From green revolution to green agriculture: horizons to rethinking and transforming agrifood systems for people and the planet
By Boris Boincean, Research Professor, Doctor habilitate of agricultural sciences
Agriculture all over the world has followed the same path of intensification since the Second World War. The concept of a “green revolution,” proposed by Norman Borlaug, the crop breeder of winter wheat from the International Maize and Wheat Improvement Center in Mexico, has contributed to a significant increase of yields for the majority of crops.
The concept was based on an industrial model of agriculture intensification. The idea was to increase yields via various tactics, including using new crop varieties and hybrids with higher yield potential, applying higher rates of mineral fertilizers (for crop nutrition) and pesticides (for the control of weeds, pests and diseases), and by taking advantage of mouldboard ploughs and irrigation. The circumstances after World War II have been favourable for the promotion of this concept, given the cheap non-renewable sources of energy and their derivates (mineral fertilizers, pesticides, fuel, etc.) and negligence regarding the negative consequences of industrial inputs on the environment and on people’s health.
Since most efforts in agriculture have been oriented towards yield increase and profit, and soil fertility also has been neglected.
Borlaug believed in science, technology and innovation. During the same period, his opponent William Vogt considered that people should live in smaller communities, closer to the earth, in order to control the exploitative forces of the market. The market economy externalizes the consequences of the industrial model of agriculture intensification.
The main mission of agriculture is to enable plants to use solar energy through the process of photosynthesis. However, instead of predominantly using solar energy and other local sources of renewable energy, we have emphasized technological aspects by implementing industrial technologies in agriculture based on non-renewable sources of energy. Putting it more simply, we have replaced green agriculture with “black agriculture”, meaning that agriculture depends to a great extent from non-renewable sources of energy like oil, coal, natural gas, instead of green (solar) energy, at the cost of soil fertility.
Soil organic matter is the integral index of soil fertility. The share of soil fertility in yield formation is significantly higher than the share of nutrients, especially nitrogen and phosphorus from mineral fertilizers. This has been proven in the long-term field experiments with crop rotations and monoculture at Selectia Research Institute of Field Crops in Balti, Republic of Moldova. According to the same data, the initial yield increases for most crops have been followed by yield stabilization and then yield decrease during the past 25 to 30 years.
In his last book “The Natural Laws of Husbandry,” from 1863, Justus Liebig, the founder of agrochemistry, changed his initial understanding regarding the role of mineral fertilizers by learning from practical farmers. He wrote that rational agriculture can’t be done without perennial grasses (clover) and farmyard manure.
Unfortunately, modern agriculture has become oversaturated with annual crops – especially with raw crops, including technical crops – that deplete soil fertility in combination with mechanical soil tillage, especially mouldboard ploughing and irrigation. The divorce of crop husbandry from animal husbandry has contributed to soil exhaustion. Given the lack of a balanced farming system, these conditions have contributed to soil decarbonization and, as a consequence, to increases in greenhouse gas emissions and global warming. Many challenges faced by modern agriculture are the consequences of simplification and negligence of the main regularities of agronomy and ecology. “In human society,” Liebig wrote, “ignorance is undoubtedly the fundamental, and therefore the very greatest, evil.”
Our calculations of the energy efficiency of growing the majority of crops in the Republic of Moldova have shown that we have been bankrupt, from an energy point of view, ‘80s of the previous century. The energy expenditures for synthesizing mineral fertilizers (especially nitrogen), pesticides and fuel, together with the content of energy in the uncompensated annual losses of soil organic matter, are higher than the amount of energy from the sun accumulated in crops.
In other words, we have become miners in agriculture: We are using more energy from non-renewable sources than from local renewable sources, such as the sun. Instead of recycling water and nutrients in each farm, we are using industrial inputs and irrigation water. We are compensating for a lack of crop rotation, with its higher diversity of primary and cover crops, with extra amounts of mineral fertilizers and pesticides.
The industrial model of agriculture intensification is based on the domination of nature. In reality, we should use natural ecosystems as a model for agroecosystems. A marriage between the laws of agronomy and ecology should be the foundation for the transition to a real green and sustainable agriculture.
We must rethink not only agricultural production, but the whole system of food production.