Next Article in Journal
Reproductive and Vegetative Yield Component Trade-Offs in Selection of Thinopyrum Intermedium
Previous Article in Journal
Design and Experiment of an Inter-Plant Obstacle-Avoiding Oscillating Mower for Closed-Canopy Orchards
Previous Article in Special Issue
Intensification of Pea (Pisum sativum L.) Production in Organic Farming: Effects of Biological Treatments on Plant Growth, Seed Yield, and Protein Content
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Agronomy
Volume 15
Issue 12
10.3390/agronomy15122894
agronomy-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Enhancing Maize–Climbing Bean Intercropping with Biostimulants: Implications for Yield and Silage Quality

by
Rafał Górski
1,*,
Anna Sikorska
1,
Robert Czaplicki
1 and
Iwona Mystkowska
2
1
Faculty of Engineering and Economics, Ignacy Mościcki University of Applied Sciences in Ciechanów, 06-400 Ciechanów, Poland
2
Department of Dietetics, John Paul II University in Biała Podlaska, Sidorska 95/97, 21-500 Biała Podlaska, Poland
*
Author to whom correspondence should be addressed.
Agronomy 2025, 15(12), 2894; https://doi.org/10.3390/agronomy15122894
Submission received: 17 November 2025 / Revised: 14 December 2025 / Accepted: 15 December 2025 / Published: 16 December 2025
(This article belongs to the Special Issue Cereal–Legume Cropping Systems)
Browse Figures
Versions Notes

Abstract

In the face of climate pressure and threats to biodiversity, intercropping cereals with legumes and using biostimulants can increase feed yield and quality. This research evaluated a two-year intercropping system of maize and climbing beans for silage in central Poland, comparing four sowing schemes 90,000 ha−1 maize with 90,000 (90 + 90); 45,000 (90 + 45) or 27,500 (90 + 27.5) climbing beans ha−1 and sole maize, as well as five biostimulant application: control object, liquid microelement fertilizer (Zn-8.0%) containing zinc acetate, liquid extract from Ecklonia maxima algae, Methylobacterium symbioticum bacteria, Bacillus halotolerans bacteria. The aim of the field research was to evaluate the biomass components, yields, and crude protein content in silage. The intercropping pattern and biostimulants had a significant effect on dry matter and yields, with limited interactions. Single maize plant weight and yield were highest in the single crop and 90 + 27.5 treatments, while total intercrop yield peaked at 90 + 45, exceeding single maize by 14%. Biostimulants increased maize yields by 3–8% and intercrop yields by up to 6%, but reduced bean yields compared to controls. The crude protein content of silage was lowest for maize alone and highest for 90 + 45; biostimulants increased protein content by 5–9%, mainly for Methylobacterium symbioticum. Overall, the combination of 90 + 45 with Ecklonia maxima or Methylobacterium symbioticum optimized silage biomass and protein. The presented research is the first to evaluate the intercropping of maize with runner beans in orderly sowing and under the influence of biostimulants. It may constitute an important step in improving the efficiency of intercropping for implementation in agricultural practice. Further research should evaluate reduced mineral fertilization in this system.

1. Introduction

The increasingly progressive climate change around the world and the continuous growth of the people population pose a serious challenge to agriculture, mainly in terms of ensuring food security [1]. An additional problem facing agriculture is the loss of biodiversity caused by the expansion and intensification of modern agriculture [2]. An interesting approach to meeting this challenge is intercropping systems, which can significantly improve crop efficiency while contributing to sustainable development [3]. The main aim of intercropping is to increase production in a given area through better use of resources that would not be available to sole cropping [4]. In addition, the inclusion of legumes in intercropping improves the biodiversity of ecosystems and provides significant support for pollinator populations in the environment [5]. Intercropping cereals and legumes reduces weed infestation, increases resistance to pathogens, improves soil properties, increases yield and crop quality, and stabilizes yields in variable conditions [6]. An important element of successful intercropping is the appropriate selection of plant species and sowing rates so as not to cause excessive competition in cultivation [7]. Intercropping of cereals and legumes can be cultivated for cereal feed, green fodder, or silage. In many countries, maize is the main fodder crop for silage, mainly due to its high green fodder yield and favorable chemical composition [8]. However, in intercropping, the choice of maize component can be problematic due to its growth rate and the resulting intense shading of generally low legumes [9]. Studies on intercropping maize and soybeans have shown significant morphological changes in soybean plants, such as low photosynthetic activity, increased height, reduced stem diameter, and higher lodging index, which led to an overall decrease in grain yield of up to 45% [10,11]. Therefore, climbing beans seem to be a suitable component in intercropping with maize. In sole crops, beans need artificial supports to grow, whereas in intercropping with maize, the stiff and tall maize plants can provide natural support [12]. This also eliminates the problem of maize shading legumes. The root systems of maize and beans are also compatible because they use nutrients from different depths of the soil [13].
Biostimulants may also be helpful in addressing the challenges facing agriculture related to population growth and climate change [14]. Plant biostimulants are defined as compounds containing substances or microorganisms that, when applied to plants or the rhizosphere, stimulate natural processes to increase or improve nutrient uptake, nutrient use efficiency, abiotic stress tolerance, and crop quality [15]. Biostimulants do not have a direct effect against pathogens, but they synthesize compounds that inhibit pathogen growth, induce the production of allelochemicals, and modify the composition of plant secretions to combat pests and pathogens [16]. Biostimulants can therefore support farmers in adapting their production systems to climate variability, contribute to sustainable food production, and promote the implementation of environmentally sustainable agricultural models [17]. Field research conducted by other authors has demonstrated the positive effects of biostimulants on maize yield and quality [18,19] and other forage crops [20,21], including legumes [22] in sole crops. However, when biostimulants were used in intercropping, the dominant component, such as cereals, generally responded better compared to the small or no effect on legumes [23]. Thus, different species in intercropping may respond differently to the use of biostimulants [24]. However, the effect of biostimulant use in intercropping is generally positive [25].
Intercropping maize and legumes, such as soybeans, is a well-known technique, but it encounters problems such as excessive competition from maize. On the other hand, replacing soybeans with climbing beans in intercropping is not well understood. Manuscripts describing field experiments with maize and runner bean intercropping also take into account the reduction in maize sowing rates in intercropping compared to single cropping, which is a serious problem in terms of reducing the overall yield. The presented research is the first to describe the orderly sowing of maize with climbing beans in a twin system with a constant maize sowing rate. There are also no studies describing the effect of biostimulants on the intercropping of maize with climbing beans. Thus, the presented field research fills this research gap.
The aim of the field research was to determine the impact of sowing patterns for intercropped maize and climbing beans and the use of biostimulants on crop yields, crop characteristics, and protein content in the silage obtained. The research hypothesis assumed that sowing climbing beans in intercropping with maize and the use of biostimulants would increase yields and improve the protein content of the silage obtained.

2. Materials and Methods

2.1. Field Research

The field research was conducted in 2023–2024 in central Poland, near Ciechanów (52°59′52″ N 20°27′47″ E). Two experimental factors were analyzed: I—intercropping: I1 90 + 90, I2 90 + 45, I3 90 + 27.5 thousand seeds ha−1 of maize + climbing beans and 90 thousand seeds ha−1 of maize (control object), II—use of biostimulants: control object (without the use of biostimulants), B1 liquid microelement fertilizer (Zn-8.0%) containing zinc acetate, B2 liquid extract from Ecklonia maxima algae, B3 Methylobacterium symbioticum bacteria, B4 Bacillus halotolerans bacteria. The experiment was realized in a split block design with three replicates in each year of the research. A single experimental object consisted of 6 rows of maize and 6 rows of climbing beans over a length of 5 m. The Farmurmel maize variety and the WAV615 climbing bean variety were used for sowing. The plants were sown using the twin system. The scheme of individual experimental objects is presented in Figure 1.
Sowing on experimental objects was carried out each year at the beginning of May. Before sowing, climbing bean seeds were inoculated with Rhizobium faseolus bacteria. The inoculant used contained 2 × 109 CFU mL−1. Fertilization of crops included pre-sowing application of a nitrate-urea solution (N 32%) at a rate of 200 L ha−1 (92.4 kg N ha−1) and, during sowing, direct application of a compound fertilizer at a rate of 130 kg ha−1 containing 18% N, 46% P2O5, and 5% SO3 (23.4 kg N ha−1, 26.1 kg P ha−1, 2.6 kg S ha−1) directly under the seeds. For pre-emergence weed control, a herbicide containing dimethenamid-P—212.5 g L−1 (19.7%) and pendimethalin 250 g L−1 (23.2%) was applied at a rate of 3 L ha−1. The scheme for the application of biostimulants on individual experimental sites was as follows: B1—liquid micronutrient fertilizer (Zn-8.0%) containing zinc acetate at a dose of 1.2 L/200 L of water/ha foliar application in the four-leaf stage of maize; B2—liquid extract from Ecklonia maxima algae at a dose of 3.0 L/200 L/ha foliar application in the four-leaf stage of maize, B3—Methylobacterium symbioticum bacteria (powder containing 3 × 107 CFU g−1) at a dose of 333 g/200 L of water/ha foliar application in the four-leaf stage of maize, B4—Bacillus halotolerans bacteria (powder containing 1 × 108 CFU g−1) at a dose of 100 g/200 L of water/ha, applied to the soil immediately after plant emergence. All doses of biostimulants used were based directly on the manufacturers’ recommendations. Biostimulants were sprayed using a hand sprayer in the afternoon on warm, cloudy days. The soil conditions during the field experiment are presented in Table 1, and the weather conditions in Figure 2. Weather data were obtained from the meteorological station of the Ignacy Mościcki University of Applied Sciences in Ciechanów. The average temperature during cultivation in 2023 was 16.9 °C, while the total rainfall was 247.5 mm. The average temperature/ total precipitation in each month was as follows: May—13.7/15.6; June—18.8/24.0; July—20.0/69.8; VIII—20.7/56.4; IX—18.1/10.4; X—10.1/71.3. The average temperature in 2024 was 17.5 °C, while the total precipitation was 266.3 mm. In the following months, the average temperature/total precipitation was V—17.1/36.8; VI—19.2/40.1; VII—21.3/61.6; VIII—20.7/56.4; IX—17.8/36.7; X—9.2/34.7. The temperature during the experiment was similar in both years, while precipitation was uneven, especially in 2023. Thus, 2024 was more favorable for intercropping.

