Udhaya Nandhini and SomasundaramAvailable Ind. online J. Pure at App.www.ijpab.com Biosci. (2020 ) 8(2), 133-143 ISSN: 2582 – 2845 DOI: http://dx.doi.org/10.18782/2582-2845.8007 ISSN: 2582 – 2845 Ind. J. Pure App. Biosci. (2020) 8(2), 133-143 Review Article Intercropping – A Substantial Component in Sustainable Organic Agriculture D. Udhaya Nandhini1* and E. Somasundaram2 1Post Doctoral Fellow, Centre of Excellence in sustaining Soil Health, Anbil Dharmalingam Agricultural College & Research Institute, Trichy-620 027 Tamil Nadu 2Professor and Head, Department of Sustainable Organic Agriculture, Tamil Nadu Agricultural University, Coimbatore-641 003, Tamil Nadu, India *Corresponding Author E-mail: [email protected] Received: 3.03.2020 | Revised: 7.04.2020 | Accepted: 11.04.2020 ABSTRACT st The greatest challenge of the 21 century in many developing countries are to produce more and more basic necessities namely food, fodder, fuel and fibre for ever increasing human and animal population from the limited available land. The availability of land for agriculture is shrinking every day as it is increasingly utilized for non-agricultural purposes. Under this situation, one of the important strategies to increase agricultural output is development of high intensity cropping systems including intercropping system which involves biotic and abiotic stress resistant, soil building, protein rich and oil producing crops. Intercropping is a ways to increase diversity in an agricultural ecosystem. This review summarizes the most important aspects of intercropping system in organic agriculture. Keywords: Intercropping, Stress resistant, Agricultural ecosystem, Diversity INTRODUCTION agricultural systems following objectives such Sustainable agriculture is a type of agriculture as: ecological balance, more utilization of that is more efficient in use of resources, for resources, increasing the quantity and quality the benefit of human, and is in balance with and reduce yield damage to pests, diseases and the environment. In other words, sustainable weeds. Restoring on-farm biodiversity through agriculture must be ecologically appropriate, diversified farming systems that mimic nature economically justified and socially desirable. is considered to be a key strategy for One of the key strategies in sustainable sustainable agriculture. On-farm biodiversity, agriculture is restoration diversity to if correctly assembled in time and space, can agricultural ecosystems, and its effective lead to agro-ecosystems capable of management. Intercropping is a ways to maintaining their own soil fertility, regulating increase diversity in an agricultural ecosystem. natural protection against pests, and sustaining Intercropping as an example of sustainable productivity. Cite this article: Udhaya Nandhini, D., & Somasundaram, E. (2020). Intercropping – A Substantial Component in Sustainable Organic Agriculture, Ind. J. Pure App. Biosci. 8(2), 133-143. doi: http://dx.doi.org/10.18782/2582-2845.8007 Copyright © March-April, 2020; IJPAB 133 Udhaya Nandhini and Somasundaram Ind. J. Pure App. Biosci. (2020) 8(2), 133-143 ISSN: 2582 – 2845 Intercropping is an age old practice of growing & Choubey, 1991). Best utilization of simultaneously two or more crops on the same nutrients, moisture, space and solar energy can field such that the period of overlap is long be derived through mixed/intercropping enough to include vegetative stage (Gomez & system. Gomez, 1983). Intercropping has been a Sarkar et al. (1995) reported that regular practice followed by the farmers of intercropping not only stabilizes crop India, Africa, Sri Lanka and Malaysia. production by reducing the impact of weather Intercropping is mainly practiced to cover the vagaries, but also increases cropping intensity risk of failure of one of the component crops considerably. due to vagaries of weather or pest and disease An enormous variety of intercropping incidence. Yield advantages in intercropping systems exists, reflecting the range of crops system are mainly because of differential use and management practices farmers throughout of growth resources by component crops. The the world use to meet their requirements for complementarity will occur when the growth food, fiber, medicine, fuel, building materials, patterns of component crops differ in time. forage, and cash. Intercropping systems may Intercropping of legumes in involve mixtures of annual crops with other association with non-legumes helps in annuals, annuals with perennials, or perennials utilization of nitrogen being fixed by legumes growing together and coexisting for a time in the current growing season, but also helps in (figure 1). residual build up of nutrients in soil (Sharma Fig. 1: Depending on the degree of both