The objective of this study was to characterize the arbuscular mycorrhizal fungi (AMF) community associated with local varieties of Pinot noir, Sauvignon blanc, and Chardonnay grown in the Malleco and Cautín valleys, in La Araucanía region, Chile. The research attempted to answer the following question: How do soil and climatic conditions, as well as cultivar characteristics could influence root colonization, spore abundance, and AMF composition in vineyards in this emerging region? Rhizosphere samples were collected from two locations and six grapevine cultivars. Root colonization rates and AMF spore abundance were measured, and the spores present were morphologically identified. In addition, differences in the AMF community were evaluated regarding cultivar and plant age. The results showed root colonization rates higher than 50

Interaction of Claroideoglomus claroideum co-inoculation with saprophytic phosphofungi: effect on the development of micropropagated native potato plantlets Interacción de la co-inoculación de Claroideoglomus claroideum con fosfohongos saprófitos: efecto en el desarrollo de plántulas micropropagadas de papa nativa In many agricultural crops, arbuscular mycorrhizal fungi co-exist and interact with saprophytic fungi. This study aimed to analyze the effects of two free-living phosphofungi on the growth of potatoes co-inoculated with Claroideoglomus claroideum. Micropropagated native potato plantlets were transferred to a sterile Andisol previously inoculated with C. claroideum and subsequently two saprophytic fungi. The treatments were: C. claroideum (T0), C. claroideum + Talaromyces pinophilus (T1), C. claroideum + Penicillium albidum (T2), and C. claroideum + T. pinophilus + P. albidum (T3). At harvest, the most relevant results show that in T3 the height, shoot dry weight, root length and P acquisition of the potato plants were increased. Therefore, dry weight and P absorbed by minitubers were enhanced two and three-fold, respectively, compared with T0, along with an increase in the length of the thinnest roots. It is concluded that co-inoculation of this fungal consortium could be an advantageous alternative to be used as a bioinoculant by potato tuber seed producers in sustainable agriculture.

Arbuscular mycorrhizal fungi (AMF) communities associated to several grapevine cultivars were analyzed from 1,000 km long of crop area in Chile. The effect that different cultivars of Vitis vinifera L. may have on AMF communities has been scarcely studied, especially in non-organic managements. Our objective was to describe the AMF communities and quantify the arbuscular mycorrhizal root colonization associated to several grapevine cultivars in different grapevine ages along a 1,000 km long cropping surface and to test whether factors such as grapevine cultivar and grapevine age, as well as soil chemical factors shapes AMF communities. The vineyards were distributed along 1,000 km across Chile, passing through several administrative regions of the country. The different grapevines ranged from 1 to 41 years old. AMF identification and taxonomy was performed based on spore morphological analyses. AMF spores abundance, root colonization and extraradical mycelium (ERC) were also evaluated. More than 94,000 AMF spores were identified in the 34 vineyards investigated. In total, 15 AMF species were identified in this study. The AMF community was mainly represented by species belonging to the families Acaulosporaceae, Entrophosporaceae and Glomeraceae, dominated by the genera Acaulospora, Claroideoglomus, Septoglomus and Simiglomus. Regardless of grapevine age, soil chemistry and geographic location, the AMF community structure was influenced by grapevine cultivar. Grapevine age, soil chemistry and geographic location no affect AMF richness, AMF spores abundance, root colonization and extraradical mycelium (ERC). The AMF species identified in our work could be indicators of agricultural systems exposed to biotic and abiotic stresses in different grapevine age, soil chemistry and geographic location, according to the transect investigated. A role of vineyard cultivar in determining the structure of the AMF community was revealed. The use of AMF species target in regenerative vineyards management could be determining factors for the AMF community establishment.

