Highest Sugar Production Research Articles

Life cycle assessment of bioproducts from bamboo residues with biphasic phenoxyethanol-acid based biorefinery technology

Utilizing bamboo residues to produce decarbonization energy products or materials diverts wastes from low-value treatment and supports the circular bioeconomy at the same time. This study develops a cradle-to-grave life-cycle assessment (LCA) for a biorefinery converting bamboo residues into bioproducts (ethanol, polylactic acid (PLA), and bio-based wood adhesive) in China. To combat the low enzymatic hydrolysis performance of bamboo residues and valorize the lignin, this study adopts a biphasic pretreatment by coupling phenoxyethanol and sulfuric acid solution (1%) to achieve high fermentable sugar production. The LCA study is coupled with a process simulation for an industrial-scale biorefinery based on the experimental data. Our results show that the life-cycle Global Warming Potential (GWP) is 17.0–32.1 gCO2e/MJ for ethanol cases and 3.2–3.7 kgCO2e/kg for PLA cases, when biphasic pretreatment is adopted. The lower GWP values are achieved by using 1:1 phenoxyethanol: acid solution, though it has a lower product yield than 4:1 phenoxyethanol: acid solution cases. Without biphasic pretreatment, the GWP is 135.8 gCO2e/MJ ethanol and 4.4 kgCO2e/kg PLA. For the perspective of treating 1 dry t bamboo residues, with biphasic pretreatment, the GWP is −174 to −66 kgCO2e for ethanol cases and −542 to −432 kgCO2e for PLA cases. The lower GWP is also from using 1:1 phenoxyethanol: acid solution (1%). These GWP ranges are lower than conventional landfilling (2969 kgCO2e) and landfilling with landfill gas recovery (−28 kgCO2e).

An integrated pretreatment strategy for enhancing enzymatic hydrolysis efficiency of poplar: Hydrothermal treatment followed by a twin-screw extrusion

To reduce the dependence on chemical inputs during biomass pretreatment, an integrated process on the basis of hydrothermal pretreatment followed by twin-screw extrusion for poplar was proposed. A comparative study was conducted on the pore structure, crystallinity, relative surface lignin concentration, cellulose accessibility, and enzymatic hydrolysis efficiency of the pretreated materials. Results suggested that the relative surface lignin concentration of fibers pretreated by hydrothermal treatment (conducted at 170 ℃ for 90 min) coupled with extrusion (HE) treatment was decreased compared to the sole hydrothermal (H) process, which had a positive impact on the subsequent enzymatic hydrolysis. Additionally, the HE process resulted in an increase in pore size by 34.4%, pore volume by 447.5%, and specific surface area by 93.5%, which enhanced the penetration and interaction of water into the fibers and thus increased cellulose accessibility by 143.2%. SEM and TEM observations revealed that fibers were separated and finely fibrillated, large amounts of fragmentary structure and cracks appeared on the fiber. In addition, the cell wall structure was deformed and damaged, when pretreated by HE process. Overall, this work showed that hydrothermal treatment followed by twin-screw extrusion was an achievable strategy for high fermentable sugar production of hardwood.

Chemical-free saturated steam pretreatment of oil palm empty fruit bunch for improved enzymatic saccharification

Oil palm empty fruit bunch (EFB) as the main lignocellulosic residue from the oil palm industry serves as suitable feedstock for enzymatic saccharification, yielding fermentable sugars. Due to complex inter-association between hemicellulose, cellulose and lignin within EFB lignocellulosic matrix, different saturated steam conditions at 140-230 °C, 0.3-2.3 MPa was chosen as a pretreatment strategy, targeted to hydrolyze hemicellulose and reduce crystallinity of cellulose to enhance enzymatic saccharification which need no chemical requirement and potential for energy recovery. As a result, SEM analysis of EFB morphology indicated that the enhanced silica body removal from 190-230 °C of saturated steam pretreatment correspondingly led to substantial 82% removal of hemicellulose. Consequently, enzymatic saccharification yielded between 0.621-0.637 g glucose per g EFB, equivalent to 93-95% of cellulose saccharification by Acremonium cellulase on EFB treated with saturated steam at 210-230 °C. Notably, a short duration pretreatment of EFB at 210 °C for 2 min was proved sufficient for high fermentable sugar production. The potential energy estimated for employing saturated steam pretreatment of EFB in a palm oil mill was sufficient by 2.2 x 1012 kJ/year.

