Intercropped Species Research Articles

Sustainable diversification in Indian agriculture: Effectiveness of integrating horticultural crops as intercrops in mono-cropping coconut system

Coconut, also known as Kalpaviruksha, is a gift from nature that is grown all over the world for its many uses. The distinctive characteristics of the coconut tree indicate that mono-cropping coconut results in extremely low land use efficiency. Another drawback of mono-cropping from an economic standpoint is the substantial initial investment required to develop the crop until it reaches bearing age, which may be beyond the means of smallholders. In most coconut-growing countries, planting coconut alongside a range of other crops is a popular practice to maximise land use efficiency. It has been determined that over 100 distinct crop and system combinations can be cultivated as intercrops alongside coconut plantations. Intercropping is more efficient than mono-cropping and increases yield, if the components of the intercrop utilize natural resources in ways that complement each other's utilization of those resources, which generates a higher benefit-cost ratio than the sole crop. The relevance and possibilities of multiple-cropping and intercropping systems suitable for different coconut stands are covered in this article. The results provide an overview of coconut farming's lucrative and sustainable intercrop species that support the income of farmers, as well as the advantages, drawbacks, and prospects of several multiple-cropping systems. The paper concludes by outlining potential research avenues for the effective adaptation of different cropping systems based on coconut.

Rubber-Based Agroforestry Systems Associated with Food Crops: A Solution for Sustainable Rubber and Food Production?

Agroforestry is often seen as a sustainable land-use system for agricultural production providing ecosystem services. Intercropping with food crops leads to equal or higher productivity than monoculture and results in food production for industry and subsistence. Low rubber price and low labor productivity in smallholdings have led to a dramatic conversion of rubber plantations to more profitable crops. The literature analysis performed in this paper aimed at better understanding the ins and outs that could make rubber-based agroforestry more attractive for farmers. A comprehensive search of references was conducted in March 2023 using several international databases and search engines. A Zotero library was set up consisting of 415 scientific references. Each reference was carefully read and tagged in several categories: cropping system, country, main tree species, intercrop type, intercrop product, level of product use, discipline of the study, research topic, and intercrop species. Of the 232 journal articles, 141 studies were carried out on rubber agroforestry. Since 2011, the number of studies per year has increased. Studies on rubber-based agroforestry systems are performed in most rubber-producing countries, in particular in Indonesia, Thailand, China, and Brazil. These studies focus more or less equally on perennials (forest species and fruit trees), annual intercrops, and mixed plantations. Of the 47 annual crops associated with rubber in the literature, 20 studies dealt with rice, maize, banana, and cassava. Agronomy is the main discipline in the literature followed by socio-economy and then ecology. Only four papers are devoted to plant physiology and breeding. The Discussion Section has attempted to analyze the evolution of rubber agroforestry research, progress in the selection of food crop varieties adapted to agroforestry systems, and to draw some recommendations for rubber-based agroforestry systems associated with food crops.

Intercropping Chickpea with Durum Wheat Enhances Nutrient Uptake and Grain Yield Under Low Phosphorus Availability

ABSTRACT Intercropping is a traditional farming system that increases crop diversity to strengthen agroecosystem functions while decreasing chemical inputs and minimizing negative environmental effects of crop production. However, the effect of intercropping legume-cereal in enhancing nutrient uptake and use efficiency under low phosphorus (P) soils is poorly understood. Growth, nodulation, P uptake and use efficiency, and changes in inorganic P availability in the rhizosphere of intercropped species were thus investigated in a field experiment with durum wheat and chickpea either grown alone or intercropped. The results showed that both plant biomass and grain yield, and consequently, the amount of P uptake by intercropped durum wheat increased significantly (30%, 12%, and 46%, respectively) compared with sole cropping during the two seasons. P availability increased in the rhizosphere of the two species, either grown as sole crops or as intercrops, and was enhanced by intercropping. Moreover, total biomass, grain yield, and P uptake were significantly improved, as indicated by higher land equivalent ratio (LER > 1) in intercropping over sole cropping treatments. The increased biomass and grain yield for intercropped durum wheat were associated with the stimulation of P absorption and use efficiency. Furthermore, intercropped wheat was more competitive than their respective chickpea over two growing seasons. The results of this study suggest that changes in the intercropped chickpea rhizosphere may enhance plant growth, P uptake, and use efficiency of the intercropped wheat under low-P soils.

