Soybean Intercropping Research Articles

Impacts of corn intercropping with soybean, peanut and millet through different planting patterns on population dynamics and community diversity of insects under fertilizer reduction.

Corn is one of the key grain crops in China and the excessive use of chemical fertilizers and pesticides seriously damages the ecological environment in fields. To explore a more scientific and reasonable way to plant corn and simultaneously reduce the overuse of chemical fertilizers and pesticides, the impact of corn intercropping with soybean, peanut, and millet, respectively, through five planting patterns, including three intercropping patterns (2 corn rows to 2, 3 and 4 rows of soybean/peanut or 2, 4 and 6 millet rows, respectively) and two monoculture patterns of corn and soybean, peanut or millet under normal (600 kg/ha) and reduced (375 kg/ha) levels of NPK (N:P2O5:K2O = 15:15:15) fertilization on the population abundance and community diversity of insects, leaf nutrients, and induced plant hormones jasmonic acid (JA) and salicylic acid (SA) was studied in 2018 and 2019. The results showed that the insect community indexes of the species number (S), the diversity index (H), and the uniformity index (E) generally increased under intercropping and were significantly higher than those under corn monoculture. The prevalence of Asian corn borer (Ostrinia furnacalis) on the intercropping corn plants decreased by based on the average of seven surveys per year for each treatment 2.9 to 17 heads per 30 plants compared with that on the monoculture corn plants. The number of natural enemy insect species on corn plants under intercropping was significantly higher than that under corn monoculture. That is, intercropping may decrease the population of Asian corn borers by increasing S, H, E, and natural enemy insect species (NEI). Moreover, intercropping type and fertilizer level significantly affected corn leaf nutrient contents. Compared with the normal fertilizer level, fertilizer reduction significantly reduced the foliar contents of amino acids, soluble protein, and soluble sugar in corn plants. In addition, corn-soybean and corn-peanut intercropping significantly increased the three nutrient contents in corn leaves compared with corn monoculture. In terms of corn nutrients, intercropping could compensate for the effects of fertilizer reduction. The foliar content of JA in corn-soybean intercropping was significantly higher than in corn monoculture. Under corn-soybean and corn-peanut intercropping, SA was significantly lower than under corn monoculture. Overall, intercropping, not fertilizer reduction, can significantly increase insect community diversity while reducing the population abundances of the key insect pest species on corn plants. Intercropping reduced the SA content, increased amino acids and thus reduced the susceptibility of corn to the pest insects.

Effects of Maize Varieties on Biomass Yield and Silage Quality of Maize–Soybean Intercropping in the Qinghai–Tibet Plateau

Forage deficiency is the bottleneck that restricts the development of plateau animal husbandry. Maize (Zea mays L.)–soybean (Glycine max L.) intercropping can improve the forage biomass yield and silage quality. This experiment was conducted in Ganzi Tibetan Autonomous Prefecture to explore the effects of four maize varieties (M1, Rongyu Silage No. 1; M2, Yayu 04889; M3, Demeiya No. 1; M4, Zhenghong 505) on biomass yield, nutritional composition, and silage quality in maize–soybean intercropping. The results showed that M1S had the highest total dry matter yield (18.03 t ha−1), M3S had the highest crude protein (CP) content (8.46% DM), and soybeans had the highest water-soluble carbohydrate (WSC) content (8.55% DM). After silage, the CP content (13.44% DM) of mixed silage in M3S was higher, and the contents of neutral detergent fiber (39.42% DM) and acid detergent fiber (25.42% DM) were lower than those in maize silage alone. The WSC content (4.45% DM) of mixed silage in M3S was higher and the pH value (4.46) and ammonia–nitrogen to total nitrogen (3.97%) were lower than those of soybean silage alone. The results of membership function analysis showed that M3S was the best in fresh feeding and silage utilization, followed by M1S. Therefore, M3S (Demeiya No 1. intercropped with soybeans) is recommended in high-altitude areas.

Effects of Row Spacing and Planting Pattern on Photosynthesis, Chlorophyll Fluorescence, and Related Enzyme Activities of Maize Ear Leaf in Maize–Soybean Intercropping

With the continuous improvement of the mechanization level and the development of new crop varieties, the optimal strip width for intercropping crops is important. In this study, field experiments were conducted to analyze the effects of different row spacings and planting patterns on photosynthesis, chlorophyll fluorescence, and the related enzyme activities of maize ear leaves in a maize–soybean intercropping system using two planting patterns (wide–narrow rows of 80–50 cm and uniform ridges of 65 cm) and two intercropping ratios (four rows of maize and four rows of soybean; six rows of maize and six rows of soybean). The results showed that the pattern of wide–narrow-row spacing significantly improved the photosynthetic capacity of maize compared with the uniform-ridge planting pattern, along with marked elevation in the values of stomatal conductance (Gs), the transpiration rate (Tr), and the photosynthetic rate (Pn). On the other hand, the values of photochemical quenching (qP), actual photochemical efficiency (φPSII), and maximum photochemical efficiency (Fv/Fm) also significantly increased, and the effect of D-M6S6 treatment was the most significant on these parameters. Similarly, the activities of phosphoenolpyruvate carboxylase and ribulose-1,5-bisphosphate carboxylase/oxygenase also increased significantly. Among different treatments, the yield under the D-M6S6 treatment was the highest. Therefore, based on the planting pattern of the wide–narrow-row spacing, the intercropping of six rows of maize and six rows of soybean is the better design in the semi-arid regions of western China.

Aktivitas Nitrat Reduktase (ANR) Tanaman Jagung pada Pola Tumpangsari yang Diberi Serasah Jagung-Kedelai serta Biochar di Lahan Suboptimal Sidondo Sulawesi Tengah

The aim of the study was to examine the relationship between nitrate reductase activity and N uptake, tissue N content, N uptake, and chlorophyll content of corn plants in intercropping patterns which are given corn-soybean litter and biochar. The use of plant litter and biochar derived from crop residues as a source of organic matter in different intercropping patterns affected nitrate reductase activity, tissue N content, N uptake, and chlorophyll content of maize. This experiment was carried out on sub-optimal Sidondo land, Central Sulawesi with the main limiting factors being the availability of water and alkaline soil pH (7.21) which were arranged in a divided plot design with five litter treatments as subplots and five cropping patterns as the main plot with three replicates. Parameters observed were N levels, plant tissue N uptake, chlorophyll, and nitrate reductase activity. Collected data were analyzed using Anova and Duncan's multiple random tests. The results showed that corn litter, soybean mixed corn + soybean litter and their biochar in different intercropping patterns affected nitrate reductase activity, nitrogen uptake, chlorophyll levels very significantly (P˂0.01), increased nitrate reductase activity by 9710.86 mol NO2- -1g-1hour-1 at the age of 55 DAP, while N uptake (2237 mg.kg-1), tissue N content (4.33%), and total chlorophyll content (10.61 mg.l-1) were the highest in the litter treatment, corn and soybeans as well as biochar in corn and soybean intercropping (1:2), and (2:4). Thus, the provision of corn and soybean litter and biochar in intercropping systems can increase nitrate reductase activity, N uptake, tissue N levels, and corn chlorophyll levels in the corn-soybean intercropping system.
 
 Keywords: chlorophyll, N content of corn plant tissue, nitrate reductase activity, N uptake

Morphological and physiological variation of soybean seedlings in response to shade.

Soybean (Glycine max) is a legume species that is widely used in intercropping. Quantitative analyses of plasticity and genetic differences in soybean would improve the selection and breeding of soybean in intercropping. Here, we used data of 20 varieties from one year artificial shading experiment and one year intercropping experiment to characterize the morphological and physiological traits of soybean seedlings grown under shade and full sun light conditions. Our results showed that shade significantly decreased biomass, leaf area, stem diameter, fraction of dry mass in petiole, leaf mass per unit area, chlorophyll a/b ratio, net photosynthetic rate per unit area at PAR of 500 μmol m–2 s–1 and 1,200 μmol m–2 s–1 of soybean seedling, but significantly increased plant height, fraction of dry mass in stem and chlorophyll content. Light × variety interaction was significant for all measured traits, light effect contributed more than variety effect. The biomass of soybean seedlings was positively correlated with leaf area and stem diameter under both shade and full sunlight conditions, but not correlated with plant height and net photosynthetic rate. The top five (62.75% variation explained) most important explanatory variables of plasticity of biomass were that the plasticity of leaf area, leaf area ratio, leaflet area, plant height and chlorophyll content, whose total weight were 1, 0.9, 0.3, 0.2, 0.19, respectively. The plasticity of biomass was positively correlated with plasticity of leaf area and leaflet area but significant negative correlated with plasticity of plant height. The principal component one account for 42.45% variation explain. A cluster analysis further indicated that soybean cultivars were classified into three groups and cultivars; Jiandebaimaodou, Gongdou 2, and Guixia 3 with the maximum plasticity of biomass. These results suggest that for soybean seedlings grown under shade increasing the capacity for light interception by larger leaf area is more vital than light searching (plant height) and light conversion (photosynthetic rate).

Yield Advantage and Economic Performance of Rice–Maize, Rice–Soybean, and Maize–Soybean Intercropping in Rainfed Areas of Western Indonesia with a Wet Climate

Cereals–soybean intercropping is not well studied, despite the importance of these crops in increasing agricultural profitability and ensuring nutritional and food security in Southeast Asia. We compared different intercropping practices (IPs) with monocropping practices (MPs) for their yield and economic performance by small-scale farms without mechanization. The treatments were IPs of rice–maize, rice–soybean, or maize–soybean compared with MPs of rice, maize, or soybean as sole crops, across three provinces in the rainfed areas of western Indonesia with a wet climate. Our results show that the yield advantages using the land equivalent ratio of the IPs were 44% for rice–maize, 54% for rice–soybean, and 63% for maize–soybean compared to MPs. Rice equivalent yield, maize equivalent yield, and the gross margin under IPs were significantly higher per cycle than under MPs; IPs provided a substantially lower cost of production and of paid workers. Compared to just rice, there were additional net return gains of USD 160 and USD 203 ha−1 per cycle under rice–maize and rice–soybean intercropping. Maize–soybean intercropping resulted in an additional net return gain of USD 153 ha−1 compared to just maize. These results suggest there is considerable potential for small farmers to increase their yields and profits by intercropping in rainfed areas with a wet climate.

Evaluation of the growth characteristics, forage productivity, and feed value of the maize–soybean intercropping system under different fertilization levels

Evaluation of the growth characteristics, forage productivity, and feed value of the maize–soybean intercropping system under different fertilization levels

Biochar and Cropping Systems Changed Soil Copper Speciation and Accumulation in Sweet Corn and Soybean.

In order to explore the effects of biochar and cropping systems on soil copper (Cu) speciation and copper accumulation in sweet corn (Zea mays L. var. Rugosa Bonaf.) and soybean (Glycine max (L.) Merr.), three ratios of biochar (C0, 0%, C1, 2%, C2, 5% by mass ratio, (w/w)) and three cropping systems (monocropped sweet corn, MC; monocropped soybean, MS; sweet corn–soybean intercropping, CS) were studied under three Cu levels (Cu0, 0 mg·kg−1, Cu1, 200 mg·kg−1, and Cu2, 400 mg·kg−1) in a pot experiment. The following results were obtained: (1) Compared with C0, adding biochar (C1, C2) could significantly reduce the Cu concentration in sweet corn, and C2 significantly reduced the Cu concentration in soybean under Cu1 and Cu2; the Cu concentrations in sweet corn and soybeans under Cu1 were lower than 10 mg·kg−1. (2) Compared with MC or MS, C2 significantly reduced the Cu concentration (below the detection limit) in sweet corn and the Cu concentration (1.65 mg·kg−1) in soybean straw in CS under Cu1. The Cu concentration in sweet corn ears and soybean straw in CS under Cu2 also decreased significantly, reaching 1.84 and 10.36 mg·kg−1, respectively. (3) Compared with C0, C2 significantly reduced the soil acid-soluble Cu concentration under Cu1 and Cu2, but significantly increased soil oxidated Cu concentration. (4) Compared with MC, the concentration of soil acid-soluble Cu was significantly decreased in CSC1 under Cu2. Under Cu1, the concentrations of reducible Cu were significantly increased in CSC1 and CSC2, and the oxidizable Cu concentration was increased in CSC2. In conclusion, sweet corn–soybean intercropping combined with biochar 5% (w/w) is beneficial to reducing the concentration of acid-soluble Cu, and increases the concentration of oxidizable Cu in copper-contaminated soil. Under Cu1 (200 mg·kg−1), the Cu concentrations in sweet corn and soybean were lower than 10 mg·kg−1, which meets the national food safety standard of China. Under Cu2 (400 mg·kg−1), the Cu concentration in sweet corn was lower than 10 mg·kg−1, but it was higher than 10 mg·kg−1 in soybean.

