Comparative efficacy of two methods os fertiliser placement in mature oil palm and cocoa planting. - (:unkn) unknown
In oil palm, rubber and cocoa plantations, fertilisers are normally surface applied. Under certain conditions, some of the applied fertilisers may be lost due to volatilisation, leaching, surface run-off and soil erosion. As fertiliser costs can account for up to 30 per cent of total production costs, fertiliser efficiency must be maximised to optimise yields and profit. This paper reports on the results of two trials comparing the relative efficacy of two methods of fertiliser placement i.e. surface broadcasting vs pocketing, in mature oil palm and cocoa plantings. In both trials, surface broadcasting of fertilisers resulted in significantly higher (15-20 per cent) crop yields than pocketing of fertilisers. The poorer performances with pocketing was linked to poor uptake of phosphate (P), especially from phosphate rock. Due to limited contact with soil and feeder roots, P dissolution and uptake was likely to have been affected. With the more water-soluble TSP, no significant differences in cocoa yields was recorded between the two placement methods, although P uptake was still superior with broadcasting. On the other hand, no differences in N uptake was observed in mature oil palm, when urea was applied either in pockets or broadcast. However, K uptake from MOP was significantly better with pocketing although this is likely to be due to K-Ca antagonism rather than to actual differences in the efficacy of the two placement methods. The effect of fertiliser placement on N and K uptake requires further verification especially in areas where good crop response to both these nutrients can be obtained.
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In oil palm, rubber and cocoa plantations, fertilisers are normally surface applied. Under certain conditions, some of the applied fertilisers may be lost due to volatilisation, leaching, surface run-off and soil erosion. As fertiliser costs can account for up to 30 per cent of total production costs, fertiliser efficiency must be maximised to optimise yields and profit. This paper reports on the results of two trials comparing the relative efficacy of two methods of fertiliser placement i.e. surface broadcasting vs pocketing, in mature oil palm and cocoa plantings. In both trials, surface broadcasting of fertilisers resulted in significantly higher (15-20 per cent) crop yields than pocketing of fertilisers. The poorer performances with pocketing was linked to poor uptake of phosphate (P), especially from phosphate rock. Due to limited contact with soil and feeder roots, P dissolution and uptake was likely to have been affected. With the more water-soluble TSP, no significant differences in cocoa yields was recorded between the two placement methods, although P uptake was still superior with broadcasting. On the other hand, no differences in N uptake was observed in mature oil palm, when urea was applied either in pockets or broadcast. However, K uptake from MOP was significantly better with pocketing although this is likely to be due to K-Ca antagonism rather than to actual differences in the efficacy of the two placement methods. The effect of fertiliser placement on N and K uptake requires further verification especially in areas where good crop response to both these nutrients can be obtained.
Keywords: Aplicación de fertilizantes; Cacao; palma madura; Palma de aceite; Cacao; Cacao