Long-term effects of potassium fertilization and straw return on soil potassium levels and crop yields in north-central China

Abstract

Understanding the changes in soil potassium (K) and crop yield under K fertilization and straw return is important for proper K fertilizer management. A field experiment involving a wheat (Triticum aestivum L.)-maize (Zea mays L.) rotation was conducted to study the effects of long-term (20-year) K fertilization and straw return on soil K and crop yield in north-central China. Fertilization treatments included: nitrogen and phosphorus fertilizers (NP), NP plus wheat straw (NPS), NP and K fertilizers (NPK), and NPK plus wheat straw (NPKS). Annual soil K budget increased with increasing K inputs (including fertilizer K and straw K) in the order of NP.