Corn-soybean Intercropping Research Articles

Interspecific Competition as Affected by Nitrogen Application in Sweet Corn–Soybean Intercropping System

Corn (Zea mays L.)–soybean (Glycine max (L.) Merr.) intercropping is one of the main traditional intercropping systems used. We hypothesized that sweet corn–soybean intercropping with reduced nitrogen application could improve the crops’ fresh grain yield and nitrogen acquisition. We clarified whether sweet corn intercropped with soybean has the advantages of improved crop yield and carbon and nitrogen accumulation and assessed interspecific competition in the intercropping systems. A four-year (2017–2020) field experiment was conducted with three nitrogen application levels (0, 150, and 300 kg∙ha−1) and three planting patterns (monocropped sweet corn, monocropped soybean, sweet corn–soybean intercropping) at Jiangxi Agricultural University, Nanchang, China. The LER (land equivalent ratio), AG (aggressivity), and CR (competitive ratio) were calculated using the fresh grain yield and nitrogen and carbon accumulation of sweet corn and soybean. The LER values were greater than 1.0 in most of the intercropped patterns, except for the value based on the crops’ fresh grain yield without nitrogen application in 2020. Sweet corn had greater values of CR and AG than soybean in the intercropping system. Compared with common nitrogen application (300 kg∙ha−1), reduced nitrogen application (150 kg∙ha−1) did not significantly reduce the LER or the average CR and AG values. Under reduced nitrogen application, the values of LER, CR, and AG, based on the crops’ fresh grain yield and nitrogen acquisition, were not significantly different between the four years. In conclusion, based on the LER, CR, and AG, sweet corn–soybean intercropping had the advantage of crop yield and nitrogen acquisition, and sweet corn was the superior competitor. Sweet corn–soybean intercropping with nitrogen application (150 kg N ha−1) showed good inter-annual stability of crop productivity and competitiveness of the sweet corn.

Effect of the Number of Rows and Cultivars of Soybeans on Damage Intensity of Pest and Predator Populations in Corn-Soybean Intercropping, South Sulawesi Indonesia

Background: Soybean productivity in Indonesia remains low yield due to the occurrence of pests and diseases. Here, our study aimed to determine the number of soybean rows and varieties in the soybean-corn intercropping system and the damage level, pest and predator populations. Methods: The study used a split-plot design with three replications. The main plot was soybean varieties (Dena-1, Detap-1 and Deja-1) and the subplots consisted of monoculture (soybean); three rows of soybeans and two rows of corn; four rows of soybean and two rows of corn; six rows of soybean and two rows of corn. Result: The six rows of soybeans and two rows of corn showed the lowest attack rate of Spodoptera litura and Etiella zinckenella, the lowest population of Aphis glycines and Riptortus linearis, the highest predatory population of Crocothemis servilia and Coccinella sp. and the highest predator populations of Euborellia annulata. The highest attack rate of S.litura was in Dena-1. In contrast, the highest intensity of E.zinckenella pest damage was in Dena-1 and Deja-1. The corn-soybean intercropping was recommended as the best practice for sustainable agriculture production due to facilitating in the increase of growth of predator population and reducing the level of crop damage due to pest attacks.

Comparative Advantage of Productivity and Soil Properties on Corn-Soybean Intercropping to Monoculture System in Marginal Dry Land of Gunungkidul

Most of agricultural land in Gunungkidul Regency is in the form of dry land. The appropriate cropping pattern in term of optimizing land in secondary planting season is intercropping system. The aim of this study was to show the comparison between corn or soybean monoculture with corn-soybean intercropping of two different varieties on growth, yield, LER value and soil properties on dry land of Gunungkidul. This study was conducted on Kampung, Ngawen, Gunungkidul. Soybean seeds were planted 14 days before corn seeds to avoid hindering the irradiation of soybean plant. Soybean seeds were planted 5 rows between two rows of corn with a spacing 40 cm x 20 cm. The soybean varieties were used Dena-1 and Grobogan, while corn varieties used Pioneer 35 and Bisi-2. The planting distance of corn were used the legowo system, that was (65-50) cm x 30 cm. Results of the study was shown that the highest corn productivity was achieved by Pioneer 35 variety, which intercropped with Dena-1 variety, that yielded 6.73 ton. ha−1 dry corn and 1.65 ton.ha−1 soybean seeds.. This yield was lower 9.11% and 10.13%, respectively compare to monoculture system on the same corn or soybean cultivation. The advantage of intercropping corn-soybean system was added biomass of soybean, which can be used as animal feed. The chemical soil properties of corn-soybean intercropping increased on N total about 33.33%, P and K available increased 25.71% and 23.62%, respectively. Soil CEC increased about 19.53%, while soil pH did not significantly different compared to monoculture.

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.

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

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.

Response of Corn-Soybean Intercropping to Fertilizer Packages in Dry Land with Dry Climate

Intercropping soybean with corn on dry land with dry climate (DLDC) is an alternative program to expand the soybean cultivation harvested area. This study evaluated the effectiveness of fertilization performance in the intercropping of soybean-corn in DLDC. The experiment in this study was arranged in a randomized block design, consisting of seven fertilizer package treatments with four replications. The spacing between corn (Pertiwi 3) and soybean (Dena 1) was (50 cm x 200 cm) x 40 cm (2 plants/clump) and between soybeans (Dena 1) was 40 cm x 15 cm (2-3 plants/clumps). The observations consisted of soil analysis (pH, organic matter, total N (Kjeldahl), available P, Ca-dd, Mg-dd, K-dd, and Na-dd), soybean leaf chlorophyll index (45 and 60 days after planting/dap), plant height at (45 daps and harvest), number and weight of root nodules (45 daps); Corn: chlorophyll index (56 daps), plant height (harvest), analysis of corn and soybean plant tissue (60 daps), yield, and yield components of dry seeds of soybean and corn per hectare. The results showed that effective fertilization for the intercropped crops was 53 kg N + 1,500 kg of manure per hectare in corn plant and 7 kg N + 22 kg P2O5 + 18 kg K2O + 1,500 kg/ha manure + Rhizobium Iletrisoy/Agrisoy in soybean crops.

Study of “ Turiman Jale 2-7” system production in acid dry agroecosystem in Lampung Region

Acid dry land is characterized as suboptimal land with low productivity. The “Turiman Jale 2-7” corn-soybean intercropping technology innovation has the potential to provide additional yields on acid dry land. The purpose of this study was to examine the yields of corn and soybeans grown using the “Turiman Jale 2-7” system on acid dry land. The assessment was carried out at the Tegineneng Experimental Garden, Mandah Village, Natar District, South Lampung Regency, Lampung Province. Methods with demonstration plots in the field of 0.75 ha, with 2 treatments using corn and soybean varieties. The research period was January to June 2020. The soybean varieties planted were Dega, Dena, Detam, Detap, Devon, and local Tanggamus. Corn varieties planted were Balitbangtan JH-37 and existing hybrid corn (Bisi-18, DK-771, NK-22. P-27). The corn-soybean intercropping system used a pattern of alternating 2 rows of corn and 7 rows of soybeans. Corn crop rows used a zigzag cropping pattern. The data observed were components of plant vegetative and generative growth. Data analysis using factorial analysis of variance. The results showed the “Turiman Jale 2-7” system produced an average corn productivity of 14,110 kg/ha and an average soybean productivity of 2,370 kg/ha. The “Turiman Jale 2-7” system is able to optimize the productivity of acid dry land which relies on rainwater. The innovation “Turiman Jale 2-7” contributed to increasing the Cropping Index (CI) from CI = 100 to CI = 150-200.

Corn-Soybean Intercropping Improved the Nutritional Quality of Forage Cultivated on Podzols in Boreal Climate.

Intercropping systems could be a potential source of nutrient-rich forage production in cool climates on podzolic soils common in boreal ecosystems. In this study, we evaluated the effects of corn–soybean intercropping (IC) on the nutritional quality of forage. Two silage corn varieties were cultivated as monocropping (MC) or were intercropped with three forage soybean varieties using a randomized complete block design. IC significantly increased the crude protein (22%) and decreased the acid detergent (14%) and neutral detergent (6%) fibers. Forage net energy, total digestible nutrients, ash, dry matter intake, digestible dry matter and relative feed value were also significantly increased (p ≤ 0.05) in the IC treatments compared to corn MC. The macro and micro nutrients were higher in IC than corn MC. Intercropping increased the omega 3 fatty acid (FA) contents (67%) compared to corn MC. IC also increased the active microbial community in the plant root zone, which may contribute to the improvement in forage nutritional quality because the active soil microbial community composition showed significant correlations with soluble sugars, soluble proteins and potassium contents of the forage. These results demonstrate that corn–soybean IC could be a suitable cropping system to increase the nutritional quality of forage cultivated on podzols in boreal climates. The resultant forage has the potential to be a source of high-value animal feed for livestock production in cool climate regions of the world.

