Examinando por Materia "Peru"

Mostrando 1 - 19 de 19

Agro-morphological characteristics and sensory evaluation of native peruvian chili peppers
(David Publishing Company, 2016-09-28) Patel, Kirti; Calderon, Rosa; Asencios, Edgard; Vilchez Palomino, Dioliza; Marcelo Salvador, Mavel Nansi; Rojas, Rosario
In this work, 31 native Peruvian chili peppers were evaluated for their agro-morphological characteristics and sensory attributes. The descriptive sensory analysis (DSA) was used to evaluate the 31 chili pepper samples based on their acid, bell pepper, sweet, tomato, apple, citrus, fruity, herbal, oregano and passion fruit attributes. The data obtained from the DSA enabled the grouping of these 31 chili peppers into six groups based on their different sensory attributes, such as fruity, bell pepper and herbal. The most abundant group (12 of the 31) had the bell pepper, apple, herbal, fruity and sweet attributes. Each group contained different species and different physical appearances, indicating that species or different forms of chili pepper do not define that sensory attribute. Considering the fact that Peruvian peppers are in high demand, the results achieved would be useful for growers, producers and chefs, as well as for further breeding activities.
Challenges and opportunities of genetic improvement in alpacas and llamas in Peru
(Wageningen Academic Publishers, 2018-02-16) Gutierrez, G.; Gutierrez, J.P.; Huanca Mamani, Teodosio; Wurzinger, M.
Alpacas and llamas play an important role in the livelihood of many rural families in the High Andes of Peru. The census of 2012 indicates a population of 3 million alpacas and 746,269 llamas. Both species are kept in extensive, low-input, pasture-based systems in altitudes between 3800 m and up to 5000 meters above sea level. Smallholders keep mixed herds of sheep, alpaca and llamas as a mitigation strategy against fluctuating market prices. Since 1997 the Peruvian Ministry of Agriculture manages a genealogy registry for alpacas and llamas, but so far the up-take rate by farmers and inscription rate of animals is low. The national research organisation INIA (Instituto Nacional de Innovación Agaria) runs an ex-situ in-vivo conservation program for coloured alpacas (21 different colours) and llamas. INIA is also doing research in the area of embryo transfer, artificial insemination and controlled mating. There is no national breeding program for alpacas, but all individual initiatives from private companies, NGOs and farmers´ cooperatives aim to improve fibre quality by reducing fibre diameter. At the moment these various local programs are not connected. There is also no national breeding program in place for llamas. Little attempts have been made to set up functional breeding programs for this species. Furthermore, there is no a national conservation plan in place. However, INIA have just started the formulation phase of a National Bank for Agrobiodiversity Conservation that include ex situ in vitro conservation of SACs. The Peruvian Ministry of agriculture prioritizes in the recently launched national livestock development plan for 2017 – 2027 alpacas and llamas. Support for the development of breeding plans is mentioned as one action line to increase productivity in both species.
Digital mapping tool: a territorial approach for containment of Fusarium wilt TR4 in Peru
(International Society for Horticultural Science, 2023-05-16) Clercx, L.; Cozzarelli, M.; Balarezo Camminati, D.; Rojas Llanque, Juan Carlos
Fusarium wilt caused by the tropical race 4 (TR4) of Fusarium oxysporum f. sp. cubense is known as the most serious and devastating banana disease. In April 2021 the presence of TR4 was detected on a plot in Chocán, in the district of Querecotillo in the Chira Valley, Peru. Organic banana cultivation for export is located in this valley, between Sullana and Piura, in Morropón and Lambayeque; altogether, 10,000 ha. There are two dozen mid-sized banana farms; but the export sector is mainly made up of approximately 9,000 small producers, with average plot sizes of 0.5-1.0 ha, organized in around 35 producer associations and cooperatives. To a great extent, the banana sector depends on flood irrigation. Harvesting is done by dozens of harvesting teams, who cut and carry banana bunches on their shoulder to one of the hundreds small packing stations, walking their shortest way through the banana plots. The export banana sector in Peru is small and young, with only an incipient institutional development and leadership. Typical biosecurity protocols to prevent entrance of the fungus are designed for farms; and need ‘re-invention’ for the highly fragmented context of Peru. All these characteristics make the sector extremely vulnerable to further spreading of TR4. Between April 2021 and June 2022, 82 TR4 outbreaks were detected by the phytosanitary agency SENASA in the districts of Querecotillo, Salitral and Marcavelica. Together with the data processing company Opus Insights, and in a broad alliance with other companies and institutions, the importer of Fairtrade and organic banana AgroFair started a project to carry out detailed aerial mapping, as tool for implementation of risk analysis and biosecurity measures with a territorial approach. The digital maps were completed in July 2022. We will examine the first practical experiences with this tool, formulate recommendations and indicate institutional conditions favorable to develop strategies for coping with TR4.
Distribution Models of Timber Species for Forest Conservation and Restoration in the Andean-Amazonian Landscape, North of Peru
(MDPI, 2020-09-25) Cotrina Sánchez, Dany A.; Barboza Castillo, Elgar; Rojas Briceño, Nilton B.; Oliva Cruz, Manuel; Torres Guzmán, Cristóbal; Amasifuen Guerra, Carlos Alberto; Bandopadhyay, Subhajit
The Andean-Amazonian landscape has been universally recognized for its wide biodiversity, and is considered as global repository of ecosystem services. However, the severe loss of forest cover and rapid reduction of the timber species seriously threaten this ecosystem and biodiversity. In this study, we have modeled the distribution of the ten most exploited timber forest species in Amazonas (Peru) to identify priority areas for forest conservation and restoration. Statistical and cartographic protocols were applied with 4454 species records and 26 environmental variables using a Maximum Entropy model (MaxEnt). The result showed that the altitudinal variable was the main regulatory factor that significantly controls the distribution of the species. We found that nine species are distributed below 1000 m above sea level (a.s.l.), except Cedrela montana, which was distributed above 1500 m a.s.l., covering 40.68%. Eight of 10 species can coexist, and the species with the highest percentage of potential restoration area is Cedrela montana (14.57% from Amazonas). However, less than 1.33% of the Amazon has a potential distribution of some species and is protected under some category of conservation. Our study will contribute as a tool for the sustainable management of forests and will provide geographic information to complement forest restoration and conservation plans.
Evaluation of Heat-sensitive Micronutrients in Fresh, Sun-dried and Solar-dried Capsicum Varieties Grown in Peru
(University of Hohenheim, 2011-10) Nagle, Marcus; Jankowsky, Birgit; Peña Pineda, Karla Mónica; Ríos Lobo, Llermé; Jäger, Matthias; Nohr, Donatus; Müller, Joachim
In this study, the vitamin and carotenoid content of three local varieties and six accessions of a gene bank in Peru were identified. It was observed that drying in the traditional way was almost impossible under Peruvian winter conditions (coast) and resulted in microbiological degradation, whereas almost all solar dryer samples reached the aimed moisture content. Dried capsicum with higher carotenoid and vitamin content provides products of better nutritional and economic value, which will contribute to food security.
