Mapping soil slaking index and assessing the impact of management in a mixed agricultural landscape

Abstract. Soil aggregate stability is a useful indicator of soil physical health and can be used to monitor condition through time. A novel method quantifying stability, based on the relative increase in footprint area aggregates as they disintegrate when immersed water, has been developed performed using smartphone application – SLAKES. In this study SLAKES was obtain slaking index (SI) values topsoil samples (0 10 cm) at 158 sites assess mixed agricultural landscape. large range SI 0 7.3 observed. properties land use were found correlated with observed values. Soils clay content >25 % cation exchange capacity (CEC) : ratio >0.5 had highest Variation for these soils driven by organic carbon (OC) which fit segmented exponential decay function. An OC threshold 1.1 observed, below most extreme under dryland irrigated cropping lower higher compared perennial cover. These results suggest that farm managers mitigate effects implementing management practices content, such minimum tillage or cover cropping. regression-kriging utilising Cubist model suite spatial covariates map across area. Accurate predictions produced leave-one-out cross-validation, giving Lin's concordance correlation coefficient (LCCC) 0.85 root-mean-square error (RMSE) 1.1. Similar validation metrics an independent test set consisting 50 observations (LCCC = 0.82; RMSE 1.1). The potential impact promote sequestration explored simulating how 0.5 1.0 would observation points then mapping Overall, maps have guide decisions identifying areas currently experience highlighting are expected significant reduction increasing content.