We advocate for soil structure maintenance year-round
Seasonal variances include periods of minimal rainfall and others where autumn rainfall norms in various regions surged up to 200%, equating to 200 mm over two months. Consequently, fields experience ponding due to the soil's inability to absorb such water volumes, largely attributable to poor soil structure. Cultivation is critical for establishing appropriate soil structure, but it also has the potential to disrupt it. Rolmako subsoilers and chisel plows mitigate these adverse effects, enhancing the soil's capacity for water and nutrient absorption.
Excessive Densification
It is generally acknowledged that our soils experience excessive compaction. This is attributed to several factors, including:
- Cultivation under inappropriate, overly humid conditions
- Use of heavy equipment, also in overly humid conditions (necessary for high work efficiency)
- Low content of organic matter in the soil
- Low soil pH.
At this stage, our focus is on the initial two factors that mechanically influence soil structure. Following substantial rainfall and operations under challenging conditions, such as corn harvest, beet harvest, or late wheat sowing, degradation of soil structure is inevitable. It is essential to note that tilling the soil inflicts less damage when it is overly dry compared to when it is excessively wet. Consequently, any activity conducted in overly moist soil will result in future structural issues.
Insufficient Air
The structure deteriorates, for example, due to compression. Depending on the conditions, driving heavy machinery across the field causes soil compaction, according to various sources, by 3–6 cm. This results in 300-600 m3 of air being expelled from the ground per hectare. Consequently, soil pores that can store water are eliminated. Assuming an ideal system with 50% air pores and 50% water pores, compaction as described reduces water storage in the soil by 150-300 m3/ha (or 15-30 l/m2). This example considers soil compression of 3-6 cm over an entire hectare. However, we understand that the entire field surface is not equally compacted after machinery passes, illustrating the impact of frequent field traversal. Rolmako offers various tillage solutions aimed at increasing efficiency and reducing the number of work trips, adhering to the principle of performing as many tillage treatments as necessary.
Cultivate the soil intensively in autumn and extensively in spring
The soil should be cultivated to maximize water retention, ensuring its availability to plants during dry periods. Recently, increased rainfall in autumn has shifted the optimal time for creating water-retentive soil structures to the autumn season. Treatments should focus on creating as many water-storing pores as possible. Whether employing a plowed or simplified system, promptly remove stubble after harvest using tools such as a mulch harrow like SpringExpert. This aids in weed management and reduces water evaporation from the soil. Other tools, such as traditional disc harrows, ultra-shallow disc harrows like SpeedCutter, or cultivators like ComboTill, are also effective. The initial treatment should be shallow, allowing for initial mixing of residues with the soil. A depth of 5 cm suffices when little residue is left (e.g., post-cereal harvest with collected straw), while straw remnants in the field necessitate cultivation up to 10 cm. The subsequent treatment should reach a depth of 10-15 cm. Prior to this, apply lime or phosphorus fertilizers to ensure they are placed within the root zone. Lime adjusts pH throughout the soil profile, while phosphorus must be near the roots due to its limited mobility in the soil.
Deep Tillage
The subsequent treatment involves deep cultivation. The depth of this treatment should be adjusted according to the specific site conditions. For lighter soils without a clay base that tends to compact, a depth of 20-25 cm is sufficient. For heavier soils with a risk of plow sole formation, due to cultivation under excessively wet conditions or at the same depth for years, a depth of 30-35 cm is recommended. This deeper treatment is necessary only once every few years, as it is costly in terms of fuel consumption. The intervals between deep cultivation should be tailored to the soil type, organic matter content (with lower content requiring more frequent cultivation due to increased compaction), and moisture levels (shallower cultivation in high moisture, deeper if the soil is dry). Cultivation simplifications, such as using the Rolmako U436 no-plow cultivator, are more effective than traditional plowing methods for better water management in the soil.
What about the subsoiler?
Before heading to the field with a subsoiler, two factors are crucial: soil moisture and whether it is actually necessary in that location. If it's too wet, let's skip subsoiling. We will do less damage with a subsoiler to soil that is too dry than to soil that is too wet. Smearing areas near the working element of the subsoiler is the worst thing we can do. In such spots, no roots will grow, and water won't penetrate. Very dry soil is also not worth subsoiling because it offers too much resistance, increasing fuel consumption, and it can lead to the extraction of larger clods, especially in heavier soil that is hard to refine.