Exploration of underutilized crop diversity of Capsicum peppers in their primary center of diversity in Bolivia and Peru
(2014-06) Van Zonneveld, Maarten J.; Ramírez, Marleni; Williams, David E.; Petz, Michael; Meckelmann, Sven W.; Avila, Teresa; Bejarano Martinez, Carlos; Ríos Lobo, Llermé; Libreros, Dimary; Scheldeman, Xavier
The genus Capsicum is a highly diverse complex of domesticated and wild species that displays abundant variation in its main center of domestication and diversity in Bolivia and Peru but that remains under-researched. New collecting expeditions undertaken in 2010 by the Instituto Nacional de Innovación Agraria (INIA) in Peru and the Centro de Investigaciones Fitoecogenéticas de Pairumani (CIFP) in Bolivia have significantly increased the size of the collections. INIA Peru now maintains 712 accessions of the five domesticated species, making it one of the largest and most diverse national collections of native Capsicum pepper varieties in the world. The collection in Bolivia contains 492 accessions, including the five domesticated species, four wild species, and one wild botanical variety of a domesticated species. We report on the identification of promising native Capsicum germplasm for potential use in the development of differentiated products. Identification of promising material representative of native Capsicum diversity in both collections followed several steps: (1) Identification of a core collection of nearly 100 accessions per country representing the different species and their geographic distribution. Dried samples of these accessions were biochemically screened for commercially interesting attributes including capsaicinoid content, polyphenols, antioxidant capacity, carotenoids, lipid content and color; (2) Based on results of the biochemical screening, sub-sets of 44 Bolivian and 39 Peruvian accessions were selected, representing the different species and variation in biochemical attributes; and (3) The selected materials were grown in different environments to identify the agro-ecological conditions were they best express the special properties of commercial interest. The biochemical screening and agromorphological characterization and evaluation revealed that Capsicum accessions from Bolivia and Peru have unique combinations of functional attributes, confirming that a wealth of commercially valuable properties can be found in Capsicum’s primary center of diversity. This study was financed by GIZ.
First report of Raoiella indica (Acari: Tenuipalpidae) in Peru
(Systematic and Applied Acarology Society, 2020-10-02) Escobar Garcia, Héctor Alonso; Andrade, Daniel Junior
Genotyping-by-sequencing reveals a high number and quality of single nucleotide polymorphisms in guinea pigs (Cavia porcellus) from the Peruvian Andes
(John Wiley & Sons Inc., 2023-10-05) Borja Lozano, María Victoria; Vigil Santillán, Bianca Estefani; More Montoya, Manuel J.; Morón Barraza, Jonathan A.; García Serquén, Aura Liz; Gutiérrez Reynoso, Gustavo; Yalta Macedo, Claudia Esther
Guinea pigs are a major source of animal protein for Peruvian Andean families. Despite the economic and cultural relevance of guinea pigs, their genomic characterization has been scarcely addressed. Genotyping-by-sequencing (GBS) has emerged as an affordable alternative to genotyping of livestock and native animals. Here, we report the use of GBS for single nucleotide polymorphism (SNP) discovery of traditionally raised guinea pigs from six regions of the Peruvian Andes and one group of breeding animals. The paired-end (2 × 150 bp) sequencing of 40 guinea pig DNA samples generated a mean of 6.4 million high-quality sequencing reads per sample. We obtained an average sequencing depth of 10× with an 88.5% mapping rate to the Cavia porcellus reference genome. A total of 279 965 SNPs (102 SNPs/Mbp) were identified after variant calling and quality filtering. Based on this SNP set, we assessed the genetic diversity and distance within our selected guinea pig populations. An overall average minor allele frequency of 0.13, an observed heterozygosity of 0.31, an expected heterozygosity of 0.35, and an F-value of 0.1 were obtained, while the SNP-based neighbor-joining tree suggests a closer genetic relationship between individuals from geographically close locations. We showed that GBS is a cost-effective tool for SNP discovery and genetic characterization of Peruvian guinea pig populations. Therefore, it may be considered as a suitable and affordable tool for genomic characterization of poorly studied native animal species.
Integrated pest management in Peru
(CABI Publishing, 2003) Palacios Lazo, María; Lizárraga Travaglini, Alfonso; Velásquez Ochoa, Ricardo; Carranza Hernández, Enrique; Segovia, Isaías
The successful Peruvian cotton IPM program, begun in the 1950s, has now been extended to various other countries. Currently, IPM in export crops such as cotton, citrus, sugarcane, mango and asparagus has improved marginal profits for Peruvian producers. In crops for domestic consumption such as potato, IPM has improved the food supply for the Andean population. In addition, it has reduced the risk of pesticide exposure, pesticide residues in food and in the environment. Potato IPM has also socially impacted the resource-poor farmers on Peruvian mountains.