Facilitation between intercropped species increases micronutrient acquisition and controls rust disease on maize

Context or ProblemGlobal food security is threatened by plant disease, and crop diversification often promotes productivity through reduced disease and facilitation for increased nutrient acquisition. However, whether such facilitation is a factor in disease resistance is unknown. Objective or Research QuestionInvestigate how crop diversity affects crop productivity and rust disease on maize, and whether competition or facilitation between crop species correspond with resistance. MethodsFive irrigated intercropping experiments with different fertilization and crop combinations were conducted at two sites for four years. Productivity (542 data points) and disease severity (27150 data points) of maize monoculture, maize - legume and maize - non-legume intercropping were compared. A meta-analysis of literature was performed to confirm the broader applicability of results from these field experiments. ResultsLegume-based intercropping increased the aboveground biomass of intercropped maize by 8% and grain yields by 10% in comparison to non-legume-based intercropping. Disease severity on maize intercropped with legumes was reduced by 45% and 48%, compared to monocultures of maize and maize intercropped with non-legumes, respectively. Moreover, as interactions among intercrops became more facilitative, the concentrations of zinc (Zn), copper (Cu) and iron (Fe) in maize increased, and these increases were highly correlated with decreasing disease severity. The global meta-analysis was consistent with our field experiments, as lower disease severity was associated with greater intensity of interspecific facilitation or with lower intensity of interspecific competition. Conclusions or SignificanceLower disease severity was closely related to enhanced acquisition of nutrients that can enhance the resistance to crop diseases, driven by stronger interspecific facilitative effects in intercropping systems. Facilitative effects on maize was increased by the identity of leguminous companion crop species, and was increased by sufficient irrigation, but reduced by applications of nitrogen and phosphorus fertilizers. ImplicationsOur findings identify a novel facilitative mechanism in general and advance the understanding of the facilitative mechanisms that underly disease control through crop diversification.

Effect of crop combination on yield performance, nutrient uptake, and land use advantage of cereal/legume intercropping systems

ContextCrop type and temporal synchronization are crucial for improving the productivity of intercropping systems, especially with reduced inputs (nitrogen, N, and phosphorus, P). However, the effects of crop type and temporal dynamics on nutrient uptake and yield advantage of cereal/legume intercropping systems are still unclear. ObjectiveThe objective of this study was to assess the effects of different temporal dynamics of intercrops on growth, nutrient-use advantage, land productivity, and economic viability of cereal/legume intercropping systems under arid irrigated conditions. MethodsIn this field study, we used the equal land proportion for all intercrops in both intercropping systems: wheat/chickpea intercropping (wheat/chickpea), where legume (chickpea) was the first-sown crop; and wheat/soybean intercropping (wheat/soybean), with cereal (wheat) being the first-planted crop), and all strip intercropping results were compared with their sole systems: sole chickpea (SCp), sole wheat (SW), and sole soybean (SS). Results and conclusionsHere, we revealed that the improved complementarity and facilitation interactions in wheat/chickpea linked with better phenological synchronization between wheat and chickpea, which resulted in higher relative grain yields, primarily gained from greater biomass accumulation and its translocation towards ears/pods, seeds, and seed weight, than the wheat and soybean in wheat/soybean. Similarly, the intercropped wheat accumulated a significantly higher N (15%) and P (14%) under wheat/chickpea than in wheat/soybean, whereas, in legumes, the N and P uptake of chickpea in wheat/chickpea was 19% and 13% higher than that of soybean in wheat/soybean, respectively. On average, in wheat/soybean, wheat and soybean achieved 62% of SW and 58% of SS yields, while in wheat/chickpea, wheat and chickpea produced 71% and 67% of SW and SCp yields, respectively, demonstrating the advantage of sowing legumes earlier than cereals in intercropping systems. Overall, in wheat/chickpea, the system-level nutrient- and land-use advantage, measured as the land, nitrogen, and phosphorus equivalent ratios, were 1.38, 1.59, and 1.62, respectively, which increased the net profit of wheat/chickpea by 55% compared to wheat/soybean, suggesting that intercropping systems require fewer anthropogenic inputs to produce higher crop yields than sole systems. SignificanceOur results contribute to understanding the effects of crop type and temporal synchronization of intercrop species for maximizing the land productivity of cereal/legume intercropping systems in arid irrigated regions.