Study on production of several soybean varieties with corn intercropping system on dry land in East Lampung, Lampung Province

Soybean is a commodity which is less desirable for farmers to be planted yet it has an increasing high demand for processed food products made from soybean (tofu, tempeh, soy sauce, soy milk, etc.). As a strategic commodity,innovations are needed to provide solutions in order to maintain soybean production, especially in dry land. The purpose of this study was to assess the level of production of several soybean varieties grown using the intercropping system (turiman) with corn on suboptimal dry land. The study was conducted in East Lampung during the 2nd planting season from December 2019 to March 2020. The soybean varieties planted are Dena, Devon, Anjasmoro, and the local one (Tanggamus). The varieties of corn planted are the local existing one. The intercropping system used a corn-soybean pattern of 2 rows of corn and 7 rows of soybeans (Jale 2-7). The corn planted with zigzag pattern. The land area used for intercropping crops is 1 ha. The results showed that the intercropping system between soybeans and corn provided optimal soybean and corn production. The average soybean production was 1.548 kg/ha. The highest soybean production was the Devon variety (2,141 kg/ha) intercropping with corn (BS-18). Meanwhile, the Anjasmoro variety yielded 1.249-1.775 kg/ha, Dena variety yielded 1.428-1.541 kg/ha, and the local Tanggamus variety yielded 971-1.790 kg/ha. Corn production was 11.879-18.672 kg/ha of wet shelled corn. The average corn production was 15.110 kg/ha. The corn-soybean (Jale 2-7) intercropping system was able to optimize the use of dry land based on rainwater irrigation. This innovation contributed to the improvement of the cropping index from CI = 100 to 150-200.

The farmer’s response to the improvement of cropping index through intercropping of maize – soybean and groundnut monoculture in Pemalang

One of efforts to increase cropping index (CI), in rainfed lowland areas is by intercropping. In this system land can be planted with two or more types of plants at almost in same time, to improve farmer profit. Farmers’ adoption of this technology varies and its response was influenced by the introduction process. This study aimed to determine the level of farmers response to corn-soybean intercropping technology and factors which affecting farmers response to the application of intercropping technology at Pemalang Central Java. This study using descriptive and quantitative data analysis from observation, interview and documentation. Thirty farmers as respondent were selected. In this study, analytical method was employed to determine the level of farmer response, meanwhile, regression analysis was used to determine the factors which influencing farmer response. The results showed that farmer response was high on land processing (69.57%), seed treatment (78.26%), spacing (95.65%), ease of planting corn (95.65%), ease of harvesting turiman-jale. (69.57%) and the ability to increase IP (65.22%). The variable of land area has significant effect to the response of turiman-jale technology and its increase linearly in farmer response for each addition of 0.88 hectares of land.

Intercropping irrigated corn with two soybean maturity groups at different planting rates for forage

AbstractIncreasing silage production and quality is paramount for dairy and beef feedlot production. We aimed to (a) increase dry matter, protein production, and profit per acre of corn (Zea mays L.) by intercropping it with soybean [Glycine max (L.) Merr.]; (b) compare soybean maturity groups (MGs) intercropped or grown as the sole crop; and (c) quantify the soybean planting rate's influence on land equivalent ratios (LER), total dry matter yield, nutrient concentration and economic return per acre in corn–soybean intercropping systems. A 2‐yr field study was conducted with two soybean MGs (MG1 and MG7) and four soybean planting rates: 0 (control), 38,000 (1×), 76,000 (2×), and 152,000 (4×) seeds acre−1. Intercropping with MG7 increased soybean dry weight by 33% compared with MG1. The MG7 4× rate in 2012 and the 1× and 2× rates in 2013 maximized yield and LER when forage contained 7 to 10% soybean. Averaged over years, the MG7 soybean planting rate had a significant quadratic influence on nutrient value, peaking at the 2× rate at $23 ton–1 more than monoculture corn. Intercropping with the 2× MG7 soybean increased the net economic return per acre on a nutrient value basis by $238 acre−1. The soybean concentration in the mix that produced the highest total dry matter yield 5 and 7% and 7 and 10% for gross economic return per acre in 2012 and 2013, respectively. On a tonnage only basis, intercropping 2× MG7 soybean increased yield and produced $26 acre−1 more profit than monoculture corn.