Molecular tools against the illegal exploitation of the threatened Pacific seahorse Hippocampus ingens Girard, 1858
(ELSEVIER, 2021-06-12) Marín, Alan; Alfaro, Ruben; Villegas Llerena, Claudio; Reyes Flores, Lorenzo E.; Alvarez Jaque, Irina B.; Robles, Christian; Ingar, Claudia; Yzásiga Barrera, Carmen G.; Calado, Leonardo L.; Zelada Mázmela, Eliana
The high demand for syngnathid species in the traditional Chinese medicine (TCM) trade is drastically affecting seahorse populations worldwide. Powdered seahorse not only represents the main material for the preparation of remedies in either TCM or folk medicine but is also being used to facilitate smuggling and avoid customs authorities in different countries. Here, we present the first primer set and standardized real time quantitative PCR (qPCR) protocol designed for a fast, accurate, sensitive, and reliable identification of one of the most threatened fish species in the world, the Pacific seahorse Hippocampus ingens, using DNA traces from powdered material. Our protocol efficiently detected quantities as low as 0.85 pg of seahorse DNA, showing a high specificity even in the presence of DNA from other non-target fish species. The qPCR protocol reported herein may be utilized as a powerful tool to monitor the illegal domestic trade and international trafficking of H. ingens, not only in poaching hotspot countries such as Ecuador and Peru but also in transit and final market destinations such as Hong Kong and China. In addition, we show photographic evidence of seahorse extraction and trade in northern Peru and southern Ecuador, highlighting the need for increased efforts to protect the Pacific seahorse.
Morphometric evaluation of guinea pigs (Cavia porcellus) in Southern Peru
(Learning Gate, 2024-07-19) Quispe Condori, Dennis; Huacani Pacori, Ferdynand Marcos; Mamani Paredes, Javier; Mamani Cato, Ruben Herberht
The aim of this study was the morphometric evaluation of guinea pigs in southern Peru. The study was carried out at the Agrarian Experimental Station Illpa (AESI) of the National Institute of Agrarian Innovation (NIAI) in Puno at 3824 meters above sea level. 120 guinea pigs were used (females n = 60 and males n = 60) with an average age of 22 days. The morphometric characteristics evaluated were: body weight (BW), chest circumference (CC), abdominal perimeter (AP), neck perimeter (NP), head length (HL) and head width (HW). To evaluate the effect of sex on morphometric characteristics, a completely randomized design was used. To determine the equation that best predicts body weight, stepwise regression was used, and correlations between morphometric characteristics were obtained using Pearson's correlation. The results show that the sex factor does not significantly influence BW, CC, AP, NP, HL, and HW (p≥0.05); likewise, the equation that best predicts the body weight of the guinea pigs was: BW = -530.50 + 21.98(CC) + 12.72(AP) + 10.16(NP) + 57.23(HW), with R2 = 84%. Pearson correlations between morphometric characteristics were of high magnitude, positive, and statistically significant (p<0.001). It is concluded that in conditions of the Peruvian highlands, the sex factor does not influence the morphometric characteristics. It is also possible to predict body weight from CC, AP, NP, and HW, and the correlations were high and positive.