The second factor is determining whether subsoiling is necessary. It may emerge that the soil below the deepest cultivation in crop rotation is not compacted, rendering subsoiling unnecessary. The optimal method to assess this is by examining a soil profile through digging a pit. If a knife cannot be easily inserted horizontally in the profile below the standard cultivation depth, the soil requires loosening. This soil will also appear different, lacking pores and fine roots that are unable to penetrate it. Soil compaction can also be indicated by waterlogging in the field, though standing water is more likely at headlands or on technological tracks where compaction is more common.
When selecting a subsoiler, it is important to consider the working element to minimize the tractor's power requirements, such as the Atlas tine. Ripper or Michel used by Rolmako can also help reduce fuel costs.
Did you loosen? Compact
In theory, if we cultivate to a specific depth, we should compact the soil again with a roller to the same depth. However, this theory only applies to a certain extent, as the deeper we cultivate, the more challenging it becomes to compact the entire cultivated soil layer. Nonetheless, this process should always be carried out. It is important to note that string or pipe rollers are ineffective for this purpose. These only level the surface and often produce suboptimal results (they disperse light soil and fail to eliminate lumps in heavier soil). Deep-running ring rollers are most suitable for this task. Thus, a cultivator designed for deep cultivation should ideally be equipped with a V-ring roller, a heavy roller of steel rings, or a cast iron Crosskill roller. Similarly to the plow, when cultivating in the plowing system, it is optimal to use a Campbell roller. It is always best to pull the roller behind the plow, especially when time is limited before sowing. We should avoid pressing the roller on overly wet soil, and plowing it is also inadvisable (smearing and expelling air only from the top layer results in poor compaction of excessively wet soil, particularly heavier soil). Rolmako offers over 30 different models of tillage rollers, tailored for use with various machines, designed for different soil types, and delivering diverse outcomes in the field.
In the spring, we should perform only the necessary tilling operations. The soil's water retention capacity should be enhanced in the autumn. In the spring, simply prepare it for sowing. The Strip-Till technology, which refines the soil, allows for fertilization, and sowing in one pass, is effective here. However, if the appropriate structure was not established in the autumn, Strip-Till tools will not achieve it in the spring. Therefore, on excessively waterlogged fields, this method may not be the best. Excess water displaces air from the soil over time, causing natural compaction. Strip-till will remove compaction only in the strip prepared for sowing, leaving the soil in between undisturbed. This can lead to future issues, such as reduced permeability of the overall profile or severe compaction during drought periods, which roots cannot penetrate.
Wet soil in spring requires careful consideration
How should you approach cultivating soil that is too wet in spring? Unfortunately, you must wait for appropriate conditions that will allow you to enter the field. Without this, effective preparation of the position is impossible. Entering the field too early results in deterioration of the structure, which is already partially damaged by excess water.
MWet soil will take longer to warm up in spring, thereby delaying the initial cultivation procedures. However, if entry is possible, the soil should first be loosened shallowly, preferably with a cultivator, to accelerate its heating and drying. If this procedure proves sufficient, such as in lighter soil, it can be prepared for sowing at this stage. If not, a deeper cultivation may be necessary, especially for crops like corn, which require a deeper, well-prepared site.
Summary
1. We establish the appropriate soil structure in autumn for both winter and spring crops.
2. We avoid cultivating soil that is excessively wet. In such cases, we wait for conditions to improve.
3. We cultivate soil with lower moisture levels more deeply to eliminate compaction in the lower profile layers.
4. Ensure soil is compacted to the same depth it was tilled, in both simplified systems and plowing.
5. In spring, refrain from tilling excessively wet soil. The initial treatment should be shallow if the site had water in winter, to quickly warm the soil and release excess water.
6. For plants requiring deeper cultivation, such as potatoes or corn, re-till to the necessary depth, ensuring the treatment does not smear or compact the soil. Once smeared soil dries, it forms lumps that must be broken down before the next crop planting.