Spatial differences influence nitrogen uptake, grain yield, and land-use advantage of wheat/soybean relay intercropping systems

Cereal/legume intercropping is becoming a popular production strategy for higher crop yields and net profits with reduced inputs and environmental impact. However, the effects of different spatial arrangements on the growth, grain yield, nitrogen uptake, and land-use advantage of wheat/soybean relay intercropping are still unclear, particularly under arid irrigated conditions. Therefore, in a three-year field study from 2018 to 2021, soybean was relay intercropped with wheat in different crop configurations (0.9 m, narrow strips; 1.8 m, medium strips; and 2.7 m, wide strips), and the results of intercropping systems were compared with their sole systems. Results revealed that intercrops with wide strips outperformed the narrow and medium strips, when the objective was to obtain higher total leaf area, dry matter, nitrogen uptake, and grain yield on a given land area due to reduced interspecific competition between intercrops. Specifically, at maturity, wide strips increased the dry matter accumulation (37% and 58%) and its distribution in roots (37% and 55%), straw (40% and 61%), and grains (30% and 46%) of wheat and soybean, respectively, compared to narrow strips. This enhanced dry matter in wide strips improved the soybean’s competitive ability (by 17%) but reduced the wheat’s competitive ability (by 12%) compared with narrow strips. Noticeably, all intercropping systems accumulated a significantly higher amount of nitrogen than sole systems, revealing that wheat/soybean relay intercropping requires fewer anthropogenic inputs (nitrogen) and exerts less pressure on the ecosystem than sole systems. Overall, in wide strips, intercropped wheat and soybean achieved 62% and 71% of sole wheat and soybean yield, respectively, which increased the greater total system yield (by 19%), total land equivalent ratio (by 24%), and net profit (by 34%) of wide strips compared to narrow strips. Our study, therefore, implies that the growth parameters, grain yields, nutrient accumulation, and land-use advantage of intercrop species could be improved with the proper spatial arrangement in cereal/legume intercropping systems.

Limited environmental and yield benefits of intercropping practices in smallholder fields: Evidence from multi-source data

To ensure food security in sub-Saharan Africa, it is necessary to improve crop yields while minimizing environmental impacts. Intercropping has been demonstrated to deliver such outcomes, but their performance in smallholder fields has received limited attention therefore insufficient to capture the complexity of real-world crop fields run by smallholder farmers. This study examines the benefits and management of intercropping practices in real smallholder fields in Malawi. We collected field data on intercrop types, the number of intercropped species and maize yield in intercropped maize fields. Field data was then combined with geospatial and household survey data to investigate the yield benefits, agricultural inputs, and factors related to intercropping choices. We used Pearson correlation and Tukey’s test to test the statistical significance in the difference between intercropped fields and monoculture fields. We found that more intercrops were planted in fields with smaller sizes, drier conditions, and higher soil erosion levels, with adoption rates increasing from 75 % in 2010 to 84 % in 2020. In addition, our field data shows that intercropping is associated with reduced primary maize yield (2.7 t/ha) compared to pure maize yield (3.8 t/ha). Conversely, satellite data demonstrates an improvement in overall field yield in intercropped fields. Meanwhile, intercropped fields require higher labor inputs (11 h more per season) and increased weeding times than monocultures, however agrochemical inputs (fertilizers and pesticides) do not necessarily decrease in intercropped fields compared to monocultures. Our results suggest that while smallholder farmers in Malawi adopt intercropping to improve land use efficiency, drought resilience, and soil fertility, they are not realizing the full benefits observed in experimental trials. More evidence on the benefits and best practices of intercropping in smallholder fields is necessary in order to better understand this practice as an option for sustainable intensification.