Green solvents extraction-based detoxification to enhance the enzymatic hydrolysis of steam-exploded lignocellulosic biomass and recover bioactive compounds

A novel strategy for pre-treated biomass detoxification combining emerging green solvents and low environmental impact extraction technologies was evaluated. Steam-exploded biomass was subjected to microwave-assisted or orbital shaking extraction using bio-based or eutectic solvents. The extracted biomass was enzymatically hydrolysed. The potential of this detoxification methodology was studied in terms of phenolic inhibitors extraction and sugar production improvement. The effect of adding a post-extraction water washing step before hydrolysis was also evaluated. Excellent results were achieved when steam-exploded biomass was subjected to the microwave-assisted extraction combined with the washing step. The highest sugar production was achieved when ethyl lactate was used as extraction agent (49.80 ± 3.10 g total sugar/L) over the control (30.43 ± 0.34 g total sugar/L). Results suggested that a detoxification step based on green solvents would be a promising option to extract phenolic inhibitors, which can be revalorized as antioxidants, and improve the sugar production from the extracted pre-treated biomass.

High Sugar Production from Hydrolysate of Pineapple Residues via Integrated Enzyme‐Membrane System

The enzyme-membrane integrated system has become an attractive method for the depolymerization of lignocellulosic biomass. This research was planned to evaluate the effect of pH, temperature, enzyme loading, and reaction time in order to maximize the sugar production. Hydrolysate extracted from pineapple leaves was used as a substrate. The feed substrate was hydrolyzed by β-xylosidase under different working conditions using the one factor at a time (OFAT) method. The best working conditions, obtained via enzymatic hydrolysis were used in the enzyme-membrane integrated system. OFAT results revealed that the best working conditions were pH 7.5, 50 °C, 1% (w/v) and 30 mins. Sugar yield at simultaneous reaction and filtration was higher (293.94%) than the reaction alone (32.23%).

Ferric chloride aided peracetic acid pretreatment for effective utilization of sugarcane bagasse

The synergetic impacts of ferric chloride aided peracetic acid (FPA) pretreatment were investigated to enhance the total biomass utilization through effective cellulose conversion and high-quality lignin production. The sugarcane bagasse pretreatment with 2% peracetic acid (PAA) and 0.1 mol/L ferric chloride (FeCl3) effectively removed 57.3% of lignin and 72.2% of xylan while preserving ∼ 97% of cellulose from sugarcane bagasse under mild temperature (90 °C). The FPA pretreated sugarcane bagasse was effectively hydrolyzed with a glucose yield of 313.0 mg/g-biomass, which was 4.5 times higher than the yield of untreated biomass (69.75 mg/g-biomass) and 1.6 and 3.6 times higher than that of individual PAA and FeCl3 pretreated sugarcane bagasse, respectively. The regenerated lignin (FPA lignin) showed great potential for further valorization by preserving the major interunit linkage (up to 86% of β-O-4) without significant carbohydrate contamination and lignin condensation due to its mild reaction conditions. In this study, the combination of PAA and FeCl3 synergistically enhanced the pretreatment efficiency on sugarcane bagasse and resulted in high fermentable sugar and high-quality lignin production.

STUDY OF SUGAR CANE SUGAR AGROINDUSTRY MECHANICAL METHODS AND CONVENTIONAL METHODS: A COMPARISON OF INCOME

Cane sugar agroindustry is the processing of sugarcane juice into sugar cane using conventional methods. However, along with the development of this agroindustry innovation began to adopt technology with mechanical methods. In the production process, there is the use of inputs that differentiate the impact on agroindustry income which is not yet known for certain, therefore this study aims to: 1) determine the description of the sugar cane agroindustry method mechanical and conventional methods at Kayu Aro, Kerinci District, 2) knowing the comparative income of sugar cane agroindustry with mechanical and conventional methods at Kayu Aro, Kerinci District. This research was conducted on August 10th to September 10th, 2020 at Sungai Asam Village, Kayu Aro, Kerinci District purposively, with the consideration that Sungai Asam Village has the largest area of sugarcane land, sugarcane production, sugar production and the largest number of craftsmen and there are more processing methods from one. The number of samples was 47 people, divided into 33 mechanical craftsmen and 14 conventional craftsmen. The data analysis method used is descriptive analysis, income analysis and comparative analysis of sugar cane agroindustry income with a two difference test mean. (1) The difference in the methods used causes the difference in the amount of sugarcane juice raw material produced by the mechanical method is greater which affects the amount of use of auxiliary materials and the fuel needed is also greater which results in higher sugar production than conventional. So that mechanical processing is better than conventional processing. (2) The income of the mechanical method of cane sugar agroindustry is 40% higher than conventional. This occurs as a result of the difference in the amount of bulk sugar production which is greater than the sugar production at different price levels.Keywords: Sugar Cane, Mechanical, Conventional, Income, Comparison