Cover crops in sustainable agrosystems are becoming more and more applied. However, legacy effects on the growth of companion plants or following crops in rotation systems are still poorly understood, especially when Andean and ancestral crops are involved. In this work, two wheat (Triticum aestivum L.) cultivars differing in P efficiency (Kiron higher than Chevignon) were cropped together with two non-mycorrhizal plants, quinoa (Chenopodium quinoa Willd.) and amaranth (Amaranthus spp.), to study the interactions and the effects produced in the wheat rhizosphere, plant growth and mycorrhizal parameters at harvest. The plants were grown in a three-compartment plexiglass rhizobox containing an Andisol. The central compartment separated by a nylon mesh was used for the cover crops, and wheat was sown on each side. A habitual pre-crop rapeseed (Brassica napus L.), also non-mycorrhizal, was used as control. At harvest, soil (pH, available P, acid phosphatase, microbial-P), plant (phytomass, organic acid exudation, P uptake efficiency, Zn and Mn in shoots), and mycorrhizal properties (root colonization, glomalin, spore number, and hyphal density) were measured in both wheat rhizospheres. Results show that wheat cultivars differed in soil and plant characteristics affected by non-host plants being the most efficient one, better. Surprisingly, mycorrhizal propagules were not depressed, and even fungal spores with amaranth (10543 spores 100 g-1) increased 2.6-fold than control (3910 spores 100 g-1) in the P-efficient cultivar. Data obtained suggest being cautious in selecting the best wheat cultivar when using these ancestral crops, especially for wheat natives' smallholders working in this type of soil.

Soil biological properties are sensitive indicators of soil quality changes due to perturbations occurred under agricultural management. The effects of contrasting tillage, increasing nitrogen fertilization doses, and crop rotations [e.g., bean, maize, bean (BMB) and bean, amaranth, bean (BAB)] on soil physicochemical and biological properties in an Andean soil from Ecuadorian highlands were evaluated in this study. Acid phosphatase, β-Glucosidase, fluorescein diacetate hydrolysis, microbial biomass carbon (Cmic), soil basal respiration (BR), arbuscular mycorrhizal fungi (AMF) spore density, total glomalin content (TGRSP), and soil physicochemical properties were analyzed. Conventional tillage (CT) and crop rotation showed significant effects on soil physicochemical and biological properties. Towards the final crop rotations, no-tillage (NT) promoted BR, TGRSP, and higher AMF spore density in both crop rotations; the Cmic kept stable along time in BMB and BAB, while BR doubled its value when compared to CT. Results indicated that the AMF spore density increased by 308% at the end of the BMB, and 461% at the end of the BAB, while TGRSP increased by 18% and 32% at the end of BMB and BAB, respectively. Biological traits demonstrated to be strongly associated to the organic matter accumulation originated from crop residues under the NT post-harvest which improved soil moisture, biological activity, and AMF interaction. The conservative soil management system has definitively improved general soil properties when compared to soil conditions under the intensive soil management system in this research.

Los parámetros biológicos son usados como indicadores tempranos en la calidad de un suelo (ICS) agrícola, ya que responden rápidamente al manejo antrópico. El objetivo de esta investigación fue determinar el efecto del sistema de labranza: siembra directa (SD) y labranza convencional (LC), y de la fertilización nitrogenada después de los cultivos de fréjol y maíz, sobre ciertos indicadores biológicos de la calidad del suelo. El estudio se realizó sobre un molisol de la región andina del Ecuador. Se determinó la biomasa microbiana (BM), respiración microbiana (RM), y actividad enzimática (fosfatasa ácida, hidrólisis de la fluoresceína-diacetato [FDA], y β-glucosidasa [β-G]). Los resultados mostraron que la fosfatasa presentó la mayor actividad bajo LC, la FDA respondió al efecto de los niveles altos de nitrógeno (N), la actividad de la enzima β-G fue mayor en LC. Adicionalmente, el análisis de componentes principales seleccionó a los indicadores biológicos estudiados, como ICS. Se concluye que los indicadores biológicos del suelo fueron afectados por las prácticas de manejo estudiadas.

This study aimed to analyze the differences in root traits of two wheat cultivars and their relationship with phosphorus (P) acquisition in a soil with low P availability. For that, biomass production, root morphology, acid phosphatase activity, carboxylate exudation, and arbuscular mycorrhizal colonization were examined in "TCRB14" and "STKI14" wheat cultivars grown in pots. Biomass production was highly correlated with P acquisition and was greater in TCRB14. Mycorrhizal colonization and oxalate concentration in rhizosphere soils were also greater in TCRB14. STKI14 presented higher acid phosphatase activity in their rhizosphere, although not significantly. Overall, TCRB14 showed longer, larger, more branched, and thinner root systems, directly correlating with P acquisition. In this study, morphological root traits were the predominant component of P acquisition and, along with AM symbiosis and oxalate exudation, could comprise key targets for breeding programs orientated to more sustainable agricultural production under P-restricted scenarios.