2.2. Data Collection

The green matter was harvested at the optimal time for maize in the dough stage. Immediately before harvesting, the plants in the rows of maize and climbing beans were counted, and then three randomly selected plants were taken from each experimental object in order to assess the biomass yield and the mass of the above-ground parts of individual plants. The collected plants were separated into cobs/pods, leaves, and stems. The samples obtained were shredded and dried in an Ecocell 111 BMT dryer (BMT Medical Technology, Brno, Czech Republic) at 65 °C to a constant weight. The samples were then weighed on a laboratory scale. Immediately before harvesting, the number of plants in rows was determined and converted into the actual plant density per hectare. The yield of maize and climbing beans was determined as the product of the dry weight of a single plant and the number of plants per hectare. The actual density of maize and climbing bean obtained immediately before harvest is presented in Table 2.
The final biomass harvest was performed with a self-propelled forage harvester. After harvesting each experimental object, shredded biomass samples were taken and placed in liter jars, then tamped down with a heavy steel pestle for ensiling. After thorough tamping and filling, the jars were tightly closed and additionally sealed with sealing tape. The jars were then transferred to a separate dark room and stored for chemical analysis. After 90 days of fermentation, the jars were opened and samples were taken for quality assessment. The resulting silage was sent to the laboratory for protein content analysis. Near-infrared spectroscopy was used with an NIRFlex N-500 spectrometer (Büchi, Flawil, Switzerland).

2.3. Statistical Analysis

For statistical analysis, a ANOVA was used to analyze the effects. The significance of sources of variability was tested using the Fisher–Snedecor F-test (p ≤ 0.05) and the differences between the compared averages were verified using Tukey’s HSD test (p ≤ 0.05). All the calculations were performed in Statistica, version 13.3 (Hamburg, Germany). The method of presenting averages from two years was used to obtain a more representative picture of the phenomena studied in variable weather and environmental conditions, to increase the reliability of the data by averaging the results from two growing seasons, and to limit the impact of random factors typical for a given year.

3. Results

Field research has demonstrated a significant impact (p < 0.001) of the proportion of components in intercropping on the dry matter of maize cobs, maize leaves, maize stalks, and the use of biostimulants on the weight of maize cobs, maize leaves, and maize stems. However, no statistically significant interaction between biostimulant and intercropping was found (Table 3).
The highest average maize cob weight was observed in plots with sole maize cultivation and in I3, while it was significantly lower in objects I1 and I2. Compared to the object with sole maize cultivation, cultivation I1 presented a 12% lower maize cob weight, while I2 presented an 11% lower maize cob weight. With regard to the biostimulants used, the highest average maize cob weight was obtained in the objects where B1 was used. However, the average maize cob weight on this object did not differ significantly from that obtained on objects where B3 was used. Compared to the object without the use of biostimulators, the use of B1 increased the maize cob weight by 15% and B3 by 9%. In the case of dry maize leaf weight, the highest statistical value was obtained in the case of sole maize cultivation, but it did not differ statistically from that obtained in I3. Significantly lower leaf weight was obtained in cultivation I1 and I2. The maize leaf weight in I1 was 18% lower, and in I2 it was 19% lower compared to the control. After applying each of the analyzed biostimulants, a significant increase in the average dry weight of maize leaves was obtained in relation to the controls. Significantly higher dry weight of maize leaves was obtained after the application of B2 (an increase of 27% compared to the control) and B3 (an increase of 31% compared to the control). When analyzing the dry weight of maize stems, the same highest statistical level was obtained for single cultivation and I3. Significantly lower average values of dry stems weight were characteristic of maize in the I1 and I2 cultivation systems. Compared to the control objects, a lower dry stems mass was obtained by 24% for I1 and 26% for I2. The use of biostimulants also caused differentiation in the dry weight of maize stems, but it was less statistically differentiated. The highest average dry stems weight was found in the plots after the application of B2, but the same statistical level was also found for the other objects on which biostimulants were used. Compared to the non-application of biostimulants on object B2, the dry stems weight was 17% higher.
Field research demonstrated a significant impact (p < 0.001) of the intercropping system used on the dry matter of pods, leaves, and stems of climbing beans. Similarly, the use of biostimulants significantly affected (p < 0.05) the dry weight of pods, leaves, and stems (p < 0.01) of climbing beans (Table 4). However, no significant interaction between biostimulant and intercropping was observed for any of the analyzed characteristics.
The highest average dry weight of climbing bean pods was observed in intercropping I2, significantly lower in I3 and lowest in I1. On average, the dry weight of pods was 65% lower in I1 and 32% lower in I3 compared to I2. After the application of biostimulants, the dry weight of pods decreased in relation to the control object from 9% for B2 to 21% for B4. Thus, the highest dry weight of climbing bean pods, equal to 5.32 g, was found when no biostimulants were used. In the I2 intercropping, the highest average dry weight of climbing bean leaves was obtained, but the same statistical level was also obtained for I3. Compared to the leaves weight obtained in I2, the average value obtained in I1 was 51% lower. The use of biostimulants resulted in a decrease in the dry weight of climbing bean leaves from 5 to 16%. The highest average value was obtained for the control objects, but the same statistical level was obtained for biostimulants B1, B2, and B3. The lowest value was obtained after the application of B4, but in this case, no statistically significant differences between the other biostimulants were noted. The highest average weight of climbing bean stems as a result of intercropping, equal to 43.02 g, was obtained for I2. With regard to the other sowing pattern, significantly lower values were obtained, for I1 lower by 47% and for I3 by 36%. As in the case of the other analyzed characteristics of climbing beans, the use of biostimulants resulted in a reduction in the dry weight of the stems. The highest values were obtained in the control object, but no significant differences were found between the average for these objects and for the use of B1 and B3. Significantly lower values were obtained after the use of biostimulants B2 and B4. In general, however, the use of biostimulants resulted in a reduction in the dry weight of climbing bean stems by 12 to 18%.
The intercropping, the biostimulants used, and the interaction between the biostimulant and intercropping (p < 0.001) significantly differentiated the yield of a single maize plant (Table 5).
When analyzing the sowing pattern, the highest dry weight of a single maize plant was obtained with single sowing (252.26 g) and in I3 (247.72 g). A significantly lower weight (by 16%) was obtained in I2, and the lowest in I1. On average, the weight of a single maize plant in I1 was 19% lower than in the control objects. The biostimulants used caused a significant increase in the dry weight of a single maize plant, ranging from 7 to 10% compared to the control objects. The highest values were obtained for plots where B2 and B3 were used, and no statistical difference was found between these plots and those where B1 was used. The demonstrated interaction between the biostimulant and the intercropping revealed, regardless of the biostimulant used or its absence, the highest dry matter of single maize was in sole cropping and in I3, and the lowest in the cultivation I1.
The main effects of the field experiment had a significant impact (p < 0.001) on the dry weight of a single climbing bean plant (intercropping and biostimulant). However, in the case of the dry weight of climbing beans, no statistically significant interaction between the biostimulator and intercropping was found (Table 6).
The highest dry weight of a single climbing bean plant, equal to 81.11 g, was found in crop I2. The use of other sowing patterns resulted in a significant reduction in dry matter, by 58% in I1 and 28% in I3. With regard to the second main effect, the highest average dry matter of a single climbing bean was obtained on control objects without the use of biostimulants. After the use of the analyzed biostimulants, the dry matter of climbing beans decreased by 8 to 12%. Significantly, the lowest value was obtained after the use of biostimulant B4, but in this case, the same statistical level was also revealed after the use of B1 and B2.
In the field experiment analyzed, maize yield was significantly influenced by the sowing pattern, biostimulants (p < 0.001), and their interaction (p < 0.05) (Table 7).
Significantly higher maize yields compared to the sowing patterns were obtained with single cultivation and I3, with a difference of only 1% between these objects, which was not statistically significant. A significant reduction of 9% was observed in I2 and 14% in I1. The use of biostimulants in the tested crops resulted in a significant increase in maize yield of approximately 8%, with the exception of B4. The highest maize yields in relation to the use of biostimulants were observed in the objects where B1, B2 and B3 were used. Statistically confirmed interaction showed that without the use of biostimulants and with B4, the lowest maize yields were obtained for crops I1 and I2. However, when using B1, B2, and B3 for the I1 sowing pattern. The highest yields were obtained without the use of biostimulants, B1, and B2 in single maize cultivation. In turn, when using biostimulator B3 for intercropping I3, and when using B4, no significant differences in maize yield were found between sole maize cultivation and B4.
The dry matter yield of climbing beans was also significantly differentiated (p < 0.001) by the intercropping pattern and the biostimulants used, but no statistically significant interaction between biostimulant and intercropping was found (Table 8).
When analyzing the average values obtained as a result of intercropping, the highest yields of climbing beans were obtained for I2, significantly lower for I1, and the lowest for I3. In relation to I2, the yields obtained in I1 were 49% lower and in I3 72% lower. With regard to the second main effect, the highest average yield of climbing beans was obtained on control objects without the use of biostimulants. The use of each of the analyzed biostimulants resulted in a significant reduction in the dry matter yield of climbing beans by 7 to 11%. In addition, the biostimulants used caused a reduction in yield to the same statistical level.
Field research demonstrated a significant impact (p < 0.001) of component sowing in cultivation and the use of biostimulants on the dry matter yield of intercropping maize with climbing beans, while no statistically significant interaction between biostimulant and intercropping was found (Table 9).
Under the influence of the sowing pattern, the lowest average dry matter yields were obtained in crop I1 and sole maize. The introduction of climbing beans into the crop resulted in a significant increase in yield. In crop I3, a significantly higher yield of 10% was obtained, while in I2 it was 19%. The use of biostimulants also resulted in a significant increase in the dry matter yield of the intercropping, with the exception of B4. The lowest yield was obtained on objects where biostimulants were not used and on B4. The highest dry matter yield from intercropping was obtained after the application of B1, B2, and B3, which was about 3% higher than in the control objects.
The specific crude protein content in silage from the analyzed crops was significantly differentiated (p < 0.01) by the sowing pattern, the use of biostimulants, and their interaction between biostimulant and intercropping (Table 10).
With regard to the sowing pattern, the lowest crude protein content was obtained on objects where maize was grown in sole cropping, while the addition of climbing beans to the sown seeds resulted in a significant increase. A significantly higher crude protein content in silage at the same statistical level was obtained in I1 and I3. However, the highest content was obtained in crop I2, where the crude protein content was 41% higher than in the control plot. When analyzing changes in the crude protein content in silage under the influence of the second main effect, the lowest content was found on plots where biostimulants were not used. After the application of biostimulants, an increase in crude protein content of 5 to 9% was recorded, with the highest content obtained on plots where B3 was used. The interaction between the biostimulant and the intercropping demonstrated that, regardless of the biostimulant used or its absence, the lowest crude protein content was found in silage from sole maize cultivation, while the highest was found in cultivation I2. Additionally, after using B3 and B4, no statistically significant differences were found between silage obtained from I1 and I3.

