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How to retain water in the soil so that plants can make good use of it?

Retaining water in the soil is a must! Especially nowadays, when we can no longer count on regular rainfall. Therefore, it's worth knowing methods that will reduce the loss of water from the soil. Retaining water in the soil after harvesting is a necessity. Soil that is deprived of any protection quickly loses water and is also very susceptible to erosion. During prolonged droughts, it loses its crumbly structure. Moreover, the lack of water in the soil reduces its biological activity, and plants cannot absorb mineral nutrients dissolved in water.

Take care of the soil and provide it with what it needs

It is worth realizing that the farmer also significantly influences how plants will cope during a drought period. First and foremost, attention should be paid to the varieties selected for the field. Here, it is worth highlighting the advantages of purchasing certified seed material, especially new varieties. It is worth choosing varieties with increased drought tolerance. The health of the seed material also affects not only the germination process but also the later vigor of the plants. Remember, the healthier and better-nourished the plants, the better they will cope with drought. Any damage caused by pests and diseases affects the transport of nutrients and water in the plant, which also impacts the yield size. Therefore, it is worth taking care of plant health through appropriate protection. It is also worth noting that proper fertilization is essential. To support plants in preparing for the adverse effects of drought, it is worth considering proper fertilization based on resource analysis and considering the needs of the plants. Remember phosphorus, which influences the development of the root system. It is also advisable to plan for potassium fertilization, which regulates water transport in the plant. Plants with insufficient potassium supply handle drought conditions poorly. A common symptom visible during drought in plants with potassium deficiency is their rapid wilting. Additionally, it is worth remembering micronutrient fertilization, especially with manganese. Nutrients are not only essential for the plants; their content in the soil also determines the humus formation process. Soil is a habitat for beneficial organisms that transform forms of elements unusable by plants and participate in soil structure-forming processes. Unfortunately, we often overlook the role of soil, which is the growth medium for plants. In drought conditions, an aggregate structure and the humus content in the soil play a very important role. These two components are interconnected because humus stabilizes the soil structure.

Immediate cessation of evaporation after plant harvesting is crucial

Post-harvest cultivation should commence as soon as possible after crop harvesting. However, this is often challenging due to logistical issues (e.g., volume of field work) or adverse weather conditions (e.g., drought). Neglecting this step is a significant error, as uncultivated soil rapidly loses moisture through evaporation. It is essential to prevent moisture from reaching the soil surface immediately. Soil capillaries that transport moisture from deeper layers should be disrupted. Water loss from this process during hot, sunny days can reach up to 80 liters per square meter per day, equivalent to the average monthly rainfall in July. Cultivation should not be delayed and must be executed with precision. For expedient and effective post-harvest cultivation, equipment such as the SpringExpert mulch harrow or knife rollers (ProCut and TurboCut) from Rolmako are recommended. Operating speeds of 20-25 km/h facilitate rapid intervention, interrupting evaporation and encouraging weed germination and destruction during subsequent cultivation. This prevents unwanted plants from competing for water with actual crops.

The size of soil particles is crucial

The amount of water that evaporates from the soil is influenced by the size of soil aggregates in the seed layer. Ideally, the diameter of soil particles should range from 0.02 to 50 mm, optimally at 2 mm. These particles are intermediate, neither too small to cause capillary rise nor too large to be aerated, preventing soil from drying out. Particles of this size form a cover that limits water evaporation. The smallest soil aggregates, with a diameter below 0.02 mm, belong to the dust fraction where capillarity occurs, leading to seepage of water from deeper soil layers. Intensive seepage accelerates water evaporation, so particles of this size are not recommended. Particles with a diameter larger than 50 mm are also not recommended because they are too large. The movement of air between them increases water evaporation, causing the soil to dry out.

Soil structure is critical

As mentioned earlier, the structure of the soil affects the retention of water in it. Humic acids' ability to create a lumpy soil structure is particularly important for both sandy soils (increasing compactness) and heavy soils (loosening and aeration). Plants growing in soils with appropriate structure receive equal amounts of water and nutrients throughout the growing season. On land with a permanent structure, plants achieve a water utilization rate of 85%. However, on soils with a disturbed structure, utilization typically does not exceed 15%. It is essential to remember that land losing its structure cannot store the necessary water for plants. Crops on non-structural soils fare worse during drought compared to those on structured soils, which also handle excess rainfall better. To support structure-forming processes, consider using preparations containing humic acids. This solution is recommended for "tired," less fertile soils that have lost their natural structure and soils frequently flooded by heavy rainfall, reducing fertility. These preparations stimulate biological activity, improve nutrient availability and use, enhance soil properties, and support root system development and the uptake of nutrients and water by the roots.

