Soybean Intercropping System Research Articles

Productivity and Economic Assessment of Maize and Soybean Intercropping under Various Tillage and Residue Levels in Chitwan, Nepal

A field experiment was conducted at National Maize Research Program (NMRP) in Rampur, Chitwan, Nepal during May-Nov 2013. The experiment was laid out in strip- split design with twelve treatments and three replications. Treatments consisted of two different tillage methods namely conventional tillage (CT) and zero tillage (ZT) as vertical factor, two different levels of residue (residue kept and residue removed) as horizontal factor and three different levels of cropping systems namely sole maize, sole soybean and maize + soybean intercropping system as sub plot factor. Manakamana-3 and Puja were the variety of maize and soybean used for the experiment respectively. The results revealed that the grain yield and yield attributing components of maize and soybean was significantly influenced by cropping systems but not by tillage methods and residue levels. The grain yield of maize obtained under sole cropping (4.76 t ha-1) was significantly higher than maize + soybean intercropping system (4.27 t ha-1). Similarly, the grain yield of sole soybean was significantly higher (1.99 t ha-1) than that of maize + soybean intercropping system (1.26 t ha-1). Moreover, the total grain yield equivalent of 6.45 t ha-1 obtained from sole soybean system was significantly higher and was followed by maize and soybean intercropping system with 4.99 t ha-1. Whereas, sole maize produced significantly the lowest maize grain yield equivalent of 3.47 t ha-1. Significantly, higher LER (1.38) was recorded with maize and soybean intercropping system over sole system (1.0). Tillage and residue levels did not affect the gross and net return and B: C ratio but the effect was found obvious due to intercropping system. Significantly higher net return (NRs.140.49 thousands ha-1) was recorded in intercropping of maize with soybean as compared to sole soybean (NRs. 89.85 thousands ha-1) which was at par with sole maize system (NRs. 80.91 thousands ha-1). Maize and soybean intercropping system produced significantly the higher (2.47) B: C ratio than sole soybean (2.28) and was at par with sole maize (2.18).

Preface to Special Issue on Conservation Agriculture for Sustainable Intensification

Soil erosion and nutrient losses, depleting soil organic matter and water resources, ever increasing cost of production and scarcity of agricultural labor are some of the key constraints of conventional intensive tillage based agricultural production system. Conservation agriculture (CA) as an alternative system to conventional agriculture consists of minimum soil disturbance, maintenance of soil cover and crop rotations. It has been reported that CA increases the systems productivity resulting in yield differences ranging from 20 to 120% for CA compared with conventional tillage systems [1-6]. Beneficial impacts in terms of resource efficiency include reduced need for fertilizer application over time, reduced labor demand, lower runoff and increase resilience to pest and disease. All these result in significant savings, which, combined with yield increases, may translate to significant financial benefits for farmers relative to conventional ploughing practice. In addition, a number of positive externalities, with cost-saving or income-boosting effects, were also reported, including reduced soil erosion, increased resilience to climate-related shocks, increased soil carbon, improved water productivity, reduced debt, livelihood diversification and improved household-level food security. Therefore, in the longer run, CA aims at sustainable intensification (SI), since it is defined as a process or system where agricultural yields are increased without adverse environmental impact and without the conversion of additional non-agricultural land. Therefore, CA seems to be one of the important sub-systems of SI. Considering the above facts, the works done in the area of CA that contributes to SI, World Journal of Agricultural Research (WJAR) called for papers for its special issue “Conservation Agriculture for Sustainable Intensification”. The papers are listed below: 1. Maize Production under No-Tillage System in Nepal, 2. Soil Organic Carbon Sequestration in Rice-Wheat System under Conservation and Conventional Agriculture in Western Chitwan, Nepal, 3. Productivity and Economic Assessment of Maize and Soybean Intercropping under Various Tillage and Residue Levels in Chitwan, Nepal, 4. Conservation Agriculture based Practices Affect the Weed Dynamics in Spring Maize and 5. Conservation Agriculture as an Alternative for Soil Erosion Control and Crop Production in Steep-Slopes Regions Cultivated by Small-Scale Farmers in Motozintla, Mexico The paper deals with various issues of the CA covering its application in maize, maize and soybean intercropping system, rice-wheat system, sloppy land agriculture system. Preliminary results and the matured outcomes are also presented in the papers. Despite the fewer number of articles retrieved so far for the special issue, we hope it will improve the knowledge base of CA among the technicians, students and faculties, researchers and policy makers.

