Changes In Soil Properties And Crop Yields Of Farmland Over A 20-Year Reclamation Period From Grassland In The Hilly Areas Of Hebei, China

We investigated the effects timing after reclamation with imported soil on soil organic carbon (SOC), total nitrogen (TN), aggregates, and crop yield of farmland converted from grassland. Soil samples collected in farmland plots after 1, 3, 6, 10, 15, and 20 years of reclamation were ananlysed. Maize yield was also measured. The SOC and TN content slightly decreased initially, and then increased up to their grassland levels in 20 years. The SOC and TN content of the 20-year reclaimed farmland increased by 168% and 103%, respectively, compared with that in 1-year reclaimed farmland in the 0-10 cm soil layer. It improved over reclamation years compared with that in the imported soil. Over time, macroaggregate proportion in the 0-10 cm layer decreased by 8%, whereas that in the 10-20 cm and 20-40 cm increased by 3% and 13%, respectively. The grassland had higher water stability of developed aggregates than the farmland. The maize yield initially increased and plateaued after 15 years. Overall, grassland reclamation to cropland through imported soil engineering alters soil properties, such as SOC, TN, and soil water stability, they initially decreased and subsequently stabilized after 10 reclamation yeas.