Paternal ancestry of Peruvian creole cattle inferred from Y-chromosome analysis
(El Sevier, 2020-12-15) Yalta Macedo, Claudia Esther; Veli Rivera, Eudosio Amancio; Díaz Ortiz, Gerardo Ramón; Vallejo Trujillo, Adriana
The aim of this study was the identification of the genetic diversity and paternal origin of Peruvian creole cattle. A panel of 7 Y-chromosome specific markers (INRA189, UMN0103, BM861, UMN307, BYM-1, DDX3Y_1STR and ZFY10) were analyzed in 229 cattle from 6 regions of the Peruvian highlands. The creole cattle exhibited low genetic diversity (H= 0.50) mostly explained by within-population variation (98%) and absence of population structure (FST = 0.019) in the analyzed regions. These results are in concordance to other studies in Spanish cattle populations. The overall frequency and distribution of the major B. taurus haplogroups: Y1 (19%) and Y2 (81%), suggests that Peruvian creole cattle derived from the Iberian Peninsula cattle. Furthermore, our results some degree of male-mediated African cattle influence in the Peruvian creoles, supporting the findings of other studies in South American creole cattle populations. Altogether, our results revealed unique genetic characteristics of Peruvian creole cattle that may have important implications for future conservation programs.
Patterns of Plumericin Concentration in Leaves of Himatanthus tarapotensis (Apocynaceae) and Its Interactions with Herbivory in the Peruvian Amazon
(MDPI, 2022-04-08) Amasifuen Guerra, Carlos Alberto; Patel, Kirti; Delprete, Piero G.; Spina, Andréa P.; Grados, Juan; Vásquez Ocmín, Pedro; Gadea, Alice; Rojas, Rosario; Guzmán, Jesús; Sauvain, Michel
We explored the concentration patterns of the bioactive metabolite plumericin produced by Himatanthus tarapotensis (Apocynaceae) under different edaphic conditions and variations in rainfall intensity, as well as its potential role in the chemical defense against insect herbivores. Values of plumericin concentration from leaves were obtained by High-Performance Liquid Chromatography, and evaluated as a function of differences in soil types, variation of precipitation, and variation of the abundance of insect herbivores, using first a Repeated Measures Correlation (rmcorr) and then a Generalized Linear Mixed Model (GLMM) analysis. Plumericin concentration is highly variable among plants, but with a significantly higher concentration in plants growing on clay soil compared to that of the white-sand soil habitat (p < 0.001). Plumericin concentration is not affected by precipitation. The caterpillar of Isognathus leachii (Lepidoptera: Sphingidae) is the most conspicuous herbivore of H. tarapotensis, and its presence is continuous but not related to plumericin concentration, probably because of its capacity to elude the chemical defense of this plant. Nevertheless, our multivariate model revealed that plumericin concentration is related to the abundance of Hymenoptera (Formicidae), and this relationship is significantly influenced by the soil parameters of carbon percentage, clay percentage, and phosphorous percentage (p < 0.001). Plumericin is a mediating agent in the interaction between H. tarapotensis and its natural environment. Variation in plumericin concentration would be induced by the abundance of Hymenoptera (Formicidae), probably as a chemical response against these insects, and by differences in soil nutrient availability.
Pelmatellus amicorum Delgado and Ruiz-Tapiador (Coleoptera: Carabidae), a New Species from the Andean Altiplano of Peru
(BioOne, 2020-03-25) Delgado Mamani, Pedro Ernesto; Ruiz Tapiador, Ildefonso
A new species of ground beetle, Pelmatellus amicorum Delgado and Ruiz-Tapiador (Coleoptera: Carabidae), from the Andean Altiplano of Peru is described. The state of knowledge of the genus and the relationship of the new species with known congeneric species are reviewed.
Performance and physiological quality of Escallonia resinosa seeds: prospects for their use in reforestation and restoration
(John Wiley and Sons Inc, 2022-12-10) Huayta Hinojosa, Luis David; Nolasco Lozano, Emily Gisella Ninfa; Guerra, Damaris; Hermoza Gamboa, Joel; Quispe Melgar, Harold Rusbelth
In the Andes, many native forest species are not used in reforestation or restoration programs mainly due to a lack of information about their propagation. In this study, we evaluated the performance of the seeds of Escallonia resinosa by analyzing fruit and seed productivity and characteristics, seed physiological quality, and the germination rate of seeds collected at different stages of fruit physiological maturity, using tetrazolium and standard germination tests. Our results show an estimated production (mean ± SD) of 34,252.5 ± 25,900 fruits per tree and 26.5 ± 20 million seeds per tree. Seed length was 1.0 ± 0.13 mm and seed weight was 12.4 ± 1 μg. We recognized two different morphological types of seeds: Type I seeds (lacking testa) were unviable, whereas all Type II seeds (with testa) germinated. Seed viability and germination rates were 10.5 and 48.6%, respectively; therefore, the viability test underestimated the actual germination rate. Morphological or microsite variables of the parent tree did not influence seed viability or germination. Germination rates were highest (41.8 ± 2.5%) for the seeds of fruits harvested at the initial maturity stage (green fruits). Our results show that E. resinosa is a species with potential for reforestation and restoration projects in the Andes: it has high seed production and good germination performance, and seeds can be harvested from fruits collected at different stages of physiological maturity.
Regional development in Amazonas, Peru: science-society interactions for sustainability
(SAGE Journals, 2020-09-16) Mick, Carola; Fernández, María E.; Alvarado Chuqui, Cástula; Amasifuen Guerra, Carlos Alberto; Kleiche Dray, Mina; López Minchán, Ana Paula; Silva López, Jhonsy Omar
Scientific-technological knowledge maintains the anthropocentric power-pattern and exploitive attitude with regard to nature, but sustainability science asks for an integration of territorial and decontextualized knowledge systems. Visual participatory methodologies involving diverse local stakeholder facilitate dialogue on environmental and sustainability issues. Inspired by visual ethnography and mediated discourse analysis, the present article uses semiological analysis to reconstruct the depicted narratives on the nature-society system in drawings representing “regional development”. The drawings were elaborated in a series of participatory workshops involving university faculty and students, regional government and non-governmental organizations and farmers from local communities in the northern Amazonian region of Peru. The analysis reveals a prevailing anthropo and technology centered, “colonial” conception of the nature-society system, and a marginalization of alternative narratives. Beyond confirming the potential for visual participatory methods to enhance multi-stakeholder dialogue, it demonstrates how semiological analysis can be used to deepen an understanding of the cultural, organizational and technological constraints facing critical, trans-disciplinary efforts to decolonize the technology-centered, anthropocentric mainstream worldview of nature and society.
Screening Genetic Resources of Capsicum Peppers in Their Primary Center of Diversity in Bolivia and Peru
(Boris Alexander Vinatzer, Virginia Tech, UNITED STATES, 2015-09-24) Van Zonneveld, Maarten J.; Ramírez, Marleni; Williams, David E.; Petz, Michael; Meckelmann, Sven W.; Avila, Teresa; Bejarano Martinez, Carlos; Ríos Lobo, Llermé; Peña Pineda, Karla Mónica; Jäger, Matthias; Libreros, Dimary; Amaya, Karen; Scheldeman, Xavier
For most crops, like Capsicum, their diversity remains under-researched for traits of interest for food, nutrition and other purposes. A small investment in screening this diversity for a wide range of traits is likely to reveal many traditional varieties with distinguished values. One objective of this study was to demonstrate, with Capsicum as model crop, the application of indicators of phenotypic and geographic diversity as effective criteria for selecting promising genebank accessions for multiple uses from crop centers of diversity. A second objective was to evaluate the expression of biochemical and agromorphological properties of the selected Capsicum accessions in different conditions. Four steps were involved: 1) Develop the necessary diversity by expanding genebank collections in Bolivia and Peru; 2) Establish representative subsets of ~100 accessions for biochemical screening of Capsicum fruits; 3) Select promising accessions for different uses after screening; and 4) Examine how these promising accessions express biochemical and agromorphological properties when grown in different environmental conditions. The Peruvian Capsicum collection now contains 712 accessions encompassing all five domesticated species (C. annuum, C. chinense, C. frutescens, C. baccatum, and C. pubescens). The collection in Bolivia now contains 487 accessions, representing all five domesticates plus four wild taxa (C. baccatum var. baccatum, C. caballeroi, C. cardenasii, and C. eximium). Following the biochemical screening, 44 Bolivian and 39 Peruvian accessions were selected as promising, representing wide variation in levels of antioxidant capacity, capsaicinoids, fat, flavonoids, polyphenols, quercetins, tocopherols, and color. In Peru, 23 promising accessions performed well in different environments, while each of the promising Bolivian accessions only performed well in a certain environment. Differences in Capsicum diversity and local contexts led to distinct outcomes in each country. In Peru, mild landraces with high values in health-related attributes were of interest to entrepreneurs. In Bolivia, wild Capsicum have high commercial demand.
Secondary succession of mixed plantations established to rehabilitate abandoned pasture in the Peruvian Amazon
(Japan Soc Tropical Ecology, 2014-09-01) Kobayashi, Shigeo; Soudre Zambrano, Manuel Antonio; Ricse Tembladera, Auberto
Secondary succession or facilitation processes carried out at sites established for rehabilitating abandoned pastures and degraded forests (prurmas) are instrumental in their return to original forest status. An understanding of these secondary succession processes contributes to the rehabilitation of degraded forest ecosystems and to the livelihoods of local communities, and aids in conserving biodiversity. We studied secondary succession in mixed species plantations that were established to rehabilitate abandoned land. The initial vegetation in these abandoned pastures and croplands was grassland composed of three dominant species: Rottboellia exaltata, Imperata brasiliensis, and Brachyaria decumbens. After tree planting and weeding had been carried out, the site was first invaded by R. exaltata and Baccharis floribunda. These two species, which depend solely on sexual and not vegetative reproduction, facilitated secondary succession and elevated species diversity by enabling subsequent invasion by several species. By contrast, B. decumbens, I. brasiliensis, and Hyparrhenia rufa depend mainly on vegetative reproduction involving rhizomes and tillers, and subsequent invasion by other species was relatively less in stand types dominated by these three species. We found that further adequate rehabilitation techniques were necessary for the respective vegetation types.
Soil organic carbon balance across contrasting plant cover ecosystems in the Peruvian Amazon
(Instituto de Investigaciones Agropecuarias, INIA, 2023-10-31) Vallejos Torres, Geomar; Gaona Jimenez, Nery; Lozano, Andi; Paredes, Christopher I.; Lozano, Carlos M.; Alva Arévalo, Alberto; Saavedra Ramírez, Jorge; Arévalo, Luis A.; Reategui, Keneth; Mendoza, Wilfredo; Baselly Villanueva, Juan Rodrigo; Marín, César
The Peruvian Amazon has been significantly affected by land use and climate change, decreasing decomposition processes, which cause a significant depletion of soil C stocks. In this study, we estimated soil organic C (SOC) mediated by different plant covers in coffee (Coffea arabica L.) plantations and secondary forests in several districts of the San Martín Region, Peru. We calculated the critical threshold, saturation point, and the organic C deficit of these Amazonian soils. The association between geography, soil physical-chemical characteristics, and SOC was estimated through principal component analysis. Across all sites of the study, SOC stock had an average value of 69.19 t ha-1, with 48.95 t ha-1 constituting inorganic C. The highest SOC stock (225.28 t ha-1) was observed under secondary forest in the Jepelacio district. The SOC stocks were positively correlated with altitude and CaCO3 content only in secondary forests. The current measured amount of organic C within 15 cm soil depth was 28.5 g C kg-1, which is very low and close to the critical threshold (20.6 g C kg-1) -estimated based on its clay and silt contents. Our SOC stocks measurements indicated a worrisome situation, as they are close to the critical threshold, which exposes this area to a greater and stronger degradation.