Agriculture Reference
In-Depth Information
>1800 entrepreneurs in Bangladesh. An additional 60 briquette machines have been
exported to Africa to produce briquettes for field trials.
The second important component of FDP is the placement of briquettes below the
soil surface. When used to fertilize irrigated rice, briquettes are centered between
four plants at a depth of 7-10 cm up to 10-14 days after transplanting using a self-
loading mechanical applicator (Figure 3.14). Once in the soil, the briquette gradually
releases nutrients into the root zone as it dissolves, coinciding with the crop's initial
nutrient requirements, unlike broadcast urea applied to flooded rice fields where
significant losses of nutrients (especially N) occur via surface water runoff, vola-
tilization, and nitrification/denitrification. When N is deeply placed into the soil, it
remains primarily in the form of ammonium, which is much less mobile than the
nitrate form of N predominating with broadcast application. Therefore, losses to
the atmosphere, groundwater, and waterways are drastically reduced. Only 3%-4%
of N from deep-placed urea fertilizer is lost to the environment, compared with
about 35% when N as urea is applied via broadcasting. FDP dramatically improves a
crop's absorption of N, with two-thirds being absorbed in the grain and straw, com-
pared with one-third when broadcast application is used (Savant and Stangel 1990;
Mohanty et al. 1999).
Currently, >2.5 million Bangladeshi farmers have used FDP on >1.5 million ha,
and it is being introduced to an additional 1 million farmers across the country.
In the last 3 years, the FDP technology has increased rice production by 1.35 Mt,
increased farm income by $364 million, and generated savings in government sub-
sidy on urea of about $65 million. In 2009, IFDC initiated its African FDP initiative
targeting lowland rice in 13 countries across the continent. As in Bangladesh, the
initial results support FDP as a technology with agronomic and economic advan-
tages (Figure 3.15).
FIGURE 3.14
Briquette applicator.
