Meeting Cereal Demand While Protecting Natural Resources and Improving Environmental Quality

Abstract

Agriculture is a resource-intensive enterprise. The manner in which food production systems utilize resources has a large influence on environmental quality. To evaluate prospects for conserving natural resources while meeting increased demand for cereals, we interpret recent trends and future trajectories in crop yields, land and nitrogen fertilizer use, carbon sequestration, and greenhouse gas emissions to identify key issues and challenges. Based on this assessment, we conclude that avoiding expansion of cultivation into natural ecosystems, increased nitrogen use efficiency, and improved soil quality are pivotal components of a sustainable agriculture that meets human needs and protects natural resources. To achieve this outcome will depend on raising the yield potential and closing existing yield gaps of the major cereal crops to avoid yield stagnation in some of the world's most productive systems. Recent trends suggest, however, that increasing crop yield potential is a formidable scientific challenge that has proven to be an elusive goal.

Declining global per capita agricultural production and warming oceans threaten food security

“…9a) for some of these regions in 2030 reach beyond 7,000 kg ha −1 . These projected yields may be beyond practical limits (Cassman et al 2003). Western, Middle, and Eastern Africa, conversely, have exhibited very slow growth in yields (Table 5), with annual changes in yields of less than 110 kg ha −1 annum −1 .…”

“…Yield trends, on the other hand, reflect increases in human knowledge, innovation, social and economic organization, as well as the ability and willingness to invest in improving agricultural production (Lo and Sene 1989;Watts 1989;Turner et al 1993). Yield trends everywhere in the world have been positive over the past 50 years (Cassman et al 2003). Together, per capita harvested area and yield trends describe the direction of per capita cereal production, one major determinant of food security.…”

“…Our projected yields in Eastern Asia and Northern America reach 7,500 kg ha −1 . Yields of this magnitude assume further innovation and increasing petrochemical inputs, and may not be technically feasible (Cassman et al 2003). However, regionally, a continuation of recent trends that include vast disparities of access to food will probably expose hundreds of millions more people to chronic food insecurity, even if increasing cereal demands as a result of biofuels and increased consumption are ignored.…”

“…8) combined with rainfall assumed to either i) trend along observed patterns, ii) trend according to rainfall predicted from Indian Ocean precipitation, or iii) to have no trend at all. The green bars show a scenario based on observed rainfall trends and an agricultural growth scenario Indonesia and wheat yields in India and France, for example, have not increased substantially in the past decade (Cassman et al 2003). Increasing yields beyond levels attained in these countries will require either enormous investments in freshwater irrigation systems or a transformation of the agricultural systems to incorporate new technological advances, both of which are highly unlikely in the next few decades.…”

Influence of Doses of Mineral Fertilizers on Anatomical Structure of Vegetative Organs of Rice Varieties in Kazakhstan

“…Photosynthesis, the accumulation of biomass and the formation of spikelet that determines the yield of rice due to its role, nitrogen is the main nutrient [9]. Increased use of fertilizers, especially nitrogen fertilizers, affects a significant improvement in crop yields [10]. [1968][1969][1970].…”