Impact of Organic and Chemical Nitrogen Fertilizers on the Crop Yield and Fertilizer Use Efficiency of Soybean–Maize Intercropping Systems

The effect of the mixture (1:1) of chemical and organic nitrogen (N) fertilizer on crop yield quality and N fertilizer use efficiency remains elusive. A nitrogen field experiment was conducted in the growing seasons of 2020 and 2021 to investigate the effects of the mixture of chemical and organic N fertilizer on the crop yield, crop quality and nitrogen fertilizer use efficiency in a maize–soybean intercropping system in China. Four treatments applied at 150 kg N ha−1 were used: no nitrogen fertilizer (CK), chemical N fertilizer (ChemF), mixture (1:1) of chemical and organic N fertilizer (ChemF + OrgF) and organic N fertilizer (OrgF). The results showed that the yield and aboveground N accumulation of both soybean and maize increased with the application of fertilizer. The ChemF + OrgF treatment had lower maize and soybean seed yields than for ChemF treatment, but higher than the other two treatments in both years, and the maize yield of the (ChemF + OrgF) treatment was significantly higher (14.9%) in 2021 than 2020. Yields were significantly positively correlated with aboveground N accumulation and fertilizer use efficiency, measured using the nitrogen partial productivity (NPP), nitrogen agronomic efficiency (NAE) and nitrogen fertilizer recovery rate (NFRR). The protein content tended to increase and the oil content tended to decrease under (ChemF + OrgF) applications in soybeans. The (ChemF + OrgF) treatment had the lowest starch content in maize. There was no significant difference in the nitrogen harvest index among treatments, while the NPP, NAE and NFRR were the highest for the application of chemical N fertilizer and significantly decreased with the addition of organic N fertilizer. We conclude that the mixture (1:1) of chemical and organic N fertilizer increased the seed yield and quality of maize, but only the seed yield of soybean.

Soil Organic Matter, Aggregates, and Microbial Characteristics of Intercropping Soybean under Straw Incorporation and N Input

Soil organic matter (SOM), soil aggregates, and soil microbes play key roles in agriculture soil fertility. In intercropping systems, the influences of straw incorporation and N input on the dynamics of soil physicochemical and microbial properties and their relationships are still unclear. We explore the changes in soil physicochemical and microbial properties with two straw managements, i.e., wheat straw incorporation (SI) and straw removal (SR), and four N supply rates for intercropped soybean, i.e., 60 (N60), 30 (N30), 15 (N15), and 0 (N0) kg N ha−1, in the wheat–maize–soybean relay strip intercropping systems. The results showed that SOM and SOM fractions contents, soil macroaggregate stability, and microbial and fungal α-diversity, e.g., Chao1 and Shannon indices, increased through straw incorporation and N input. The α-diversity was significantly positively correlated with soil physicochemical characteristics. Compared with SR, the relative abundance of ActinobacteriaandMortierellomycota in SI increased, but the relative abundance of Proteobacteria, Acidobacteria, and Ascomycota in SI decreased. In SI treatment, soil physicochemical characteristics and microbial diversity improved through N input, but that difference was not significant between N60 and N30. In conclusion, SI+N30 was the most effective way to maintain soil fertility and reduce the N fertilizer input in the wheat–maize–soybean relay strip intercropping.

