An innovative multifunctional machine for top dressing with mineral nitrogen fertilizers, cover crops, and for chemical and mechanical weed control in corn cultivation

Corn is the agricultural crop with the greatest economic importance in the world. For many years, it has been considered one of the most important sources of renewable raw materials with a wide range of applications, including in the food, fermentation, energy, and paper industries, as a vegetable, and as a high-protein and energy-rich feed for livestock.

In corn cultivation, an important factor affecting yield is the supply of nitrogen to plants, which, along with phosphorus, is one of the basic elements influencing the size and quality of the crop. The appropriate dose of fertilizer, adjusted to the nutritional needs of plants in particular stages of development, affects their growth and development. Any deficiencies of this element contribute to a reduction in the dry mass of plants, which leads to a decrease in the height and quality of their yield.

One of the most effective and environmentally friendly ways to replenish nitrogen in the soil is through intercropping. Intercrops, sown between main crops or as undersown crops, perform many agronomic and environmental functions:

• binding mineral forms of nitrogen present in the soil, which prevents their leaching,
• enriching the soil with nitrogen in the case of legume cultivation,
• replenishing organic matter and improving soil structure,
• reducing weed infestation and improving the phytosanitary condition of the site,
• protection against physical, chemical, and biological degradation,
• soil regeneration after intensive mineral fertilization and pesticide use,
• supporting soil biological life, including the development of soil microorganisms,
• mitigating the effects of simplified cultivation technologies and reducing nutrient losses.

Corn is one of the plants whose cultivation is characterized by a negative organic matter reproduction coefficient. Therefore, the possibility of growing catch crops is an opportunity to change this unfavorable situation. Due to the late harvest date of corn, especially when grown for grain, catch crops are grown as catch crops. The cultivation of intercrops makes it possible to bind mineral forms of nitrogen found in the soil and enrich the soil with this component when leguminous plants are grown. The introduction of intercropping replenishes organic matter in the soil, reduces weed infestation, improves soil condition, and prevents the loss of nutrients, especially nitrogen.

In the face of the challenges of globalization, advancing climate change, and growing food demand, corn remains one of the foundations of modern agriculture—a crop that requires responsibility and an innovative approach on the part of farmers to fully realize its potential. The future of corn is closely linked to proper soil management, fertilization, and sustainable development, which are the keys to success in 21st-century agriculture.

In the context of growing challenges related to climate change, water conservation, and the need to reduce the pressure of agriculture on the environment, the role of intercropping and precision fertilization is becoming crucial. Combining these elements in an integrated corn cultivation technology—using innovative machinery—provides an opportunity to simultaneously increase production efficiency and improve the sustainability of agricultural ecosystems.

The aim of the planned activities within the project is to increase the efficiency of top dressing with nitrogen fertilizers in corn cultivation, improve the effectiveness of cover crop cultivation, and increase the effectiveness of weed control, particularly in no-till and monoculture systems. According to the project assumptions, achieving the above effects should lead to an improvement in the yield and quality of corn, both in terms of grain production and green plant mass.

A key element of the research was the use of an innovative prototype of a multifunctional machine designed and built as part of the project, intended for top dressing, soil sowing of mineral nitrogen fertilizers, catch crops, and for chemical and mechanical weed control, equipped with a system of tines ending in coulters for in-soil sowing of mineral fertilizers at a specified depth in close proximity to the root system of corn plants, a system of coulters for in-soil sowing of catch crops as an interplanting in the 6-8 leaf stage of the protective plant, such as corn, a spraying section or a mechanical section (depending on the cultivation system used) for weed control in the inter-rows, and tanks for fertilizer, seeds, and plant protection products, as well as a drive and control system for individual functional units.

The expected result of the new solution will be a reduction in soil moisture loss, a reduction in the mineralization of organic matter, a reduction in nitrogen loss, and a reduction in the risk of water and wind erosion. The simultaneous combination of several agrotechnical treatments in a single pass is also expected to reduce the number of field operations, reduce fuel consumption, and reduce the pressure of the drive systems on the soil.

The implementation of the project will enable the introduction of modern solutions in corn cultivation technology, contributing to improved resource management efficiency and reducing the negative impact of agriculture on the environment.

Project activities

Main tasks completed and results achieved:

