Insights from eAgronom's Trials

Insights from eAgronom's Trials

As the demand for sustainable farming practices grows, regenerative agriculture is stepping into the spotlight. This approach emphasizes soil health, biodiversity, and resource efficiency, making it an essential tool for tackling climate change and ensuring food security. Two standout practices that often get the most attention are direct drilling and cover cropping, both of which hold transformative potential when integrated into farming systems.

Direct Drilling demonstrations 

Direct drilling demo day has been one of the main events for eAgronom farmers in Estonia for 2 years in a row. Reason being that while reduced tillage is widely adopted practice, no-till farming might be more complicated to get right. The benefits of this method lead to multiple important benefits, like:

• Improved soil structure: Reduced compaction and better water-holding capacity.

• Erosion prevention: Residues on the surface protect the soil from wind and water erosion.

• Carbon emissions reduction: Less fuel consumption and greater soil carbon retention.

Lessons from the field

eAgronom demo days in Estonia provide practical insights into the nuances of direct drilling. Our demo days are organised as farm trials, thus statistically significant differences have not been calculated and plots are not in repetition. The biggest benefit of field demonstration events comes from attending the event and seeing different direct drills live in action. More detailed overview of drills and the trial conditions can be found from our previous blog posts (https://blog.eagronom.com/) . 

Our learnings from 2 years of direct drilling days are following: 

• True direct drills disturb the soil minimally by cutting the slot for the seed and closing it, without cultivating the rows. 

• Residue management is critical to prevent “hairpinning,” where straw interferes with seed placement. If straw is not distributed evenly a straw harrow should be used.

• Preconditions for success: correct drainage, eliminated compaction, levelled field and proper soil pH are preconditions for success.

• Practical tips: Crop rotation and starting with "easier" crops (like cereals) make transitioning to direct drilling more manageable.

• Tine seeders vs disc seeders: both have their pros and cons, but tine seeders tend to bring more stones to the surface. 

With proper implementation, direct drilling saves time, fuel, and labor while improving the soil health.

Cover Cropping: Feeding the soil for the future

Growing cover crops offers numerous benefits for improving soil health:

• Soil protection: Preventing erosion and reducing nutrient leaching.

• Biodiversity boost: Supporting soil microbes and beneficial insects.

• Nitrogen fixation: Leguminous species, like clover and vetch, reduce the need for synthetic fertilizers.

• Soil organic matter increase: Additional benefits, like improved soil structure, increased nutrient availability, improved water infiltration and water holding capacity 

eAgronom cover crop trials main purpose is to test and demonstrate different cover crop species and mixes suitability to specific field conditions. We are also focusing on showing the effect of early and late sowing time, effect of fertilisers and different types of sowing techniques. 

In 2023 we had a diverse trial in the ground with different cover crop mixes, but we also grew single species in order to understand the performance of unique species. This gave us a chance to hold a small nitrogen trial, where 25 kg of N was spread to the plots approximately a month after sowing. The trial field was a sandy loam type with a thin upper layer and total profile only 40-50 cm deep, after which a bedrock of limestone appeared. This means the field is prone to drought and lacks natural fertility. In a situation of low soil fertility or late sowing date, adding a bit of nitrogen to get cover crops growing is one option. Our trial field showed that 25 kg of N doubled the aboveground biomass production. 

Figure 1: Nitrogen fertiliser effect on cover crop aboveground biomass growth, Estonia 2023

Figure 2: Nitrogen effect on white mustard and phacelia, 2023. Author: Simon Boughton

The importance of sowing dates can’t be overstressed- the earlier, the better. In 2024 we tested different drilling dates and techniques. We started with an outcast system on a sprayer and spread the seed mix into the standing wheat crop at the end of July. We used a mix of phacelia, tillage radish, white mustard and buckwheat. The next sowing date was on the day of harvest (7-th of August), followed by different seeding techniques the next day. Last sowing dates were 2 weeks after the previous ones. 

