Don Erbach 2015-02-23 23:29:34
How will the world’s population be fed in 2050? Soil-based plant production has fed humanity throughout history and will likely continue to be our primary food source. Although most people think little about soil, productive land is critical to human well-being. Earth has a soil resource easily sufficient to produce food for the world’s growing population, but only if attitudes, policies, and practices allow that resource to be properly managed and effectively used. The past 36 years have seen important advances in plant production. Significant technological advances have been made in plant genetics, mechanization, pest control, and nutrient management—advances that have resulted in major increases in yields and improvements in crop quality. It seems reasonable to expect similar productivity improvements to continue through 2050. Although most crops are grown in soil, plants really do not care about soil. In fact, they can be grown perfectly well without soil in controlled environments, such as hydroponics and aeroponics. However, plants do care about water, nutrients, light, heat, and physical support. Outdoor culture in good-quality soil provides these growth requirements effectively, efficiently, and economically. Controlled environment agricultural production will increase but, for economic reasons, most plant production will continue to be soil based in a natural outdoor environment. Although it’s as common as dirt, soil is an extremely complex physical-chemical-biological material, the condition of which may be subjectively characterized as its tilth. Soil tilth is a result of a combination of many factors, some of which are particle size distribution, aggregate size distribution, pore size distribution, water holding capacity, degree of aeration, pH, and organic matter content. Soil with good tilth is well suited for crop production. The overall quality of the world’s soil resource is, and will continue to be, critical to feeding the population. Better-quality soil can produce more and better-quality food, along with providing greater economic returns to farmers and lower prices for consumers. Unfortunately, at present, much of the world’s soil is, for a variety of reasons, of poor tilth. Fortunately, a soil with poor tilth can be physically, chemically, or biologically modified to improve its condition. Improving soil characteristics, such as by increasing soil organic carbon, plant rooting depth, and water holding capacity, can improve production efficiency. Depending on the depth and nature of the modification required, treatment may be difficult and expensive. As the demand for high-quality soil increases, more extensive modifications will become economically realistic, especially for production of high-value specialty crops on small land areas. A cause for concern is the amount of agricultural land being converted to commercial, residential, transportation, recreational, and other uses. If the conversion of land from agriculture continues, as is likely, then future food production may be jeopardized. Without a serious food shortage, famine, or other significant event that focuses attention on the importance of soil, the next 36 years will see agricultural land area decrease and soil quality degrade. Water is also a problem. Insufficient water seriously limits crop production. Rainfed agriculture is at the mercy of timely rainfall, and irrigated agriculture depends on a dependable, economical, and adequate supply of water. Even though the amount of water on Earth is huge, the supply of fresh water is limited, and it is not always available in adequate amounts at the right time and in the right place. Desalination of seawater, powered by sustainable, renewable energy, must be developed to alleviate fresh water shortages. With the adoption of appropriate policies and development of the necessary infrastructure, sufficient water for food production, and other needs, can be supplied. Public and political awareness of the importance of maintaining a high-quality world soil resource must be heightened. Supportive government policies are essential for ensuring that agriculturally important land remains agricultural land, that soil is managed effectively, and that its quality is enhanced. Proper management of the soil resource will require expanded efforts to understand soil and to develop practices for sustainable soil resource management. Realistically, the complexities of soil will cause this progress to be slow. How will the world’s population be fed in 2050? Soil is the key, but it needs some help. If properly managed, the world’s soil resource will be adequate and capable of producing sufficient food to meet nutritional needs. However, for all to be properly fed in 2050, political, ethnic, nationalistic, class, economic, religious, and other strife must not interfere with efficient use of soil to produce food and must not hinder distribution of that food. Unfortunately, this is where the dream of Utopia begins. Time will tell. ASABE Fellow Don Erbach, Past-President of ASABE and National Program Leader (Retired), USDA Agricultural Research Service; email@example.com. Top and mid-page photos Viktor Pravdica | Dreamstime.
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