Expanding agricultural output

For three reasons our terrestrial agricultural area has to expand tremendously the 21ste century.

1. First, global human population is rapidly increasing, especially since the second half of the 20th century and predictions made by the United Nations estimate that ≈ 9.2 billion people will live on our planet in 2050.
2. Secondly, this growing world population has an increasing demand for wealthy –economically more costly mainly veterinary production like dairy products, eggs and meat. It is estimated that by 2050 food production must increase by 70% in order to meet the demand of a growing world population, rising incomes and the urbanization that is occurring around the world, particularly in developing countries. A required substantial increase of global food production of 70 percent by 2050 would require an additional quantity of nearly 1 billion ton of cereals and 200 million tons of meat.
3. A third reasoning is that the potential agricultural area has been shrinking already with 7% of the world’s land area because soils are affected by salt. Also climate change tremendously decreases our food production e.g. in Sub-Saharan countries such as Sudan and Senegal, rising temperatures could cause up to a 50% reduction in yields. Our present and future agricultural challenges and demands are outlined in Table 1 Näsholm et al. (2009). These authors conclude that the major causative factor in order to meet our present and the near future food production needs or its resources are at first global fresh water (expressed in water stressed countries), followed by the demands for fertilizers (N & P). So fresh water becomes a vulnerable production factor and the same for our fertilizers (N & mainly P). For these reasons arable area and fresh water is becoming a scarce commodity very rapidly (see Table 1).

The challenges we have to address in amble three-four decades are clearly defined by the arithmetical experts of the FAO and WHO and given in Table 1.

Item	1960 year	2000 year	2030-2040 years
Food production (Mt)	1.8 * 109	3.5 * 109	5.5 * 109
Population (billions)	3	6	8 (perhaps 10)
Irrigated land (% of arable)	10	18	20
Cultivated land (ha)	1.3 * 109	1.5 * 109	1.8 * 109
Water-stressed countries	20	28	52
N fertilizer use (Tg)	10	88	120
P fertilizer use (Tg)	9	40	55-60

Table 2: Comparison of plant productivity in several ecosystems and terrestrial plant communities (land-based) versus aquatic (several mono-stock cultured seaweeds). Terrestrial crops were specially selected because they were already known among terrestrial Plant-physiologist as the “champions” in biomass production for example enlisted XX &: See Addendum literature search at least per seaweed spp. 10 references.Table 1: Future scenario for human mankind with its already failing terrestrial agriculture food producing system (Source: Nasholm (2007). New Phytologist 157: 423-427)

The urgency for a direct action to transform our global food production system is now compelling because this has to take place before the midst of the 21st century when around 10 billion people will live at our planet; a period of ample three decades. => In summary, during this period our green biomass production has to grow with around 70% in order to provide every person its primary needs like energy, water, shelter and food.

Energy and Matter

Before studying ecosystems in any further detail, it is important to appreciate the difference between energy and matter. Energy and matter are quite different things and cannot be inter-converted.

Energy comes in many different forms (such as heat, light, chemical,potential, kinetic, etc.) which can be inter-converted, but energy can never be created, destroyed or used up. If we talk about energy being “lost”, we usually mean as heat, which is radiated out into space. Energy is constantly arriving on earth from the sun, and is constantly leaving the earth as heat, but the total amount of energy on the earth is constant.