Monday, December 19, 2011

dry season irrigation/climate change and tropical farming

Because of uncertainties in global weather patterns, it is becoming more and more necessary for farmers to implement adaptive strategies during extensive dry periods or floods. On my own cocoa farm, I have consulted with local vegetable farmers (who employ irrigation during the dry season) and cocoa farmers to gather ideas about dry season farming. I have come up with a hybridized solution (hopefully) to deal with slow-growing cocoa seedlings and plantains during the dry season.

Typically, the dry season begins in late December and ends in early March. This year, however, the dry season started mid-November and the harmattan winds (dusty winds that blow south from the Sahara desert) began covering the south in dust early this month (December). There hasn't been any rain for almost two months now, and almost every maize plot has failed. Farmers in the Volta Region rely on rains through mid-December to insure a good maize harvest, but this year those rains have failed. Cocoa and plantains can withstand the dry season, but if the dry season continues for a "longer than normal" time frame, they can begin dying off. Climate change, savannization, and desiccation of previous humid and wet areas present serious obstacles to cocoa farmers in forest-savanna transition areas.

My plan during this dry season is to sink wells on five of the La Rose Cocoa Farm plots, providing a source for irrigation of the cocoa seedlings and plantains. This will be done by hand-digging wells that can go up to 30 or 40 feet in depth and then pumping water from the water table with a diesel water pump. This pump will be connected to polypipe that will extend up the side of each plot and across. Hoses will be attached to the pipe at strategic points to insure that all parts of the plot can receive water.

The first task during the dry season, however, is to weed out all of the failed maize that was intercropped with the cocoa and plantains. The maize was planted as a short-term economic plan, but the rains failed to nourish it to the point where it matured to harvest-level. A vast majority of farmers who planted maize this year experienced the same problem - maize is very sensitive to weather perturbations and this year the rainy season expired one month early. I am here pictured weeding out unproductive maize plants:





The second task is to create fire belts to protect plots from the very real threat of bush fires. These fire belts are about 15 yards wide and are clear from any vegetation except for seedlings and plantains that are adjacent to boundary lines (obviously, one can not construct a fire belt on someone else's land). During particularly dry harmattan periods, these fire belts can determine whether a farm will survive:

Finally (and this rather experimental), the third task this dry season was to sink wells to provide water for the cocoa seedlings and plantains during the dry seasons. The well pictured here is now about 15 feet deep, and we are hoping to hit the water table at around 30 feet. Ditches and polypipes with hose connections will be placed throughout the plot: