Grand challenges in agroecology and land use systems

Historically, agroecosystems the world over have responded rather resiliently to the increasing pressure for producing food for the expanding human population. Over the years, the two major strategies for producing more food were to increase the area under crops and to increase the production per unit area. The former was the main strategy until agriculture became commercialized, especially in industrialized nations, after World War II. With increasing understanding about the catastrophic consequences of clearing more area for agriculture (commonly referred to as deforestation), sheer lack of additional area to be brought under agriculture in some places, and rapid increase in human population, the emphasis shifted to ways of increasing production per unit area of land. The cornerstone of that strategy was the opportunities offered by the invention and/or introduction of the benefits of science and technology in agriculture by way of fertilizers and other agrochemicals, improved crop varieties capable of producing higher yields, and efficient manipulation of crop environment through management of resources such as soil and water. The Green Revolution, as it would become known, paid rich dividends during the latter part of the twentieth century in enhancing food production and averting large-scale hunger. During the second half of the century, for example, the global grain production tripled to about 2 billion tons (2 Pg), whereas the total global area under cultivation increased by only about 10%, to 660 million ha. This remarkable achievement was brought about by the input of science and technology to agriculture (Borlaug and Dowswell, 2004). Today, however, we face a two-pronged challenge on the food-production front: increasing the production at a much rapid rate than before to cope with the demands of the ever-increasing population, and to do that sustainably. The human population is expected to grow from the current 7 billion to an estimated 9 billion by 2050 (UNPD, 2010). The impact of this population increase on the food system is much more complex than a proportional increase in the demand for food. Today, nearly a billion people go hungry, while another billion over-consume and increase the risks from obesity-related diseases. Moreover, with incomes rising fast in emerging economies, diets shift toward higher consumption of calories, fats, and animal products; at least 3 billion people move up the food chain consuming more grain-intensive livestock and poultry products. These issues of who grows food and how and where it is grown have enormous bearing on the capacity of agroecosystems to produce the food sustainably. These sustainability issues are intricately related to the use—often misuse—of natural resources leading to their degradation and depletion, human migration to urban areas and across borders, and political and economic instability of nations. The Green Revolution heralded the era of intensified agriculture characterized by increased (often excessive) use of agrochemicals and unsustainable levels of exploitation of natural resources to promote food and wood production. This led in many instances to serious degradation of ecosystems and disruption of ecosystem services the world over during the past few decades. It is not only intensified agriculture that causes these problems; non-scientific practices of subsistence farming such as the bush-fallow and other forms of shifting cultivation also have contributed to serious degradation of ecosystems (Nair, 2013). As global demand for food, fodder, and bioenergy crops grows, many agricultural systems are depleting soil fertility, reducing biodiversity, and impacting water resources (Beddington et al., 2011). Modern industrialized farming may look good only when the success is measured narrowly and the costly side-effects are ignored. It is often forgotten that agriculture affects the basis for its own future through land degradation, salinization, over-extraction of water, and the reduction of genetic diversity in crops and livestock. These effects have been most serious in developing countries where agricultural expansion has extended over areas that are ecologically unsuitable for crop production. Thus, agroecosystem management is at crossroads today. We are under serious pressure to enhance the productivity of the system to cope with the increasing needs on the one hand, and maintain the sustainability of the production base on the other. The objective of this short paper is to examine the major environmental challenges facing the agroecosystems and discuss how agroecology principles could be applied to ecosystem management to ensure production of commodities while protecting the integrity and sustainability of the production base.