The Diversity and Dominance of Weeds in Various Population Proportions of Intercropping Soybeans With Corn

Soybean is an important food crop for Indonesia after rice and corn. Soybean productivity in Indonesia is still low because most farmers use monoculture cropping patterns which has many weaknesses. Intercropping is an alternative to increase soybean productivity because it has many advantages. Soybeans can be intercropped with corn because the two plants have different physical characteristics, physiology and growth patterns. This research aimed to obtain information about the diversity and abundance of weeds in soybean and corn intercropping. The study was conducted using a single factor treatment design which will be arranged in a single plot field design, using Grobogan variety soybean and Bisma variety corn. The treatment was the proportion of soybean and corn populations which consisted of 4 proportions, i.e. 2:1, 3:1, 4:1, and 5:1, and monoculture soybeans were also planted as a control. Observations on weeds were carried out at the age of 2, 8, and 12 weeks after planting (before harvest) with vegetation analysis. The size of each sample is 0.5 m x 0.5 m with 15 sample plots/plots. The results showed that based on the summed dominance ratio (SDR) in the research area, 16 species of weeds were dominated by broadleaf weeds, with the dominant types of weeds being Phyllanthus urinaria L., Eleusine indica L., and Oryza sativa L. The results showed that based on the Summed Dominance Ratio (SDR) in soybean there were 16 species of weeds that were dominated by broadleaf weeds, with the dominant types of weeds being Phyllanthus urinaria L., Eleusine indica L., and Oryza. sativa L. Weeds growing on soybean intercropping with corn and soybean monoculture have a medium diversity index (H').

The residual effect of different levels of rice mill ash on maize-soybean intercrop

A two year (2013 and 2014) field trial was conducted to study the residual effect of different fertility levels of rice mill ash (RMA) on maize-soybean intercrop. The experiment was arranged in a randomized complete block design (RCBD) comprising of nine (9) treatments and three (3) replications. The treatments where sole maize (SMO), sole soybean (SBO), maize/soybean intercrop without application of rice mill ash (IMBO), soybean + 10 t/ha rice mill ash (SB10), sole maize + 10 t/ha rice mill ash (SM10), maize - soybean intercrop + 10 t/ha rice mill ash (IMB10), sole maize + 20 t/ha rice mill ash (SM20); sole soybean + 20 t/ha rice mill ash (SB20) and maize/soybean intercrop + 20 t/ha rice mill ash (IMB20). Data generated was subjected to analysis of variance of which the result of the study showed that for 2 years under study, incorporated rice mill ash (RMA) and intercropping system significantly increased the soil productivity, yield and yield components of maize and soybean studied. The RMA at the rate of 20t/ha performed competitively better than the other treatments with strong residual impact on the parameters assessed. Findings from the study equally showed an intercrop advantage.

Effect of Maize (Zeal mays) and Soybean (Glycine max) Intercropping on Yield and Root Development in Xinjiang, China

Intercropping is a breakthrough in land-use optimization. This work aimed to study the effects of intercropping patterns on the growth, yield, root morphological characteristics, and interspecific competition of maize and soybean, as well as provide a reference for the development of intercropping patterns of maize and soybean in Northwest China. Three different cropping patterns were designed: monocropping maize, monocropping soybean, and maize-soybean intercropping. Agronomic traits, intercropping indicators such as land equivalent ratio (LER), aggressivity (A), competition ratio (CR), and actual yield loss (AYL), as well as root morphological characteristics were assessed. The results showed that, compared with monocropping, the intercropping maize plant height increased by 6.07–8.40%, and the intercropping soybean plant height increased by 35.27–38.94%; the root length density (RLD) of intercropping maize was higher than that of monocropping maize, the RLD of intercropping soybean was lower than that of monocropping soybean, in the 0–40 cm soil layer the intercropping increased maize RLD by 1.79–7.44% while the soybean RLD was reduced by 3.06–9.46%; the aggressivity of maize was greater than 0 and the competition ratio was greater than 1, which was the dominant species; the maize/soybean land equivalent ratio was 1.18–1.26, which improved the land utilization rate. Therefore, the effect of increasing yield can be achieved by changing the maize and soybean planting method, which is beneficial to the ecological strategy of sustainable development in the northwest region.

