A Review on the Comparative Advantage of Intercropping Systems

Mono-cropping style production has significant problems and that there exists a sufficient justification for studying intercropping approaches. Consequently, researchers have proposed general categories of benefits and utilities of intercropping. Benefits of intercropping are crop yield, productivity of various plant constituents, economic return, yield stability, social benefits, pest control, and fertilizer use efficiency. The most important advantage of intercropping systems includes both tall and short plant components for their potential complementarity in sunlight utilization for crop production. Because of these advantages intercropping is practiced in many parts of the world. Furthermore, because of some favorable exudates from the component legumes, greater land-use efficiency, greater yield stability and increased competitive ability towards weed, intercropping is advantageous over mono-cropping.  This review summarizes the most important aspects of intercropping system comparative to mono-cropping system. The objectives of this review are therefore, (1) to assess the available literatures on the intercropping systems so as to indicate the system as an optional cropping system where it is required accordingly, (2) to show the scientific justifications on the advantages and disadvantages of the system in an attempt to provide the comparative advantages over the mono-cropping system for selection and its influence on food security and the economy of a country especially where there is no a problem of labor, and (3) to indicate as the system can allow more efficient uses of on farm resources like water in order to enable sustainable crop production for a nation. Keywords: competition, complementarity, intercropping, mono-croppin

A Review on the Comparative Advantages of Intercropping to Mono-Cropping System

Mono-cropping style production has significant problems and that there exists a sufficient justification for studying intercropping approaches. Consequently, researchers have proposed general categories of benefits and utilities of intercropping. Benefits of intercropping are crop yield, productivity of various plant constituents, economic return, yield stability, social benefits, pest control, and nutrient use efficiency. Both above ground and below ground potential complementarities of component plants are the most important advantage of intercropping systems which includes both tall and short plant components in sunlight utilization by their areal parts whereas shallow and deep rooted plant components in water and nutrient exploitation for crop production. Because of these advantages intercropping is practiced in many parts of the world, especially in the developing countries. Furthermore, because of some favorable exudates from the component legumes, greater land-use efficiency, greater yield stability and increased competitive ability towards weed, intercropping is advantageous over mono-cropping.  Therefore, this review summarizes the most important aspects of intercropping system comparative to mono-cropping one. The objectives of this manuscript are therefore, (1) to review the available literatures on the intercropping systems so as to indicate the system as an optional cropping system where it is required accordingly, (2) to show the scientific justifications on the advantages and disadvantages of the system in an attempt to provide the comparative advantages to the mono-cropping system for selection and its role on food security and the economy of a country especially where there is no a problem of farm labor for field management, and (3) to indicate as the system can allow more efficient use of on farm resources like water in order to enable sustainable crop production for a nation. Keywords: competition, complementarity, intercropping, mono-croppin

The Potential of Intercropping Food Crops and Energy Crop to Improve Productivity of a Degraded Agriculture Land in Arid Tropics

Degraded agricultural lands in the arid tropics have low soil organic carbon (SOC) and hence low productivity. Poor farmers that their livelihoods depend highly on these types of lands are suffering. Cropping strategies that are able to improve the soil productivity are needed. In the present study, some intercropping models of food crops with bio-energy crop of castor (Ricinus communis L.) were tested to assess their potential to improve the degraded land productivity. The intercropping models were: (1) castor - hybrid maize, (2) castor – short season maize, (3) castor – mungbean, and (4) castor –short season maize – mungbean. The results show that yields of the component crops in monoculture were relatively the same as in intercropping, resulted in a high Land Equivalent Ratio (LER). The highest LER (3.07) was calculated from intercropping castor plants with short season maize crops followed by mungbean with intercropping productivity of IDR 15,097,600.00 /ha. Intercropping has a great potential to improve degraded agriculture land productivity and castor is a promising plant to improve biodiversity and area coverage on the land

Early planting and relay cropping: pathways to cope with heat and drought?

Maize (Zea mays) is an important food and cash crop of uplands in Southeast Asia, where it is often prone to drought and heat stress associated with climate change. This study aimed at assessing the effect of heat and drought on maize performance, testing coping strategies under such weather extremes, and understanding associated mechanisms. The experiment was carried out during 2018 in Thailand, using a split-plot design with three replications. Treatments were: July-planted maize sole cropping (control), July-planted maize-mungbean (Vigna radiata) relay cropping, and June-planted maize sole cropping. High temperatures and dry spells during July-August 2018 decreased maize growth strongest in the control and less so in maize relay cropping during generative growth stages, but not in June-planted maize sole cropping. Stress reduced maize nitrogen nutrition index by 40%. Relay-cropped maize had a significantly higher potential to keep stomata open (320 mmol m-2 s-1) than sole-cropped maize (100 mmol m-2 s-1). Δ13C of maize grains confirmed that June-planted maize (‑9.43‰) was less affected by dry spells and heat stress than July-planted sole cropped maize (‑10.23‰). Under relay cropping, the latter showed less water stress (δ13C: ‑10.12‰) compared to sole cropping and a higher soil water use. Maize was better able to cope with heat and drought stress when relayed-cropped, although less compared to early-planting of maize. Hence, the tested coping strategies are able to mitigate heat and drought effects on maize growth, while improving food security and crop diversification when relay-cropped with mungbeans

