Total cereal production in Brazil amounts to 122.8 million tonnes or around 694 kg per inhabitant. The current average yields are: maize, 3.0 t/ha; beans, 0.7 t/ha; wheat, 1.6 t/ha; rice, 3 t/ha; soybeans 2.7 t/ha. Of those crops, only soybeans have a high average yield level, a yield that is comparable to the world’s best. However, higher yields of food crops are obtained by good farmers in most regions of the country, for example 10 t/ha for maize, 3.5 t/ha for irrigated beans, 6 t/ha for wheat and 8 t/ha for irrigated rice. Thus the problem of low average yields is due not to the lack of relevant agricultural technologies but rather to the poor implementation of these technologies.
In the case of the export crops (coffee, sugar cane, citrus and soybeans) advanced production technologies are used. These include not only appropriate rates of fertilization but also the application of a series of other agronomic recommendations. It is in the sector of food crops for domestic consumption (rice, maize, beans and cassava) that average yields are far below those attainable. One of the reasons for the low yields is inadequate mineral fertilizer application. This is particularly the case with subsistence farming, which is practiced in the poorer areas of the country, especially in the Northeast region, and in which practically no mineral fertilizers are used.
In general terms, the fertilizer nutrient balance in Brazilian agriculture is unsatisfactory. The removal of nutrients by the 16 main crops is higher than the quantities applied in the form of mineral fertilizers. The deficit is much greater in the case of nitrogen than in those of phosphorus and potassium. Thus the soil is being seriously depleted of nutrients and this represents a serious threat to long-term agricultural sustainability.
In spite of having the largest cattle herd in the world and a very large number of poultry and other livestock, the production and use of manure is limited largely to subsistence and family farms and to some large farms that integrate livestock and cereal crop production.
Some suggestions concerning measures that might be taken to help to remedy some major problems are:
a. In the short-term, emphasis should be placed on the reclamation of areas that are being degraded or are already degraded. The conversion of only 30 million hectares of the current 90 million hectares of degraded pastures into land for cereal production with an average yield of three tonnes per hectare would represent an annual increase of 90 million tonnes of cereals.
b. In the medium term, the highest priority should be given to measures whereby farmers implement sustainable technologies for increasing crop yields. Farmers should increase their production by improving yields in areas that are already being farmed rather than by expanding the area they cultivate. These measures should include the permanent monitoring of nutrient availability in soils and crops and the adoption of balanced fertilization.
c. The transformation of subsistence agriculture into profitable family farms requires long-term measures that would lead to a cultural change in this segment. Agricultural and social policy measures should include:
1. Re-activation of the rural extension programmes in the relevant regions, communicating to subsistence farmers information on simple and sustainable technologies that would achieve not only large increases in crop yields but also help to prevent erosion and contribute to environmental preservation.
2. Alphabetization and the implementation of family planning, health care and other basic measures that could improve their standard of living.
3. Advice on how to increase the returns from their agricultural products through their sale in local markets.