The key to success lies in proper soil cultivation and fertilization

Water significantly determines crop size. Farmers influence soil water storage through specific agrotechnical treatments. In field production, both droughts and intense, often torrential rainfall are detrimental, as they can damage soil structure and cause water erosion. Appropriate cultivation without a plow, and avoiding a plow sole, creates a better environment for root systems. To minimize unnecessary water losses and enhance effective water usage by plants, shallow soil loosening is recommended to interrupt capillary seepage to the surface zone, where evaporation is rapid and unproductive. Early spring dragging and harrowing post-pre-winter plowing also help reduce water losses. Before sowing seeds, loosen the soil to the sowing depth and place the seeds on a moist substrate to aid water absorption into germinating seeds. For planted seedlings, loosen the soil slightly deeper to allow proper planting and acceptance. Maintain high levels of organic substance content in the soil, which absorbs and retains significantly more water (3-5 times) than the soil's mineral fraction. Achieve this by systematically mixing natural and organic fertilizers into the soil. Keep optimal pH and nutrients in the soil, including potassium and sometimes sodium, which optimize plant water management, facilitate water uptake and flow through root cells, and aid in water transport within conductive bundles. Consequently, plants use less water to produce a unit of dry matter and better withstand drought periods. Sow phosphorus and potassium fertilizers deeper (5-10 cm for cereals and 10-20 cm for other crops) to enhance their utilization due to more favorable water conditions and stronger root growth, which expand and penetrate deeper soil layers in search of nutrients and water. Use specialized soil preparations, such as "hydrogels," which absorb large amounts of water and then release it to plants during water deficiency periods. These have long-lasting effects, averaging five years, after being introduced into the ground. Conduct shallow mechanical soil processing soon after harvest to retain soil water, reducing evaporation losses. Rolmako's portfolio of agricultural machines includes a range of disc harrows, such as the SpeedCutter model, ideal for ultra-shallow soil cultivation, maximizing water retention in the ground. The ComboTill combination of tillage tools—comprising a cultivator and mulch harrow—also fits the conservation tillage model perfectly.

How to Manage Stubble ?

Post-harvest cultivation should typically be executed shallowly, at a depth of just a few centimeters—5 to 8 cm. This practice effectively mixes the stubble and prevents weed emergence, which can extensively absorb water from the soil. Stubble aggregates are frequently used to break down and shred crop residues, mixing them evenly with the soil. Examples include the Rolmako U436 multifunctional cultivator or the U497 four-beam pre-sowing and stubble cultivator. Disc harrows combined with rollers are also popular, such as the Rolmako disc harrows models U622, U693, U652, or U671. Their use is inadvisable when couch grass is present in the field, as the discs cut the rhizomes, encouraging intensive growth. In such cases, after applying a herbicide containing glyphosate, cultivation should be conducted with a cultivator to bring the couch grass runners to the soil surface. The arable plow is now less commonly used among farmers due to its energy-intensive nature and inefficiency. Additionally, the plow layers crop residues in a manner that does not promote rapid decomposition in the soil. The choice of machinery depends largely on what is available on a specific farm.

Tillage machinery and techniques that retain water in the soil

Tillage machinery that retain water in the soil are crucial for sustainable agriculture, particularly in regions with low humidity or prone to drought. Below are some relevant machines and technologies.

Agricultural machinery that protects soil against water loss

Stubble cultivators: These devices process the soil to a greater depth, aiding in water retention at deeper levels. They improve soil structure, enhancing its water retention capacity. Application of cultivators for no-plough soil cultivation is recommended, e.g., the U436 stubble cultivator.

Subsoilers: Chisel plows and subsoilers work at greater depths than typical plows. They loosen and aerate deeper soil layers by breaking the plow sole, thereby improving water management. These machines operate at significant depths, breaking up hard soil layers and facilitating water penetration. The U624 chisel plow is ideal for breaking the plow sole and ensures optimal soil loosening. For tractors with lower pulling power, it is advisable to use subsoilers such as U602, U614, and others from the Rolmako portfolio.

Disc harrows: This tillage machinery conserves water by reducing soil erosion, preventing soil particles from entering water systems. Proper disc harrow use enhances soil water retention, increasing water availability during dry periods. Maintaining soil structure and preventing erosion reduces the amount of pesticides, fertilizers, and chemicals entering ground or surface water. Effective cutting of plant debris and soil mixing improve nutrient availability, minimizing the need for additional fertilizers. Responsible use and monitoring are essential for these benefits. Rolmako specializes in disc harrow production, offering machines with a 12m working width. Popular models include the U693, U652, SpeedCutter disc harrows, and the U671 heavy stubble harrow.