Evaluating agroforestry patterns to increase land productivity of Falcataria moluccana private forests in Central Lombok Regency, West Nusa Tenggara

Developing agroforestry systems in private forests is expected to increase productivity. This study aims to determine the appropriate agroforestry design for Falcataria moluccana-based private forests in Central Lombok Regency. Three intercrop species were tested: small taro (Colocasia esculenta), ginger (Zingiber officinale), and vanilla (Vanilla planifolia Andrews). This study was established using a completely randomized design. The three planting combinations were examined in three replications for a total of nine test plots: F. moluccana+vanilla+small taro (FmVT), F. moluccana+vanilla+ginger (FmVG), and F. moluccana+vanilla+ginger+small taro (FmVGT). Each test plot was 10 x 10 m and was located at 3 x 3 m spacing under a 3-year-old F. moluccana stand. The measured variables were crop survival rates, plant yields, and microclimatic data. The correlation between the variables was examined using the Pearson Product Moment, Duncan's advanced multiple range test (DMRT), and analysis of variance (ANOVA). The market price was used to determine the crop's economic value. The best agroforestry design was based on the economic value of crop production and the land equivalent ratio. The results indicated that the combination of F. moluccana, vanilla, ginger, and small taro, which generated an additional income of IDR 11,851,250 ha-1 a year, should be widely promoted and adopted.

An increase in intercropped species richness improves plant water use but weakens the nutrient status of both intercropped plants and soil in rubber–tea agroforestry systems

An increase in intercropped species richness improves plant water use but weakens the nutrient status of both intercropped plants and soil in rubber–tea agroforestry systems

Arbuscular Mycorrhizal Fungi Inoculation and Intercropping Combine to Control Nematodes in Bananas

Aims: To investigate the combined effect of Arbuscular Mycorrhizal Fungi (AMF) and intercropping on the control of the nematode Radopholus similis in banana.
 Study Design: The study involved an experiment in which banana-banana monocrops alongside banana-groundnut and banana-sweet potato intercrops were inoculated with AMF Rhizophagus irregularis MUCL 41833 to control the nematode R. similis.
 Place and Duration of Study: Centre Africain de Recherches sur les Bananiers et Plantains (CARBAP), from September 2016 to April 2017.
 Methodology: An experiment was conducted under greenhouse conditions (photoperiod 12 h. average temperature 24 - 28°C and 70 - 80% relative humidity) and R. irregularis were tested against R. similis with banana intercropped with either groundnut, sweet potato or banana itself. The plants were cultivated in boxes (30 x 15 x 10 cm) containing sterilized (2x1hour at 121°C) sand/coffee ash substrate (proportion 1:2 v/v), as an intercropping system with the following plant combinations: Banana-banana, banana-groundnut and banana-sweet potato. The experimental set-up was a completely randomized design comprising four treatments and six replicates: (1): Nematode (Nem), (2) AMF, (3) AMF + Nema and (4) control without nematode and without AMF. The ratio of banana: intercrop was 1:1 in the intercropping treatments. A total of 72 boxes was considered in the experimental set-up.
 Results: AMF root colonization of banana was clearly affected by intercropping with about 25% increment observed in banana co-cultivated with groundnut or sweet potato compared to banana-banana combination. Positive effects of AMF expressed as an increase in banana biomass compared to the control treatment was observed in root fresh as well as shoot dry weights. However, the impact of AMF colonization in intercropping systems on R. similis did not confirm its bioprotective effect. Intercropping had a significant (P < .05) effect on R. similis and sweet potato has been shown to be more effective in controlling R. similis with 62% reduction compared to groundnut (24% reduction). Contrarily, banana plant growth decreased in the banana / sweet potato combination.
 Conclusion: Findings in this study indicate that R. similis biological control in the banana intercropping system is more dependent on the intercrop species than on AMF.

Simultaneous Assessment of Water and Nitrogen Use Efficiency in Rain-Fed Chickpea-Durum Wheat Intercropping Systems

