Fertilizer N, Crop Residue, and Tillage Alter Soil C and N Content in a Decade

Soils as open systems can either regulate or contribute to atmospheric gas pools. This chapter focuses on two experiments on a Typic Cryoboralf and on a Typic Cryoboroll in north central Alberta for 11 years to study the interactions among tillage, straw disposal, and fertilizer nitrogen (N) on barley productivity and soil quality. It examines how, after more than a decade, these treatments influenced soil organic carbon (C) and total soil N in the top 15 cm. At both sites, tillage, crop residue, and fertilizer-N induced significant changes both in concentration and mass of C and N in the surface 0.15 m after 11 years of continuous treatment. The maintenance of organic matter in soils has long been recognized as a strategy to prevent soil degradation. In Alberta, the cultivation of land over the last 100 years has decreased, in most cases, both concentration and mass of soil organic C.