Effects of Lime Application On Soil Acidity and Coffee Yields in the Province of Caranavi-Taipiplaya, Nor Yungas Region of La Paz.

Abstract

The goal of this project was to determine the effect of hydrated lime on soil physical-chemical properties and coffee (Coffea arabica L.).  In this four year old coffee cultivar study, five rates of lime were applied to soil with a pH ranging from 4.3 to 4.5.  Lime rates were  0, 3.3, 4.3, 4.6 and 5.6 Mg Ca(OH)₂  ha^-1. The soil and plant tissue analysis was performed before and after the amendment. Similarly, variables such as growth of secondary branches, number of leave pairs and leaf area were measured before and after liming as well as the productivity of coffee cherries.
Surface liming raised pH from 4.34 (0.0 Mg ha^-1)  to 5.54 (4.6 Mg ha^-1).  Liming   reduced the content of exchangeable Al in the soil from 2.28 (0.0 Mg ha^-1) to 0.20 cmol_c  kg^-1 (5.6 Mg ha^-1).
The base saturation values were 53, 76, 82, 81, and 94% in the  0, 3.3, 4.3, 4.6 and 5.6 Mg Ca(OH)₂  ha^-1, respectively. Soil organic carbon values were 2.0, 3.75, 3.86, 3.9, and 3.45% in the 0, 3.3, 4.3, 4.6 and 5.6 Mg Ca(OH)₂  ha^-1, respectively . Cation exchange capacity (CEC) was 8.45, 16.75, 17.55, 18.83, and 16.63 cmol_c kg^-1  in the  0, 3.3, 4.3, 4.6 and 5.6 Mg Ca(OH)₂  ha^-1, respectively, while P increased from 7.94 to 8.47 ppm in the 0 and 5.6 Mg Ca(OH)₂  ha^-1.  The maximum coffee cherry yields were 28 t per ha (12% moisture) at 4.6 Mg Ca(OH)₂  ha^-1 showing that the lime applied in the 0- 25 cm depth was appropriate for surface liming recommendation in a no-till organic coffee field. Liming with 4.6 Mg Ca(OH)₂  ha^-1 produces a return of $2.93 per kg.
Key words: Liming, soil acidity, coffee yield, plant tissue, amendment