Loading...As part of carbon farming, the aim of PDT is to enrich agricultural soils with carbon through the sustainable development of humus, while also breaking up compaction. This approach helps store some of the CO2 emitted by humans into the atmosphere within the soil. A higher humus content improves soil fertility and subsequently leads to higher yields.
By embracing this historical practice, the project aims to merge past innovations with modern sustainability goals, offering a promising strategy for both agricultural productivity and climate protection.
Funding from the Federal Ministry of Food and Agriculture (BMEL) has resulted in the creation of a special carbon farming plough for PDT to transform farming practices and enhance soil health.
Developed in collaboration with Lemken, the plough’s design features. normal plough bodies alternating with specialised carbon farming (CF) bodies which work deeper into the soil.
Before PDT
soil layers in balance
The aim of PDT is to break up soil compaction and increase soil fertility. In PDT, the subsoil is mixed into the topsoil. The topsoil is not deepened over the entire area, but only in sections, in shafts about 75cm apart. In practice, it is already proven on sandy and sandy loam soils in moraine areas, increasing the soil humus content.
After PDT
compaction is alleviated
By breaking up the compacted soil, plant roots can better access resources, especially water and nutrients in the subsoil. After 10 years, the PDT can be repeated, initially offset between the shafts, and then another 10 years later at right angles to the previous direction of work.
Effects of PDT
April 2023
Analyses using satellite technologies enable farmers to monitor plant health and growth and are particularly suitable for precision farming. As part of the ‘CarbonTillage’ project, satellite images of a maize field were taken after PDT to investigate the effect on yield. The dark stripe represents the part of the field on which the PDT was carried out.
Effects of PDT
October 2023
IYields increased significantly within just six months. In addition, different productivity zones within the fields could be visualised. This helps farmers to identify areas with high (green), medium (yellow) and low (red) yield potential. On the stripe treated with PDT (green), the maize grew particularly well.
As the plough moves, it creates 10cm wide shafts at 75cm intervals, reaching depths of up to 55cm. During this process, about 20% of the subsoil is exchanged with topsoil. This exchange breaks through compaction zones, allowing plant roots to access deeper layers rich in nutrients and water.
Michael has been conducting research on the Carbon Tillage project since 2022.
“Our trials demonstrated a stable yield increase of 300-500kg/ha of grain following the implementation of PDT,” he says.
“This 5% yield boost mirrors results observed in the 1960s to 1980s and is confirmed by current field trials at ZALF.
How PDT contributes to climate protection
Humus-rich soils, containing about 50% carbon, play a crucial role as natural carbon reservoirs. The carbon stored in these soils originates from plant photosynthesis and biomass The carbon eventually becomes part of the soil through roots, residues and microbial decomposition products.
By mixing low-carbon subsoil with topsoil, an imbalance is created, prompting the topsoil to accumulate carbon compounds until equilibrium is reached.
The subsoil mixed into the topsoil develops into new topsoil in the 10 years following PDT.
Marisa Gerriets, a PhD student at the Leibniz Centre for Agricultural Landscape Research (ZALF) has been working on the PDT project since 2019.
“The subsoil mixed into the topsoil develops into new topsoil within the 10 years after a PDT, corresponding to carbon sequestration,“ explains Marisa Gerriets, a PhD student working on the project.
A project with roots in the GDR
Looking back at the history of PDT – it can be traced back to the late1950s when it was known as ’segment ploughing in the GDR. ‘Initially aimed at improving yields and reducing the risk of crop losses, PDT was carried out on a large scale, predominantly on arable land, and primarily in moraine landscapes but also in isolated loess areas, until German reunification.
The development of the plough from the 1960s to today
As part of the ’Krumensenke’ project, ZALF researchers revealed the shafts that had been created remained intact 40 years later. Using archived soil samples from the 1980s, Michael and his team were able to prove the long-term sustainability of PDT after confirming that the current topsoil had a 50% higher carbon content compared to the original.
Sandy soils can store an additional 10t/ha of CO2 equivalent within 10 years of PDT activity, while loamy soils can store as much as 30t, making PDT a significant contributor to climate protection.
From segment plough to carbon farming plough
“The biggest challenge was developing a tool that mixes topsoil and subsoil correctly without negatively impacting plant growth during seeding,” says Andre. “We have invested many hours in field trials and tested various tool combinations to get the plough just right.”
For example, the plough currently uses a wide furrow blade to fill the topsoil into the shaft created by the CF body. “The required power of the carbon farming plough varies depending on the soil conditions. On soils that have not been tilled for a long time, especially in deeper soil layers, the required tractive force can double.”
The carbon farming plough is currently in the pre-series phase and set for release in 2026.
The CarbonTillage project
Funded by the German Innovation Partnership (DIP) for Agriculture, the Federal Agency for Agriculture and Food (BLE) and the Federal Ministry of Food and Agriculture (BMEL).
Project period:
April 2022 to July 2025
Partner:
LEMKEN GmbH, Agrathaer GmbH
Leibniz Centre for Agricultural Landscape Research (ZALF)