4. Discussion

Maize is one of the world’s staple feed crops, largely due to its high biomass yields [26]. As a result, during intercropping with legumes, reducing the amount of maize seeds sown significantly lowers the total yield [27], as the yield of legumes is not able to compensate for this [28]. Therefore, when designing the presented field experiment, it was decided not to reduce the maize sowing rate in relation to sole sowing, but to use a quantitatively differentiated additional sowing of climbing beans. Similar research has been conducted for other intercropping systems of cereals and legumes [29]. High plant density per unit area could cause competition in later stages of plant growth. Although no clear competition was observed in the initial stage of plant development (Supplementary Materials, Figure S1), the density determined immediately before harvest on the I1 objects clearly indicates a reduction in the ratio of seeds sown to plants at harvest. Therefore, the plant density used in I1 (a total of 180,000 plants per hectare) is too high. On one of the experimental objects, a higher actual plant density was obtained before harvest compared to the planned sowing. This may have been due to sowing tolerance resulting from the technical accuracy of the seed drill. Despite this, there is a clear tendency for plants to persist from emergence to harvest.
However, to the authors’ knowledge, this is the first report evaluating the presented, structured patterns of sowing maize with climbing beans under the influence of biostimulants.

4.1. Intercropping

The field research presented here reported a decrease in the dry weight of maize cobs, leaves, and stems, which ultimately led to a decrease in the dry weight of individual maize plants and maize yield with increasing amounts of climbing beans added. Studies conducted by other authors on maize cultivation with other legumes such as soybeans [30] or lablab bean [31] demonstrated the opposite trend, i.e., an increase in the biomass of single maize plants when grown in intercropping, but with reduced maize plant density. The variation in the results obtained was most likely due to differences in the morphological characteristics of the legumes. In general, field research tested plants that were significantly smaller in height than maize [32]. Thus, there was no competitive interaction for light resources in relation to maize. However, in the case of climbing beans, which use maize as a natural support [12], the competitive interaction could have been significant. This is confirmed by research conducted by Villwock et al. [33], also on the intercropping of maize with climbing beans, but in random sowing. They found, similarly to the presented results, a decrease in maize yield with an increase in the amount of climbing beans sown. The increase in the overall plant density per unit area was certainly also significant. Suárez et al. [34] found in their experiment that increasing the maize density in intercropping reduces the dry matter of the vegetative parts of maize. In turn, Nurk et al. [12] reported possible excessive competition for resources in the early stages of intercropping, but no such effect was found in the experiment (Supplementary Materials, Figure S1). A possible reason for the absence of clear competition in the early stages of plant growth was the high mineral fertilization adapted to maize cultivation in sole cropping, which requires high doses of N to produce a high yield [35]. Thus, both maize and climbing beans had sufficient soil resources and did not compete for them. However, the impact of the intercropping pattern on climbing beans in the field research appears to be much more complex. In many field research, the authors reported a reduction in legume yields in intercropping with maize, mainly as a result of shading stress, which adversely affects physiological and morphological characteristics and reduces nutrient accumulation [36,37,38]. Certainly, in the authors’ own research, competition from maize also occurred and hindered the free development of climbing beans. However, the aforementioned use of maize as a support for the growth of climbing beans, and thus growth to a similar height above the ground, to some extent eliminated competition for light (Supplementary Materials, Figure S2). An interesting finding, however, is that the highest dry matter of all vegetative parts and the highest yield of climbing beans were obtained for a planting density of 90,000 maize plants + 45,000 climbing beans (I2). Despite using twice as many climbing beans in I1, the yield obtained was nearly 19% lower. Research conducted by Baez-Gonzalez et al. [39] demonstrated lower yields from individual plants of another bean species, but increased density compensated for this fact and ultimately the yield was comparable. Musana et al. [40], on the other hand, found, as in the present research, lower biomass yields of another bean species at high plant density. This finding therefore suggests that a lower planting density of climbing beans is more advantageous for obtaining higher yields, which is also economically justified due to the cost of seed. A higher share of climbing beans in the total yield also translated into an improvement in total protein content. Thus, the highest total protein content was found in I2. The results obtained are consistent with those of other authors who found a higher protein content in feed with a higher proportion of legumes in intercropping [41,42].

