1. Advances in Molecular Approaches for Understanding Soil Organic Matter Composition, Origin and Turnover – A Historical Overview<br>Ingrid Kogel-Knabner and Cornelia Rumpel<br>2. On the Use of Silicon as an Agronomic Mitigation Strategy to Decrease Arsenic Uptake by Rice<br>Angelia L. Seyfferth, Matt A. Limmer and Gretchen E. Dykes<br>3. Cracks and Pot-holes in Vertisols: Characteristics, Occurrence and Management<br>J. Somasundaram, Rattan Lal, N. K. Sinha, Ram Dalal, A. Chitralekha, R. S. Chaudhary and A. K. Patra<br>4. The Importance of Sustained Grassland and Environmental Research: A Case Study from North Wyke Research Station, UK, 1982-2017<br>M. S. A. Blackwell, S. C. Jarvis, R. J. Wilkins, D. A. Beaumont, L. M. Cardenas, D. R. Chadwick, A. L. Collins, J. A. J. Dungait, M. J. Gibb, A. Hopkins, M. R. F. Lee, T. H. Misselbrook, P. J. Murray, J. R. B. Tallowin<br>5. Legacy Nutrient Dynamics at the Watershed Scale: Principles, Modeling and Implications<br>Dingjiang Chen, Hong Shen, Mingpeng Hu, Jiahui Wang, Yufu Zhang, Randy A. Dahlgren