Jm. Hamlett et Dj. Epp, WATER-QUALITY IMPACTS OF CONSERVATION AND NUTRIENT MANAGEMENT-PRACTICES IN PENNSYLVANIA, Journal of soil and water conservation, 49(1), 1994, pp. 59-66
Citations number
14
Categorie Soggetti
Water Resources",Ecology,"Agriculture Soil Science
A field-scale microcomputer model, CREAMS, was used to assess the impa
cts of selected best management practices (BMPs) and nutrient manageme
nt programs (NMPs) on sediment and nutrient losses from three location
s with three soil and field configurations common to the Chesapeake Ba
y drainage area in Pennsylvania. Several BMPs were evaluated, with CRE
AMS simulations conducted for runoff, erosion, sediment and nutrient d
elivery to the field boundary, and percolation and nitrate leaching th
rough the crop root zone. Two separate NMPs were evaluated in combinat
ion with the BMPs. The baseline NMP followed traditional manure and fe
rtilizer application practices and the improved NMP used an improved,
high management system that incorporated best timing, placement, and t
ypes of nutrient additions. BMPs increased percolation and decreased r
unoff compared to moldboard plowing with no conservation practices. Se
diment exported from the fields was also reduced by the use of BMPS. R
eductions in total nitrogen (N) and phosphorus (P) losses varied great
ly for different BMPs and sites. Although BMPs reduced sediment-associ
ated N and P losses, the improved NMPs, as compared with the tradition
al baseline NMP, bad little effect on these losses. BMPs tended to inc
rease, whereas the improved NMPs substantially reduced, nitrate leachi
ng. The improved NMPs also greatly reduced P losses from those sites w
here P loss was predominantly in soluble form rather than sediment ass
ociated. The use of BMPs and improved NMPs together effectively reduce
d sediment and total nutrient losses.