English

The present study was carried out to evaluate the productivity of maize soybean intercropping system and to identify the best combination that maximizes productivity of the system. Maize hybrid (BH540) at 44,444 plants ha -1 and three soybean varieties (AFGAT, Awassa-95 and Crawford) in a factorial combination of three planting densities (25%, 50% and 75%) of the recommended population density of soybean with the respective sole of each variety of component crops were arranged in a randomized complete block design with three replications. Sole cropped maize grain yield (3189.80 kg ha -1 ) was non-significantly greater than intercropped (2753.70 kg ha -

Crop yield, nitrogen acquisition and sugarcane quality as affected by interspecific competition and nitrogen application

While economic efficiency of sugarcane (Saccharum sinensis Roxb)–legume intercropping has attracted a lot of attention around the world, interspecific competition between sugarcane and legume has not been studied so far. A three-year (2009–2011) field experiment was conducted by using a randomized block design with two N application levels (N1, 300kghm−2 and N2, 525kghm−2) and four crop arrangement patterns (soybean monoculture, sugarcane monoculture, 1:1 row sugarcane–soybean intercropping, 1:2 row sugarcane–soybean intercropping). The crop yield and nitrogen acquisition of sugarcane and soybean, and quality of sugarcane juice were determined at the maturity stages of soybean or sugarcane. Land equivalent ratio (LER) was used to evaluate the potential advantages of the intercrops, aggressivity (AG), and competitive ratio (CR) which based on crop yield and nitrogen acquisition were used to evaluate interspecific competition between sugarcane and soybean. The results indicated that sugarcane–soybean intercropping system had intercropping advantages based on total LER in the three-year. Sugarcane had lower AG and CR values than soybean. The quality of sugarcane juice was not significantly different between intercropping and monoculture, except the excessive nitrogen application (N2) in 2011, which reduced the apparent purity and gravity of sugarcane juice significantly compared with normal nitrogen application (N1). This paper suggests that the intercropping advantage of sugarcane–soybean system is mainly contributed by soybean. The introduction of soybean in a sugarcane field does not significantly affect the quality of sugarcane juice.

Dependence of the productivity of maize and soybean intercropping systems on hybrid type and plant arrangement pattern

Intercropping systems could improve utilization of the most important resources (soil, water and nutrients), provide a better control of weeds, pests and diseases, and finally higher productivity, especially under rain-fed growing conditions. This study aimed to determine the effects of three maize (Zea mays L.) prolific hybrids (FAO 500, 600 and 700) and the spatial intercrop patterns on the above-ground biomass and grain yields of maize and soybean (Glycine max L. Merrill), on chernozem soil type at Zemun Polje, Belgrade, in 2003, 2004 and 2005. The experimental design was a complete randomized block with four replications and three treatments: 3 rows of maize and 3 rows of soybean in strips for each maize hybrid (three variants, 3 rows of maize and 3 rows of soybean in alternate rows for each hybrid (another three variants) and monocrops of both maize and soybeans. To optimize the ecological and economic benefits of maize/soybean intercrop in terms of yield, variety selection and compatibility of the component crops should be made using established agronomic management practices involving the two crops. Suitable maize varieties for maize/soybean intercrop systems are varieties that have less dense canopy. These varieties would therefore have lesser shading effect to the understory beans. However, establishment of an appropriate spatial arrangement of the component crops would be essential to alleviate negative effects especially on the less competitive crop. The intercropping system in alternate rows showed significantly higher above-ground biomass and grain yields in comparation with both the strip intercropping system and maize monocrops in 2004. Soybean gave significantly lower above-ground biomass and grain yield in intercrops than in monocrops. Maize prolific hybrid growing in intercropping with soybean as legume crop, increased productivity of cropping system, especially in favourable agroecological conditions. Maize and soybean yields reduction could have also been due to interspecific competition for resources such as nutrients and water. Moreover, performance of the currently grown varieties in the semi-arid regions depends on the amount of rainfall received during the growing season.