4.2. Biostimulants

The use of biostimulants, both synthetic and microbiological, had a positive effect on the development of the vegetative parts of maize, which resulted in higher biomass yields. However, the opposite effect was observed in climbing beans, where the use of biostimulants on intercropping resulted in lower biomass yields of this legume. Finally, however, the total dry matter yield of intercropping showed an increase under the influence of biostimulants, mainly due to the increase in maize biomass yield. The mechanism of the positive effect of biostimulants on crops may vary depending on their type, but in general, they enrich the soil with nutrients for plants, thereby improving plant condition and increasing the efficiency of nutrient uptake [43,44]. Zinc-containing biostimulants can affect various physiological processes, including hormonal regulation, gene regulation and expression, and cell membrane integrity [45]. Research conducted by Ratajczak et al. [46] on maize cultivation demonstrated an increase in chlorophyll, chlorophyll fluorescence, and photosynthesis, which means greater production of photosynthates responsible for plant growth and development, ultimately leading to higher yields. In other research on many crops such as maize [47], soybeans [43], and rice [48], the authors obtained results similar to those presented in this research. According to Sharma et al. [49], extracts from algae result in higher yields of better quality without any negative effects. One of the mechanisms cited in scientific reports for improved crop productivity after the application of an extract from algae is the stimulation of somatic tissue growth [50]. Pienaar et al. [51] also point to an increase in the photosynthetic potential of plants through improved chlorophyll concentration in shoots. Tandathu et al. [52] additionally pointed out that the use of a biostimulant containing extracts from algae has a positive effect on root development by supporting the formation of lateral roots and increasing root volume, thus improving the ability to absorb nutrients. The increase in yield under the influence of algae extract is also confirmed by the presented research, although the increase in dry matter yield compared to the control of both intercropping (6%) and maize (8%) was lower than that reported by Matysiak and Adamczewski [53], who obtained a 21% increase in maize yield, or the 15.5% increase obtained by Ratajczak et al. [46]. The differences in the results obtained may have been due to the time of application of the algae extract and environmental conditions [54]. El-Katony et al. [55] and Ratajczak et al. [46] emphasize the high effectiveness of algae use in environmental stress conditions, while the research did not involve water or temperature stress. With regard to the use of biostimulants containing Bacillus halotolerans, the research also showed an increase in the dry matter yield of the intercropping. Similarly, other authors also observed an improvement in plant yield after the application of these microorganisms. El-Akhdar et al. [56] reported a significant increase in grain yield, plant dry matter, plant height, and protein content in wheat. Çam et al. [57], on the other hand, observed an increase in the dry matter of the above-ground parts and roots of maize after the application of Bacillus halotolerans. The positive effect of Bacillus halotolerans on plant growth promotion is attributed to the production of indole-3-acetic acid (IAA), which causes cell elongation, division, and differentiation, as well as root and shoot development [58], the production of siderophores [59], the production of 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, which lowers the level of ethylene, which is often elevated under adverse stress conditions such as salinity, drought, and heavy metals, thus mitigating its inhibitory effect [60], or atmospheric nitrogen fixation and dissolution of essential minerals, thereby increasing soil fertility and providing plants with bioavailable nutrients under both normal and stressful conditions [61]. In our own research, the effect of Bacillus halotolerans on improving the yield of intercropping was lower than that of other biostimulants. This may be due to the fact that the effectiveness of Bacillus halotolerans is particularly evident in difficult conditions, such as salinity stress or water stress [62], while no such conditions were observed during the field experiment. Under the conditions of the experiment, an increase in biomass production was also obtained by intercropping after leaf application of a biostimulant containing Methylobacterium symbioticum. Studies by other authors on the inoculation of agricultural crops with this bacterium are divergent. Similarly to our own research, Feitoza de Jesus Santos and Da Cas Bundt [63] reported a significant improvement in maize yields under various soil and water conditions. The positive effects of using Methylobacterium symbioticum are attributed to the production of phytohormones that improve vegetation indicators and thus prolong the greenness of leaves [64]. The positive effect of this bacterial species is also related to the fact that these bacteria colonize the phyllosphere, using methanol as a source of C and energy, and in return supplying N to plants [65]. In contrast, Rodrigues et al. [66] demonstrated no significant effect on maize yields, similarly to Arrobas et al. [67] in lettuce cultivation. According to Rodrigues et al. [66], differences in the effectiveness of the results obtained may be due to the availability of N to the plant—the greater the availability of N from other sources, the lower the effectiveness of Methylobacterium symbioticum. Weather conditions during plant cultivation also seem to be important, as poor plant condition results in less C available in the plant for this species of bacteria, and thus weaker condition and development. Under the conditions of the experiment, the use of biostimulants resulted in an increase in the total yield of intercropped crops and maize plants, both in intercropping and sole cropping. However, a decrease in the yield of climbing beans was observed under the influence of biostimulants. This contradicts the results of other authors regarding the use of biostimulants in legumes. Gyogluu Wardjomto et al. [68] obtained an increase in the yield of sowing beans under the influence of algae extract, and Serafin-Andrzejewska et al. [69] obtained an increase in the productivity of faba beans under the influence of Methylobacterium symbioticum. The different results obtained in the field experiment are most likely not due to the negative effect of biostimulants on climbing bean cultivation, but rather their positive effect on maize cultivation. Thus, the better development of maize plants increased their competitiveness with climbing beans, which resulted in limiting their growth. Under the conditions of the experiment, a positive effect of the use of biostimulants on the protein content in silage from intercropping was also obtained. An increase in crop quality under the influence of biostimulants has also been reported by other authors: Vasantharaja et al. [70] in beans under the influence of algae extract, Al-Temimi and Al-Hilfy [71] in maize also after the application of algae extract, and Kalman et al. [72] in maize as a result of the application of Bacillus bacteria. The increase in crop quality under the influence of biostimulants is associated with improved nutrient availability in the soil, better plant condition and development, and thus increased nutrient uptake and mitigation of the effects of abiotic stress [73]. However, Ocwa et al. [73] also point out that biostimulants have a clear impact on crop yields but little effect on the quality of the crops obtained.

5. Conclusions

The most favorable results of intercropping maize with climbing beans using biostimulants were obtained using a cultivation pattern of 90,000 maize plants + 45,000 climbing beans per hectare with the use of Ecklonia maxima algae extract or Methylobacterium symbioticum bacteria. With this combination of factors, the highest biomass yields (an increase of 28% and 21%, respectively, compared to single maize objects without the use of biostimulants) and the highest total protein content in silage were obtained (an increase of 46% and 53%). Thus, this technology of intercropping maize with climbing beans for silage can be recommended for agricultural practice. In the perspective of further research in this area, the possible reduction in mineral fertilizer use should be tested in order to meet the challenges of sustainable agriculture.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/agronomy15122894/s1, Table S1. Average results of field reserch in 2023 and 2024, Figure S1. Intercropping of maize and climbing beans in the beginning stage, Figure S2. Intercropping of maize and climbing beans before harvest.

Author Contributions

Conceptualization, R.G. and A.S.; methodology, R.G. and A.S.; software, R.G.; validation, I.M. and R.C.; formal analysis, R.G. and A.S.; investigation, I.M.; resources, R.C.; data curation, R.G., A.S. and R.C.; writing—original draft preparation, R.G. and A.S.; writing—review and editing, I.M. and R.C.; visualization, R.C.; supervision, I.M.; project administration, R.G. and A.S.; funding acquisition, R.G., A.S. and R.C. All authors have read and agreed to the published version of the manuscript.

Funding

The research was funded by a subvention for the development of lecturer Ignacy Mościcki University of Applied Sciences in Ciechanów.

Data Availability Statement

Data are contained within the article.

Conflicts of Interest

The authors declare no conflicts of interest.