The potential of corn-soybean intercropping to improve the soil health status and biomass production in cool climate boreal ecosystems

Intercropping (IC) is a promising approach used to improve soil health and sustainable crop production. However, it is unknown whether IC improve the soil health status and biomass productivity of crops cultivated in podzols under cool climate in boreal ecosystems. Two silage corn and three forage soybean genotypes were cultivated either as inter or monocrop (MC) treatments in a randomized complete block design. IC resulted in 28% increase in total forage production (FP). A reduction in rhizosphere soil pH (RS-pH) was observed in the IC treatments. Conversely, the rhizosphere soil acid phosphatase (RS-APase) activity was significantly higher (26–46%) in the IC treatments and occurred concomitant with a significant increase in available phosphorus (RS-Pavailable) (26–74%) in the rhizosphere. Furthermore, IC enhanced the active microbial composition and strong positive correlations were observed between RS-Pavailable, RS-APase, microbial biomass and FP; while RS-pH was negatively correlated with FP, RS-APase and RS-Pavailable. These findings suggested silage corn intercropped with forage soybean could be a viable approach to enhance FP through improved active microbial community structure, RS-APase activity and RS-Pavailable when cultivated on podzols in cool climate boreal ecosystem.

Corn-soybean intercropping and nitrogen rates affected crop nitrogen and carbon uptake and C:N ratio in upland red soil

The objective of this research was to determine the effect of corn-soybean intercropping and nitrogen rates on crop biomass, nitrogen (N) and carbon (C) accumulation, and crop C:N ratio in upland red soil. Crop dry matter yields, nitrogen and carbon contents (including grain, straw and root) were measured. Compared with sole corn, corn dry matter yield and carbon accumulation decreased in intercropped soybean. Intercropping decreased the corn C:N ratio, whereas it increased soybean C:N ratio. Nitrogen application significantly increased corn yield, nitrogen and carbon accumulation, but reduced those of soybean. Nitrogen application decreased corn straw C:N ratio and increased soybean straw C:N ratio in most intercropping systems. In conclusion, intercropping and nitrogen rates affected the growth of corn and soybean, changed the allocations of nitrogen and carbon, and altered C:N ratios in different parts of the crops.

Rhizobium inoculation reduces P and K fertilization requirement in corn-soybean intercropping

The field experiment was carried out at Tanzania Coffee Research Institute (TaCRI) for two consecutive years to assess the effects of Rhizobium inoculation, supplemented with phosphorus and potassium on nutrient uptake in soybean intercropped with maize. The experiment was laid out in split-split plot design with 2×4×7 factorial arrangement replicated thrice. The main plots had two rhizobial inoculation treatments, while the sub plots were comprised of four cropping systems: Maize (sole-crop), Soybean (sole-crop) and two intercropping at different soybean spacing (75 × 20 and 75 × 40cm). The sub-subplots were assigned to fertilizer levels (kgha−1): control; 20K; 40K; 26P; 52P; 26P + 20K; 52P + 40K. The statistical analysis was performed using ANOVA. The fisher's L.S.D. was used to compare treatment means at p=0.05 level of significance. The results indicated that soybean pure-stand significantly improved the uptake of Mg over the soybean under intercropping systems for the two cropping seasons. The uptake of Fe increased in intercropped soybean for the first cropping season relative to soybean pure stand. Rhizobium inoculation significantly improved the uptake of all other macro nutrients (N, K, P, and Mg) and micronutrients (Fe, Cu, Zn, Mn) in soybean shoots over un-inoculated soybean. Fertilization of soybean with P and K significantly increased the uptake of N, P and K for both cropping seasons. However, the uptake of macro nutrients such as calcium (Ca) and Magnesium (Mg) and micro nutrients such as Fe and Cu decreased with the increase of P and K fertilizers. P and K fertilization did not significantly affect the uptake of Mg and Mn for the two cropping seasons. Based on the findings of this study, Rhizobium inoculation and P and K fertilization at lower rates are recommended for improved uptake of macro and micro nutrients in legumes such as soybean.