1. A prototype of a multifunctional machine was built for top dressing with mineral nitrogen fertilizers, cover crops, and for chemical and mechanical weed control. The machine was equipped with a tine with a coulter with adjustable fertilizer sowing depth, to a set depth closest to the area occupied by the corn root system, and an innovative coulter sowing system with adjustable cover crop sowing depth, ensuring better seed germination and seedling emergence, more even coverage of the field (between rows) and protection of the soil against water and wind erosion. The prototype under construction also features: a fertilizer box, a tank for liquid fertilizers (plant protection products), and a global GPS automatic driving system mounted on a cooperating tractor to control the straightness and parallelism of working passes during the establishment and management of the plantation.
2. Experimental and control objects (without soil-applied nitrogen fertilizers and with traditional cover crop sowing) were designated (using traditional measurement methods) within the indicated farm belonging to the consortium (2 locations - corn grown for grain and green mass) in the Podlaskie Province. All sites were subjected to existing condition tests, including: soil tests (before the experiment and after harvest) to determine: pHH20 and pHHCl, total N content, mineral nitrogen (N-NH4 and N-NO3), Corg. (humus), available forms of P, K, and Mg in the soil, post-harvest plant testing for macroelement content (N, P, K, Ca, Mg) in corn grain, straw, and green fodder.
3. Top dressing with mineral nitrogen fertilizer was applied in the 6-8 leaf stage of corn plants and the effectiveness of fertilization was assessed in comparison to top dressing without mixing the fertilizer with the soil. The effectiveness of top dressing with mineral fertilizers on the yield of corn silage and grain (NDVI index, yield, protein content) was tested.
4. Two sowing methods were used: combined sowing of corn seeds with catch crops and separate sowing of corn seeds and catch crops in the 6-8 leaf stage of corn plants.
5. The effectiveness of undersowing was assessed based on the above-mentioned indicators, as well as on emergence and the degree of inter-row vegetation cover and green mass yield.
6. The effects of soil application of mineral nitrogen fertilizers and soil application of catch crops were assessed by analyzing the measurement data of the tested parameters, data from soil and plant material analyses, meteorological observations, and moisture conditions. For this purpose, databases were created for mathematical and statistical processing. Technologies for soil application of mineral nitrogen fertilizers and catch crops during the growing season were developed. The results of the research and development work were disseminated in an information brochure and during a conference.

The main benefits of the project

The expected effect of the planned activities is to increase the effectiveness of top dressing of corn with nitrogen fertilizers and the effectiveness of cover crop cultivation, especially in no-till and monoculture farming, as well as weed control, in order to improve the yield and quality of corn seeds and green mass, through the use of the proposed prototype of a multifunctional machine for top dressing with mineral nitrogen fertilizers, catch crops, and for chemical and mechanical weed control, equipped with innovative technical solutions.

The planned operation, thanks to the establishment of a broad consortium comprising a university, an agricultural advisory center, a farmer, and an innovative company in the field of agricultural mechanization, creates an opportunity to implement new, innovative solutions directly into agricultural practice. The initiation of a group cooperating in the implementation of modern technical solutions and technologies will create a platform that can serve as a model for other entities and organizations. The planned dissemination activities through demonstrations, presentations, training courses, seminars, and conferences will have an impact not only on individual farmers, but also on farmers' organizations and non-governmental institutions operating in rural areas. In addition, they will also integrate rural communities and stimulate similar activities. 

The interdisciplinary nature of the entities comprising the group creates an opportunity for mutual inspiration among its members. It will contribute to the commercialization of newly developed technologies. 

Practice summary

The proposed design solution for a multi-purpose machine for mineral fertilization, sowing catch crops, and chemical and mechanical weed control in corn cultivation for grain or green mass will allow for high-quality yields. In addition, the use of this machine will reduce the number of working passes (simultaneous sowing of fertilizers and seeds of crops grown as catch crops), reduce the use of nitrogen fertilizers, and enable mechanical weed control in the 6-8 leaf stage, thereby reducing the amount of plant protection products used. It will also have a positive effect on soil fertility, reducing the risk of wind and water erosion.

The proposed technical solution will indirectly contribute to increasing the profitability of production by increasing the efficiency of nutrient uptake from nitrogen mineral fertilization and the soil. It will also ensure rational use of seed material, better utilization of fertilizer and soil nutrients by plants, and less unreliable emergence. As a result, these solutions will ensure higher yields of valuable biomass, improved soil properties, and a reduced number of passes, saving time and production resources. The use of this multi-functional machine in the production process, utilizing the proposed technical and organizational solutions, will allow for a more sustainable use of environmental resources (less waste and higher nitrogen content in the soil).

Results achieved

The use of a multifunctional (multi-purpose) machine for top dressing, soil sowing of mineral nitrogen fertilizers, cover crops, and chemical and mechanical weed control in corn cultivation has shown a positive effect on plant development, increasing both grain and green mass yield. The research showed that precise application of fertilizers in the root zone of corn, adapted to the developmental stage of the plants and habitat conditions, can improve nitrogen use efficiency. Unfortunately, the drought during the growing season made it difficult to evaluate the machine unequivocally.

An unquestionable advantage of the proposed machine design is the possibility of performing several agrotechnical operations simultaneously in a single pass, which reduces the number of working passes, decreases soil compaction, and optimizes the use of production resources. Reducing the frequency of cultivation operations translates directly into savings in time, fuel, and costs, as well as a reduction in the negative impact on soil structure.

Assessments of the degree of inter-row coverage with catch crops (seradella and vetch) showed a low level of growth effectiveness regardless of the sowing date. Low scores were obtained on both dates (from 5 to 1 points on a 9-point scale), which corresponded to only 10-50% coverage of the inter-row area. The main reason for the poor development of the cover crops was unfavorable weather conditions—drought, high temperatures, and low soil moisture—especially during the critical period of emergence and initial growth. The delayed development of cover crops meant that, under conditions of dynamic corn growth, the cover crops were dominated and smothered by the main crop, resulting in their premature drying out and the inability to recover growth later in the growing season.

Ultimately, the use of a multifunctional machine enables more sustainable and efficient management of environmental resources, increasing the profitability of corn production while reducing its negative impact on soil and climate.