Abbreviations

The following abbreviations are used in this manuscript:
CFUColony Forming Units

References

  1. Raza, A.; Asghar, M.A.; Ahmad, B.; Bin, C.; Iftikhar Hussain, M.; Li, W.; Iqbal, T.; Yaseen, M.; Shafiq, I.; Yi, Z.; et al. Agro-techniques for lodging stress management in maize-soybean intercropping system—A Review. Plants 2020, 9, 1592. [Google Scholar] [CrossRef]
  2. Norris, K. Agriculture and biodiversity conservation: Opportunity knocks. Conserv. Lett. 2008, 1, 2–11. [Google Scholar] [CrossRef]
  3. Vogel, E.; Meyer, R. Climate change, climate extremes, and global food production—Adaptation in the agricultural sector. In Resilience; Elsevier: Amsterdam, The Netherlands, 2018; pp. 31–49. [Google Scholar] [CrossRef]
  4. Pierre, J.F.; Latournerie-Moreno, L.; Garruña, R.; Jacobsen, K.L.; Laboski, C.A.M.; Us-Santamaría, R.; Ruiz-Sánchez, E. Effect of maize–legume intercropping on maize physio-agronomic parameters and beneficial insect abundance. Sustainability 2022, 14, 12385. [Google Scholar] [CrossRef]
  5. Secretariat of the Convention on Biological Diversity. Biodiversity and Agriculture: Safeguarding Biodiversity and Securing Food for the World; Secretariat of the Convention on Biological Diversity: Montreal, QC, Canada, 2008; ISBN 978-92-9225-111-6. [Google Scholar]
  6. Księżak, J.; Staniak, M.; Stalenga, J. Restoring the importance of cereal-grain legume mixtures in low-input farming systems. Agriculture 2023, 13, 341. [Google Scholar] [CrossRef]
  7. Annicchiarico, P.; Collins, R.P.; De Ron, A.M.; Firmat, C.; Litrico, I.; Hauggaard-Nielsen, H. Do we need specific breeding for legume-based mixtures? Adv. Agron. 2018, 157, 141–215. [Google Scholar] [CrossRef]
  8. Marchesini, G.; Serva, L.; Chinello, M.; Gazziero, M.; Tenti, S.; Mirisola, M.; Garbin, E.; Contiero, B.; Grandis, D.; Andrighetto, I. Effect of maturity stage at harvest on the ensilability of maize hybrids in the early and late FAO classes, grown in areas differing in yield potential. Grass Forage Sci. 2019, 74, 415–426. [Google Scholar] [CrossRef]
  9. Ahmed, S.; Raza, M.A.; Zhou, T.; Hussain, S.; Khalid, M.H.B.; Feng, L.; Wasaya, A.; Iqbal, N.; Ahmed, A.; Liu, W. Responses of soybean dry matter production, phosphorus accumulation, and seed yield to sowing time under relay intercropping with maize. Agronomy 2018, 8, 282. [Google Scholar] [CrossRef]
  10. Yang, F.; Liao, D.; Wu, X.; Gao, R.; Fan, Y.; Raza, M.A.; Wang, X.; Yong, T.; Liu, W.; Liu, J. Effect of aboveground and belowground interactions on the intercrop yields in maize-soybean relay intercropping systems. Field Crops Res. 2017, 203, 16–23. [Google Scholar] [CrossRef]
  11. Raza, M.A.; Feng, L.Y.; van Der Werf, W.; Iqbal, N.; Khalid, M.H.B.; Chen, Y.K.; Wasaya, A.; Ahmed, S.; Din, A.M.U.; Khan, A. Maize leaf-removal: A new agronomic approach to increase dry matter, flower number and seed-yield of soybean in maize soybean relay intercropping system. Sci. Rep. 2019, 9, 13453. [Google Scholar] [CrossRef] [PubMed]
  12. Nurk, L.; Graß, R.; Pekrun, C.; Wachendorf, M. Effect of sowing method and weed control on the performance of maize (Zea mays L.) intercropped with climbing beans (Phaseolus vulgaris L.). Agriculture 2017, 7, 51. [Google Scholar] [CrossRef]
  13. Lithourgidis, A.S.; Dordas, C.A.; Damalas, C.A.; Vlachostergios, D. Annual intercrops: An alternative pathway for sustainable agriculture. Aust. J. Crop Sci. 2011, 5, 396. [Google Scholar]
  14. Li, J.; Van Gerrewey, T.; Geelen, D. A Meta-analysis of biostimulant yield effectiveness in field trials. Front. Plant Sci. 2022, 13, 836702. [Google Scholar] [CrossRef] [PubMed]
  15. European Biostimulants Industry Council (EBIC). Plant Biostimulants Contribute to Climate-Smart Agriculture. Available online: https://biostimulants.eu/issue/plant-biostimulants-contribute-to-climate-smart-agriculture (accessed on 15 September 2025).
  16. Silva, M.S.R.D.A.d.; Santos, B.D.M.S.D.; Silva, C.S.R.D.A.D.; Antunes, L.F.D.S.; dos Santos, R.M.; Santos, C.H.B.; Rigobelo, E.C. Humic substances in combination with plant growth-promoting bacteria as an alternative for sustainable agriculture. Front. Microbiol. 2021, 12, 719653. [Google Scholar] [CrossRef] [PubMed]
  17. Mackiewicz-Walec, E.; Olszewska, M. Biostimulants in the production of forage grasses and turfgrasses. Agriculture 2023, 13, 1796. [Google Scholar] [CrossRef]
  18. Sobiech, Ł.; Grzanka, M.; Idziak, R.; Blecharczyk, A. The effect of post-emergence application of biostimulants and soil amendments in maize cultivation on the growth and yield of plants. Plants 2025, 14, 1274. [Google Scholar] [CrossRef]
  19. Boscaro, R.; Panozzo, A.; Piotto, S.; Moore, S.S.; Barion, G.; Wang, Y.; Vamerali, T. Effects of foliar-applied mixed mineral fertilizers and organic biostimulants on the growth and hybrid seed production of a male-sterile inbred maize line. Plants 2023, 12, 2837. [Google Scholar] [CrossRef]
  20. Ciepiela, G.A. The Effect of biostimulants derived from various materials on the yield and selected organic components of italian rye grass (Lolium multiflorum Lam.) against the background of nitrogen regime. Appl. Ecol. Env. Res. 2019, 17, 12407–12418. [Google Scholar] [CrossRef]
  21. Alharbi, K.; Hafez, E.M.; Omara, A.E.-D.; Nehela, Y. Composted bagasse and/or cyanobacteria-based bio-stimulants maintain barley growth and productivity under salinity stress. Plants 2023, 12, 1827. [Google Scholar] [CrossRef]
  22. Petropoulos, S.A.; Fernandes, Â.; Plexida, S.; Chrysargyris, A.; Tzortzakis, N.; Barreira, J.C.M.; Barros, L.; Ferreira, I.C.F.R. Biostimulants application alleviates water stress effects on yield and chemical composition of greenhouse green bean (Phaseolus vulgaris L.). Agronomy 2020, 10, 181. [Google Scholar] [CrossRef]
  23. Mazurenko, B.; Sani, M.N.H.; Litvinov, D.; Kalenska, S.; Kovalenko, V.; Shpakovych, I.; Pikovska, O.; Gordienko, L.; Yong, J.W.H.; Ghaley, B.B.; et al. Biostimulants-induced improvements in pea-barley intercropping systems: A study of biomass and yield optimization under Ukrainian climatic conditions. J. Agric. Food Res. 2025, 22, 102074. [Google Scholar] [CrossRef]
  24. Bulgari, R.; Cocetta, G.; Trivellini, A.; Vernieri, P.; Ferrante, A. Biostimulants and crop responses: A review. Biol. Agric. Hortic. 2014, 31, 1–17. [Google Scholar] [CrossRef]
  25. Mosalman, S.; Rezaei-Chiyaneh, E.; Mahdavikia, H.; Dolatabadian, A.; Siddique, K.H. Enhancing rainfed safflower yield, oil content, and fatty acid composition through intercropping with chickpea and stress-modifier biostimulants. Front. Agron. 2024, 6, 1389045. [Google Scholar] [CrossRef]
  26. Gao, C.; El-Sawah, A.M.; Ali, D.F.I.; Alhaj Hamoud, Y.; Shaghaleh, H.; Sheteiwy, M.S. The integration of bio and organic fertilizers improve plant growth, grain yield, quality and metabolism of hybrid maize (Zea mays L.). Agronomy 2020, 10, 319. [Google Scholar] [CrossRef]
  27. Kintl, A.; Huňady, I.; Vítěz, T.; Brtnický, M.; Sobotková, J.; Hammerschmiedt, T.; Vítězová, M.; Holátko, J.; Smutný, V.; Elbl, J. Effect of legumes intercropped with maize on biomass yield and subsequent biogas production. Agronomy 2023, 13, 2775. [Google Scholar] [CrossRef]
  28. Zhang, W.; Gao, S.; Li, Z.; Xu, H.; Yang, H.; Yang, X.; Fan, H.; Su, Y.; Fornara, D.; Li, L. Shifts from complementarity to selection effects maintain high productivity in maize/legume intercropping systems. J. Appl. Ecol. 2021, 58, 2603–2613. [Google Scholar] [CrossRef]
  29. Corre-Hellou, G.; Dibet, A.; Hauggaard-Nielsen, H.; Crozat, Y.; Gooding, M.; Ambus, P.; Dahlmann, C.; von Fragstein, P.; Pristeri, A.; Monti, M.; et al. The competitive ability of pea–barley intercrops against weeds and the interactions with crop productivity and soil N availability. Field Crops Res. 2011, 122, 264–272. [Google Scholar] [CrossRef]
  30. Fu, Z.; Chen, P.; Zhang, X.; Du, Q.; Zheng, B.; Yang, H.; Luo, K.; Lin, P.; Li, Y.; Pu, T.; et al. Maize-legume intercropping achieves yield advantages by improving leaf functions and dry matter partition. BMC Plant Biol. 2023, 23, 438. [Google Scholar] [CrossRef]
