.664	0.566	0.591	0.673	0.769	0.595
2ND	4	0.576	0.714	0.724	0.409	0.449	0.660	0.484	0.672	0.669	0.606	0.613	0.749	0.752	0.621
2ND	8	0.536	0.698	0.689	0.533	0.472	0.602	0.528	0.595	0.631	0.542	0.638	0.743	0.753	0.612
2ND	16	0.580	0.729	0.725	0.573	0.487	0.661	0.498	0.590	0.640	0.598	0.617	0.680	0.712	0.622
2ND	32	0.564	0.715	0.698	0.609	0.432	0.631	0.548	0.622	0.592	0.548	0.606	0.639	0.688	0.607
2ND	64	0.525	0.596	0.589	0.421	0.156	0.599	0.511	0.556	0.464	0.501	0.538	0.602	0.614	0.513

¹Analytes that predicted poorly 𝑅² (<0.5) included: N (<0.303), P (<.355), Cu (<0.358), B (<0.169), S (<0.282), and P saturation (<0.127).