Impact of grassland renovation/conversion on greenhouse gas emissions, water pollution and need-oriented fertilization
What is the impact of grassland renewal by reseeding on N2O emissions and nitrate leaching? Are procedures to renew grassland without killing off the sward suitable to lower emissions? We tackle these questions in two field studies in Lower Saxony.
Current economical and structural changes in agriculture are associated with intensification of grasslands and conversion of grassland to arable land. Following tillage during grassland renewal or conversion, negative environmental impact (e.g. enhancement of groundwater pollution due to nitrate leaching and increased greenhouse gas emission) can occur.
There is few knowledge on site-specific effects by different techniques of grassland renewal, maintenance or conversion on carbon (C) and nitrogen (N) transformations, although these aspects are highly relevant for adapted fertilization, greenhouse gas emissions and groundwater pollution. In this project, we will assess the impact of different techniques of grassland renovation/conversion on greenhouse gas emissions, water pollution and need-oriented fertilization.
Field plot trials comparing grassland renewal/conversion techniques are conducted in cooperation with the Lower Saxony Chamber of Agriculture on two sites with different soils (Plaggic Anthrosol at Wehnen; Histic Gleysol at Ihausen) with weekly measurements of C and N dynamics over two years.
We test the following treatments:
N2O, CH4 and CO2 emissions are measured using closed chambers. Stable isotope data are used to investigate production and consumption processes of N2O. N losses via nitrate leaching are estimated from weekly measurements of mineral N (Nmin) in surface soils and measuring 0 to 90 cm Nmin profiles twice a year in spring and fall. Further elucidation of N dynamics will be obtained from isotope tracer experiments with intact soil columns.
1.2013 - 12.2015
Project funding number: Graduiertnekolleg 1397
Project status: finished