Project news

 

Teilprojekt (TP) 2-1 Soil sampling and insertion of litter bags

Soil samples were taken in the upper and lower layer of top soils in the middle of the tree line as well as in different distances from the tree line. Hereafter, samples will be analyzed for indices for microbial activity (community-level physiological profiling (CLPP) by substrate-induced respiration and enzyme activity) as well as microbial biomass (C and N), ergosterol and microbial residues (amino sugars). Spatial variation will be analyzed considering the variation of SOC, total N, pH-value and soil texture.

Sampling of top soils in an agroforestry poplar tree line

Sampling of top soils in an agroforestry poplar tree line

In October 2016, litter bags with 15N labelled maize leaves have been buried in 1-5 cm soil depth at all sites, treatments and distances. Collecting of litter bags and sampling of soil below will be conducted after 6 to 8 months. Litter samples and soil below the litterbags will be analyzed for isotopic composition (δ13C and δ15N) for differentiation between mass loss and litter decomposition.

Insertion of litter bags in the top soil at the grassland site Mariensee

Insertion of litter bags in the top soil at the grassland site Mariensee

 

 

 

 

 

 

 

 

 

 

Field installations – get an impression

Mariensee, climatological mast on agroforestry plot

Mariensee, climatological mast on agroforestry plot

Mariensee, reference plot in the open

Mariensee, reference plot in the open

 

The summer is over and a huge amount of data already entered our data base. We successfully installed all of our weather masts at the SIGNAL sites. Each mast is equipped with the same set of instruments, for measuring the air temperature, relative humidity, atmospheric pressure, global- and net radiation, wind speed, precipitation and the ground heat flux. After a complex data processing procedure, we are able to estimate the amount of water entering or leaving the agroforestry and reference site, respectively.
Get an impression about our field sites and what our stations are looking like 🙂

 

Site Forst, mast on agroforestry plot

Site Forst, mast on agroforestry plot

Site Forst, reference plot

Site Forst, reference plot

Wendhausen, agroforestry plot

Wendhausen, agroforestry plot

 

 

 

 

The regrowth of willows – a photo story

Harvested willow tree strips at site Mariensee

Harvested willow tree strips at site Mariensee

In january 2016, at our agroforestry site in Mariensee, all the tree strips were harvested.

Lots of woodchips were produced and used for thermal energy production.

Woodchips from willow for energy production

Woodchips from willow for energy production

In spring, the tree stumps showed the first tender shoots.

Resprouting of willow from the stumps in next spring

Resprouting of willow from the stumps in next spring

But there were hundreds of hungry animals attacking the fresh green.

Insects attacking the fresh shoots of willow

Insects attacking the fresh shoots of willow

However, the willows were stronger than the pest, and the SIGNAL staff cared well for them. Thus, at the end of the vegetation  period, the willows have generated lots of new biomass J

Fresh tender shoots of willow, having survived the pest attack

Fresh tender shoots of willow, having survived the pest attack

Willow regrowth from shoots at end of vegetation period

Willow regrowth from shoots at end of vegetation period

 

 

 

 

 

 

 

 

 

 

 

Happy Scientists in the field!

Our plants are growing quickly and harvest time will begin soon. So long we enjoy the shade in the barley field in Reiffenhausen and play „hide and seek“ with our samples in oilseed rape in Wendhausen.

Hide and seek in rape field at SIGNAL site Wendhausen

Hide and seek in rape field at SIGNAL site Wendhausen

 

In the midst of maturing barley

In the midst of maturing barley

 

 

 

 

 

 

 

 

Field season is beginning

Suction cup lysimeters are used to see how much of the soil nutrients are washed out below the rooting zone. They are installed in all five sites, treatments and distances. By applying negative pressure with a vacuum pump, soil water from below the rooting zone will be sucked trough ceramic tips into hoses and will be collected in insulated glass bottles. In the following, the samples will be analyzed for element concentrations of Nitrogen by continuous flow injection colorimetry and Phosphorus, Calcium, Magnesium, Potassium by inductively coupled plasma atomic emission spectrometry (ICP-AES) in our lab.

Installation of equipment for suction lysimetry

Installation of equipment for suction lysimetry