The Temporal-Spatial Distribution of Light Intensity in Maize and Soybean Intercropping Systems

Intercropping can improve field microclimates, decrease the incidence of crop diseases, and increase crop yields, but the reasons for this remain unknown. Solar radiation is the most important environmental influence. To understand the mechanisms of intercropping we established an experiment consisting of three cropping patterns: a monocropping control (treatment A) and two intercropping treatments (B: two rows of maize and two rows of soybean intercropping; C: two rows of maize and four rows of soybean intercropping). Results show that compared to monocropping, intercropping increased the amount of light penetrating to inferior leaves in maize plants. Light intensity reaching maize plants at the heading stage in intercropping increased over two-fold at 30 cm above ground and 10-fold at 70 cm above ground, compared with monocropping. At the flowering to maturity stage, light intensity at 110. 160 and 210 cm above ground among maize plants was greatly increased in intercropping compared with monocropping, by some five-fold, two-fold and 12%, respectively. Moreover, light intensity declined more slowly at the measured heights in the intercropping system compared with monocropping. From the 7–18th leaf, light intensity per leaf increased two-fold in intercropping compared with monocropping. Daily light duration increased more than a mean of 5 h per day per leaf in intercropping compared with monocropping. The biological characters of maize including thousand kernel weight, yield per plant and area of ear leaves were all greater in intercropping than monocropping. These results suggest that, for maize, intercropping improves light density and duration significantly and this may contribute to biomass and yield increases.

Crop root behavior coordinates phosphorus status and neighbors: from field studies to three-dimensional in situ reconstruction of root system architecture.

Root is a primary organ to respond to environmental stimuli and percept signals from neighboring plants. In this study, root responses in maize (Zea mays)/soybean (Glycine max) intercropping systems recognized soil phosphorus (P) status and neighboring plants in the field. Compared to self culture, the maize variety GZ1 intercropping with soybean HX3 grew much better on low P, but not in another maize variety, NE1. This genotypic response decreased with increasing distance between plants, suggesting that root interactions were important. We further conducted a detailed and quantitative study of root behavior in situ using a gel system to reconstruct the three-dimensional root architecture. The results showed that plant roots could integrate information on P status and root behavior of neighboring plants. When intercropped with its kin, maize or soybean roots grew close to each other. However, when maize GZ1 was grown with soybean HX3, the roots on each plant tended to avoid each other and became shallower on stratified P supply, but not found with maize NE1. Furthermore, root behavior in gel was highly correlated to shoot biomass and P content for field-grown plants grown in close proximity. This study provides new insights into the dynamics and complexity of root behavior and kin recognition among crop species in response to nutrient status and neighboring plants. These findings also indicate that root behavior not only depends on neighbor recognition but also on a coordinated response to soil P status, which could be the underlying cause for the different growth responses in the field.

Influence of intercropping systems and weed management practices on the growth and yield of irrigated cotton

Field experiments were conducted at Agricultural College and Research Institute, Killikulam to find out the suitable intercrop and weed management practices on cotton under irrigated condition. The results revealed that higher growth and yield attributes and yield were recorded in sole cotton than cotton intercropped with either cowpea or soybean. Pre-emergence application of metolachlor at 1.00 kg ha' through herbigation with one hand weeding on 40 DAS significantly enhanced the growth, yield attributes and yield of cotton. The interaction between intercropping and weed management practices indicated that cotton and soybean intercropping system applied with the metolachlor herbicide as pre-emergence at 1.00 kg ha' through herbigation with one weeding on 40 DAS registered higher growth, yield attributes and yield.

Effect of weed control, fertilizer application and Rhizobium - on nutrient uptake under maize + soybean intercropping system

A field experiment was conducted during rainy season (kharif) 1993 and 1994 on clay-loam soils of Rajasthan College of Agriculture, Udaipur. Maximum NPK uptake by maize and soybean was recorded under manual weeding twice, followed by application of metolachlor and pendimethalin 1.0 kglha. Among weed-control treatments, unweeded check recorded the highest NPK uptake by the weeds. Fertilizer levels and Rhizobium inoculation to intercrop had no effect on nutrient uptake of maize, but significantly increased the nutrient uptake of soybean.

Effect of nutrient-and moisture-management practices on crop productivity, water-use efficiency and energy dynamics in rainfed maize (Zea mays) + soybean (Glycine max) intercropping system

A field experiment was conducted during the rainy season of 2012 at New Delhi, to study the effect of cropping systems, nutrient-and moisture-management practices on productivity and water-use efficiency (WUE) of maize (Zea mays L.) + soybean [Glycine max (L.) Merr.] intercropping system under rainfed conditions. Treatment com- prised 2 cropping systems (maize sole and paired row planting maize + soybean) and 2 moisture-management practices (control and Kaolin 6% + organic mulch) in main plots, and 4 nutrient levels, viz. control, 50% recom- mended dose of fertilizer (RDF) + 50% recommended dose of nitrogen (RDN) through FYM, 50% RDF + 50% RDN through vermicompost and 100% RDF in subplots of splitplot design. However, maize-equivalent yield (3.47 t/ha) was the highest under paired row planting maize + soybean. The 100% RDF registered significantly higher grain yield (2.99 t/ha) of maize over control (2.03 t/ha) and 50% RDF+ 50% RDN through FYM (2.74 t/ha), 50% RDF+ 50% RDN through vermicompost (2.85 t/ha). Paired-row planted maize + soybean also registered more consumptive use (CU) of water (331.7 mm) than sole maize (324.6 mm). Moisture-conservation practices showed considerable variation in CU. Maximum water-use efficiency (WUE) was recorded with Kaolin 6% + or- ganic mulch. Fertility levels also influenced the CU with highest value with100% RDF (330 mm) followed by 50% RDF + 50% RDN through vermicompost (329.1 mm). Significantly higher WUE was observed under paired row planted maize + soybean (10.9 kg/hamm). Cropping systems altered the soil-moisture extraction pattern in all the 3 layers (015, 1530 and 3045 cm). Energy output, energy input and energy-use efficiency was higher in paired-row planted maize + soybean, Kaolin 6% + organic mulch and 100% RDF than their respective counter- parts.

Effect of spatial arrangement and phosporus fertilization in pigeonpea (Cajanus cajan)soybean (Glycine max) intercropping system

A 2-year experiment was conducted on a clayey deep Vertisols of Bhopal to study the effect of row ra- tios and phosphorus fertilization on pigeonpea [Cajanus cajan 6 . ) Millsp.]soybean [Glycine mar 6 . ) (Merr.)] intercropping system. At 120 cm row spacing higher, number of branches, graindpod and yield were recorded in sole croppirig compared with intercropping systems. Among intercropping, 1 : 3 ratio gave significantly higher number of branches, pods, graindpod, 1,000-grain weight and grain yield than 1 : 1 ra- tio, and pigeonpea-yield equivalent increased by 31.6 and 35.3% over 1 : 1 ratio and sole pigeonpeaat 60 cm row spacing respectively. The highest landequivalent ratio (1.39), monetary yield advantage (Rs 6,712/ hala) and benefit : cost ratio of 2.8 were recorded at 1 : 3 row ratio, followed by 1 : 2 row ratio (27.5% higher pigeonpea-grain-yield equivalent over sole pigeonpea at 60 cm row spacing). Consumptive water use and water-use efficiency also increased with intercropping at higher row ratios of 1 : 2 and 1 : 3. lncrease in the dose of 30 kg to 90 kg P@Qa resulted in increase of grain yield of both pigeonpea and soybean. The pigeonpea-grain-yield equivalent was increased by 28.2%, the water-use efficiency by 7.7 kgha-cm, net profit by Rs 5,733rna and benefit : cost ratio by 3.45.

Effect of row ratio and fertility levels on productivity, economics and nutrient uptake in maize (Zea mays) + soybean (Glycine mar) intercropping system

A field experiment was conducted during the rainy seasons of 2003 and 2004 at Udaipur, to study the effect of row ratios and fertility levels on maize (Zea mays L.) + soybean [Glycine max (L.) Merr.] inercropping system in south Rajasthan. The highest maize-equivalent yield was observed with 2:2 maize + soybean intercropping sown at 30 at 30 cm distance with each other. Application of 75% recommended dose of fertilizer (RDF) to maize (90 kg Nlha and 40 kg Plha) and 50% to soybean (60 kg Nlha and 40 kg Plha) significantly increased their re- spective yields, maize-equivalent yield, net returns and benefit : cost ratios over 50% RDF in maize and no fertil- izer in soybean. The nutrient uptake by maize was highest with 1 :I ratio, while by soybean it was with 3:3 ratios. Increasing levels of fertility to maize and soybean up to 100% recommended dose increased the total nutrient uptake significantly over 75 and 50% in the both crops in intercropping system.

Fertilizer Management in Hybrid Maize with Soybean Intercropping System under Irrigated Condition

Fertilizer Management in Hybrid Maize with Soybean Intercropping System under Irrigated Condition

Sustainable weed management programme for rainfed cotton based cropping system

Field experiments were conducted for two seasons (September '97 to April '98 and October 98 to May '99) at Fredrick Institute of Plant Protection and Toxicology (FIPPAT), Padappai, to develop a sustainable weed management programme in rainfed cotton. Results revealed that, intercropping of soybean and sesame led to weed suppression in rainfed cotton to the extent of 39.6 and 28.4 per cent respectively. The seed cotton yield obtained from cotton + soybean intercropping system under unweeded conditions was similar (1196 kg ha) to the yield of sole cotton supplenfented with single hand weeding alone (1220 kg ha¹). Similarly, single hand weeding operation in the cotton + soybean cropping system resulted in a substantially higher seed cotton yield (1528 kg ha-1), than the yield of sole cotton crop supplemented with two hand weedings (1432 kg ha¹). So, the adoption of Soybean, as a intercrop in rainfed cotton is an effective method for checking the weeds population as well as enhancing the yield potential in rainfed cotton and also labour saving, by minimising to one hand weeding. Similar effects were also found in cotton + sesame intercropping system. Furthermore, in labour scarce situation, the application of pre-emergence herbicide Fluchloralin @ 1.0 kg a.i ha in cotton-soybean intercropping system could be an alternative method.

Consórcio soja-milho: V. efeito de sistemas de consórcio e de semeadura do milho

O presente trabalho foi realizado com o objetivo de avaliar o comportamento da soja [ Glycine max (L.) Merrill ] cultivar Doko e do milho (Zea mays L.) cultivar BR 201 quando consorciados em diferentes sistemas de semeadura. O experimento foi conduzido no ano agrícola 1992/1993. em área experimental da Universidade Federal de Lavras, em Latossolo roxo distrófico, textura argilosa. O delineamento experimental utilizado foi blocos casualizados, com três repetições em esquema fatorial (3x3+4) constituído por três sistemas de consórcio (soja na linha do milho; soja na entrelinha do milho e soja em ambas linha e entrelinha) e três formas de semeadura do milho uma planta a cada 25cm, duas plantas e cada 50cm e quatro plantas a cada 100cm e mais 4 tratamentos adicionais representados pelos monocultivos das três formas de semeadura do milho e a da soja. A cultura do milho não foi influenciada pelos sistemas de semeadura empregados e nem pela presença da cultura da soja em consórcio. A soja consorciada em relação ao monocultivo apresentou maior acamamento e menor rendimento de grãos. Entre os sistemas de consórcio, a semeadura simultânea de soja nas linhas e entrelinhas do milho foi o que proporcionou o maior rendimento de grãos. A eficiência dos sistemas consorciadas sobre o monocultivo foi evidenciado com valor médio da razão de área equivalente (RAE) de 1,40.

Legislation & Regulation

Water scarcity seriously hinders the sustainable development of the fruit tree–crops intercropping system in the Loess Gully Area of western Shanxi. The combination of mulch measures and appropriate irrigation would help to maintain soil moisture and improve crop yield and water use efficiency (WUE). This study investigated the combined effects of mulch and irrigation on soil water and root distribution, yield, and water use of an apple–soybean intercropping system. A three-year field trial was performed with two factors: two types of mulch, namely straw mulch (M1), and plastic mulch (M2), and three levels of maximum irrigation (55%, 70%, or 85% of field capacity [Fc]), which were designated W1, W2, and W3, respectively. Three groups of non-irrigation controls i.e., CK0 (no mulch), CK1 (straw mulch), and CK2 (plastic mulch) were also included. These results indicated that the soil water contents (SWC) in each treatment initially decreased and then increased with increasing distance from the tree, whereas it increased gradually with depth. The SWCs in various sampling points under straw mulch was generally higher than under plastic mulch. The root length density (RLD) of apple tree decreased with increasing distance from the tree in the horizontal direction, while the opposite trend was observed for soybean. The RLD of both apple tree and soybean in the soil layer (0–60 cm) under plastic mulch was higher than that under straw mulch, and increased with increased irrigation level. The underground interspecific competition intensity index (UICII) of the apple–soybean intercropping system under straw mulch was higher than that under plastic mulch, and increased with the increased irrigation amount. Water consumption, soybean yield, and WUE under plastic mulch were significantly higher than under straw mulch. The results of this study suggested that the combination of plastic mulch and irrigation water supplied at 70–85% Fc could effectively increase the yield and WUE of the apple–soybean intercropping system.

