Chapter 3 - Crops and fertilizer consumption

The permanent and annual crops of Cuba cover some 3.7 million hectares. The principal permanent and annual crops, according to the survey of December 31 1997 are shown in Table 3.

Sugar cane dominates agriculture in Cuba, accounting for approximately half of the cultivated area.

In contrast with other countries of the region, the use of fertilizers in Cuba, from the beginning of the eighties in the last century, took account of soil characteristics, particularly the soil nutrient content, the expected yields and other factors involved in the efficient utilization of the products.

For all crops, there are well established fertilizer application standards based on many field experimental results obtained under different conditions (Table 4), although the current financial limitations prevent, in many cases, their implementation.

Sugar cane

Sugar cane has historically consumed most of the fertilizers because of its area and the priority given to the crop. It is the principal export crop and is important for the economy of the country.

There is a sophisticated, integrated advisory system for fertilizer recommendations on sugar cane, which includes soil analysis, demonstration plots, advice, annual training courses, recommended rates and other actions associated with efficient fertilizer use. Each producer has a service contract with the Agro Industrial Complex (CAI), representing all the associated producers and INICA, the institution in charge of this activity. At the start of every year the producer pays 3.35 pesos per hectare for this service. Tables 5 and 6 show the percentage of the area fertilized and the application rates with their corresonding yields.

The cultivated arable area in Cuba is about 1.4 millions hectares, with about a million ha harvested every year. Limitations imposed by the crisis faced by the country have had a negative impact on yields. Among the causes of the reduced yields are the aging of plantations, inadequate attention to the crop, shortage of fuel, shortage of herbicides, reduction of water and other limitations. This is in a global environment in which sugar prices scarcely cover production costs. The imports of fertilizers for sugar cane are shown in Table 8.

Figure 3
Sugar cane production, 1990 to 2002

Source: FAOSTAT.

Tables 9 and 10 present data on nutrients applied and the areas fertilized. Fertilizer is not applied to the entire area since nitrogen is not necessary for newly planted crops. Also nitrogen is not applied on the fields with yields below 25 t/ha, where other factors are limiting production.

Phosphorus and potassium are applied where the soil levels are below the critical levels according to soil analyses.

The sugar cane farmers buy fertilizers from a specialized agency of the Sugar Ministry (MINAZ). They pay at the moment of acquisition a nationally fixed price that includes transportation costs. The prices are 420, 355, 302, 322 and 217 Cuban pesos for ammonia, urea, ammonium nitrate, triple super-phosphate and potassium chloride, respectively.

Farmers are obliged to have their plantations checked by the Fertilizers and Amendments Recommendations Service (SERFE), in order to purchase fertilizers.

Tables 11, 12 and 13 show data on nutrient consumption on sugar cane in the different regions of the country.

Crops other than sugar cane

This group includes vegetables and cereals, on which fertilizer use has decreased drastically. The only exception is the potato crop. In the 1986 to 1990 period, the crops in this group consumed a total of 856 416 tonnes of complex (NPK) fertilizers, with a maximum of 180 000 tonnes in 1989, but in 1995 the quantity had fallen to 50 843 tonnes and 35 000 tonnes in year 2000. The main grades of complex fertilizers are 9-13-17, 9-10.5-16 and 8-6-15. The areas and percentage fertilized are shown in Table 14.

This situation has made it necessary to optimize the use of fertilizers by concentrating their application on specific areas, adding zeolites to a fifth of the formulations, increasing the use of organic and organo-mineral products and biofertilizers, among other measures.

Fertilizer use on these crops showed average rates of application in 2000/2001 of 9, 11 and 13 kg/ha of N, P₂O₅, K₂O and respectively. This level is far from the established recommendations. The low rates are limiting the yields and progressively exhausting the soil fertility.

Bananas

Bananas constitute an important item for the food security of Cuban people, particularly in the eastern regions of the country, where potato production is limited by conditions not suited to the crop.

For comparison, in 1986 there was no consumption of urea but 35 542 tonnes of compound fertilizers and 31 946 tonnes of potassium chloride were applied to the crop.

Despite limited fertilization, the production level of the banana crop has been maintained or even increased (Table 15). This is remarkable in view of the fact that irrigation was also affected by lack of fuel. This is the result of:

• introduction of new management technologies
• improved clone structure
• better quality seed obtained by tissue culture
• substitution of mineral fertilizers by organic materials

• improved incomes and higher prices for the producer

Another factor that contributed to the maintenance of yields was the presence of nutrient reserves (P and K) in the soil. In the past nutrients had sometimes been applied in quantities that exceeded soil needs. However the national specialists consider that it will not be possible to maintain current production levels if the nutrients needed by the crop are not applied. This observation is supported by the fact that in areas with drip irrigation the yield in year 2000 was only 23 t/ha compared with 37 t/ha in 1992. This reduction is attributed in large measure to the nutrient limitations.

Potato

The state gives priority to the production of potatoes in view of the importance of the crop to food security. The entire potato area is fertilized. During the five-year period 1997 to 2001 the rates of application of nutrients per ha were stable, averaging 237 kg/ha N, 184 kg/ha P₂O₅ and 230 kg/ha K₂O.

Table 16 gives the figures of the nutrients applied to this crop. The important areas are concentrated in Havana, Matanzas and Ciego de Avila. There is little irrigation and the yield levels are acceptable for tropical conditions such as those of Cuba.

Typically some 1 400 to 1 500 kg per ha of complex granulated fertilizers (NPK) are applied, plus a second application of 223 kg per ha of urea. The usual complex fertilizer grades are 9-13-17 and 8-9-14.

Rice

This cereal constitutes the basis of the Cuban diet. The national production does not satisfy domestic demand and there is a high level of imports.

During the period 1994 to 1999, the nutrient application per hectare averaged 234 kg, which is sufficient for a yield of over four t/ha of grain (Table 17). However, the yield was well below this level, which indicates that there were other factors limiting production, such as lack of irrigation, poor weed control, incorrect sowing stage, salinity, shallow soils, etc.

Tables 18 and 19 show the areas, rates of nutrient applied and yields obtained in nine rice zones. Fertilizer efficiency in terms of the ratio of kg grain/kg active nutrient was in all cases inferior to 15, which is considered to be low.

Tobacco

Tobacco has been a crop associated with Cuba, ranking second in importance in the island's agriculture and an important source of income. Cuba has occupied an important place as an exporter not in terms of volume but for the quality of the tobacco produced. Table 20 chows the area occupied by tobacco, the fertilizer application and related yields.

Citrus

Citrus is a major commercial crop and generates significant revenues for Cuba. On average between 1999 and 2002, there were 58 249 ha of citrus fruits, with a production of 614 thousand tonnes, that is, 10.5 t/ha (Table 21).

In the first half of the 1990s citrus production fell by about 55 percent (Figure 4).

Figure 4
Citrus fruit production

Source: FAOSTAT.

Vegetables

The main vegetables produced in Cuba are onions, peppers and tomatoes. Tables 22 to 24 show the areas sown, fertilizer applications and related yields.

Onions

Peppers

Tomato

Urban and peri-urban areas, various crops

The success of Cuba's national transformation to sustainable agriculture is also evident in the achievements that have taken place in promoting and establishing urban agriculture in Havana. Enhancing food security in Havana and other Cuban cities became a particular focus with an emphasis on developing urban agriculture (Table 25).