Effect of P fertilization and Spraying by Micronutrients on Productivity of Intercropped Maize and Soybean and Competitive Relationships under Different Farming Systems

Effect of P fertilization and Spraying by Micronutrients on Productivity of Intercropped Maize and Soybean and Competitive Relationships under Different Farming Systems

Root plasticity and interspecific complementarity improve yields and water use efficiency of maize/soybean intercropping in a water-limited condition

Intercropping maize and soybean is renowned for improving crop production and resource use efficiencies. Interspecific competition and complementarity with respect to root plasticity is essential knowledge for understanding the mechanisms of overyielding and optimizing intercropping species selection. We conducted a three-year field experiment (2017–2019) to quantify land and water productivities in relation to above- and below-ground interspecific interactions, root growth and distribution under different nitrogen rates in maize/soybean intercropping. The land productivity in terms of land equivalent ratio (LER) in maize/soybean intercropping was 1.10 across all years and N rates. The yield increase in intercropped maize was mainly gained from an 45% increase in kernel numbers, while the yield loss of intercropped soybean was caused mainly by an 35% decrease in the pod numbers compared to sole cropping. The system level water use efficiency, defined as water equivalent ratio (WER) was also 1.10. Compared with sole stands, intercropped maize consumed more water during the vegetative stage, but intercropped soybean took up more during the reproductive stage. That indicated a temporal complementarity of water use in the intercrop, which benefited maize kernel formation and partially offset the negative shading effect of soybean grain filling. Soybean showed a marked increase in root length density (RLD). Compared to the produced aboveground biomass (DM) in the intercrop, the intercropped soybean invested more assimilates into root than shoot, as defined as root plasticity, the RLD/DM ratio of soybean in the intercrop was 76% more than sole system. However, the intercrop did not change root plasticity of maize. The overlap of maize and soybean roots, i.e. interspecific interaction interface, occurred mainly within the position between two border rows and at first soybean row. Under interspecific competition, soybean in the intercropping created both temporal and spatial differentiation for water uptake, which might be a key reason for enhancing intercropping land and water productivities. Our results contribute to understanding the mechanism of interspecific interaction for maximizing land and water productivities in rain-fed intercropping. • Maize/soybean intercrop enhanced land and water productivities in rainfed conditions. • The yield increase of intercropped maize was due to an 45% increase in kernel number. • The yield loss of intercropped soybean was caused by an 35% decrease in pod number. • Shaded soybean in intercrop produced more roots than aboveground biomass. • Interspecific complementarity enhanced crops water use efficiencies in intercrop.

The intercropping soybean searches in The National Center for Biotechnology Information (NCBI)

The increasing soybean production is constrained by land area, so alternative cultivation is needed through an intercropping system, including sustainable use of oil palm plantations. This study aims to obtain online information at the National Center for Biotechnology Information (NCBI)”to access soybean intercropping information regarding the literature on biological information data, the PubMed database, health, genomes, genes, and proteins. Reportedly there are: 1 book and report; 159 online books; 576 DNA and RNA nucleotides reported;”and 969 full-text journal articles on intercropping soybean cultivation. Soybean intercropping in biotechnology research provides information about research on intercropping, including soybean-oil palm integration in oil palm plantations that has not been reported inNCBI.

Effects of reduced nitrogen application on soil aeration and root nodule growth of relay strip intercropping soybean

<p id="C3">To study the effects of planting system and nitrogen application rate on soybean soil aeration environment and nodulation and nitrogen fixation, we adopted a two-factor split area experiment design, with the main area of planting pattern [soybean monoculture (SS), maize/soybean relay strip intercropping (MS)], and the sub-regions of different nitrogen application rates [no nitrogen application (NN: 0 kg hm^-2), reduced nitrogen application (RN: 45 kg hm^-2), and constant nitrogen application (CN: 60 kg hm^-2)]. The dynamic changes of soil O₂ content and soil respiration rate during soybean growth period was monitored, the differences of soil water-stable aggregates, bulk density, and porosity of each treatment were analyzed, and the variation characteristics of nodulation amount and nitrogen fixation capacity during soybean growth period were discussed. Two years’ data showed that, compared with monoculture soybean, relay strip intercropping soybeans increased soil O₂ content, the percentage of aggregates with a particle size &gt; 2 mm, significantly increased soil porosity and soil respiration rate during the late growth period in soybean; reduced the percentage of aggregates with a particle size of &lt; 1 mm and soil porosity. There was no significant difference in the dry weight of nodules at R5 stage, but the number of nodules was significantly increased by 39.9%. Nitrogenase activity and nitrogen fixation potential were also significantly higher than those of monocrops. Among the various nitrogen application rates, the soil O₂ content, the percentage content of 0.25-1.00 mm particle size, and the soil respiration rate of relay strip intercropping soybean were the highest in RN treatment. Nitrogen application decreased the percentage content of water-stable aggregates with particle size &lt; 0.25 mm and soil bulk density; nitrogen application significantly inhibited the nodulation amount, nitrogenase activity and nitrogen fixation potential of monoculture soybean in the early stage, but the inhibitory effect of nitrogen fertilizer was alleviated at R5 stage. Reduced nitrogen application increased nodulation at the late stage of relay strip intercropping soybean, and it could significantly enhance the nitrogenase activity and nitrogen fixation potential of soybeans during the growth period. Relay strip intercropping soybean combined with reduced nitrogen application promoted the formation of large aggregates, increased soil porosity, improved soybean soil aeration environment, maintained higher soil O₂ content, promoted soil respiration, and facilitated the nodulation and nitrogen fixation of soybean at later stages.

