The consumption of fertilizers is a function of the cultivated area, the area fertilized and the rate of fertilizer per hectare.
During the 1960s there was practically no use of fertilizers on the extensively grown crops in the Pampa region. It was during the 1970s, especially with the introduction of genetically improved crops, that the response to nitrogen became evident.
In 1973, the Plan Canje (see Chapter 6) and the importation of fertilizer through state purchases were conceived. State intervention promoted increased fertilizer use, regulated the price of urea and stabilized the price relationship between the input and the agricultural product (Del Bello, 1991).
In 1990, at the same time as the introduction of currency convertibility at one Peso = one US$, levies on exported cereals and customs barriers protecting the national urea industry were removed, opening the way to a large increase in fertilizer imports and use. This was accompanied by a high level of investment in the infrastructure, particularly the port infrastructure. The suppliers also began to invest in distribution facilities and the provision of services. The highest level of fertilizer consumption was reached during the 1996/97 season, when a large area sown to wheat and maize coincided with a favourable fertilizer price: cereals price ratio.
During the past five years (1998 to 2002) fertilizer sales have not increased to the extent promised by the spectacular increase in the period 1993 to 1997 (Figure 6). This was due to a progressive decrease in the price of cereals, lack of finance, modification of the cropping pattern in favour of soybeans at the expense of cereals and a progressive diminution of the economies of scale. Between 1996 and 2002, cereal prices to the producer fell by more than 15 percent in absolute value (Figure 7).
At the end of the 1990s, with the increasing intensification of agriculture and falling levels of soil nutrients, responses to nutrients other than N and P were identified. Especially on soils with a low organic matter content and which had been cultivated for a long period of time, deficiencies in sulphur were identified (Melgar, 1998; Melgar et al., 2002). Then deficiencies in potash and in micronutrients such as zinc and boron were identified (Ratto de Miguez and Fatta, 1990; Melgar, 2001).
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FIGURE 6
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Source: SENASA.
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FIGURE 7
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Source: www.sagpya.mecon.gov.ar
