Soil services

Lead organisation: Brittany Regional Chamber of Agriculture (CRAB)

Yield production and Climate regulation constitute ecosystem services provided by soils. Concerning the impact of reducing tillage practices on yield, these soil services appeared uncertain and contradictory as they can increase or decrease the crop production and also depend on the time since conversion to reduced tillage (Labreuche, 2002; Chervet et Sturny, 2007, Six et al 2004; Lee et al., 2006. Moreover laboratory studies have shown that different earthworm functional groups and their effects can have a significant impact on N2O emissions (Rizhiya et al., 2007; Giannopolous et al. 2010). There is a strong need to verify these effects under field conditions.
WP4 aims to evaluate soil services such as food production (yield, technologic and sanitary values) and greenhouse gas (GHG) mitigation.

Task 4.1. Food production (crop production)
Crop production will be evaluated in terms of yield (t ha-1) and in terms of quality of harvested products.
For the French sites, the crop production will be measured on all three experimental sites (FKA, FKO, FKT) at Kerguéhennec. Moreover, we will use existing long-term data recorded on these sites. Three different crops will be evaluated (maize, wheat, rape). Food quality will be assessed by measuring protein content for wheat and maize (Total nitrogen assay) and oil content for rape. Mycotoxin will be assessed using existing data.
At the NL sites, crop production has been measured since the beginning of the field experiments (2008 for Lelystad, and 2009 for Westmaas) and these data together with measurements for 2011 and 2012 will be available to the project. Assessments of the quality of the harvested products will be available for Lelystad only.

Task 4.2. GHG
At the NL sites, soil CO2 and N2O emissions have been monitored since the beginning of the field experiment at Lelystad (2008). These data will be available to the project. Flux measurements of N2O and CO2 are taken at regular time intervals at least biweekly, depending on temperature conditions and field operations For flux measurements, the soil surface is sealed for a fixed time interval using a polyethylene lid equipped with two rubber septa. N2O and CO2measurements are taken with a photo-acoustic infrared gas analyzer according to Velthof et al., (2002) and Giannopolous et al. (2010). Data will be complemented with results on changes in soil C stocks with time that have been measured at all the sites in France and the Netherlands. As a final dataset soil C stocks will be assessed across all sites in 2012.