Changes in the Density and Composition of Rhizosphere Pathogenic Fusarium and Beneficial Trichoderma Contributing to Reduced Root Rot of Intercropped Soybean.

The dynamic of soil-borne disease is closely related to the rhizosphere microbial communities. Maize–soybean relay strip intercropping has been shown to significantly control the type of soybean root rot that tends to occur in monoculture. However, it is still unknown whether the rhizosphere microbial community participates in the regulation of intercropped soybean root rot. In this study, rhizosphere Fusarium and Trichoderma communities were compared in either healthy or root-rotted rhizosphere soil from monocultured and intercropped soybean, and our results showed the abundance of rhizosphere Fusarium in intercropping was remarkably different from monoculture. Of four species identified, F. oxysporum was the most aggressive and more frequently isolated in diseased soil of monoculture. In contrast, Trichoderma was largely accumulated in healthy rhizosphere soil of intercropping rather than monoculture. T. harzianum dramatically increased in the rhizosphere of intercropping, while T. virens and T. afroharzianum also exhibited distinct isolation frequency. For the antagonism test in vitro, Trichoderma strains had antagonistic effects on F. oxysporum with the percentage of mycelial inhibition ranging from 50.59–92.94%, and they displayed good mycoparasitic abilities against F. oxysporum through coiling around and entering into the hyphae, expanding along the cell–cell lumen and even dissolving cell walls of the target fungus. These results indicate maize–soybean relay strip intercropping significantly increases the density and composition proportion of beneficial Trichoderma to antagonize the pathogenic Fusarium species in rhizosphere, thus potentially contributing to the suppression of soybean root rot under the intercropping.

Growth and yield of Sunflower (Helianthus annuus)in additive Intercropping system with Mung bean.

