Low soil fertility is challenging the sustainable production of yam and other staple crops in the yam belt of West Africa. Quantitative soil measures are needed to assess soil fertility decline and to improve crop nutrient supply in the region. We developed and tested a mid-infrared (mid-IR) soil spectral library to enable timely and cost-efficient assessments of soil properties. Our collection included 80 soil samples from four landscapes (10ĝ€¯kmĝ€¯×ĝ€¯10ĝ€¯km) and 20 fields per landscape across a gradient from humid forest to savannah and 14 additional samples from one landscape that had been sampled within the Land Health Degradation Framework. We derived partial least squares regression models to spectrally estimate soil properties. The models produced accurate cross-validated estimates of total carbon, total nitrogen, total sulfur, total iron, total aluminum, total potassium, total calcium, exchangeable calcium, effective cation exchange capacity, and diethylenetriaminepentaacetic acid (DTPA)-extractable iron and clay content (R2>0.75). The estimates of total zinc, pH, exchangeable magnesium, bioavailable copper, and manganese were less predictable (R2>0.50). Our results confirm that mid-IR spectroscopy is a reliable and quick method to assess the regional-level variation of most soil properties, especially the ones closely associated with soil organic matter. Although the relatively small mid-IR library shows satisfactory performance, we expect that frequent but small model updates will be needed to adapt the library to the variation of soil quality within individual fields in the regions and their temporal fluctuations. © 2021 Philipp Baumann et al.
Tag: landscape ecology
Re-integrating ecology into integrated landscape approaches
Integrated landscape approaches (ILAs) that aim to balance conservation and development targets are increasingly promoted through science, policy, and the donor community. Advocates suggest that ILAs are viable implementing pathways for addressing global challenges such as biodiversity loss, poverty alleviation, and climate change mitigation and adaptation. However, we argue that recent advances in ILA research and discourse have tended to emphasize the social and governance dimensions, while overlooking ecological factors and inadequately considering potential trade-offs between the two fields.