Study of Palm Plant Productivity (Arenga pinnata merr.) Based on Differences in Companion Plants

This research was conducted in Aek Nabara Village, Marancar District, South Tapanuli Regency. This study aims to determine the production of sap and palm sugar production based on differences in companion plants. Plant samples were taken from rubber companion plants, salak companion plants, cinnamon companion plants, durian companion plants, and cocoa companion plants. The highest sap production was found in sugar palm plants with durian companion plants, while the lowest sap production was found in sugar palm plants with rubber companion plants. The highest sugar production was found in palm plants with rubber companion plants, while the lowest sugar production was found in sugar palm plants with cinnamon companion plants.

Plantlet Formation and Acclimatization of Sugarcane cv. PS 881 with Different Types and Concentration of Auxin

This research has been carried out with a view to induce rooting and plantlet formation, followed by acclimatization. Micro shoots of sugarcane cv. PS 881 were cultured on Murashige and Skoog medium supplemented with different types and concentration of auxins for root induction. This research conducted experimentally using a split-plot design. The main plots were three types of auxins, which consisted of IAA, IBA, and NAA. The subplots were auxin concentrations with four levels, i.e. 0 I¼M, 5 I¼M, 10 I¼M, and 15 I¼M. Significantly faster root emergence time and higher number of roots observed in the Murashige and Skoog basal medium supplemented with 10 I¼M NAA. The best root length obtained in the Murashige and Skoog basal medium supplemented with NAA 0 I¼M. Plantlets derived from NAA 10 I¼M treatment showed the best performance during acclimation with a 100% survival rate. NAA at a concentration of 10 µM considered to be the best treatment in plantlet formation and acclimatization of sugarcane cv. PS 881. This study showed that the use of MS medium with 10 uM NAA is able to increase the growth of PS 881 sugarcane plantlets. The results of this study can increase the availability of high quality seedlings and increase national sugar production.

The state of the I crystallization massecuite food system with the cumulative effect of surfactants, sugar decolorant, descaling agent

At the present stage for the sugar beet factories of the CIS countries in connection with the entry into the world market, a trend for high quality white sugar production appeared. It is shown that the white sugar quality is largely determined by the state of the food system of the I crystallization massecuite, in the formation of which technological aids for the functional groups of surfactants, sugar decolorants, and descaling agents (descalers) are used. It is noted that between the means applied, joint interactions are possible in the form of antagonism-synergism, which ultimately affect the white sugar quality. In this regard, it is advisable to study the cumulative effect of the means of these functional groups on the change in the state of the nutritional system of the massecuite I. This task was solved using the previously developed methodological approach based on determining of representative indicators of the solid and liquid phases of the massecuite food system — crystal content, heterogeneity coefficient, average crystals size, viscosity, chromaticity, calcium salts content, the optimal values of which indicate the food system steady state, deviations from them - unstable. The experiments scheme included 5 combinations with local and joint ontroduction of Defospum surfactant, E 221 sugar decolorant, Kebo DS descaler. It was revealed that with the combined application of surfactants and sugar decolorant, the food system of the massecuite was characterized by a steady state at the best values of indicators: the color of the liquid phase was 5.8% lower compared to the autonomous use of decolorant, viscosity - 1.6% lower than the autonomous use of surfactants. It was suggested that this is due to the synergistic effect, in the first case - surfactant on the functional effect of the sugar decolorant, in the second - on the contrary, the decolorant on the functional effect of the surfactant. It was shown that the sugar obtained from such a food system corresponded to the white sugar of the TC1 category. Descaler residual quantities migrating into the food system of the massecuite antagonist to the decolorant of sugar and surfactant, makes it unstable

Does straw mulch partial-removal from soil interfere in yield and industrial quality sugarcane? A long term study