  31. Zhang, H.; Shi, W.; Ali, S.; Chang, S.; Jia, Q.; Hou, F. Legume/maize intercropping and N application for improved yield, quality, water and N utilization for forage production. Agronomy 2022, 12, 1777. [Google Scholar] [CrossRef]
  32. Javanmard, A.; Machiani, M.A.; Lithourgidis, A.; Morshedloo, M.R.; Ostadi, A. Intercropping of maize with legumes: A cleaner strategy for improving the quantity and quality of forage. Clean. Eng. Technol. 2020, 1, 100003. [Google Scholar] [CrossRef]
  33. Villwock, D.; Kurz, S.; Hartung, J.; Müller-Lindenlauf, M. Effects of stand density and N fertilization on the performance of maize (Zea mays L.) intercropped with climbing beans (Phaseolus vulgaris L.). Agriculture 2022, 12, 967. [Google Scholar] [CrossRef]
  34. Suárez, J.C.; Anzola, J.A.; Contreras, A.T.; Salas, D.L.; Vanegas, J.I.; Urban, M.O.; Beebe, S.E.; Rao, I.M. Influence of simultaneous intercropping of maize-bean with input of inorganic or organic fertilizer on growth, development, and dry matter partitioning to yield components of two lines of common bean. Agronomy 2022, 12, 1216. [Google Scholar] [CrossRef]
  35. Wysokinski, A.; Kożuchowska, M. Increasing silage maize yield and nitrogen use efficiency as a result of combined rabbit manure and mineral nitrogen fertilization. Sci. Rep. 2024, 14, 5856. [Google Scholar] [CrossRef]
  36. Wu, Y.; Gong, W.; Yang, W. Shade inhibits leaf size by controlling cell proliferation and enlargement in soybean. Sci. Rep. 2017, 7, 9259. [Google Scholar] [CrossRef]
  37. Khalid, M.; Raza, M.; Yu, H.; Sun, F.; Zhang, Y.; Lu, F.; Si, L.; Iqbal, N.; Khan, I.; Fu, F. Effect of shade treatments on morphology, photosynthetic and chlorophyll fluorescence characteristics of soybeans (Glycine max L. Merr.). Appl. Ecol. Environ. Res. 2019, 17, 2551–2569. [Google Scholar] [CrossRef]
  38. Feng, L.; Raza, M.A.; Li, Z.; Chen, Y.; Khalid, M.H.B.; Du, J.; Liu, W.; Wu, X.; Song, C.; Yu, L. the influence of light intensity and leaf movement on photosynthesis characteristics and carbon balance of soybean. Front. Plant Sci. 2018, 9, 1952. [Google Scholar] [CrossRef]
  39. Baez-Gonzalez, A.D.; Fajardo-Diaz, R.; Padilla-Ramirez, J.S.; Osuna-Ceja, E.S.; Kiniry, J.R.; Meki, M.N.; Acosta-Díaz, E. Yield performance and response to high plant densities of dry bean (Phaseolus vulgaris L.) cultivars under semi-arid conditions. Agronomy 2020, 10, 1684. [Google Scholar] [CrossRef]
  40. Musana, R.F.; Rucamumihigo, F.X.; Nirere, D.; Mbaraka, S.R. Growth and yield performance of common bean (Phaseolus vulgaris L.) as influenced by plant density at Nyagatare, East Rwanda. AJFAND 2020, 20, 16249–16261. [Google Scholar] [CrossRef]
  41. Soe Htet, M.N.; Wang, H.; Yadav, V.; Sompouviseth, T.; Feng, B. Legume integration augments the forage productivity and quality in maize-based system in the Loess Plateau Region. Sustainability 2022, 14, 6022. [Google Scholar] [CrossRef]
  42. Iqbal, M.A.; Hamid, A.; Ahmad, T.; Siddiqui, M.H.; Hussain, I.; Ali, S.; Ali, A.; Ahmad, Z. Forage sorghum-legumes intercropping: Effect on growth, yields, nutritional quality and economics returns. Bragantia 2018, 78, 82–95. [Google Scholar] [CrossRef]
  43. Liu, R.; Lal, R. Synthetic apatite nanoparticles as a phosphorus fertilizer for soybean (Glycine max). Sci. Rep. 2014, 4, 5686. [Google Scholar] [CrossRef] [PubMed]
  44. Kocira, A.; Świeca, M.; Kocira, S.; Złotek, U.; Jakubczyk, A. Enhancement of yield, nutritional and nutraceutical properties of two common bean cultivars following the application of seaweed extract (Ecklonia maxima). Saudi J. Biol. Sci. 2018, 25, 563–571. [Google Scholar] [CrossRef]
  45. Guardiola-Márquez, C.E.; Santos-Ramírez, M.T.; Segura-Jiménez, M.E.; Figueroa-Montes, M.L.; Jacobo-Velázquez, D.A. Fighting obesity-related micronutrient deficiencies through biofortification of agri-food crops with sustainable fertilization practices. Plants 2022, 11, 3477. [Google Scholar] [CrossRef] [PubMed]
  46. Ratajczak, K.; Sulewska, H.; Panasiewicz, K.; Faligowska, A.; Szymańska, G. Phytostimulator Application after cold stress for better maize (Zea mays L.) plant recovery. Agriculture 2023, 13, 569. [Google Scholar] [CrossRef]
  47. Dong, Y.J.; He, M.R.; Wang, Z.L.; Chen, W.F.; Hou, J.; Qiu, X.K.; Zhang, J.W. Effects of new coated release fertilizer on the growth of maize. J. Soil Sci. Plant Nutr. 2016, 16, 637–649. [Google Scholar] [CrossRef][Green Version]
  48. Gupta, S.D.; Agarwal, A.; Pradhan, S. Phytostimulatory effect of silver nanoparticles (AgNPs) on rice seedling growth: An insight from antioxidative enzyme activities and gene expression patterns. Ecotoxicol. Environ. Saf. 2018, 161, 624–633. [Google Scholar] [CrossRef] [PubMed]
  49. Sharma, H.S.; Fleming, C.; Selby, C.; Rao, J.R.; Martin, T. Plant biostimulants: A review on the processing of macroalgae and use of extracts for crop management to reduce abiotic and biotic stresses. J. Appl. Phycol. 2014, 26, 465–490. [Google Scholar] [CrossRef]
  50. Siwik-Ziomek, A.; Szczepanek, M. Soil extracellular enzyme activities and uptake of N by oilseed rape depending on fertilization and seaweed biostimulant application. Agronomy 2019, 9, 480. [Google Scholar] [CrossRef]
  51. Pienaar, B.C.; Majeke, B.M.; Wittenberg, M.F.; Adetunji, A.E.; Nephali, L.; Tugizimana, F.; Rafudeen, M.S. Mitigating salt stress in maize using Ecklonia maxima seaweed extracts. Plant Stress 2025, 16, 100828. [Google Scholar] [CrossRef]
  52. Tandathu, T.; Kotzé, E.; Van Der Watt, E.; Khetsha, Z.P. Effect of Biostimulants and Glyphosate on morphophysiological parameters of Zea mays (L.) seedlings under controlled conditions. Agronomy 2024, 14, 2396. [Google Scholar] [CrossRef]
  53. Matysiak, K.; Adamczewski, K. Wpływ bioregulatora Kelpak na plonowanie roślin uprawnych. Prog. Plant Prot. 2006, 46, 102–108. (In Polish) [Google Scholar]
  54. Glińska, S.; Bartczak, M.; Oleksiak, S.; Wolska, A.; Gabara, B.; Posmyk, M.M. Effects of anthocyanin-rich extract from red cabbage leaves on meristematic cells of Allium cepa L. roots treated with heavy metals. Ecotox. Environ. Safe 2007, 68, 343–350. [Google Scholar] [CrossRef] [PubMed]
  55. El-Katony, T.M.; Ward, F.M.; Deyab, M.A.; El-Adl, M.F. Algal amendment improved yield and grain quality of rice with alleviation of the impacts of salt stress and water stress. Heliyon 2021, 7, e07911. [Google Scholar] [CrossRef]
  56. El-Akhdar, I.; Elsakhawy, T.; Abo-Koura, H.A. Alleviation of salt stress on wheat (Triticum aestivum L.) by plant growth promoting bacteria strains Bacillus halotolerans MSR-H4 and Lelliottia amnigena MSR-M49. J. Adv. Microbiol. 2020, 20, 44–58. [Google Scholar] [CrossRef]
  57. Çam, S.; Küçük, Ç.; Almaca, A. Bacillus strains exhibit various plant growth promoting traits and their biofilm-forming capability correlates to their salt stress alleviation effect on maize seedlings. J. Biotechnol. 2023, 369, 35–42. [Google Scholar] [CrossRef]
  58. Lata, D.L.; Abdie, O.; Rezene, Y. IAA-Producing bacteria from the rhizosphere of chickpea (Cicer arietinum L.): Isolation, characterization, and their effects on plant growth performance. Heliyon 2024, 10, e39702. [Google Scholar] [CrossRef]
  59. Khan, A.; Doshi, H.V.; Thakur, M.C. Bacillus spp.: A Prolific siderophore producer. In Bacilli and Agrobiotechnology; Islam, M.T., Rahman, M., Pandey, P., Jha, C.K., Aeron, A., Eds.; Springer International Publishing: Cham, Switzerland, 2016; pp. 309–323. ISBN 978-3-319-44409-3. [Google Scholar]
  60. Misra, S.; Chauhan, P.S. ACC deaminase-producing rhizosphere competent Bacillus spp. mitigate salt stress and promote Zea mays growth by modulating ethylene metabolism. 3 Biotech 2020, 10, 119. [Google Scholar] [CrossRef]
  61. Jain, S.; Varma, A.; Choudhary, D.K. Perspectives on nitrogen-fixing bacillus species. In Soil Nitrogen Ecology; Cruz, C., Vishwakarma, K., Choudhary, D.K., Varma, A., Eds.; Springer International Publishing: Cham, Switzerland, 2021; pp. 359–369. ISBN 978-3-030-71206-8. [Google Scholar]
  62. Rafanomezantsoa, P.; El-Hasan, A.; Voegele, R.T. Potential of Bacillus halotolerans in mitigating biotic and abiotic stresses: A comprehensive review. Stresses 2025, 5, 24. [Google Scholar] [CrossRef]
