Sustainability in Potato Production, According to Crop-Livestock Integration System Approach

The state of Minas Gerais, is the largest Brazilian producer of potatoes and most part of the production is concentrated in the southern region of the state. This region has an agrarian structure formed by a large number of small farms that cultivate potato and exploit and dairy farming in the form of family business. Family business farming has great social importance, and it is related to the creation of jobs (agricultural and non-agricultural), food production, income and local development (ROCHA, PAULA, 2005). For family farmers it is of fundamental importance the diversification of production and not only reaching high productivities obtained by the monocultures or livestock. This strategy reduces the financial difficulties in periods of low prices for potatoes or milk, which represent the most important sources of income for households in the region. Lesser the oscillations of income, more economic stability of the family is guaranteed. Diversification of production is therefore one of the strategic options in rural development policy, particularly in areas affected by the decline of certain activities or cyclical price fluctuations.

Potato cultivation and dairy farming are important economic activities in this region, although most pasture areas are degraded (MACEDO, 1995). The differentiated conditions of relief, soil and climate allow the cultivation of potatoes throughout the year, which favors the regularity of supply in the market, as well as the economy of the municipalities. In this region, the intensive use of the area with more than one cropper year predominates, with the use of inputs in quantities higher than recommended, but not obtaining higher yields (MESQUITA et al., 2008 b). The potato crop is very susceptible to pests and diseases, mainly bacterial diseases, which is why no more than two consecutive plantations are recommended in the same area. Producers use potatoes as a temporary or nomadic crop in which the farmer is generally not the owner and has no link with the land, so there is no commitment on conservation investments. This fact, overtime caused an exodus of large part of producers in the southern region of the State of Minas Gerais, who due to the loss of the sustainability of their lands migrated to other regions of the state. This predatory system of exploitation that still perpetuates has led to the degradation of soils and natural resources (MESQUITA et al., 2000 a). The causes that contributed to this scenario are associated with several factors, such as the absence of a technology of crop rotation, and the use of conservation and environmental practices. The adoption of the system of integrating crop and livestock farming, through crop rotation techniques with that of potatoes, can provide the family producer with rational and sustainable exploitation of the property, improving income and ensuring its permanence in property. Possibly, one of the most significant advances in the search for more sustainable technologies for agricultural exploration in Brazil is the evolution of the knowledge of the integrated system of "crop-livestock" production (LOPES, 2008). This system requires a conceptual and operational change of agricultural practices, both for the production of grains and other products such as potatoes in the specific case, and livestock.

Potato and dairy farming are an important socioeconomic feature of agriculture in the state of Minas Gerais. It is a powerful source of employment and income generation. In addition, potato cultivation uses labor intensively when compared to other crops of family farmers, inmost cases, activities that are complementary between these farms. The crop-livestock integration has proven to be a viable alternative in the improvement of these areas, reducing the need to "open" new planting areas for potato cultivation, establishing the producer'slink with his property and thus reducing the temporary or nomadic migratory process characteristic of the activity, in addition to guaranteeing the rural producers an income improvement. The objective of this paper is to propose and disseminate management crop techniques in the area and, mainly, the adoption of the System of Integration of the crop with the livestock (ILP) by means of crop rotation, with the potato being the main crop. This practice provides to the family producer rational and sustainable exploitation of the property, improvement of the income, ensuring its permanence in the property.