Sugarcane straw mulch left in the field after its mechanical harvest has become very valuable raw material for second generation ethanol and bioelectricity production. However, little information is available on how much straw mulch is needed to be left in the field so that agricultural productivity is not affected and high sustainability is provided for the bioenergy production system. The objective of this work was to evaluate the productivity and industrial quality of sugarcane after five years of cultivation when different amount of straw mulch is removed from the field. The experiment was installed in clay texture Eutroferric Red Latosol (Oxisol). Six treatments were evaluated: 0%, 25% (5tha−1), 50% (10tha−1), 75% (15tha−1), 100% (20tha−1) of straw mulch and burnt cane harvesting (where 100% of the straw mulch was burned). Evaluated parameters included sugarcane productivity (tons/hectare) and its industrial quality (Pol, soluble solids (°Brix), apparent purity and total sugars (TS)). Productivity was calculated at the end of the cycle whereas industrial quality parameters were evaluated during three phases i.e. 180, 240 and 350days after cutting (DAC). Straw mulch of 50 and 75% were statistically at par with each other but resulted in higher sugarcane production with 47% more productivity as compared to 0 and 25% of straw mulch as well as burned cane harvesting. Straw mulch didn’t affect the industrial quality; however, higher sugar production was supported by higher agricultural productivity, under low moisture condition. It is possible to remove 50% of straw mulch from the field for the production of second generation ethanol or bioelectricity, without any damage to the crop.

Mining sequence variations in representative polyploid sugarcane germplasm accessions

BackgroundSugarcane (Saccharum spp.) is one of the most important economic crops because of its high sugar production and biofuel potential. Due to the high polyploid level and complex genome of sugarcane, it has been a huge challenge to investigate genomic sequence variations, which are critical for identifying alleles contributing to important agronomic traits. In order to mine the genetic variations in sugarcane, genotyping by sequencing (GBS), was used to genotype 14 representative Saccharum complex accessions. GBS is a method to generate a large number of markers, enabled by next generation sequencing (NGS) and the genome complexity reduction using restriction enzymes.ResultsTo use GBS for high throughput genotyping highly polyploid sugarcane, the GBS analysis pipelines in 14 Saccharum complex accessions were established by evaluating different alignment methods, sequence variants callers, and sequence depth for single nucleotide polymorphism (SNP) filtering. By using the established pipeline, a total of 76,251 non-redundant SNPs, 5642 InDels, 6380 presence/absence variants (PAVs), and 826 copy number variations (CNVs) were detected among the 14 accessions. In addition, non-reference based universal network enabled analysis kit and Stacks de novo called 34,353 and 109,043 SNPs, respectively. In the 14 accessions, the percentages of single dose SNPs ranged from 38.3% to 62.3% with an average of 49.6%, much more than the portions of multiple dosage SNPs. Concordantly called SNPs were used to evaluate the phylogenetic relationship among the 14 accessions. The results showed that the divergence time between the Erianthus genus and the Saccharum genus was more than 10 million years ago (MYA). The Saccharum species separated from their common ancestors ranging from 0.19 to 1.65 MYA.ConclusionsThe GBS pipelines including the reference sequences, alignment methods, sequence variant callers, and sequence depth were recommended and discussed for the Saccharum complex and other related species. A large number of sequence variations were discovered in the Saccharum complex, including SNPs, InDels, PAVs, and CNVs. Genome-wide SNPs were further used to illustrate sequence features of polyploid species and demonstrated the divergence of different species in the Saccharum complex. The results of this study showed that GBS was an effective NGS-based method to discover genomic sequence variations in highly polyploid and heterozygous species.

Enhancing of Acetic Acid Production in Vinegar Production by the Consortium of <i>Aspergillus</i> spp. and Yeasts

Fresh fruit vinegar fermentation is well known for the activities of diverse groups of microorganisms at two stages of the fermentation process. Their species diversity depend on the raw materials fermented. In the study, at the first step of high sugar production, less culturable acetic acid bacterial species but more Aspergillus spp. and yeasts, non-Saccharomyces were detected. At the end, the vinegar production step, the fermented broth showed only dominant acetic acid bacteria. In the study, yeasts and fungi were isolated and inoculated to the juice. The results showed that these consortium could help increase high alcohol and later more acetic acid production when compared with the control fruit vinegar fermentation.