Tillage machines for ultra-shallow soil cultivation: Mulch harrows, rotary harrows, cultivators, disc harrows for shallow cultivation, knife rollers, and combinations of these machines. Shallower soil cultivation minimizes humus degradation and mobilizes nutrients. Farmers seek machines for ultra-shallow soil work, cutting soil broadly and mixing minimally with crop residues. Ultra-shallow stubble cultivation destroys self-seeding plants and weeds with mechanical root cutting and subsequent sun drying. This method results in significantly lower fuel consumption and protects soil against water loss.

Cultivation Techniques:

Mulching: Leaving a layer of mulch on the soil surface helps retain moisture by limiting water evaporation. Mulching involves covering the ground to protect it from direct sunlight, strong wind, or heavy rain, thereby preventing soil erosion. Organic mulches also limit weed growth and enrich the soil with nutrients. Straw is commonly used for mulching. Immediately after harvesting, knife rollers (e.g., Rolmako ProCut or TurboCut) can be employed to chop and evenly spread the straw over the field.

Minimal Conservation Soil Treatment: Ultra-shallow and no-till tillage practices minimize disturbance of the soil surface and enhance its water-holding capacity. These techniques prevent excessive drying by avoiding soil turnover.

Introducing these machines and technologies into agricultural practices can significantly improve land water retention, which is crucial for increasing crop productivity and reducing drought risks. The choice of appropriate solutions depends on the specific soil and climatic conditions of a given region.

Effective Agricultural Strategies and Practices

Retaining water in the soil for optimal plant use is essential in agriculture. Here are some effective strategies and practices to implement.

Appropriate Irrigation System: Select an irrigation system that delivers water to plants efficiently.

Mulching: Apply a layer of mulch on the soil surface to retain moisture, reduce water evaporation, and maintain stable ground temperature.

Conservation Practices: Employ conservative tillage practices such as no-till and ultra-shallow tillage to preserve soil structure and reduce erosion, thereby promoting water retention.

Rainwater Harvesting: Install rainwater harvesting systems to collect and store rainwater for irrigation during drought periods.

Improving Soil Structure: Enhance soil structure by adding organic matter like compost to increase water-holding capacity.

Establishing Appropriate Planting and Harvesting Dates: Plan planting and harvesting dates based on local climate conditions to minimize water loss.

Monitoring Hydration: Utilize soil moisture sensors to monitor moisture levels, ensuring plants receive the right amount of water and avoiding over-watering.

Optimal Fertilizer Management: Implement balanced fertilization to enable plants to use water and nutrients more efficiently.

Development of Water Retention Systems: Create ponds, retention reservoirs, and drainage ditches to collect and store water on the farm.

Drainage: Employ drainage systems to improve soil conductivity and prevent excessive soil moisture when water accumulation is high.

Retaining water in the soil is crucial for sustainable agriculture, contributing to efficient water resource use and minimizing losses through evaporation, erosion, or leaching. Adapt these practices to the specific soil and climatic conditions of a given region and crop type.

Properly selected cover crops and catch crops can significantly aid in retaining water in the soil

These plants provide ground cover, shielding the soil from direct sunlight and thereby minimizing direct evaporation. Additionally, a dense plant cover substantially reduces soil drying and erosion caused by wind. Catch crops and cover crops also safeguard the soil structure from the damaging effects of heavy rains. Furthermore, cover crops and catch crops supply organic matter to the soil, not only through plant residues mixed with the soil but also via organic compounds secreted by growing plants through their roots. These compounds are utilized by soil bacteria, including those that dissolve accumulated phosphorus and potassium, making these elements more accessible to plants, which in turn helps build plant resistance to stressful conditions.

Summary

The decrease in humus content is linked to the lack of rational fertilization, prolonged intensive cultivation, improper crop rotation, and the presence of a plow sole. Humus significantly impacts rainwater infiltration into the soil profile, limiting losses from surface runoff. Additionally, humus can retain water up to five times its weight. Improper handling of harvest residues, particularly through selling straw and not replenishing with organic matter, further reduces humus and leads to soil degradation. Improper crop rotation affects soil structure. No-till and ultra-shallow cultivation techniques, which involve mixing rather than turning the soil, help retain water by preserving humus in the upper soil layers. While these methods have supporters and opponents, it is notable that repetitive plowing at the same depth encourages plow sole formation, hindering plant root development. Therefore, intermittent subsoiling, using equipment like the Rolmako U602, U614 subsoiler, U624 chisel plow, or other Rolmako machines, is recommended every four years for deep loosening. Heavy agricultural equipment also affects soil structure negatively, but its impact can be mitigated by using twin wheels, lowering tire pressure, or employing tracked drive technology.