From the graph below we can see the effect of sowing date and minor differences between different techniques. The only anomaly is the outcome of the first sowing date, which we assumed should have grown the biggest biomass. Visual assessment on the field led us to the conclusion that spreading seed to standing crop was uneven and some seeds did not get enough soil to seed contact and thus didn’t germinate. What we also noticed was that the soil quality was very different in different parts of the field. We had a total of 30+ plots, whereas the drilling date and technique were situated on the hillside. Same cover crop species performed differently on different locations. This was specifically noticeable of phacelia.  

Figure 3: Drilling technique and date impact on cover crop biomass yield, Estonia 2024

Figure 4: Importance of sowing time. Author: Merili Toom

Three of our trials in 2024 were situated in Latvia. There we tested different cover crop mixes performance in different locations of Latvia and assessed the outcome by collecting aboveground biomass samples and measuring the nutrient content of biomass. Trials were sown in the middle of August and biomass samples were gathered on 10-th of  October.

The graphs below illustrate the biomass growth and cover crops ability to catch free nutrients from the soil. These results stress the importance of plant cover throughout the year to avoid nutrient loss to deeper layers in the soil or even to the groundwater.  

Figure 5: Yields and nutrient content of cover crop aboveground biomass on trial I, Latvia 2024

Figure 6:  Yields and nutrient content of cover crop aboveground biomass on trial II, Latvia 2024

Figure 7: Crop species in different mixes, Latvia 2024

Key learnings from cover crop trials

• Cover crops are an investment in soil health for the future: Cover crops are not just a short-term solution—they contribute to long-term soil improvement. By increasing organic matter, enhancing microbial activity, and improving nutrient cycling, they build a resilient soil system that benefits future crops. Over time, this translates into better water retention, reduced input costs, and improved yields.

• Bare ground = lost opportunity, leached nutrients and erosion: Leaving soil exposed means losing valuable nutrients, increasing erosion risk, and reducing soil fertility. Bare ground allows rainfall to wash away topsoil, leaching nitrogen and other essential elements. Cover crops act as a protective shield, keeping nutrients in place while preventing wind and water erosion.

• The growing window is narrow in the Baltics – quick-growing species and early drilling are key: In regions with short growing seasons, such as the Baltics, timing is everything. Delayed sowing reduces biomass production and limits the effectiveness of cover crops. The key to success is choosing fast-establishing species (e.g., phacelia, buckwheat, mustard) and drilling them immediately after harvest to maximize their benefits.

• Soil fertility and pre-crop nutrition influence cover crop biomass production: The effectiveness of cover crops depends on the nutrient status of the soil and how well the previous crop was fertilized. If the pre-crop exhausted soil nutrients, the cover crop may struggle to establish. Balancing soil fertility through proper nutrient management ensures higher biomass production, leading to greater soil organic matter accumulation and nitrogen fixation.

• Cover crop mixes = risk management + complementary benefits: Diverse cover crop mixes help mitigate risks and maximize benefits. A well-balanced mix includes: Grasses (e.g., rye, oats) for biomass and erosion control; Legumes (e.g., vetch, clover) for nitrogen fixation; Brassicas (e.g., radish, mustard) for soil structure improvement. By combining different functional groups, farmers reduce the risk of crop failure, improve nutrient cycling, and enhance biodiversity.

• Cover crop species should be from different families than main crops: Rotating plant families in cover crops prevents disease and pest buildup. For example, if cereals dominate the cash crop rotation, avoid grass-heavy cover crops. Instead, introduce legumes, brassicas, and broadleaves to break pest cycles, improve soil structure, and optimize nutrient availability.

Feeding the soil for the future

Regenerative agriculture represents a paradigm shift—feeding the soil so it can feed us sustainably. The combination of innovative practices like direct drilling and cover cropping is not just an investment in soil health but also a commitment to a more resilient future for agriculture. As eAgronom’s trials demonstrated, these methods are practical, scalable, and transformative. Adopting both practices as part of a regenerative system ensures higher yields, reduced input dependency, and long-term farm sustainability.