Some crops perform better in intercropping systems with other crops relative to their solcropping . Sunflower (Helianthus annuus L.) was adopted to be studied in a field experiment within an additive intercropping system with mungbean (Vigna radiata L.) in a three rows in combinations (1:3 and 1:4 and 1:5) sunflower-Mung bean intercropped and sole cropped for studding growth , yield components and yield traits during the summer of 2021 at two different agro ecological locations of the governorate of Erbil- Iraq. Experiments were triplicated in a randomized complete block design (RCBD), Each location was a parcel of a local farmers land in the villages of Shamamr (Latitude: 406227, Longitude: 397954 rainfall isocline (350 mm y-1)) and Dukalla (Latitude: 358033 m, Longitude: 3993384 m),at the last of the semi insured and the first of the non-insured rainfall zones respectively . Shamamr location suppressed Dukalla location in most of morphological traits at the ages of 20 days after sowing (DAS), nd 60 DAS. Treatment row combination (1:3, 1:4 and 1:5) showed advantages in yield component traits over sole cropping of sunflower might be due to resources gains as solar radiation, conditioning heat environment and space .No advantages of intercropping were observed among cropping systems in seed yield while the treatment (1:5) possessed the highest Harvest index (0.6). Sunflower in Shamamr location is believed to perform better under intercropping system. More planting geometry is recommended to obtain more precise results. References : Abràmoff, M.D., Magalhães, P.J. and Ram, S.J., 2004. Image processing with ImageJ. Biophotonics international, 11(7), pp.36-42. Anas, M., Jabbar, A., Sarwar, M.A., Ullah, R., Abuzar, M.K., Ijaz, A. and Latif, S., 2017. Intercropping Sunflower with Mung beanfor improved productivity and net economic return under irrigated conditions. Pakistan Journal of Agricultural Research, 30(4). Bindi, M. and Olesen, J.E., 2011. The responses of agriculture in Europe to climate change. Regional Environmental Change, 11(1), pp.151-158. Dizayyee , Aryan Suad Ahmed . (2019).Modes of Interference Compatibility of Wheat, Chickpea and Wild mustard Intercropping in Different Row Proportions. PhD Dissertation , University of Salahaddin , College of Agricultural Engineering Sciences. Gebru, H., 2015. A review on the comparative advantages of intercropping to mono-cropping system. Journal of Biology, Agriculture and Healthcare, 5(9), pp.1-13. Jeon, D.J., Ki, S.J., Cha, Y., Park, Y. and Kim, J.H., 2018. New methodology of evaluation of best management practices performances for an agricultural watershed according to the climate change scenarios: A hybrid use of deterministic and decision support models. Ecological Engineering, 119, pp.73-83.(abstract). Jubr Al-Layla, M. and Shahadha Khalid Al-Juheishy, W., 2012. EVALUATION OF DIFFERENT INTERCROPPING SYSTEM IN SUNFLOWER (Helianthus annuus L.) ANDMUNGBEAN (Vigna radiata L.). Mesopotamia Journal of Agriculture, 40, pp.62-74. Khan, M. N., Shoaib Muhammad, Mahboob Asrar, M. S. Ashraf, and Qamar Rafi. "MB (Vigna radiata) intercropping enhances productivity of late season irrigated cotton in Punjab." Asian Journal of Agriculture and Biology 8, no. 4 (2020): 472-479. Lithourgidis, A.S., Dordas, C.A., Damalas, C.A. and Vlachostergios, D., 2011. Annual intercrops: an alternative pathway for sustainable agriculture. Australian journal of crop science, 5(4), pp.396-410. Mousavi, S.R. and Eskandari, H., 2011. A general overview on intercropping and its advantages in sustainable agriculture. Journal of Applied Environmental and Biological Sciences, 1(11), pp.482-486. Nawar, A.I., Salama, H.S. and Khalil, H.E., 2020. Additive intercropping of SF and soybean to improve yield and land use efficiency: Effect of thinning interval and nitrogen fertilization. Chilean journal of agricultural research, 80(2), pp.142-152. Shi, H., Tian, H., Lange, S., Yang, J., Pan, S., Fu, B. and Reyer, C.P., 2021. Terrestrial biodiversity threatened by increasing global aridity velocity under high-level warming. Proceedings of the National Academy of Sciences, 118(36). Vandermeer, J.H., 1992. The ecology of intercropping. Cambridge University Press. (book) .

Effect of Intercropping Soybean on the Diversity of the Rhizosphere Soil Arbuscular Mycorrhizal Fungi Communities in Wheat Fields

AbstractThe variations of rhizosphere soil arbuscular mycorrhizal fungi (AMF) and their impact mechanism are still unclear under different intercropping systems in the Yellow River Irrigation District of Ningxia, China. A field experiment to study variations in rhizosphere soil AMF diversity and its effects under different planting systems in this area. Three intercropping systems consisting of six rows of spring wheat intercropped with two rows of soybean (RSW), wheat monoculture (RW), and soybean monoculture (RS) were applied. The results showed that the RSW treatment has a 5.6% and 10.0% higher soil organic carbon (SOC) content than the RW and RS plots, respectively. The dominant genera in this study are Glomus and Paraglomus. The Shannon index, Simpson index, Chao1 value, and abundance‐based coverage estimator in the RSW treatment are higher than in the RS plots. Additionally, the multiple linear regression equation suggests that invertase activity is the main impact factor for the Shannon index of AMF. Moreover, the wheat yield in the RSW plot is 11.4% higher than the RW plot. The results suggest that the RSW treatment has great potential for improving soil nutrients, AMF diversity, and wheat yield to sustain soil health and crop production.