Enhancing yield and nutritive value of forage through corn soybean intercropping strategy at seventeen different places in Republic of Korea

Enhancing yield and nutritive value of forage through corn soybean intercropping strategy at seventeen different places in Republic of Korea

Enhancing Yield and Nutritive Value of Forage for Livestock Feeding Through Corn Soybean Intercropping Strategy with Several Pre-sowing Soybean Seed Coatings

Enhancing Yield and Nutritive Value of Forage for Livestock Feeding Through Corn Soybean Intercropping Strategy with Several Pre-sowing Soybean Seed Coatings

Effect of intercropping of corn and soybean on dry matteryield and nutritive value of forage corn

Cereal-based forage production could be considered to have potential to supply great deal of energy-rich feed in animal diets. Experiment was conducted to evaluate effect of corn-soybean combinations of 75:25, 50:50 and 25:75 in addition to monocrops of corn and soybean to detremine forage dry matter (DM) yield and quality in corn-soybean intercropping. The crop combination ratio had significant effects on dry matter yield and nutritive quality of forage. The ratio of 75:25 and 50:50 recorded DM yields similar to those of monocropped corn (14.77 t/ha). Forage quality in terms of crude protein (CP) (75:25 ratio 12.75%, 50:50 ratio 13.73% and 25:75 ratio 14.68%) was improved by intercropping due to higher nitrogen availability for corn in intercropping compared with its sole crop (10.83% CP). Increase ratio of corn in corn-soybean mixture, negatively affectd neutral detergent fiber (NDF), acid detergent fiber (ADF) of forage and declined with increasing ratio of soybean plants. Combination ratio of 50:50 gave higher protein yield (1886.45 kg/ha) than other crop combination ratio. Among all the combination ratios, the 50:50 corn-soybean ratio was the optimum giving highest forage yield, protein content as well as protein yield.

Productivity, relative yield and plant growth of forage corn intercroppedwith soybean under different crop combination ratio

An experiment was carried out to evaluate influence of different crop combination ratios of corn and soybean in terms of forage yield in corn-soybean intercropping. The experiment compared both corn and soybean as monocultures and in different intercropping ratios from 25:75, 50:50 and 75:25 of corn to soybean. The crop combination ratio had significant effects on physiological traits and dry matter yield of forage. The ratio of 75:25 and 50:50 recorded DM yields similar to those of monocropped corn (14.77 t/ha). Relative yield total (RYT) values of intercropping were higher than that of monocrop corn and soybean. Mixtures with 50:50 combination ratio had higher mean total relative yield values (1.15) in comparison with the other ratios. Land equivalent ratio (LER) increased with corn-soybean intercropping and the highest total LER value was recorded with 50:50 ratio (1.13). The crop ratio of 50:50 gave the best combination based on DM yield, relative yield, LER of the combined forage.

Forage yield and quality of intercropped corn and soybean in narrow strips

Maize-soybean intercropping can increase forage quality with no detrimental effect on dry matter (DM) yield. The objective of this study was to compare corn-soybean intercrop in narrow strips with corn as monocrop in terms of DM yield and forage quality. This study was conducted in Matamoros, Coahuila (Mexico) in 2006 and 2007. Intercrops were established in rows spaced 0.50 m apart, evaluating alternate corn-soybean strips with one, two, three, and four rows per crop, and a treatment using an alternate twin-row planting pattern per crop, with a 1.0-m row-spacing. As control treatments, monocrops of corn in rows 0.76 m apart and soybean in rows 0.50 m apart were evaluated. A randomized complete block design with four replications was employed. Corn-soybean intercrop produced DM yields similar to those of monocropped corn due to higher corn yields in border rows adjacent to soybean. Crude protein (CP) yields per hectare in intercrop treatments were higher (27.5 to 42.8%) than those of monocropped corn, due to greater CP concentrations in intercrops (16 to 21 g kg–1). When soybean was harvested at the beginning maturity stage (R7), neutral detergent fiber concentration was reduced by 60 to 63 g kg–1 in corn-soybean intercropping compared to corn monocrop. Acid detergent fiber was not altered by intercropping. Results indicate that maize-soybean intercrop in narrow strips can provide forage quality advantages without affecting yield.