English

Sugarcane variety development programmes primarily envisage breeding of varieties with high cane yields and high sugar content in specific environmental conditions. Key components associated with sugar yields are tonnes of cane per hectare and sucrose content. A study was undertaken to evaluate 22 introduced sugarcane genotypes with three checks (KEN 83-737, EAK73-335 and D8484) for sucrose content in western Kenya. The experiment was planted in a Latin square design with three replications at three sites namely Sugar Research Institute Kibos, South Nyanza Sugar Company and Mumias Sugar Company. Data was recorded on refractive brix, stalk thickness, fresh cane yield, sucrose content, fibre content, juice purity and sugar yield. Significant differences at (p<0.05) were observed among genotypes for, sugar yields, brix percent cane, pol percent cane, fibre percent cane and juice purity. The effects of locations on quality were significant in all the traits tested (p<0.05). Effects of G×L were not significant for all the quality traits with exception of brix% cane. Significant positive correlations were detected between sucrose content, juice purity and fiber percent cane.7 Genotypes exhibited superiority to check cultivars in quality traits and their genetic potential can be exploited for high sugar production. Key words: Checks, correlations, genotype, location, sugarcane, quality traits.

Enzymes produced by biomass-degrading bacteria can efficiently hydrolyze algal cell walls and facilitate lipid extraction

The toughness of microalgal cell walls makes lipid extraction and large-scale biodiesel production difficult. This study investigated the enzymatic hydrolysis of algal cell walls, in which the enzymes were produced by eight biomass-degrading bacterial strains. The bacteria were first cultured in mineral salt medium containing 5% (w/v) wheat bran and various lignocellulolytic enzymes, including carboxymethyl cellulase (CMCase), filter paper activity (FPase), xylanase, and laccase were monitored in order to obtain an enzymatic extract. All the strains showed marked CMCase activity, with a range of 3.0–6.9 U ml−1 after incubation for 2–5 d. Some strains also produced FPase, xylanase, and laccase. The enzymatic extract was directly added to fresh algae culture at a ratio of 1:3 (v/v) for 48 h. All the bacterial enzymatic extracts significantly disrupted algal cell walls, according to the enhancement of reducing sugar content in the culture. The lipid extraction yield was markedly increased by 10.4–43.9%, depending on the bacteria strains used. Due to its high reducing sugar production and lipid extraction efficiency, Bacillus sp. K1 was selected for a time-course experiment. Maximum lipid yield was obtained after 24 h of incubation at the room temperature, with about 40% of the cells were disrupted. These results showed that enzymes produced by biomass-degrading bacteria can weaken and disrupt cell walls and components of algae and facilitate the release of lipids from algae.

Isoglucose: what are its prospects post-quotas?

After the end of the EU sugar quota system from 1 October 2017, expansion of isoglucose production will be possible. Currently production is limited to 720,000 t in nine EU countries, which is divided among six producers. Production is concentrated in Central and Southeastern Europe, far away from the main consumption areas, where high sugarbeet yields make sugar production very competitive. The possibilities for isoglucose production expansion are discussed. An 1 mn t production increase, to about 2 mn t of sugar equivalent, seems likely after 2017 despite the high beet sugar production surplus currently seen on the EU market.

Hydrolysis behavior of various crystalline celluloses treated by cellulase of Tricoderma viride

Cellobiose and glucose are valuable products that can be obtained from enzymatic hydrolysis of cellulose. This study discusses changes in the crystalline form of celluloses to enhance the production of sugars and examines the effect on structural properties during enzymatic hydrolysis. Various crystalline celluloses consisting of group I (cell I, cell IIII, cell IVI) and group II (cell II, cell IIIII, cell IVII) of similar DPs were prepared as starting materials. The similar DP values allowed a more direct comparison of the hydrolysis yields. The outcomes were analyzed and evaluated based on the residues and supernatants obtained from the treatment. As a result: (1) action of the cellulase of Trichoderma viride decreased both DP and crystallinity, with greater changes in group II celluloses, (2) the polymorphic interconversion process that occurred for cell IIII, cell IVI, cell IIIII and cell IVII during the treatment was independent of the enzymatic hydrolysis, thus, the hydrolysis behaviors depended on the starting material of the celluloses, and (3) higher sugar production was obtained from cell IIII and group II. Therefore, the hydrolysis behavior of the various crystalline celluloses depended on the particular polymorph of the starting material.

