Potential Role of Maize-Legume Intercropping Systems to Improve Soil Fertility Status under Smallholder Farming Systems for Sustainable Agriculture in India

The Indian population is growing rapidly (1.25 billion) and it has to fulfill its food and nutrition requirement. A collaborative strategy should be adopted for increasing productivity by intensifying available land use system. Intercropping is advanced management practices of soil fertility status, consisting of cultivating two or more crops in the same space at the same time, which have been practiced in past decades and achieved the goals of agriculture. The most common advantage of intercropping is the production of greater yield on a given piece of land by making more efficient use of the available resources using a mixture of crops of different rooting ability, canopy structure, height, and nutrient requirements based on the complementary utilization of growth resources by the component crops. Moreover, intercropping improves soil fertility through atmosphere nitrogen fixation from atmosphere (150 tons/year) with the use of legumes, increases soil conservation through greater ground cover than sole cropping. Also, intercropping systems are beneficial to the smallholder farmers in the low-input and/or high-risk environment of the sub-tropic, where intercropping of maize and legumes is widespread among smallholder farmers due to the ability of the legume to contribute to addressing the problem of declining levels of soil fertility. The principal reasons for smallholder farmers to intercrop are flexibility, profit maximization, risk minimization, soil conservation, improvement of soil fertility, weed, pests and diseases minimizing and balanced nutrition. However, intercropping has some disadvantages such as the selection of the appropriate crop species, including extra work in preparing and planting the seed mixture and also extra work during crop management practices, including harvest. This is a review paper covering the role of maize legume intercropping systems to improved soil fertility status under smallholder farms of semi-arid area of India. The intercropping systems are useful in terms  Manuscript received April 23, 2015; revised June 26, 2015. of increasing productivity and profitability, water and radiation use efficiency, control of weeds, pests and diseases. The critical role of atmosphere nitrogen fixation and the amounts of N transferred to associated non-leguminous crops determines the extent of benefits. In intercropping, land equivalent ratio (LER), benefit cost ratio (B:C) and monetary advantage index (MAI) are used to assess the system productivity and its economic benefits. In this study, the work carried out by researchers about different intercropping system is discussed, and it would be beneficial to the researchers who are involved in this field.