Effects of site preparation on nitrogen dynamics in the southern Piedmont

• Published in: Forest ecology and management 1986-09, Vol.15 (4), p.241-256
• Main Authors: Fox, T.R., Burger, J.A., Kreh, R.E.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Cropping systems. Cultivation. Soil tillage; Forestry; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Soil tillage. Irrigation. Drainage; Tillage. Tending. Growth control
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/0378-1127(86)90162-3

The impact of three mechanical site preparation treatments, chop-burn, shear-disc, and shear-pile-disc, on nitrogen dynamics was examined on gauged watersheds in the Piedmont of Virginia. Samples from soil solution and streamwater and a series of soil incubations, both laboratory and in situ, were used to monitor changes in the treatment areas following site preparation. Available nitrogen reserves were lowest in the shear-pile-disc watershed where the logging slash had been piled into windrows. Larger nitrogen reserves were found in the shear-disc and the chop-burn watersheds. Nitrogen mineralization was greater in the site prepared areas than in the uncut stand and mineralization generally increased as site preparation intensity increased. Between 58 and 95 kg/ha of nitrogen were mineralized in the site prepared areas during the first year following treatment compared to only 38 kg/ha during the same period in the uncut stand. Streamwater nitrogen export increased following site preparation with the largest losses of nitrogen occurring in the shear-pile-disc watershed.