It is well known that multiple interactions can occur between nitrogen and water use, depending on climate, soil and crop characteristics, in crop growth and yield development. However, little is known about the simultaneous change in both water and N use efficiency (WUE and NUE) and their possible interactions in cereal–-legume intercropping systems. In order to advance our knowledge on the N and water facilitation mechanisms involved in the intercropping responses of N and water input co-limitations, we investigated, via four experiment years, the simultaneous optimization of water and N-fertilizer inputs, as well as its possible effects on growth, yield, N acquisition, and the NUE and WUE in intercropped species. The results indicated that intercropping increases the leaf area index by more than +0.14 and +1.03 units when compared to durum wheat and chickpea monoculture systems, respectively. This increase is particularly noticeable under higher rainfalls during the crop period (i.e., as can be seen in the 2022, 2020, and 2019 seasons). Moderate N-application enhanced both the grain yield and protein accumulation in the mixed crops by more than 0.22 t ha−1 and 57 kg ha−1, respectively. Conversely, intercropping significantly decreased the mixed grain yield when compared to durum wheat monocultures. Intercropping advantages in terms of biomass (ranged from 1 to 44%) and N-acquisition (2 to 91%) was confirmed in either low- (2021) or high- (2019 and 2022) rainfall growing periods, but only under low and moderate N-applications. Improving N nutrition under both rainfall and drought growth periods was confirmed only for the mixed crops under all applied N-fertilizer doses. Such improvements in growth, N acquisition, and yield quality were most likely achieved by positive interactions (r2 = 0.73, p ≤ 0.001) between the NUE and WUE for the chickpea–wheat intercropping. Thus, 0.62 kg m−3 of WUE promotes a significant increase of 1 kg kg−1 in NUE by mixing chickpea-durum wheat. Rain-fed chickpea-durum wheat intercropping provides a higher performance in growth and yield quality compared to sole cropping systems; this may occur from the simultaneous optimizations of both water and N fertilizer inputs in low-N soil under semiarid conditions.

Crops grown in mixtures show niche partitioning in spatial water uptake

Abstract More diverse plant communities are generally more productive than monocultures. This benefit of species diversity is supposed to stem from resource partitioning of species in mixtures where different species use the resources spatially, temporally, or chemically in distinct ways. With respect to water, the simultaneous cultivation of crops with distinct water uptake patterns might reduce niche overlaps and thus result in higher productivity. However, little is known about whether and how spatial water uptake patterns of crop species differ among different planting arrangements and whether these changes result in increased niche partitioning and explain overyielding in mixtures. Stable isotopes of water and a Bayesian model were used to investigate the spatial water uptake patterns of six different crop species and how these patterns change depending on the planting arrangement (monocultures vs mixtures). Niche overlaps and niche widths in spatial water uptake were compared among the different crop diversity levels and linked to productivity. Furthermore, spatial water uptake was related to competition intensity and overyielding in mixtures. We found evidence for increased niche partitioning in spatial water uptake, and therefore complementary spatial root distributions of crop species, and higher expected productivity in mixtures compared to expected productivity in monocultures both due to inherent species‐level differences in water uptake and plasticity in the water uptake pattern of species. We also found a significant relationship of competition and overyielding with observed patterns in spatial water uptake. These results suggest that competition was most intense in shallow soil layers and enhanced overyielding was related to a gradual increase of water uptake in deeper soil layers. Thus, overyielding might be related to a more complete spatial exploitation of available water sources. Synthesis. Differences in spatial water uptake and niche partitioning of intercropped species, driven most likely by a complementary spatial root distribution, might explain why mixtures outperform monocultures. These findings underpin the potential of intercropping systems for a more sustainable agriculture with a more efficient use of soil resources and hence reduced input demands.

Facilitation between intercropped species increases micronutrient acquisition, subsequently controlling rust disease on maize

Facilitation between intercropped species increases micronutrient acquisition, subsequently controlling rust disease on maize

Facilitation between intercropped species increases micronutrient acquisition, subsequently controlling rust disease on maize

Facilitation between intercropped species increases micronutrient acquisition, subsequently controlling rust disease on maize

Effect of row spacing under maize-soybean relay intercropping system on yield, competition, and economic returns