  63. Feitoza de Jesus Santos, A.; Da Cas Bundt, A. A inoculação foliar com Methylobacterium symbioticum SB23 melhora a fixação de nitrogênio e a produtividade do milho em diferentes condições edafoclimáticas. Agrária—Rev. Bras. De Ciências Agrárias 2025, 20, e4182. [Google Scholar] [CrossRef]
  64. Valente, F.; Panozzo, A.; Bozzolin, F.; Barion, G.; Bolla, P.K.; Bertin, V.; Potestio, S.; Visioli, G.; Wang, Y.; Vamerali, T. Growth, photosynthesis and yield responses of common wheat to foliar application of Methylobacterium symbioticum under decreasing chemical nitrogen fertilization. Agriculture 2024, 14, 1670. [Google Scholar] [CrossRef]
  65. Vera, R.T.; García, A.J.B.; Álvarez, F.J.C.; Ruiz, J.M.; Martín, F.F. Application and effectiveness of Methylobacterium symbioticum as a biological inoculant in maize and strawberry crops. Folia Microbiol. 2024, 69, 121–131. [Google Scholar] [CrossRef]
  66. Rodrigues, M.Â.; Correia, C.M.; Arrobas, M. The application of a foliar spray containing Methylobacterium symbioticum had a limited effect on crop yield and nitrogen recovery in field and pot-grown maize. Plants 2024, 13, 2909. [Google Scholar] [CrossRef]
  67. Arrobas, M.; Correia, C.M.; Rodrigues, M.Â. Methylobacterium symbioticum applied as a foliar inoculant was little effective in enhancing nitrogen fixation and lettuce dry matter yield. Sustainability 2024, 16, 4512. [Google Scholar] [CrossRef]
  68. Gyogluu Wardjomto, C.; Mohammed, M.; Ngmenzuma, T.Y.; Mohale, K.C. Effect of rhizobia inoculation and seaweed extract (Ecklonia maxima) application on the growth, symbiotic performance and nutritional content of cowpea (Vigna unguiculata (L.) Walp.). Front. Agron. 2023, 5, 1138263. [Google Scholar] [CrossRef]
  69. Serafin-Andrzejewska, M.; Falkiewicz, A.; Wojciechowski, W.; Kozak, M. Yield and seed quality of faba bean (Vicia faba L. var. minor) as a result of symbiosis with nitrogen-fixing bacteria. Agriculture 2025, 15, 960. [Google Scholar] [CrossRef]
  70. Vasantharaja, R.; Abraham, L.S.; Inbakandan, D.; Thirugnanasambandam, R.; Senthilvelan, T.; Jabeen, S.A.; Prakash, P. Influence of seaweed extracts on growth, phytochemical contents and antioxidant capacity of cowpea (Vigna unguiculata L. Walp). Biocatal. Agric. Biotechnol. 2019, 17, 589–594. [Google Scholar] [CrossRef]
  71. Al-Temimi, A.H.M.; Al-Hilfy, I.H.H. Role of plant growth promoting in improving productivity and quality of maize. Iraqi. J. Agric. Sci. 2022, 53, 1437–1446. [Google Scholar] [CrossRef]
  72. Kalman, C.D.; Kálmán, L.; Szél, S.; Salamon, K.M.; Xoltan, N.; Kiss, E.; Posta, K. Assessment of the influence of soil inoculation on changes in the adaptability of maize hybrids. Cereal Res. Commun. 2023, 51, 1055–1071. [Google Scholar] [CrossRef]
  73. Ocwa, A.; Mohammed, S.; Mousavi, S.M.N.; Illés, Á.; Bojtor, C.; Ragán, P.; Rátonyi, T.; Harsányi, E. Maize grain yield and quality improvement through biostimulant application: A systematic review. J. Soil Sci. Plant Nutr. 2024, 24, 1609–1649. [Google Scholar] [CrossRef]
Agronomy 15 02894 g001
Figure 1. The scheme of individual experimental objects. (A) I1 90 + 90; (B) I2 90 + 45; (C) I3 90 + 27.5 thousand seeds ha−1 of maize + climbing beans; (D) 90 thousand seeds ha−1 of maize.
Figure 1. The scheme of individual experimental objects. (A) I1 90 + 90; (B) I2 90 + 45; (C) I3 90 + 27.5 thousand seeds ha−1 of maize + climbing beans; (D) 90 thousand seeds ha−1 of maize.
Agronomy 15 02894 g001
Agronomy 15 02894 g002
Figure 2. Weather conditions during the field experiment.
Figure 2. Weather conditions during the field experiment.
Agronomy 15 02894 g002
Table 1. The soil conditions during the field experiment.
Table 1. The soil conditions during the field experiment.
ParameterValue
pH6.1
Organic carbon, %1.02
P, mg 100 g−1 soil12.83
K, mg 100 g−1 soil9.84
Mg, mg 100 g−1 soil5.31
Nmin 0–30 cm, mg kg−1 soil2.95
Nmin 30–60 cm, mg kg−1 soil5.60
Table 2. Number of maize and climbing bean plants per hectare immediately before harvest (average for 2023–2024).
Table 2. Number of maize and climbing bean plants per hectare immediately before harvest (average for 2023–2024).
BiostimulantsIntercropping
I1I2I3Sole Maize
MaizeClimbing BeansMaizeClimbing BeansMaizeClimbing Beans
control88,62863,63087,26447,82187,26421,45089,082
B1 183,62869,08489,99144,07083,62822,16586,355
B285,44667,26689,99145,00883,62822,16580,901
B387,26470,90288,90043,13385,44624,31079,992
B488,17376,35686,17345,47782,71922,16580,901
1 B1—liquid microelement fertilizer (Zn-8.0%) containing zinc acetate, B2—liquid extract from Ecklonia maxima algae, B3—Methylobacterium symbioticum bacteria, B4—Bacillus halotolerans bacteria; I1—90 + 90; I2—90 + 45; I3—90 + 27.5 thousand seeds ha−1 of maize + climbing beans; sole maize—90 thousand seeds ha−1 of maize.
Table 3. Dry matter above-ground parts of maize in intercropping with climbing beans under the influence of biostimulants (average for 2023–2024).
Table 3. Dry matter above-ground parts of maize in intercropping with climbing beans under the influence of biostimulants (average for 2023–2024).
Dry Matter Maize Cobs, g Plants−1
BiostimulantsIntercroppingMeans
I1I2I3sole maize
control140.30145.90161.82167.20153.80 A 2
B1 1169.89167.42183.33187.82177.11 C
B2152.40154.20174.14182.66165.85 B
B3162.49158.46173.47175.71167.53 BC
B4147.92156.21165.63168.09159.46 AB
Means154.60 A156.44 A171.68 B176.30 B
Dry Matter Maize Leaves, g Plants−1
BiostimulantsIntercroppingMeans
I1I2I3sole maize
control25.0722.1030.5932.4827.56 A
B129.5127.3634.2335.7131.70 B
B232.8833.0234.3739.8935.04 BC
B334.6435.5836.5237.8736.15 C
B428.9829.3833.0237.2032.14 B
Means30.22 A29.49 A33.75 B36.63 B
Dry Matter Maize Stems, g Plants−1
BiostimulantsIntercroppingMeans
I1I2I3sole maize
control34.7733.0547.6850.5741.52 A
B139.5540.1049.6752.2945.40 AB
B245.0645.2452.0251.5748.47 B
B341.0039.9251.7553.6446.58 AB
B435.9434.7750.7551.2943.19 AB
Means39.27 A38.62 A50.37 B51.87 B
1 B1—liquid microelement fertilizer (Zn-8.0%) containing zinc acetate, B2—liquid extract from Ecklonia maxima algae, B3—Methylobacterium symbioticum bacteria, B4—Bacillus halotolerans bacteria; I1—90 + 90; I2—90 + 45; I3—90 + 27.5 thousand seeds ha−1 of maize + climbing beans; sole maize—90 thousand seeds ha−1 of maize; 2 Means for the biostimulants in a column followed by the same capital letter (A, B, and C) do not differ significantly at p ≤ 0.05. Means for a intercropping in a cell followed by the same capital letter (A and B) do not differ significantly at p ≤ 0.05.
Table 4. Dry matter above-ground parts of climbing beans in intercropping with maize under the influence of biostimulants (average for 2023–2024).
Table 4. Dry matter above-ground parts of climbing beans in intercropping with maize under the influence of biostimulants (average for 2023–2024).
Dry Matter Climbing Beans Pods, g Plants−1
BiostimulantsIntercroppingMeans
I1I2I3
control2.957.845.185.32 C
B1 12.377.044.564.65 AB
B22.377.294.894.85 B
B32.376.714.924.67 AB
B42.086.234.384.23 A
Means2.43 A7.02 C4.78 B
Dry Matter Climbing Beans Leaves, g Plants−1
BiostimulantsIntercroppingMeans
I1I2I3
control13.5025.4020.9319.94 B
B110.6322.7019.5817.63 AB
B210.7223.0319.7417.83 AB
B312.1524.6420.3319.04 AB
B49.9621.5218.8216.76 A
Means11.39 A23.46 B19.88 B
Dry Matter Climbing Beans Stems, g Plants−1
BiostimulantsIntercroppingMeans
I1I2I3
control25.4948.4832.1835.38 B 2
B123.1944.0825.7931.02 AB
B222.3940.0826.1929.55 A
B322.3942.5826.0930.35 AB
B420.6939.8826.4929.02 A
Means22.83 A43.02 B27.35 A
1 B1—liquid microelement fertilizer (Zn-8.0%) containing zinc acetate, B2—liquid extract from Ecklonia maxima algae, B3—Methylobacterium symbioticum bacteria, B4—Bacillus halotolerans bacteria; I1—90 + 90; I2—90 + 45; I3—90 + 27.5 thousand seeds ha−1 of maize + climbing beans; 2 Means for the biostimulants in a column followed by the same capital letter (A, B, and C) do not differ significantly at p ≤ 0.05. Means for an intercropping in a cell followed by the same capital letter (A and B) do not differ significantly at p ≤ 0.05.