The use of thermochemical pretreatments to improve the anaerobic biodegradability and biochemical methane potential of the sugarcane bagasse

Abstract Lignocellulosic material can be used as biomass for power generation via biogas if it is pretreated to improve the anaerobic hydrolysis step, by either solubilising the hemicellulose (total reducing groups, TRG) or removing lignin (Lig), with consequent exposition of the cellulose fibre to anaerobic degradation. We evaluated the effects of acid, alkaline, and hydrothermal pretreatments on sugarcane bagasse to increase its anaerobic biodegradability and biochemical methane potential (BMP). The highest sugar production (31.14 g TRG/g substrate) was achieved with the acid pretreatment in 6.4 min at 138 °C, with a HCl concentration of 0.63 M, and the highest lignin removal (23.24 g Lig/g substrate) was found with the alkaline pretreatment after 47 min at 184 °C and a NaOH concentration of 0.8 M. However, the best values of BMP (197.5 L CH 4 /kg substrate) and anaerobic biodegradability (27.4%) were achieved by the hydrothermal pretreatment after 10 min at 200 °C, which was sufficient to generate power of 6.8 MJ/kg substrate. The results showed that the methane derived from the anaerobic digestion of these hydrolysates produced less energy than the direct burning of the dry bagasse. Thus, the recovered lignin, with its high added-value, may be used to improve environmental sustainability and profitability of the process. In this case, the alkaline pretreatment extracted 80.2% of the lignin present in the bagasse, and the hydrolysate could generate 313.4 L CH 4 /kg substrate.

Evaluation of cellulose degrading efficiency of some fungi and bacteria and their biofilms

In industrial applications like cellulosic biofuel production, efficient degradation of cellulose is one of the major concerns. But the efficiencies of cellulose degradation by different types of biofilms are not yet explored. This study was carried out to determine whether the community actions of fungal-bacterial biofilms may increase the rates of cellulose bio-degradation. Cellulolytic fungi and bacteria were isolated from soils, composts and leaf litter and screened for simple sugar production. To identify efficient sugar producing communities, combinations of these isolates were tested in batch cultures of cellulose broth prepared with commercial cellulose. Three different communities; fungal and bacterial monocultures, fungal-bacterial biofilms and fungal mixed cultures were tested. The monoculture of Acremonium sp. was the highest sugar yielder among all tested microorganisms. Among fungal mixed cultures, Acremonium sp. with Fusarium sp. was an effective sugar yielder. Acremonium sp. with a Bacillus sp. was effective among fungal-bacterial biofilms. These three cultures were also inoculated into broth media prepared with Eupatorium odoratum or Panicum maximum or Lantana camara or Mimosa pigra to assess their simple sugar production from plant materials . The highest sugar production was by Acremonium sp. monoculture and the lowest was by the Acremonium sp. with Bacillus sp. biofilm. This was true for all four weeds. Thus, all the fungal-bacterial biofilms tested were comparatively less effective sugar producers. DOI: http://dx.doi.org/10.4038/jnsfsr.v41i2.5710 J.Natn.Sci.Foundation Sri Lanka 2013 41 (2):155-163

Fertility and soil productivity of Colombian soils under different soil management practices and several crops

In the Caribbean, valleys of the Andes, Oriental Plains and Andean region of Columbia, there is a great diversity of soils, soil quality and ways and hazards of soil degradation caused by large variations in parent materials, climatic conditions, biodiversity and the physiographic position of the land. Soil and environmental characteristics, soil use and soil degradation in Columbia are specified. There are also opportunities for increased agricultural production. The high degree of soil diversity provides ecological niches for the successful cultivation of modern crop varieties. Alternative cropping practices are suggested. To promote sustainable effects in Colombian soils, a reduction of and change in soil cultivation practices are proposed. Sugarcane fields planted in Alfisols, Vertisols or Mollisols support production levels of >14 t ha−1 month−1 with high sugar production. In Andean or Caribbean soils, tropical fruit production can be maintained at >40 t ha−1 year−1. Oil palm fruit can reach production levels of 33–35 t ha−1. Combining practices results in an improvement in physical, chemical and biological soil properties, maintaining high production levels in soils of low, medium or high fertility. It is concluded that the productivity of Colombian tropical soils is a function of soil quality and management.