In mid-2011, world population clocks tell us that there will be 7 billion people on earth; that is, 7,000,000,000 chemical engines that require a minimum of 2,000 calories a day in food to avoid hunger.
The caloric value for our digestive system of rice and wheat, the basic starches for most of us, is around 340 per 100 g. If we only ate cereals to meet our daily caloric needs, men would reach 290 kg and women 214 kg in a year.
So we need 1.76 million every day if we were all vegetarian. Of course, many of us enjoy meat. The efficiency of energy transfer from plant to livestock means that we need approximately three times the calories from plants to provide animal protein.
Round off some numbers and proportions for meat eaters and each and every day farmland must produce the equivalent of 3 million metric tons of usable grain; more than 1 billion tons each year.
Suppose 7 billion was the peak and the population was stable for a time. Maintaining food production would become more difficult each year because nutrient depletion, soil degradation, desertification, and irrigation water shortages are spreading across much of our productive land. Demographers suggest that world population growth will slow, but not until the total number has reached between 9 and 12 billion souls. So the numbers may go back over time to maybe 6 billion by the end of the millennium.
The challenge for this generation is planning to overcome this population hump without starving.
Imagine the disputes we will have if food supplies run out. Our history is one of wars and conquests, the proximate cause of which might be the wishes of selfish empire builders, but ultimately it is about land, natural resources, and sufficient growing of food.
It would also be sensible to traverse the hump without stripping the earth of its ability to support life.
This challenge is real. Finding enough food is a daily truth for many in the developing world, but food production requires solutions from everyone, even those of us who are well fed.
So what can be done?
One solution is to keep throwing technology at the problem. For some time now, farmers have used artificial fertilizers, genetics and irrigation methods developed by scientists to avoid declining yields. These agronomic efforts have produced spectacular short-term results, particularly the green revolution of the 1970s.
In recent times more high technology has been added to the mix. Today we can see crops grown in laser-leveled fields with computer-managed irrigation to synchronize with plant water demand and fertilizers applied precisely from integrated GPS-activated hoppers linked to yield maps. This is the latest high-input system and can work very well where the soil is suitable for precise management of input and nutrient uptake. The Dutch have been especially good at perfecting these systems.
This intensive approach to farming suits us well. We really like the technological solution that decreases direct human effort and increases both the quantity and reliability of returns, although the initial investment is prohibitive for livelihood systems.
High-tech agribusinesses are doing well in our economies too. It generates a profitable product and uses many suppliers and service providers to distribute the economic benefits in the market.
Considering all these benefits, option one seems attractive and we must implement it, especially where soils, climate and management capacity are adequate.
But technology is not a universal solution.
Most agriculture is low-input and relies on nature to produce mostly unaided output. It will be difficult to offer technological solutions to agricultural lands managed with little or no external input because farmers who depend on natural soil regeneration have no alternative. They lack the resources to do otherwise. However, these lands must also produce steadily to support the growing human population.
The solution in these lands is to help nature to achieve natural regeneration and efficient recycling of nutrients. This means helping the soil to regenerate natural fertility.
Maintaining production in low-input agriculture has been the holy grail of agricultural development work for many decades. Under the guise of ‘sustainable land management’ organizations, from FAO and the World Bank to local organic cooperatives, they have sought ways to achieve sustainability.
What has been overlooked in many of the most important schemes is the simplicity of the sustainable solution. All it requires are practices that retain carbon in the soil.
So how are we going to grow enough food?
We will have to apply the technology where we can. Science will help and we cannot be too picky on issues like genetic modification.
However, the smart application of technology is essential. It cannot work everywhere and it is unwise to create large tracts of monocultures, even if they are managed with computers. Nature has a bad habit of replacing similarity with diversity. And in this case, for diversity, read pests and diseases.
However, the great solution will be to return carbon to the soil where it has been depleted and also to improve soil carbon levels whenever we can.
Soil maintained for optimal carbon levels efficiently retains and exchanges nutrients, has a good structure that supports plants and allows roots to develop, and retains moisture but also drains. In short, soil carbon promotes plant growth.
The initial solution to growing enough food on low-input land is to use carbon markets to reward farmers who store carbon in the soil. Paying farmers to grow carbon will help reduce greenhouse gas emissions and even sequester some CO2 from the atmosphere into the soil. Greenhouse gas emitters can buy greenhouse credit created by low-input farmers.
In the end, although a greenhouse benefit is not the real value of the investment; the real return is growing enough food.