Table 5. Dry matter single maize plants in intercropping with climbing beans under the influence of biostimulants (average for 2023–2024), g plants−1.
Table 5. Dry matter single maize plants in intercropping with climbing beans under the influence of biostimulants (average for 2023–2024), g plants−1.
BiostimulantsIntercroppingMeans
I1I2I3Sole Maize
control185.05 a 2193.69 b233.71 c241.73 c213.55 A
B1 1209.72 a214.45 a251.44 b254.30 b232.48 BC
B2212.19 a222.03 b252.40 c257.23 c235.96 C
B3212.94 a218.18 b253.95 c256.98 c235.51 C
B4203.16 a210.31 b247.09 c251.08 c227.91 B
Means204.61 A211.73 B247.72 C252.26 C
1 B1—liquid microelement fertilizer (Zn-8.0%) containing zinc acetate, B2—liquid extract from Ecklonia maxima algae, B3—Methylobacterium symbioticum bacteria, B4—Bacillus halotolerans bacteria; I1—90 + 90; I2—90 + 45; I3—90 + 27.5 thousand seeds ha−1 of maize + climbing beans; sole maize—90 thousand seeds ha−1 of maize; 2 values in cells for the biostimulants × intercropping followed by the same lowercase letter (a, b, c) do not differ significantly at p ≤ 0.05. Means for the biostimulants in a column followed by the same capital letter (A, B, and C) do not differ significantly at p ≤ 0.05. Means for a intercropping in a cell followed by the same capital letter (A and B) do not differ significantly at p ≤ 0.05.
Table 6. Dry matter single climbing beans plants in intercropping with maize under the influence of biostimulants (average for 2023–2024), g plants−1.
Table 6. Dry matter single climbing beans plants in intercropping with maize under the influence of biostimulants (average for 2023–2024), g plants−1.
BiostimulantsIntercroppingMeans
I1I2I3
control38.4987.5162.6362.88 C 2
B1 133.4380.4157.3457.06 AB
B232.8578.4556.7156.00 AB
B334.3181.6558.0157.99 B
B431.4777.5456.0855.03 A
Means34.11 A81.11 C58.15 B
1 B1—liquid microelement fertilizer (Zn-8.0%) containing zinc acetate, B2—liquid extract from Ecklonia maxima algae, B3—Methylobacterium symbioticum bacteria, B4—Bacillus halotolerans bacteria; I1—90 + 90; I2—90 + 45; I3—90 + 27.5 thousand seeds ha−1 of maize + climbing beans; 2 Means for the biostimulants in a column followed by the same capital letter (A, B, and C) do not differ significantly at p ≤ 0.05. Means for an intercropping in a cell followed by the same capital letter (A and B) do not differ significantly at p ≤ 0.05.
Table 7. Dry matter yield of maize in intercropping with climbing beans under the influence of biostimulants (average for 2023–2024), t ha−1.
Table 7. Dry matter yield of maize in intercropping with climbing beans under the influence of biostimulants (average for 2023–2024), t ha−1.
BiostimulantsIntercroppingMeans
I1I2I3Sole Maize
control16.84 a 217.06 a20.38 b19.93 b18.55 A
B1 117.48 a19.33 b21.03 b22.25 c20.02 B
B218.12 a19.98 b21.12 c20.84 bc20.02 B
B318.55 a19.59 b21.71 c20.57 b20.10 B
B417.91 a18.14 a20.44 b20.33 b19.20 A
Means17.78 A18.82 B20.94 C20.78 C
1 B1—liquid microelement fertilizer (Zn-8.0%) containing zinc acetate, B2—liquid extract from Ecklonia maxima algae, B3—Methylobacterium symbioticum bacteria, B4—Bacillus halotolerans bacteria; I1—90 + 90; I2—90 + 45; I3—90 + 27.5 thousand seeds ha−1 of maize + climbing beans; sole maize—90 thousand seeds ha−1 of maize; 2 values in cells for the biostimulants × intercropping followed by the same lowercase letter (a, b, c) do not differ significantly at p ≤ 0.05. Means for the biostimulants in a column followed by the same capital letter (A, B, and C) do not differ significantly at p ≤ 0.05. Means for a intercropping in a cell followed by the same capital letter (A and B) do not differ significantly at p ≤ 0.05.
Table 8. Dry matter yield of climbing beans in intercropping with maize under the influence of biostimulants (average for 2023–2024), t ha−1.
Table 8. Dry matter yield of climbing beans in intercropping with maize under the influence of biostimulants (average for 2023–2024), t ha−1.
BiostimulantsIntercroppingMeans
I1I2I3
control2.465.191.343.00 B 2
B1 12.304.541.262.70 A
B22.214.531.252.66 A
B32.444.521.412.79 A
B42.414.521.252.72 A
Means2.36 B4.66 C1.30 A
1 B1—liquid microelement fertilizer (Zn-8.0%) containing zinc acetate, B2—liquid extract from Ecklonia maxima algae, B3—Methylobacterium symbioticum bacteria, B4—Bacillus halotolerans bacteria; I1—90 + 90; I2—90 + 45; I3—90 + 27.5 thousand seeds ha−1 of maize + climbing beans; 2 Means for the biostimulants in a column followed by the same capital letter (A, B, and C) do not differ significantly at p ≤ 0.05. Means for an intercropping in a cell followed by the same capital letter (A and B) do not differ significantly at p ≤ 0.05.
Table 9. Dry matter yield of intercropping maize and climbing beans under the influence of biostimulants (average for 2023–2024), t ha−1.
Table 9. Dry matter yield of intercropping maize and climbing beans under the influence of biostimulants (average for 2023–2024), t ha−1.
BiostimulantsIntercroppingMeans
I1I2I3Sole Maize
control19.2923.1321.7219.9321.02 A 2
B1 119.7724.3122.2922.2522.15 B
B220.3325.6322.3720.8422.29 B
B320.9924.1723.1220.5722.21 B
B420.3122.9121.6920.3321.31 A
Means20.14 A24.03 C22.24 B20.78 AB
1 B1—liquid microelement fertilizer (Zn-8.0%) containing zinc acetate, B2—liquid extract from Ecklonia maxima algae, B3—Methylobacterium symbioticum bacteria, B4—Bacillus halotolerans bacteria; I1—90 + 90; I2—90 + 45; I3—90 + 27.5 thousand seeds ha−1 of maize + climbing beans; sole maize—90 thousand seeds ha−1 of maize; 2 Means for the biostimulants in a column followed by the same capital letter (A, B, and C) do not differ significantly at p ≤ 0.05. Means for a intercropping in a cell followed by the same capital letter (A and B) do not differ significantly at p ≤ 0.05.
Table 10. Protein content in silage from intercropping of maize and climbing beans under the influence of biostimulants (average for 2023–2024), g kg−1.
Table 10. Protein content in silage from intercropping of maize and climbing beans under the influence of biostimulants (average for 2023–2024), g kg−1.
BiostimulantsIntercroppingMeans
I1I2I3Sole Maize
control91.6 c 2106.3 d84.5 b75.6 a89.5 A
B1 196.5 c111.3 d93.0 b77.5 a94.6 B
B298.3 c110.3 d92.0 b78.2 a94.7 B
B399.5 b115.4 c96.7 b80.2 a97.9 C
B495.4 b109.2 c91.8 b79.4 a93.9 BC
Means96.2 C110.5 D91.6 B78.1 A
1 B1—liquid microelement fertilizer (Zn-8.0%) containing zinc acetate, B2—liquid extract from Ecklonia maxima algae, B3—Methylobacterium symbioticum bacteria, B4—Bacillus halotolerans bacteria; I1—90 + 90; I2—90 + 45; I3—90 + 27.5 thousand seeds ha−1 of maize + climbing beans; sole maize—90 thousand seeds ha−1 of maize; 2 values in cells for the biostimulants × intercropping followed by the same lowercase letter (a, b, c, d) do not differ significantly at p ≤ 0.05. Means for the biostimulants in a column followed by the same capital letter (A, B, C, and D) do not differ significantly at p ≤ 0.05. Means for an intercropping in a cell followed by the same capital letter (A and B) do not differ significantly at p ≤ 0.05.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Górski, R.; Sikorska, A.; Czaplicki, R.; Mystkowska, I. Enhancing Maize–Climbing Bean Intercropping with Biostimulants: Implications for Yield and Silage Quality. Agronomy 2025, 15, 2894. https://doi.org/10.3390/agronomy15122894

AMA Style

Górski R, Sikorska A, Czaplicki R, Mystkowska I. Enhancing Maize–Climbing Bean Intercropping with Biostimulants: Implications for Yield and Silage Quality. Agronomy. 2025; 15(12):2894. https://doi.org/10.3390/agronomy15122894

Chicago/Turabian Style

Górski, Rafał, Anna Sikorska, Robert Czaplicki, and Iwona Mystkowska. 2025. "Enhancing Maize–Climbing Bean Intercropping with Biostimulants: Implications for Yield and Silage Quality" Agronomy 15, no. 12: 2894. https://doi.org/10.3390/agronomy15122894

APA Style

Górski, R., Sikorska, A., Czaplicki, R., & Mystkowska, I. (2025). Enhancing Maize–Climbing Bean Intercropping with Biostimulants: Implications for Yield and Silage Quality. Agronomy, 15(12), 2894. https://doi.org/10.3390/agronomy15122894

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop