The cost and return of producing soybeans in three different countries are shown in Table 28. Even the production costs and returns do not correspond to the same period, they are valid for comparison purposes, obviously with that reservation. The only direct valid comparison is that of South Vietnam, in the Mekong Delta.

The importance of an improved technology or better cultural practices is evident if the costs and returns obtained by farmers during 1993 are compared with those of producing soybeans testing (experimental) better cultural practices. In this case, a dual benefit was obtained since 60 more workdays were used per hectare and a higher net return was reached. The main differences between these two production methods in Mekong Delta were the use of less seed (60 compared to 100 kg), the use of less of one of the fertilizers (50 kg compared to 70 kg) and an additional (CaCO₃, 500 kg), the use of 10 more bottles of chemicals and the additional costs of gasoline (25 litres) and other. In spite of the higher operating costs (US$ 498.3 compared to 336.8) the improved production scheme had a higher net return. This was mainly due to the increase (78 percent) in soybean productivity, which doubled the net return.

The costs and returns of producing soybeans in the US and Mexico can be compared even they are from 2 different years (subsequent). In both countries soybean farming is mechanized. In the case of Mexico, the data correspond to the costs of producing soybeans with own machinery. Data were classified in specific categories whenever the available information allowed. It is clear, that some activities include costs of required materials and labour. One of the main differences in soybean production practices in Mexico and the United States are the intense use of water (100 percent compared to 5 percent), which increase the production costs. The purchase of irrigation water represented almost 15 percent of the operating costs. In addition, the costs of chemicals, fertilizers and seed for planting are higher in Mexico than in the United States. In Mexico, the operating cost per hectare of soybeans during 1999 was US$ 442.00 (corresponding 29 percent to the cost of inputs), whereas that in the United States was US$ 196.00 during 1998. For the same periods, the net returns per hectare for Mexican and American farmers were US$58.00 and US$355.45, respectively. These numbers explain why Mexican farmers do not want to grow soybeans.

In South Vietnam, soybean farming is not mechanized. Thuy et al. (1998) reported that it often takes 2 workdays to sow a hectare of land. Weeding is done by hand. A total of 40 men are needed for weeding a hectare and this activity has to be done from 2 to 3 times during the cropping season.

In Argentina, the cost of soybean harvesting under no tillage represented 10 percent over gross profit (price x yield) (Larreche and Firpo Brenta, 1999). In Mexico, the cost of harvest the 1999 soybean crop under no tillage represented 9.4 percent of the gross profit.

There is a tendency to use less insecticide in soybean production. Argentina and Brazil are using less insecticide and lower number of applications. Larreche et al. (1999) reported insecticide costs up to US$ 5.00 per hectare for the successful control of insects. The implementation of integrated pest management has allowed these two countries the reduction in the use of insecticides.

In Mexico, soybean crop required 23.7 workdays per hectare in the 80’s (Marquez-Berber, 1989). In 1995, labour utilization was 12.7 workdays per hectare for farmers not owing machinery. In 1999, labour utilization was 10 workdays per hectare; 2 people hired and 8 people eventually hired (Banco de Mexico and FIRA, 1995; 1999). Table 29 shows the labour employed in the different operations of soybean cropping during 1995. Irrigation was the most labour demanding operation; almost 60 percent of the total labour hired performed irrigation work.

Diseases, pests and weeds are the main concern of soybean farmers worldwide. Annually, soybean yield losses are about 15 percent. In some places, yield losses are higher, especially when a new pest or disease invades the soybean fields. In Mexico, almost 16 percent of the total operating costs per hectare of soybean are spent on disease, pests and weeds control. In the United States, the expenditure for disease, pests and weeds control is about 33 percent of the total operating cost. It is worthwhile to remember that the operating cost of producing a soybean hectare in Mexico is 2.25 times higher than that in the United States. It seems that the use of resistant cultivars (to insects, diseases and herbicides), better cultural practices and integrated pest management are the most effective forms of counteracting the effects of these important biotic factors. The other losses in the post-production chain can be more easily controlled. Cares on soybean handling throughout the postharvest system will have an effect on the reduction of postharvest losses. To diminish soybean postharvest losses the following precautions should be taken:

Table 28. Net return of soybean production by farmers in three different countries.

Table 29. Labour (workday) employed per soybean hectare in Mexico, during 1995.

Source: Banco de Mexico and FIRA (1995).