The types of fertilizers and the farmers’ conception of the use of fertilizers have continued to evolve throughout the 20th century until today. Post-war agriculture has nothing to do with agriculture today, which faces environmental and health emergencies. And for good reason: agricultural issues and crop yields are no longer the same. Fertilization practices have continued to adapt accordingly within production. Discover the evolution of fertilization from the 20th century to today.
Fertilization before 1914
Competition of agricultural products and developments
The pre-war years represented a small agricultural revolution in France, but also in Europe. Technical developments are appearing: agricultural machinery, plant selection, processing of agricultural products, and chemical fertilizers. These major changes are motivated by increased competition for agricultural products from America, Asia and Oceania. Low prices are appearing on the French market, which is also experiencing an increase in the population and serious production crises. Viticulture suffers, for example, from diseases such as phylloxera.
Chemical fertilizer production
It is in this competitive agricultural context that chemical fertilizer solutions are emerging. The objective of these new products: to speed up emergency yields. Research and development laboratories then demonstrate the effectiveness of chemicals on plant development. Legislation and farms adopt these solutions. Agronomic stations and microbiology laboratories are expanding. All these actors are interested in solving decisive problems. To do this, they base their work on studies demonstrating the impact of chemical fertilizers, composed in particular of phosphorus, nitrogen and potash, on the quantitative evolution of yields.
Controversy over the role of chemical fertilizers
“Meat or alcohol?” : this is the question raised following a controversy on the role of chemical fertilizers, born in 1903 in the United States between two professors from California. Professor Whitney then argues that the role of this type of fertilizer is by no means nutritional, but that the latter act as stimulants. Investigations are taking place, and the interest in trace elements as well as in minor elements such as magnesium, sulfur, calcium and silica are highlighted. It has thus been shown that these elements, introduced in small quantities into crops, allow an increase in yields unrelated to the quantities of chemical elements applied. Exceptional results, notably through the introduction of boron and molybdenum, have been demonstrated. However, the deficiencies of plants and soils in trace elements and minor elements is still difficult to detect.
The use of fertilizers after the war and until the 2000s
The involvement of the French government
Returning from the First World War, farmers are discovering new possibilities to increase their production. The French government now controls the production and marketing of chemical fertilizers. Under his control: the North African production of phosphate, the potash deposits of Alsace, or even the production of nitrogen at the National Industrial Office of Nitrogen located in Toulouse. Advertisements on fertilizers appear as well as various support services for farmers. However, agricultural techniques are not optimal, and yields are leveling off. The threshold for winter wheat production varies on average between 20 to 30 quintals per hectare throughout the country, and can go up to 50 quintals per hectare in exceptional circumstances.
From growth to stagnating yields
Yield growth and threat
Agriculture underwent a profound transformation after the Second World War. The growth in yields during the glorious 30s was unprecedented in the 20th century. In addition, scientific progress is made continuously which changes the theoretical foundations of fertilization. In addition to the traditional use of nitrogen, phosphate and potash in fertilizer formulas, there is a new challenge relating to fertilization: the non-optimization of the quantity and quality of yields due to plant deficiencies in trace elements and problems related to soil pH.
Depletion of soils
The importance of nourishing plants and soils according to their nutritional needs is no longer to be proven for the research committees. However, the habits of consuming generic fertilizer formulas, which do not adapt to the specific needs of each crop persist. The growth in yields decreases more and more each year then stagnates, particularly from the 1990s. And for good reason: the natural nutritive reserves of the soil are exhausted, which no longer allows chemical stimulants to have their effect as in the past. . Soils poor in nutrients, no longer allow to adequately nourish plants, responding weakly to stimuli.
From fertilization to soil fertility
The 1980s marked a turning point in awareness of the benefits of reasoned fertilization on soil quality. This awareness is today reinforced by current ecological challenges, as well as by increased consumer demand for nutritious and healthy products. Fertilization must now serve the nutritional needs of the soil and plants, in order to boost the fertility of the soil and plants. The bioavailability of nutrients is essential for obtaining qualitative and quantitative yields.
Reference: Afes – From the publication “Four centuries of fertilization” – french only