A laboratory experiment was performed to evaluate the suitability of moist olive pomace (MOP) as soil amendment. Moist olive pomace was obtained from a new olive-oil industrial process called the 'two-phases method'. Soil samples were mixed with MOP to approximate a field application of 40 t ha(-1) and incubated under aerobic conditions at 20 degreesC and 60% of soil water holding capacity. To estimate the effect of different loading rates and N supply on mineralization, 40, 80, 120 and 160 t ha(-1) of MOP and 200 ppm of N as (NH4)(2)SO4 were used. Cumulative CO2-C evolution, total microbial activity and biomass-C were monitored during a 60-day period. Results indicate that the CO2-C evolution from MOP depends on soil type and is temporarily inhibited in acidic soils. Evolution of CO2-C increases with incremental addition of MOP, but the percentages of the added C that were mineralized decreased with increasing application rates. Mineral N supplements result in more efficiency of the mineralization process. Among the kinetic models tested to describe the mineralization dynamics, a first-order exponential model including a constant term provides the best fit to the experimental data. Both amount and activity of soil microbial biomass are enhanced by MOP added at the 40 t ha(-1) rate, at least in the first period of incubation. At higher rates of MOP addition, a constant increase of biomass C during incubation is observed, while the biological activity decreases at the end of incubation. Following application of mineral N, both amount and activity of microbial biomass is enhanced.
Suitability of moist olive pomace as soil amendment
SAVIOZZI, ALESSANDRO;CARDELLI, ROBERTO;
2001-01-01
Abstract
A laboratory experiment was performed to evaluate the suitability of moist olive pomace (MOP) as soil amendment. Moist olive pomace was obtained from a new olive-oil industrial process called the 'two-phases method'. Soil samples were mixed with MOP to approximate a field application of 40 t ha(-1) and incubated under aerobic conditions at 20 degreesC and 60% of soil water holding capacity. To estimate the effect of different loading rates and N supply on mineralization, 40, 80, 120 and 160 t ha(-1) of MOP and 200 ppm of N as (NH4)(2)SO4 were used. Cumulative CO2-C evolution, total microbial activity and biomass-C were monitored during a 60-day period. Results indicate that the CO2-C evolution from MOP depends on soil type and is temporarily inhibited in acidic soils. Evolution of CO2-C increases with incremental addition of MOP, but the percentages of the added C that were mineralized decreased with increasing application rates. Mineral N supplements result in more efficiency of the mineralization process. Among the kinetic models tested to describe the mineralization dynamics, a first-order exponential model including a constant term provides the best fit to the experimental data. Both amount and activity of soil microbial biomass are enhanced by MOP added at the 40 t ha(-1) rate, at least in the first period of incubation. At higher rates of MOP addition, a constant increase of biomass C during incubation is observed, while the biological activity decreases at the end of incubation. Following application of mineral N, both amount and activity of microbial biomass is enhanced.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
