Long term experiments

Six long term experiments are currently ongoing at the CARE AIL:

- EcoFoodSystem aims to reconnect our production systems with our food systems through four innovative long term rotations (8 years) optimized to correspond to the ideal diet as defined by the EAT Lancet Commission.

- SOLCOUVERT and SOLRESIDUS have as objective to monitor the evolution of crops’ growth, as well as the intensity of plant diseases and  weeds ‘dynamics when:

• several types of soil tillage are used to manage residues from the precedent culture
• cover crops are set up before the implementation of the following crop

- The centenary trial is the oldest long term experiment of GxABT. It was implemented in 1896 on 0.5 ha of lands and aims to study the fertilization (N, P, K) of winter wheat on the long term.

- The permanent pastures  are 0.3 ha of land located next to the CEPA and devoted among others to the observation and monitoring of grazing behavior of ruminants.

 - Agroforestry assay: two experimental set up were implemented in 2013 with different research objectives: the woodland strips and the agrisilviculture plot.

- Long term experiments in the TERRA-Terre Gardens of WASABI. Two long term dispositive are in place: permacultural beds and market gardening agroforestry plots.

EcoFoodSystem

In November 2020, a new long term experiment has started on 27 hectares of ground of the experimental farm of Gembloux Agro-Bio Tech.

Four innovative long term rotations (8 years), are tested in parcels of 15 x 80 meters. These rotations were designed in silico for cropping systems of the silty region of Hesbaye (Belgium) by joining crop and diet optimization tools to test if such coevolutions of agricultural and contrasting food systems are consistent or compete one with another in terms of food security, agronomical and environmental objectives. The tested systems are:

1:  The reference rotation: an hypothesis where flows are optimized at a regional scale and where the food and agricultural systems are open to the rest of the world to import and export commodities and animals are incorporated through flows of agricultural byproducts and manure. This system will be tested following two variants: with the utilization of herbicides only on one hand, and without the use of any pesticides on the other hand.

2: The ICLS rotation: an hypothesis where flows are optimized at a local scale, where crops are produced to meet more sustainable and healthy diets as proposed by the EAT-Lancet commission and where animals, especially ruminants, are used as functional tools to manage weed and pests through grazing of temporary pasture and intercrops, in addition to nutrients flows of the first system. This system will be tested without the use of any pesticides.

3:  The vegan rotation: a “zero flow” hypothesis, to simulate agriculture in a society where livestock farming would not be tolerated anymore. In this system, also managed without the use of pesticides, there will be no production for animals and no manure utilization.

Around the parcels, an ecological network has been implemented: hedges, flower bands, messicole plants, trees (agroforestry assay) to improve biodiversity and associated ecosystem services.

Each year, a steering committee including farmers, scientists and industry representatives meets to discuss the results of the trial and consider improvements to be made. This keeps the experiment in touch with the realities of the field and farmers.

Communications and Scientific publications linked to EcoFoodSystem

Read the article (August 19th 2022)

SOLCOUVERT and SOLRESIDUS

Crop residues and/or covercrops represent a biomass that can be restored to the soil, maintaining its fertility. Two adjacent experimental plots have been set up at Gembloux Agro-Bio Tech: SOLRESIDUS and SOLCOUVERT respectively in 2012 and 2008, each on 1.7 ha of land. The aims of these experiment is to monitor over time, crop growth, weed’s dynamics, microbial activity and biomass, and disease intensity resulting from the various tillage methods used to manage the crop residues from the precedent culture, and/or the implementation of covercrops to prepare the implementation of the following culture.

In the SOLRESIDUS assay, the quantity of residues ploughed depends on the exportation or not of the straws. The residues are either ploughed on 10 cm by a shallow tillage, or on 25 cm by a tillage. Weeds and pathogenic fungi present on the residues follow the same path, so the techniques used could have effects on the yields of the following cultures.

In the SOLCOUVERT assay, the implementation of a cover crop between the wheat harvest of and the spring crop, allows the production of an important quantity of organic matter and compete with weeds. Four management methods of the cover crops are compared. The reference method is a winter ploughing. It is followed by a shallow tillage for seedbed preparation made just before the implementation of the spring crop. This technique allows to bury the fresh cover crop biomass as well as the weeds that are not too much developed. In the second tested modality, the same techniques are applied but the ploughing occurs in spring, just before the seedbed preparation and the spring crop implementation. In this case, the cover crop and the weeds have continued to grow during the winter. In the third modality, a loosening work at 25 cm of depth before the implementation of the cover crop and a shallow tillage (where the organic matter from the weeds and cover crop are mixed in the first 10 cm of soil) is made in spring prior to the spring crop seeding. The last tested modality is the strip-till where only the seeding line is being worked on a width of 10 cm and a depth of 15 cm. The cover crop residues and weeds are left in surface. In the two last modalities, the cover crop is destroyed chemically if it was not destroyed by frost.

Several PhD were made using the data from this experiment, allowing to go further in the follow up of some crop parameters: germination rates, crop phenology, biomass production and evolution as well as the repartition between the plant organs, soil N content and N absorption by the crop, yield and quality of the production, presence and incidence of bio-aggressors (insects, weeds and diseases), evolution of roots’ growth, decomposition of crop residues, P and water dynamics in soil, soil structure and respiration and soil microbiota.

Communication and scientific publications linked to SOLCOUVERT and SOLRESIDUS

 

Looking for more information?

• Hiel M, Barbieux S, Pierreux J, Olivier C, Lobet G, Roisin C, Garré S, Colinet G, Bodson B, Dumont B. 2018. Impact of crop residue management on crop production and soil chemistry after seven years of crop rotation in temperate climate, loamy soils. PeerJ 6:e4836 https://doi.org/10.7717/peerj.4836
• Margaux Lognoul, Nicolas Theodorakopoulos, Marie-Pierre Hiel, Donat Regaert, François Broux, Bernard Heinesch, Bernard Bodson, Micheline Vandenbol, Marc Aubinet. 2017. Impact of tillage on greenhouse gas emissions by an agricultural crop and dynamics of N2O fluxes: Insights from automated closed chamber measurements. Soil and Tillage Research (167)  https://doi.org/10.1016/j.still.2016.11.008.
• Degrune Florine, Theodorakopoulos Nicolas, Colinet Gilles, Hiel Marie-Pierre, Bodson Bernard, Taminiau Bernard, Daube Georges, Vandenbol Micheline, Hartmann Martin. 2017. Temporal Dynamics of Soil Microbial Communities below the Seedbed under Two Contrasting Tillage Regimes. Frontiers in Microbiology (8) DOI: 10.3389/fmicb.2017.01127

The centenary trial

Communications and scientific publications linked to the centenary trial

The permanent pastures

Grazed pastures display multiple roles that can benefit the sustainability of ruminant-based agriculture, such as, lower feeding costs, higher animal welfare and lower occurrence of lameness and mastitis, good public image and increased milk quality. Pastures can play a significant role in trapping atmospheric CO₂ through soil C storage. In addition, grasslands provide many social and environmental services.  Hence, the goal of this experiment is to strengthen the role of grazing as a key element of ruminant husbandry.

Precision tools were developed to analyze this process, such as rtk-GPS and activity sensors to monitor the grazing animals and drone-based imaging to analyze at a high spatial and temporal resolution the interactions between the grazed vegetation and the gazing animals.  Such technological advances open the doors to novel grazing methods that valorize heterogeneity in the grazed vegetation and inter-individual difference in the animals as opportunities for more a sustainable management of grasslands.

Communications and scientific publications linked to the permanent pastures

 

Agroforestry assay

Two kinds of experiments are installed in sequence on the area:

- Wooded strips (WS):

2 WSs of 170 m long and 81 m apart (3 sprayer widths) were installed in spring 2013. They are mixed hedges of bushes and trees with a multifunctional purpose. The trees are carefully cared for (training pruning, pruning, protection) to produce quality logs. The sheathing shrubs participate in the formation of these logs. The bushes form the protective hedge (oriented against the northeast winds), produce fodder (species selected for their fodder value) or biomass while offering a great capacity of reception for the biodiversity (flowers, fruits, shelter…).

- Agrisilviculture plot (1.64 ha):

This plot includes 4 lines of trees spaced 29 m apart (sprayer width + safety margin); trees spaced 4 m apart on the line (overall density of 100 A/ha). The ultimate goal is to retain 33-50% of the trees after selection of the best phenotypes (33-50 A/ha). Three blocks of species were planted in the fall of 2013:

- cherry (in collaboration with an INRA agroforestry cherry genetic improvement project)

- plane tree

- hybrid walnut

 

Long term experiments in the TERRA-Terre Gardens of WASABI

Two types of long-term dispostives are in place in the TERRA-Terre Gardens, the full-ground vegetable plots of the WASABI platform:

- Permaculture raised beds:

Five types of permacultural raised beds (4.20 m long by 1.2 m wide) with different organic matter compositions are tested on the same plot (nine replicates per modality):

- Forest raised bed (alternating layers of C and N with large logs in the center)

- Sandwich raised bed (mainly composed of cellulosic materials and small diameter wood)

- Lasagna raised bed (alternating layers of C and N, without wood)

- A raised bed only composed of ground

- A non-raised culture

 These different modalities are compared to each other for the production of various types of vegetables but also to study the fertility of the soil of these mounds in the long term, and the physical, chemical and biological properties of the soil.

- Market garden agroforestry plots:

Four lines of 11 apple trees (local varieties selected in collaboration with CRAw) were planted 9 meters apart. Different vegetable species will be planted on these 9-meter wide strips. The objective of this trial is to study over time the competition (for light, nutrients, water) between the trees and the vegetable crops as a function of the distance from the tree lines and as a function of the treatments applied to the tree roots.