About the Role of Turbulence in an Intercropping System

Aims: It was analysed the role of turbulence in the interaction between the atmosphere and two types of cropping systems, a corn-soy intercrop and soybean monocrop. Study Design: Experimental. Place and Duration of Study: The crop experiment was performed between October 2010 and April 2011 at the Balcarce Integrated Research Unit - Agricultural Experiment Station of the National Institute of Agricultural Technology (INTA in Spanish) and the Faculty of Agricultural Sciences at the National University of Mar del Plata (UNMdP in Spanish), while the meteorological experiment was performed during January 2011. Methodology: The crop experiment involved two spatial arrangements: a corn-soybean intercrop and a soybean monocrop. For two days intensive measurements of the three components of air velocity were obtained with two three-dimensional wind-monitors (YOUNG GILL UVW 27005). One wind monitor was installed within the intercrop and the other in the soy monocrop arrangement. Micrometeorological data were analysed using the quadrant-hole methodology. Results: Turbulence intensity inside the intercrop canopy results greater than in corn and soybean monocrop canopies. Air ejections associated to turbulence interaction with the canopy occurred more frequently than sweeps. However, sweeps were responsible for 57-60% of momentum flux, while ejections were responsible for only 27 to 30%. Also, around 50% of momentum was transported by eddies whose size is associated with a quadrant hole greater than 5 on both types of crops. Conclusion: The interaction of turbulent eddies with the intercrop-canopy could benefit its environmental inner conditions.Fil: Gassmann, María Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentin

Conservation tillage in Kenya : the biophysical processes affecting its effectiveness