the spatial and temporal dimension of two (or more) crop species Intercropping input, risk reducing under dry farming Growing two or more crops simultaneously on situations for crop diversification and ful the same field; crop intensification is in both fillment of subsistence objectives. At higher temporal and spatial dimensions; there is input levels it will be able to necessary to re intercrop competition during all or part o crop evaluate and recombine various activities. growth. Intercropping systems tend to be low Eg. Groundnut + Redgram + Castor Copyright © March-April, 2020; IJPAB 134 Udhaya Nandhini and Somasundaram Ind. J. Pure App. Biosci. (2020) 8(2), 133-143 ISSN: 2582 – 2845 Cotton + Black gram/green gram where capital can be one ofthe major Sorghum + Redgram constraints in agricultural production, Types of intercropping microclimate modifications that require high Mixed Intercropping inputs such as theuse of synthetic shade Growing two or more crops simultaneously materials are not feasible (Jaya et al., 2001). with no distinct row arrangement. Also Microclimate modification by cheap and referred to as mixed cropping. The seeds of the simple means, such as intercropping might be crop varieties are mixed in desired proposition, acceptable as well as affordable. Maize is one sown and incorporated. of the row crops often selected for Eg. Grass legume mixture; Mixing the intercropping to provide shelter to understory seeds of sorghum and cowpea in 5:1 ratio and crops because of its wide adaptation over a broad casted. rangeof climates. Row Intercropping Insurance against crop failure Growing two or more crops simultaneously One important reason for which intercropping where one or more crops are planted in rows; is popular in the developing world is that it is often referred to as intercropping. more stable than monocropping. The stability Eg. Sorghum in paired rows under intercropping can be attributed to the intercropped with one row of cowpea partial restoration of diversity that is lost under Planting 1 row of red gram for monocropping. For farmers who have limited every 10 rows of groundnut sources, income and stability yield of Strip Intercropping agricultural systems is very important. From Growing two or more crops simultaneously in this point of view, intercropping provides high different strips wide enough to permit insurance against crop failure, especially in independent cultivation but narrow enough for areas subject to extreme weather conditions the crops to interact agronomically. Normally such as frost, drought, flood, and overall followed in sloppy lands and in soils prone for provides greater financial stability for farmers, erosion. making the system particularly suitable for Eg. Wheat and Bengal gram in labor-intensive small farms. When several alternate strips of 5-10 m crops can be grown together, fail to produce a Relay Cropping product, could be compensated by other crop, Growing two or more crops simultaneously and thereby reduces the risk. Risk of during the part of the life cycle of each. A agronomy failure in multi cropping systems is second crop is planted after the first crop has lower than pure cropping systems. It may be reached its reproductive stage of growth but an appropriate growth condition for a species before it is ready for harvest. and inappropriate for other species (Eskandari Eg. Broad casting black gram or green et al., 2009). gram in the standing rice crop about 7-10 days Increasing production before its harvest. One of the main reasons for the use of Advantages of intercropping in sustainable intercropping around the world is produced organic agriculture more than a pure cropping of same land Modification of microclimate amount (Caballero & Goicoechea, 1995). Intercropping practice could modify the Ghanbari and Lee (2002) reported that dry microclimate by reducing light intensity, air matter production in wheat and beans temperature, desiccating wind and other intercrops had been more than their pure climatic components. The emphasis of much cropping. Odhiambo & Ariga, (2001) with previous work on intercropping temperate maize and beans intercrops in different ratios crops in the tropics was mainly on soil found that production increased due to reduced microclimate characterization and not on competition between species compared within-canopy microclimate. In the tropics, competition within species. Wiley (1990) Copyright © March-April, 2020; IJPAB 135 Udhaya Nandhini and Somasundaram Ind. J. Pure App. Biosci. (2020) 8(2), 133-143 ISSN: 2582 – 2845 considers intercropping as an economic decrease dry bulk density and soil resistance to method for higher production with lower root penetration (Latif et al., 1992). Studies levels of external inputs. This