Integrating Aquaculture Into Family Farms in Northeast Argentina
Northeast Argentina has the highest poverty rates and also the largest proportion of small-scale family farms in the country. In 2003, provincial governments started to promote the introduction of aquaculture into family farms as an income diversification strategy. Family farms are dedicated to a wide variety of cash and subsistence crops including yerba mate, tea, tobacco, citrus, cassava and maize. Different state-funded programs financed the construction of 1-3 ponds per farm and the purchase of the seed (fish fry). A study was conducted to evaluate the effect of aquaculture introduction in these farming systems. On-farm interviews were conducted in 68 farms, and three group meetings were organized to discuss the results.
Fish ponds are integrated with the other activities in the farm through flows of products and by-products. Typically, products and by-products from subsistence crops such as grains, forage, cassava leaves and animal manure are used as aquaculture inputs. Most of these are directly consumed by the fish (supplementary feed), but animal manure is decomposed by microorganisms and the released nutrients promote the production of natural food (i.e., phytoplankton and zooplankton). These farms are also known as integrated agriculture-aquaculture systems and they are widespread in Asia, but they can also be found in Africa and other countries in Latin America.
Fish polyculture is a widely adopted practice in northeast Argentina. Fish from the Cyprinidae family (carps) are the most popular. While the grass carp is the only species present in all the visited farms, other species present from this family include the common, silver and bighead carps. The common carp can reproduce in captivity, but it can erode the pond banks due to its scavenging activity. As a consequence, farmers are starting to replace or reduce its proportion in the fish mix with native species such as Sábalo (Prochilodus lineatus) and silver catfish (Rhamdia quelens). Most ponds also register the presence of Lamabarí (Astyanax spp.), a small-sized self-recruited species.
There is a large gap between the average yield and the maximum yield recorded in the visited family farms. The average fish yield per pond is 2,112kg.ha-1, but when these values are adjusted by the length of the cycle, this number falls to 1.439kg.(ha.year)-1. The gap is even larger when these values are compared to similar (but experimental) production systems in Southern Brazil, where yields are more than doubled. Although there are several factors contributing to low yields, the poor quality of the seed, the prolonged length of the production cycle and the low amount and quality (in terms of energy and nutrients) of inputs are among the most important ones.
Most farms only have one pond, and a large proportion of the harvested fish is destined for self-consumption, while the remaining fish is sold to the neighbors. On average, aquaculture provides 55kg of fish for self-consumption per farm. Because only fish larger than 1kg are sold, smaller and whole fish are consumed by the family members. The consumption of fish bones increases the intake of micronutrients, such as calcium and zinc, which are usually deficient in tropical regions. Fish sales do not represent a significant source of income in farms with only one pond (less than 10 percent of total income), but the volume of fish sold increases with the amount of ponds per farm. In farms with two and three ponds, fish sales represent around 25 percent of the annual farm income. The number of ponds per farm depends directly on the type of state-funded program financing pond construction. These different programs stipulate the construction of a different amount of ponds per farm (typically between one and three), and thus it is the type of state-funded program which ultimately defines the amount of ponds per farm, and in turn, the role of aquaculture in these systems — from only providing fish for self-consumption to representing a significant portion of the farm's income.
While increasing the construction of fish ponds per farm will help increase the volume of harvested fish, pond productivity should also be increased through the introduction of better management practices. Unfortunately, aquaculture was introduced in family farms without technical support. Extension agents do not have experience in aquaculture, and they are generally not trained to work in an integrated system. In contrast, extension is typically crop-based where an expert in tea or tobacco will visit the farm and be dedicated only to this particular activity. Working with integrated agriculture-aquaculture requires a systemic approach that considers the farm as a system where on-farm activities are connected through fluxes of energy and nutrients, while taking into account specific characteristics of family farms including different economic (and non-economic) incentives, risk-aversion, availability of family labor and other factors resulting from the coincidence of the production and the domestic unit.