Nitrogen and light partitioning in a maize/soybean intercropping system under a humid subtropical climate

Land-use efficiency in a cereal/legume intercropping system is related to the complementarity of resource use in time or space. Nitrogen and light partitioning in a maize (Zea mays L.)/soybean (Glycine max (L.) Merr.) intercropping system under subtropical climatic conditions in Nepal was studied during the summers of 1988 and 1989. Factors studied included the cropping system (sole cropping vs. intercropping), three levels of nitrogen fertilization (0, 35 and 70 kg N ha−1) and two spatial arrangements of the intercrops. During the second season, a non-nodulating soybean isoline of the same cultivar was used as a control. The cropping system had a limited impact on soybean nodulation, since intercropped soybean nodules dry weights were only 11% and 6% inferior, as compared with sole cropped soybean, in 1988 and 1989, respectively. However, the seed N yield of sole cropped nodulating soybean was significantly higher than the total seed N yield of intercropped maize/nodulating soybean. The reverse effect was measured in the case of the maize/non-nodulating soybean intercropping system. Intercropping maize with soybean did not result in the interception of a higher proportion of the incident photosynthetic photon flux density (PPFD) than sole soybean, except early during the season. Intercropped nodulating soybean developed a dense underlying canopy, and was able to intercept 95% of incident PPFD after maize harvest.Key words: LER, resource capture efficiency, Bradyrhizobium japonicum, PPFD interception

Intercropping of soybean and maize for silage in northern Italy : effect of nitrogen level and plant density on growth, yield and protein content

A two-year experiment was carried out during 1990 and 1991 in north-east Italy to evaluate the yield and the protein content of forage from a maize-soybean intercrop and from the two sole crops at two levels of nitrogen fertilization (75 kg N ha-1 and 150 kg N ha-1) and at three different population den sities of soybean (8, 16 and 32 plants m-2). In both years the maize hybrid cv. Furia and the soybean cv. Kefir were used. Intercropped soybean showed an increase in height, and its vegetative biomass and pod production decreased compared with the soybean sole crop. The biomass of maize, grown as an intercrop component, decreased proportionately with the increase in the soybean component. Nitrogen fertilization had only slight effects on dry matter yield of the intercrop. The dry matter yield of the intercrop was 89 per cent greater than the soybean sole crop and 4 per cent than the maize sole crop. The average Land Equivalent Ratio of the maize soybean intercropping system was about 1.3.

Effect of Population Levels of Soybean on Physiological Growth Parameters of Sorghum CO 24 in Sole and Intercropped Stand

AbstractA field experiment was conducted during kharif, 1985 and summer, 1986 in sandy clay loam soil under irrigated condition at Tamil Nadu Agricultural University, Coimbature, with a view (i) to assess the suitable method of planting of sorghum CO 24 when intercropped with soybean, (ii) to evaluate the suitable planting ratio of sorghum ‐ soybean intercropping system, (iii) to find out the compatible population level of soybean when intercropped with sorghum CO 24.Direct sown sorghum at 4: 2 and 2: 2 recorded grater leaf area (LA) compared to transplanted sorghum in both kharif and summer. Sorghum transplanted with 14 days old seedlings recorded higher Crop Growth Rate (CGR) compared to 21 days old seedlings. Increased Net Assimilation Rate (NAR) were recorded in sorghum transplanted with 14 days old seedlings as compared to direct sown and 21 days old transplanted crop. Transplanted sorghum recorded higher Relative Growth Rate (RGR) as compared to direct sown sorghum. Summer sorghum recorded higher Relative Growth Rate (RGR) as compared to kharif season.