Interrow spacing of intercrop species directly affects yield and competition indices such as land equivalent ratio of intercropping. The objectives of this research were to analyze (i) the maize and soybean yields under different spatial arrangements in maize-soybean relay strip intercropping (MSR) and (ii) the interspecies competition to provide a basis for optimization of rowspacing in MSR. The field trial was conducted in 2011 and 2012 at the Research Farm of the Sichuan Agricultural University in Ya'an to determine the impacts of various interrow planting distances on yield and competition indices in cereal (maize crop)-legume (soybean crop) relay strip intercropping. Three planting arrangements were utilized based on the distance between maize-maize, maize-soybean, and soybean-soybean as (T1) 50, 40, and 70 cm, (T2) 50, 50, and 50 cm, and (T3) 50, 60, and 30 cm, respectively, and comparison was made with the sole maize (SM) and sole soybean (SSB). Experimental results revealed that grain yield of maize crop was improved with enhancing row spaces between maize and soybean, while "low-high-low" trend was observed for soybean yield in T$_{1}$, T$_{2}$, and T3, respectively, in both years. Competitive ratio, aggressivity, and relative crowding coefficient were consistently greater for maize than soybean in all treatments. The highest LER (1.67) was reported in T$_{2}$ treatment, which was 9% and 4% higher than in T$_{1}$ and T$_{3}$, respectively. Higher LER explains that both crops are facilitating each other in a positive way and increase the average net income of T$_{2}$ as compared to T$_{1}$ and T$_{3}$. Enhancing distance between maize-soybean rows with reducing distance between soybean rows put pressure on soybean due to intraspecific competition. Combined results of competitive indices and economic analysis showed that intercrops performed at their maximum in treatment T$_{2}$. Therefore, the maximum intercropping advantages can be achieved by changing the row spacing, which determines the competitive relationship and productivity of MSR.

Produção de alface e rúcula em cultivo consorciado e adubação orgânica

ABSTRACT Compared to monoculture, vegetable intercropping allows the optimization of environmental resources and inputs, with positive effects on the yield and profitability of the crop. This study aimed to evaluate the yield of lettuce and arugula in intercropping and intercrop evaluation indexes according to cattle manure doses. The experiment was conducted in Aquidauana, MS, Brazil. Five doses of cattle manure (0, 15, 30, 45, and 60 t ha-1) were evaluated with four replications in a randomized block design. Higher growth and yield of the intercropped species were observed when the intercrop received 60 t ha-1 of cattle manure. However, the maximum values of the variables were not reached, so better performances can be obtained with higher doses. The indexes of actual yield loss and advantage of intercropping presented higher values starting at doses of 26 and 30 t ha-1 of manure, respectively. The highest land use efficiency (1.28) was obtained with 60 t ha-1 of cattle manure, indicating the agronomic viability of the lettuce and arugula intercrop when fertilized only with cattle manure.

Economic Analysis for Yield and Carrying Capacity of Intercropped Indigofera (Indigofera zollingeriana) and Brahum (Brachiaria humidicola)

Through efficient asset management, blended societies can boost plant growth and yield. The explanation of this consider was to choose the reach similar extent of the got crops leguminosae Indigofera zollingeriana (Iz) and the tropical grass Brachiaria humicola (Bh). The explanation of this contemplate was to study the show up tantamount extent of this got alter in view of abandon and bearing limit. This test was carried out with a plan that was completely random, and it used a combination of four drugs from the planted area as follows: We used the ANOVA and HSD test to analyze the data for combination planted (C): C1, Iz planted range, which had 1.0 mx 1.0 m and Bh planted zone, which had 0.5 m x 0.25 m; C2, Iz planted range, which had 1.0 mx 1.0 m and Bh planted zone, which had 0.5 m x 0.5 m: C3, Iz planted range, which had 1.0 mx 1.5 m and Bh planted zone, which had 0.5 m x 0.25 m; C4, Iz planted range, which had 1.0 mx 1.5 m and Bh planted zone, which had 0.5 m x 0.5 m. The elements estimated were the expected acquiescence and conveying limit in view of dry matter and carrying capacity acquiescence for logical financial. The results appeared to be essentially different (P<0.01). The improved grain yields of intercrop in C3 have highest the total grain yield, carrying capacity and the net-income. Overall, these findings imply that following the optimum grain yields, and competitive interactions of intercrop species can be improved. It very well may be reasoned that Iz covered crops with an established area of 1.0 m x 1.5 m and Bh with an establishing area of 0.5 m x 0.25 m have the most fitting financial of yield and conveying limit.

Seasonal Variations of Fine Root Dynamics in Rubber-Flemingia macrophylla Intercropping System in Southwestern China.

Intercropping cover crops with trees enhance land productivity and improves the soil’s physio-chemical properties while reducing the negative environmental impact. However, there is a lack of quantitative information on the relationships between fine root biomass and available soil nutrients, e.g., nitrogen (N), phosphorus (P), and potassium (K), especially in the rubber-Flemingia macrophylla intercropping system. Therefore, this study was initiated to explore the seasonal variation in fine root biomass and available soil nutrients at different stand ages (12, 15, and 24 years) and management systems, i.e., rubber monoculture (mono) and rubber-Flemingia macrophylla intercropping. In this study, we sampled 900 soil cores over five seasonal intervals, representing one year of biomass. The results showed that the total fine root biomass was greater in 12-year-old rubber monoculture; the same trend was observed in soil nutrients P and K. Furthermore, total fine root biomass had a significant positive correlation with available N (p < 0.001) in rubber monoculture and intercropping systems. Thus, it suggests that fine root growth and accumulation is a function of available soil nutrients. Our results indicate that fine root biomass and soil nutrients (P and K) may be determined by the functional characteristics of dominant tree species rather than collective mixed-species intercropping and are closely linked to forest stand type, topographic and edaphic factors. However, further investigations are needed to understand interspecific and complementary interactions between intercrop species under the rubber-Flemingia macrophylla intercropping system.

PSXII-14 Impact of Nitrogen Application and Intercrop Forage Species on Chemical Composition and Yield of Standing Corn and Intercropped Forages

Abstract This study evaluated the impact of nitrogen (N) application rate and forage species of intercropped corn for potential grazing of beef cattle in late fall/early winter. A split plot design (4 replicates/treatment) was used at 2 experimental sites in Manitoba, Canada with 2 treatment factors: 1) N application rate as the main plot and 2) forage intercrop species as the sub plot. Nitrogen application rates were 45 kg N/ha and 112 kg N/ha. Forage species were: italian ryegrass (Lolium multiflorum), hairy vetch (Vicia villosa), graza forage radish (Raphanus sativus), red clover (Trifolium incarnatum) and a mix of all 4 forages. Intercropped treatments were compared with corn only control treatments with no intercrop at both N rates. Plots were seeded in 2019 with corn from May 8-10 and intercrops seeded from June 17-25. Chemical composition of intercropped forages and corn were determined in early October. Averaged over sites and intercrop treatment, increasing N application increased (P&amp;lt; 0.004) CP of the intercrops from 20.5% (low N) to 22.3% (high N), with CP similar at both sites. On average, radish had the greatest CP (29%), clover least (13.2%), with the remaining crops intermediate (mean 21.7%). Corn CP increased (P&amp;lt; 0.01) with N application (6.6 to 7.5% averaged over treatments), with no effect of intercrop species. Intercrop TDN was not affected by N rate, with greatest concentrations observed in radish (68.2%), least in hairy vetch and red clover (53.6%) and intermediate in the mix and italian ryegrass (mean 60.2%). Dry matter yield for all intercrop and corn treatments were less than expected at both locations due to exceptional drought conditions. Intercrop treatment and its interaction with N rate did not impact corn yield. In conclusion, intercrop CP ranged from 12-29%, thus offering the potential to increase the feeding value of corn for overwintering cattle.

Intercropping legumes and cereals increases resource use efficiency and crop productivity in low phosphorus soils under semi-arid Mediterranean conditions

ABSTRACT Intercropping ensures multiple benefits like enhancement of yield, environmental security, production sustainability, and greater ecosystem services. In order to better understand how mixed crop cultures mitigate stressful conditions, this study aims to highlight the beneficial effect of the intercropping legume–cereal in enhancing nutrient uptake for plant growth and productivity in low phosphorus (P) soils. To address this question, faba bean (Vicia faba L. cv. Sidi Aich) and barley (Hordeum vulgare L. cv. Rihane 3) were grown as sole- and inter-crops over two growing seasons in 2017 and 2018 in a northern Algerian agro-ecosystem with a semiarid Mediterranean climate. The results showed that the plant growth and nodulation were significantly increased by 18% and 32%, respectively, for intercropping than for sole cropping and so more in 2018 compared to 2017. Moreover, grain yield and resource use efficiency (N and P) were significantly improved, as indicated by higher land equivalent ratio (LER > 1) in intercropping over sole cropping treatments. Also, the P and N concentrations measured in the rhizosphere were increased compared to bulk soil and even more so in the rhizosphere of intercropped species over two seasons. Our findings suggest that intercropping cereals with legumes may achieve high crop productivity and land use efficiency at reduced input levels.