Appropriate soil management is important for improved ecosystem functioning and high crop production. This study investigates how different tillage [reduced tillage (RT) and conventional tillage (CT)], crop residue (plus and minus crop residue) and cropping systems (soybean-maize intercropping, rotation and continuous maize) affected (i) soil aggregation, (ii) composition and diversity of microbial populations, (iii) crop residue (CR) disappearance and termite activity, (iv) nitrogen fixation and (v) crop productivity in Kenya. The main experiment in Nyabeda (western Kenya) had been established in 2003, while experiments in Matayos (western Kenya) and Machang’a (eastern Kenya) were established in 2005. Soybean-maize intercropping improved macroaggregation and reduced microaggregates and free silt and clay (P The composition of both bacteria and fungi communities was markedly different in the two tillage systems. With CR application, Simpson’s indices of fungi were in the order intercropping >rotation >continuous maize. In addition, intercropping had highest bacteria diversity indices in the Nyabeda site. CR affected bacteria composition (e.g, in Matayos) and lowered diversity of soil fungi (P CR disappearance was up to 85% of the initial residue in 3.5 months, and the relative contribution of macro- and mesofauna to residue disappearance was 70-95% for surface-placed and 30-70% for buried residues. Soil of termite galleries (mainly sheetings) was more enriched in carbon (1.6%) than bulk farm soil (1.4%) and mound soil (1.2%; P250 Soybean nitrogen derived from the atmosphere (%NDfA) ranged from 42-65%; it was higher (P Seasonal average maize grain yields were 3.2-4.1 t ha-1 in continuous maize, 3.0-3.9 t ha-1 in soybean-maize rotation, and 1.8-2.8 t ha-1 in the soybean-maize intercropping system. Soybean grain yields were 0.92-0.99 t ha-1 in the soybean-maize rotation and 0.52-0.60 t ha-1 in the intercropping system. The net benefits were highest in the soybean-maize intercropping, followed by rotation > continuous maize. Soybean yields were similar between CT and RT; maize yields were lower (P We conclude that (i) despite fast disappearance of CR, its application increases soil aggregation and influences microbial composition and diversity and nitrogen fixation; (ii) for Ferralsols of western Kenya, combining RT and CR is important for improved soil structural stability and, intercropping maize and legume (soybean) leads to better soil structure and also gives higher net benefits than conventional rotation and continuous maize systems; and (iii) RT is appropriate for soybean production; maize yields are lower in RT than in CT due to surface crusing in the RT resulting from inadequate soil cover.Ressourcenschonende Landwirtschaft in Kenia : Die ihre Effektivität beeinflussenden biophysikalischen Prozesse Eine richtige Bodenbearbeitung ist wichtig für die verbesserte Funktion von Ökosystemen und für hohe landwirtschaftliche Erträge. Diese Studie untersucht den Einfluss verschiedener Bodenbearbeitungsmethoden [reduzierte Bodenbearbeitung (reduced tillage; RT) und konventionelle Bodenbearbeitung (conventional tillage; CT)], Ernterückstände (mit und ohne Rückstände) und Anbausysteme (Sojabohnen-Mais Mischkultur, Rotation und fortlaufender Maisanbau) auf (i) Bodenaggregation, (ii) Zusammensetzung und Diversität von Bodenmikrobengemeinschaften, (iii) Verschwinden von Ernterückständen (crop residue; CR) und Aktivität von Termiten, (iv) Stickstofffixierung (N) und (v) landwirtschaftliche Produktivität in Kenia. Die Hauptuntersuchungsfläche in Nyabeda (Westkenia) bestand seit 2003, während die Untersuchungen in Matayos (Westkenia) und Machang’a (Ostkenia) in 2005 begonnen wurden. Mit Sojabohnen-Mais-Zwischenpflanzung verbesserte sich die Makrostruktur des Bodens, während die Mikrostruktur und freier Schluff bzw. Ton (P Die Zusammensetzung sowohl der Bakterien- als auch der Pilzgemeinschaften unterschied sich deutlich in den beiden anderen Systemen. Die Simpson-Indices der Pilze sanken mit Anwendung von Pflanzenrückständen in der Folge Zwischenpflanzung >Rotation >ununterbrochener Maisanbau, und Zwischenpflanzung zeigte die höchsten Bakteriendiversitätindices am Standort in Nyabeda. Pflanzenrückstände beeinflussten die Bakterienzusammensetzung (z.B. in Matayos) und reduzierten die Diversität von Bodenpilzen (P Bis zu 85% der ursprünglichen Pflanzenrückstände verschwand in 3.5 Monaten und der relative Beitrag der Makro-bzw. Mesofauna hierzu war 70-95% für oberflächlich ausgebrachte bzw. 30-70% für eingearbeitete Rückstände. Der Boden der Termitengalerien (hauptsächlich überbaute Laufwege) enthielt mehr Kohlenstoff (1.6%) als Farmboden (1.4%) und Bodenmaterial in Termitenhügeln (1.2%; P250 Sojabohnenstickstoff aus der Atmosphäre (%NDfA) war höher (P-1. Gesamtfixierter Stickstoff bei RT plus CR war mindestens 55% bzw. 34% höher als bei den anderen Bodenbehandlungen (RT minus CR, CT plus CR, bzw. CT minus CR) in den Zwischenpflanzungs- bzw. Rotationssystemen. Die jahreszeitlich abhängigen durchschnittlichen Sojabohnenerträge waren ähnlich bei CT und RT; Maiserträge waren niedriger (P ununterbrochener Maisanbau. Es kann daher davon ausgegangen werden, dass (i) trotz des vollständigen Verschwindens, Pflanzenrückstände die Bodenaggregation erhöhen und die Zusammensetzung und Diversität der Bodenmikroben sowie die Stickstofffixierung beeinflussen; (ii) für die Ferralsols von Westkenia die Kombination von RT und Pflanzenrückständen wichtig ist für eine verbesserte strukturelle Stabilität der Böden, während Zwischenpflanzung von Mais und Hülsenfrüchten (Sojabohnen) zu einer verbesserten Bodenstruktur und auch zu höheren Nettonutzen im Vergleich zur konventionelle Rotation bzw. zu ununterbrochenem Maisanbau führen, und (iii) RT richtig ist für die Sojabohnenproduktion; Maiserträge sind niedriger bei RT als bei CT durch die Oberflächenverkrustung bei RT wegen der unzureichenden Bodenbedeckung

Performances of Different Varieties and Population of Soybean (Glycine max L.) under Intercropping Systems with Maize (Zea mays L.)

