Soil Property Changes during Conversion from Perennial Vegetation to Annual Cropping

Management practices for conversion of land supporting perennial vegetation to crop production are needed. Effect of haying (hayed or not hayed), cropping (annual crop with no-tillage, minimum tillage, or conventional tillage, and no-tilled perennial crop), and N fertilization (0 or 67 kg ha-1) on soil properties were measured in 1995 and 1997 at a Conservation Reserve Program (CRP) site in North Dakota having an Amor loam (Fine-loamy, mixed, superactive, frigid, Typic Haplustoll) soil in a spring wheat (Triticum aestivum L.), winter wheat, pea (Pisum sativum L.) rotation. Soil physical properties were not affected negatively by the management practices used. Haying and tillage practices influenced soil chemical properties. Organic C and total N content declined (1.2 Mg ha-1 for C and 0.1 Mg ha-1 for N) from 1995 to 1997. In hayed plots, organic C and total N increased as tillage intensity decreased while in non-hayed plots no pattern was observed. Haying and tillage influenced soil biological properties. Potentially mineralizable N at 0 to 0.05 m increased as tillage intensity decreased in 1997. In the 0.05- to 0.15-m depth, potentially mineralizable N increased from 1995 (118 kg ha-1) to 1997 (146 kg ha-1). By 1997, soil properties in hayed plots responded to cropping practices similarly to those in established cropping systems in this region. In non-hayed plots, management induced patterns had not developed by 1997. Haying, conservation tillage, and annual cropping are viable approaches for converting land to annual crop production