Intercropping is especially relevant for low-income farmers when crop production is developed in soils under the new scenario produced by climatic change, mainly water shortage and low availability of nutrients especially P. An example of this would happen in volcanic soils of Southern Chile with high P fixing capacity and where most cereals are cropped. The aim of this study was to compare the benefits obtained on soil biochemical properties and on wheat (Triticum aestivum L.) growth when sowed under monoculture or intercropped with non-mycorrhizal plants such as quinoa (Chenopodium quinoa Willd.), buckwheat (Fagopyrum esculentum Moench), canola (Brassica napus L.) and white lupin (Lupinus albus L.) Wheat plants parameters such as shoot growth and morphological root traits together with some soil biological and chemical characteristics were measured after 30 and 44 d of plant growing in pots under controlled conditions. Results showed nonsignificant differences on growth parameters (i.e., height and shoot/root biomass) and P acquisition between monocrop and intercropped wheat. Conversely, wheat root morphological traits namely total length, root area, and forks were greatly reduced (around 50%) regardless of plant species. Intercropping tended to increase P availability and significantly reduced rhizosphere soil pH, with the lowest levels observed for wheat-canola combination (from 7.5 to 5.6). Intercropping produced a slight reduction in mycorrhizal colonization but increased over 100% viable spores' number and exerted a variable effect on the microbial C-biomass, with greater values observed in wheat-canola combination (1.49 mg g-1). These results encourage us to deepen the use of some new plant combinations in family farming carried out in volcanic soils.

The crop Vitis vinifera (L.) is of great economic importance as Chile is one of the main wine-producing countries, reaching a vineyard area of 145,000 ha. This vine crop is usually very sensitive to local condition changes and agronomic practices; therefore, strategies to counteract the expected future decrease in water level for agricultural irrigation, temperature increase, extreme water stress (abiotic stress), as well as increase in pathogenic diseases (biotic stress) related to climate change will be of vital importance for this crop. Studies carried out in recent years have suggested that arbuscular mycorrhizal fungi (AMF) can provide key ecosystem services to host plants, such as water uptake implementation and enhanced absorption of nutrients such as P and N, which are key factors for improving the nutritional status of the vine. AMF use in viticulture will contribute also to sustainable agronomic management and bioprotection against pathogens. Here we will present (1) the current status of grapevines in Chile, (2) the main problems in grapevines related to water stress and associated with climate change, (3) the importance of AMF to face water stress and pathogens, and (4) the application of AMF as a biotechnological and sustainable tool in vineyards.

The possibility of modifying terpene production in plants is a defensive strategy that has been studied in conjunction with their biosynthetic pathways. A biotic factor such as Arbuscular Mycorrhizal Fungi (AMF) could modify terpene production in Trifolium pratense L. In this work, the enzymatic production of monoterpenes in Superqueli INIA cultivar with two AMF was evaluated via HeadSpace-Gas Chromatography (HS-GC). A significant increase of (S)-limonene was found in plants inoculated with Claroideoglomus claroideum as well as with the AMF mix (genera Scutellospora, Acaulospora and Glomus). Moreover, significant increases in other monoterpenes such as (-)-β-pinene, myrcene, linalool, were observed. Results showed higher monoterpene production capacities in the Superqueli-INIA cultivar, suggesting the participation of monoterpene synthases (MTS). The significant rise of (S)-limonene in red clover plants inoculated with AMF suggests this strategy could be implemented in an agronomical manage for controlling the H. obscurus, the primary pest.

BACKGROUND Tomato is widely consumed throughout the world for its flavor and nutritional value. This functional food largely depends on the implementation of new strategies to maintain the nutraceutical value, e.g. lycopene concentration, and overcome the challenges of sustainable production and food security. The use of arbuscular mycorrhizal fungi (AMF)-based biostimulants represents one of the most promising tools for sustainable management of agricultural soils, being fundamental for organic food production, reducing fertilizers and pesticides use, and decreasing environmental damage. This study aimed at elucidating whether native arbuscular mycorrhizal fungi (AMF) could positively affect tomato yield and lycopene concentration. RESULTS Native AMF inoculum consisted of two inoculum types: the single species Claroideoglomus claroideum, and a mix of Scutellospora calospora, Acaulospora laevis, Claroideoglomus claroideum, and Claroideoglomus etunicatum. At the end of the study up to 78% of the root system was colonized by single inoculum. Tomato diameters in single and mix mycorrhizal plants showed increases of 80% and 35% respectively. Fresh weights were 84% and 38% higher with single and mix inocula compared with the controls, respectively. The lycopene concentration in tomato fruits of plants with single and mix inoculum was higher than controls. The lycopene concentration was 124.5% and 113.9% greater in single and mix than non-inoculated plants. CONCLUSION Tomato diameters, fresh weight and lycopene concentration was significantly higher in plants colonized by AMF compared with uninoculated plants. Results suggest that the role of single species Claroideoglomus claroideum could generate better plant performance due to its high production of extraradical mycelium. This article is protected by copyright. All rights reserved.

This study was conducted to evaluate the effect of compost produced with agricultural residues and oat-based biochar, iron oxide and halloysite nanoparticles as additives of the process of composting on soil chemical properties, nutrient status and growth of ryegrass Lolium perenne L. For this, a 90-day mesocosm experiment was carried out under greenhouse conditions. Bare soil and a basal fertilization treatment were compared to soils amended with nonadditive compost (NA compost), compost supplied with oat-based biochar (Bioch compost), iron oxide nanoparticles (Fe compost), and halloysite nanoparticles (Ha compost). Compost supplied with nanoparticles and biochar combined were also considered. The incorporation of compost with or without additives increased the content of total C and N in soil, with N diminishing (total and mineral forms) and C/N modifications after 90 days. The addition of compost and co-composted treatments also increased the total contents of main nutrients such as Ca, K, P and S. Furthermore, the supply of additives into composting did not increase the concentration of trace toxic elements. At the end of the experiment, plant biomass increased by the addition of the different organic amendments, with the highest shoot biomass in soils amended with compost supplied with nanoparticles. These results suggest that the addition of compost based on agricultural residues with additives such as halloysite or biochar improves chemical properties and nutritional status of soil that favor and increase plant growth of Lollium perenne stablished in soils from the Mediterranean Region.

In Andisols of Southern Chile, crop yield is mainly limited by P fixation and aluminum phytotoxicity (Al 3+ ), but scarce information in these soils is known in rotations, including wheat after Andean crops. It is very relevant to the knowledge of suchcrops’ root architecture to improve productivity through a greater absorption capacity of water, nutrients, and tolerance to biotic and abiotic stresses. The objective of this work was to evaluate root architecture at early phenological stages of Andean crops in an acidic Andisol from Southern Chile. During the 2019/2020 season, a field trial was established using four non-mycorrhizal cultures: buckwheat ( Fagopyrum esculentum L.), amaranth ( Amaranthus spp.), lupine ( Lupinus albus L.), and quinoa ( Chenopodium quinoa L.), and compared with oats ( Avena sativa L.) a mycorrhizal culture. During the growth period, four plant and soil samplings were carried out, evaluating phenological stages, root architecture, together with soil pH and P-availability. During the first half of the vegetative cycle, the growth of the crops was continuous but drastically reduced at the end development cycle due to the prevailing drought during the summer months. These climatic conditions affected quinoa and lupine growth showing high sensitivity to water stress. In general, all crops showed good root architecture, suggesting a more efficient P mobilization. A greater root length was obtained in buckwheat, while a better adaptation capacity to the environmental conditions was observed in quinoa. It is concluded that through suitable agronomic management by incorporating quinoa or amaranth as pre-crops of wheat in a rotation, the P-availability for the next crop could be increased by reducing the application of chemical fertilizers.

This study aimed to examine how interactions at both plant genotype and arbuscular mycorrhizal fungus species levels affected the expression of root traits and the subsequent effect on plant nutrition and growth. We used two wheat cultivars with contrasting phosphorus (P) acquisition efficiencies (Tukan and Crac) and two arbuscular mycorrhizal (AM) fungi (Rhizophagus intraradices and Claroideoglomus claroideum). Plant growth, as well as morphological and architectural root traits, were highly dependent on the myco-symbiotic partner in the case of the less P-acquisition efficient cultivar Tukan, with mycorrhizal responses ranging from -45 to 54 % with respect to non-mycorrhizal plants. Meanwhile, these responses were between only -7 and 5 % in the P-acquisition efficient cultivar Crac. The AM fungal species produced contrasting mechanisms in the improvement of plant nutrition and root trait responses. Colonization by R. intraradices increased Ca accumulation, regardless of the cultivar, but reduced root growth on Tukan plants. On the other hand, C. claroideum increased P content in both cultivars, with a concomitant increase in root growth and diffusion-based nutrient acquisition by Tukan. Moreover, plants in symbiosis with R. intraradices showed greater organic acid concentration in their rhizosphere compared to C. claroideum-colonized plants, especially Tukan (24 and 35 % more citrate and oxalate, respectively). Our results suggest that the responses in plant-AM fungal interactions related to nutrient dynamics are highly influenced at the fungus level and also by intra-specific variations in root traits at the genotype level, while growth responses related to improved nutrition depend on plant intrinsic acquisition efficiency.

Cellulose and lignin as main components of crop residues have a significant influence on composting operations and composition of the final products. Both are strongly associated, and lignin can be considered an important barrier during the biodegradation process of lignocellulosic materials. Saprophytic fungi are efficient lignin degraders due to their complex enzymatic system. Therefore, the influence of the inoculation of saprophytic fungi (Coriolopsis rigida, Pleurotus ostreams, Trichoderma harzianum and Trametes versicolor) and the supply of inorganic additives (Al2O3, Fe2O3 and allophanic soil) that promote the stabilization of carbon (C), were analyzed in the biodegradation of wheat straw (WS). The activity of Laccase (LAC), manganese peroxidase (MnP) and beta-glucosidase and changes in temperature, pH and E-4/E-6 ratio were analyzed in a biodegradation process of 126 days. The activity of LAC, MnP and the E-4/E-6 ratio were significantly influenced and increased (enzymes) by fungi species, inorganic additives, and time of inorganic material addition, as well as their interactions (p < 0.05). The WS inoculated with T. versicolor showed the highest average activities for LAC, MnP and beta-glucosidase (2000, 220 UL-1 and 400 mu mol pNP g(-1) h(-1) respectively). Furthermore, the addition of Al2O3 and Fe2O3 increased all the activities regarded to the decomposition of WS and influenced the changes associated with the stabilization of OM in composted WS. In conclusion, the inoculation of WS with T. versicolor in combination with metal oxides improved the enzyme related to the biodegradation process of WS favorizing its stabilization in the medium time, which is of importance in the composting of residues with high C/N ratio.

Conventional tillage (CT) is a soil management system commonly used by small farmers inthe Ecuadorian highlands; they remove the soil during seedbed preparation to eliminate weeds,improve soil aeration, avoid compaction, and develop adequate rooting space. CT causes changesin physical, chemical, and biological soil properties but, in the long run, have negative effects oncrop performance. Most of these effects can be avoided by using no-tillage (NT). The objective ofthis study was to determine the initial effects of NT, different fertilization rates and depth levels ofsampling on yield and soil chemical and physical properties after the first crop cycle (prior to croprotation scheme). A long-term field experiment was established to study the soil changes derivedfrom the transition from CT to NT systems in a volcanic soil of the Ecuadorian highlands cultivatedwith the following crop rotation schemes: beans (Phaseolus vulgaris L.)-corn (Zea mays L.)-beans andbeans-amaranth (Amaranthus caudatus L.)-beans. The results for the first crop cycle show that beanyield was 42% higher under NT compared to CT, indicating that the soil improvements promoted byNT had effects on crop yield; however, only the changes in pH and water storage capacity presentedsignificant differences, levels of soil organic matter, total N, available P, and bulk density showed atrend towards improvements under NT. This suggests that NT allows for increased crop yield andimproved crop rotation performance in the medium and long term.

The utilization of additives is a strategy commonly used in composting operations to enhance the physicochemical properties and optimize the process. However, little is known about the impact of nanominerals, biochar and their combination during composting. The objective of this research was to evaluate the effects of iron oxide/halloysite nanominerals and oat hull-biochar as additives in the physicochemical properties of an aerobic composting process, the emission of greenhouse gases (GHG) and the composition of end-products. In order to analyze the biodegradability of composting end-products in grassland soils, an incubation experiment was also carried out. Wheat straw, lupine and beef manure were mixed (C/N: ~25) with iron oxide (Fe) or halloysite (Ha) nanoparticles (2% w/w), oat hull-biochar (B) (7% w/w) and their combination (BFe, BHa). pH, EC, C/N ratio, NH4-NO3 contents and the emission of CO2 and CH4 were analyzed. After 128 days of aerobic composting process, the end-products and their NaOH soluble fraction were characterized by using spectroscopic analysis that included E4/E6 ratio and solid state nuclear magnetic resonance (13CNMR). To analyze the biodegradability of produced compost in grassland soils, a respiration experiment (60 days) using Respicond Apparatus IV, combined with δ13C isotopic analysis was conducted. A decrease of final C/N ratio was observed in all treatments that was lower in B treated compost. Nitrate concentration increased as composting progressed, and compost supplied with Ha showed the higher final content of NO3 (5800 mg kg-1) and NH4 (220 mg kg-1). The addition of B significantly decreased the mean emission of both CO2 (~400 g CO2 m2 d-1) and CH4 (~4.5 g CH4 m2 d-1). Nanominerals significantly decreased the final E4/E6 ratio (<6) and the addition of B increased the aromaticity (twice), the alkyl-C/O alkyl-C ratio and the hydrophobicity which are parameters associated to stabilized end-products. In soil, the incorporation of additives reduced the loss of C (<5% after 60 days of incubation). Treatments supplied with B and Ha showed a higher mean residence time (8 and 5 years respectively) than compost without additives. These results suggest that the addition of halloysite and biochar to composting operations have significant effects on C stabilization and biodegradability of compost in grassland soils, that is relevant in the production of C sequestrant amendments. Acknowledgments to FONDECYT N° 3170677.

Metallic oxides and clay minerals have gained increasing interest as additives of composting due to their influence in greenhouse gas emissions reduction and their effectivity in the stabilization of carbon both in compost and soils, leading to a cleaner compost production and potentially C sequestrant amendments. In this study, wheat straw (WS) was co-composted with iron oxide and allophanic soil and their influence on WS composting and composition of the end-products was evaluated. WS compost and their humic like-substances (HS) fraction were characterized by chemical and spectroscopic analyzes. After 126 days of process, the elemental composition showed slight differences of the N content for compost and HS, where the C/N atomic ratio tended to decrease relative to the initial material (WS; ~130). This trend was more pronounced in the HS from co-composted treatments (<30). The addition of inorganic materials increased the total acidity and phenolic-OH group contents (~15 and 14 mEq g-1 respectively, iron oxide treatment) relative to the treatment without inorganic additives. Nevertheless, the FTIR and solid-state 13CNMR spectroscopy barely support the wet chemical analysis and revealed a similar final composition between all the studied compost treatments. These results suggest that the incorporation of these materials as compost additives had no major effect on the spectroscopic features of the end-products, however, critical changes of the properties such as the extractability, functionality and composition of HS were revealed by traditional methods. In conclusion, the supply of metal oxides and clays could impact the aerobic composting of WS favorizing the stabilization of certain C pools and adsorptive properties of the end-products, that is of importance in production of amendments suitable for being used in degraded and contaminated soils. Nevertheless, under the experimental conditions of our research C stabilization apparently depends of other mechanisms that still need to be elucidate.

Biological activities determine quality, sustainability, health, and fertility of soils. The purpose of this study was to evaluate chemical and biological characteristics of soils from Ecuadorian highlands subjected to different management practices, as well as the density and diversity of arbuscular mycorrhizal fungi (AMF). Soils from naturalized grasslands and other previously cropped plots withZea maysandSolanum tuberosumwere analyzed in laboratory for soil biochemical properties, enzyme activity, and AMF colonization to determine the effect of the soil management over its quality. The characterization of AMF propagules associated to spontaneously colonizing plants in the above soils was also performed. Soil previously cropped withS. tuberosumshowed the highest glomalin content; at the same time, naturalized grassland andZ. mayscropped soils showed higher hyphal length. The acid phosphatase activity was higher in naturalized grasslands andZ. mayscropped soils compared with that in theS. tuberosumcropped soils. Moreover, the highest AMF colonization rates and spore number were found in different spontaneous plant species growing in the naturalized grasslands. This study represents the first characterization of AMF propagules of different cropped and naturalized grassland soils, and also is one of the first reports about changes on biochemical and microbial activities occurring in Andean soils from the highlands of Ecuador, undergoing determinant soil management activities.