The field experiment was carried out at Haro Sabu Agriculture Research Center, during 2013 with the objectives of determining the effect of varieties and population density of soybean intercropped with maize on phenological and growth parameters of the component crops. The experiment was laid out in RCBD with three replication in factorial combination of three soybean varieties (Boshe, Ethio Yugoslavia and Didesa) and three soybean plant populations (25%, 50% and 75%) along with respective sole crop of soybean varieties and maize BHQPY-545. Plant population of soybean had significant (P<0.05) effect on LAI of maize. The highest LAI (3.61) was obtained from 50% soybean population. The LA, LAI and number of primary branches of soybean component showed significant difference due to plant population. The highest LA per plant (3392.60 cm2) and number of primary branches (6.22) were obtained in soybean population of 25%. However, the highest LAI (4.96) was obtained from 75% soybean population. Plant height, number of effective nodules per plant, number of primary branches, of soybean were significantly (P<0.01) affected by soybean varieties. The highest plant height (123.89cm) was obtained from Ethio Yugoslavia. The highest number of primary branches per plant was obtained from variety Boshe (7.33). The Highest number of effective nodules (30.33) was recorded for variety Didesa. Cropping system showed highly significant (P<0.01) effects on number of effective nodules per plant and significant (P<0.05) effect on leaf area index. The result revealed that cropping system had a significant effect on LAI and number of effective nodules per plant where higher LAI (6.18) and effective nodules per plant (46.44) were recorded from sole cropped soybean variety than the intercropping system. Keywords: Glycine max, intercropping, plant populations, sole cropping, Zea may

Productivity of Vegetable Crops Grown under Shade in Hawaii

Waimanalo Long' eggplant (Solanum melonaena L.), 'Kahala' soybean ^Glvcine max (L.) Merrill), 'Jumbo Virginia' peanut (Arachis hvpoaea L.), 'Waimanalo Red' sweet potato flpomea batatas (L.) Lam.), and 'Green Mignonette' semihead lettuce fLactuca sativa L.) were field-grown in two seasons at Waimanalo, Oahu, Hawaii with five artificially produced levels of shade (0, 30, 47, 63, and 73%). Yields and vegetative growth of eggplant, soybean, peanut, and sweet potato were linearly decreased with increasing shade levels. Compared to unshaded controls, yields of semihead lettuce increased significantly from 8100 kg•ha-1 to 13,600 kg•ha-1 by 30% shade in Fall 1986. During Spring 1987, semihead lettuce yields were reduced only slightly from unshaded levels of 22,000 kg•ha-1 by increasing shade up to 47%. Eggplant, soybean and lettuce maintained index leaf areas similar to unshaded controls as shade intensity increased, at the expense of leaf dry weight. By comparison, both leaf area and leaf dry weight of peanut index leaves decreased as shade increased. Leaf area and leaf dry weight of sweet potato did not respond to shading. To further investigate the effects of shade on leafy vegetables, 'Green Mignonette', 'Salinas', 'Parris Island Cos', and 'Amaral 400' lettuce (Lactuca sativa L.), 'WR-55 Days' Chinese cabbage (Brassica raoa L. Pekinensis Group), 'Waianae Strain' green mustard cabbage (Brassica iuncea (L.) Czerniak), 'Tastie Hybrid' head cabbage (Brassica oleracea L. Capitata Group), and an unnamed local selection of bunching onions (Allium ceoa L. Aggregatum Group) were field-grown in two seasons at the same location with the same five artificially produced levels of shade. Yields of cos lettuce, green mustard cabbage, and bunching onions were irresponsive or negatively affected by shade in both seasons. Yield responses of the other crops to shade varied seasonally. Optimum shading of 30 to 47% increased 'Green Mignonette', 'Salinas', and 'Amaral 400' lettuce by 36% and head cabbage and Chinese cabbage yields by 23% and 21 %, respectively, compared to full-sun plots in some trials. Index leaf areas similar to unshaded controls were maintained as shade intensity increased, at the expense of leaf dry weight in all crops except 'Salinas' and 'Parris Island Cos' lettuce. Maximum rates of net photosynthesis (Pn) were attained at about two-thirds of full sunlight (1500 umol • s-1•m-2)

Potential and Advantages of Maize-Legume Intercropping System

Intercropping provides enough scope to include two or more crops simultaneously in same piece of land targeting higher productivity from unit area. Maize, a cereal crop of versatile use, as planted in wide rows offers the opportunity for adoption of intercropping. The intercropping system with maize and legume is beneficial in multifaceted aspects. The success of maize-legume intercropping system largely depends on choice of crops and their maturity, density, and time of planting. Advantage of maize-legume combination of intercropping system is pronounced in the form of higher yield and greater utilization of available resources, benefits in weeds, pests and disease management, fixation of biological nitrogen by legumes and transfer of N to associated maize, insurance against crop failure to small holders, and control of erosion by covering a large extent of ground area. Though maize-legume intercropping system exhibits limitations like less scope of farm mechanization, dependence on more human workforce, and chance of achieving less productivity from maize, the system implies more advantages for small holders in developing countries where human workforce is not a constraint. The chapter has focused on beneficial impacts of maize-legume intercropping system