Dilemas do desenvolvimento agrário

Novaes, Washington

doi:10.1590/s0103-40142001000300006

Cited by 7 publications

(6 citation statements)

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“…Within the forest fragmentation context, one of the global biomes with the most biodiversity, the Brazilian Atlantic Forest, has experienced high rates of deforestation and fragmentation, with less than 17% of the original forest cover remaining (Ribeiro et al 2009). This biome is characterized by high levels of species endemism (Novaes 2001). Genetic conservation is especially important for endemic tree species, since forest fragmentation can lead to species extinction or loss of many tree populations.…”

Section: Introductionmentioning

confidence: 99%

Low genetic diversity and intrapopulation spatial genetic structure of the Atlantic Forest tree, Esenbeckia leiocarpa Engl. (Rutaceae)

et al. 2014

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Abstract. Studies on population genetics are the key to designing effective in situ management plans for tree species, in particular, those subjected to pressure from anthropogenic processes, such as forest fragmentation and logging. To investigate genetic diversity, inbreeding and intrapopulation spatial genetic structure (SGS) in a fragmented population of the insect-pollinated tropical tree, Esenbeckia leiocarpa, we developed specific microsatellite markers for this species and mapped and sampled 100 individuals in a forest plot. Two issues were addressed in particular: (i) the level of genetic diversity, inbreeding and effective population size, (ii) whether intrapopulation spatial genetic structure exists. Among the 14 loci developed, we only used the three that presented polymorphism to estimate the genetic parameters. Genetic diversity was low, whereby the average number of alleles per locus (A) was 3.3 and observed (H 0 ) and expected heterozygosities (H e ) were 0.336 and 0.298, respectively. The average fixation index was significantly higher than zero (F = 0.112), suggesting inbreeding. Significant SGS was found up to 7 m and between 31 to 38 m, indicating that trees growing within these distances may be related. Estimates of the effective population size indicated that the 100 sampled trees correspond to 14 individuals that are neither related nor inbred. Our results suggest that the microsatellite markers developed in this study are suitable for studies on genetic diversity and structure, mating systems, gene flow and SGS in this species.

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Section: Introductionmentioning

confidence: 99%

Low genetic diversity and intrapopulation spatial genetic structure of the Atlantic Forest tree, Esenbeckia leiocarpa Engl. (Rutaceae)

et al. 2014

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“…O fato é que a produção agrícola convencional causa uma série de problemas ambientais, tais como a poluição dos rios, salinização do solo e destruição da biodiversidade. Além disso, está associado a questões sociais, como a desigualdade na distribuição da renda agrícola, o abandono de pequenos agricultores e a perda de conhecimentos tradicionais (NOVAES, 2001;WEDIG, 2009;SOUZA, 2015;MONTEIRO et al, 2023;FONSECA, 2023).…”

Section: Agricultura Convencional Tradicional E Agroecológicaunclassified

“…Além disso, ela está associada a questões sociais, incluindo a distribuição desigual de renda agrícola, o abandono de pequenos agricultores no campo e a perda de conhecimentos tradicionais (WEDIG, 2009;FONSECA, 2022). Esses impactos compõem um panorama amplo de desafios que a agricultura convencional enfrenta em termos ambientais e sociais (Figura 4) (NOVAES, 2001;SOUZA, 2015). Diante do atual cenário, a transição para práticas agrícolas mais sustentáveis e orientadas para a conservação se torna imperativa.…”

Section: Agricultura Convencional Tradicional E Agroecológicaunclassified

Procedimentos e ferramentas de suporte à sustentabilidade agropecuária

Effgen,

Figueiredo,

Vardiero

et al. 2024

Tópicos Em Gestão Ambiental

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Apesar dos avanços proporcionados pelo modelo convencional em termos de produtividade e produção, os resultados muitas vezes não cumpriram as promessas da chamada "Revolução Verde". Os danos associados ao cultivo convencional, em comparação com cultivos alternativos, são significativos, afetando tanto o meio ambiente quanto os seres vivos, incluindo os trabalhadores envolvidos. A agricultura convencional também impacta negativamente as plantas e a fauna devido ao uso excessivo de produtos químicos. Em resposta a essas preocupações, surgiram modelos e práticas alternativas baseadas em abordagens agroecológicas, tais como a agricultura natural, a orgânica e a sintrópica. Estas propostas buscam promover práticas sustentáveis nos aspectos social, ecológico, técnico e econômico, guiadas por normas de produção. A transição de áreas agropecuárias convencionais para modelos de produção agroecológicos é uma estratégia para recuperar áreas degradadas, frequentemente alteradas pela agricultura e pecuária convencionais. Esses modelos se destacam como alternativas sustentáveis que também proporcionam emprego e renda estáveis para as famílias rurais. O controle biológico, por exemplo, é reconhecido como um dos métodos mais eficazes para lidar diversas pragas, com o bicho-mineiro: em sistemas de produção de café que seguem boas práticas agrícolas, como adensamento e uso de plantas companheiras, que são ecologicamente equilibrados, o bicho-mineiro tende a não causar danos econômicos significativos, pois os inimigos naturais favorecidos por essas práticas promovem o controle biológico natural. A influência do meio ambiente evidencia que os impactos na perda de biodiversidade são significativamente reduzidos em sistemas de produção não-convencionais em comparação aos convencionais.Palavras-chave: Agroecossistemas. Modelos de produção. Procedimentos e ferramentas pró-sustentabilidade.

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“…In Brazil, according to Takitane et al (2012) are generated more than 100 milions cubic meters by year of swine waste from cleaning of the bays through washing with hose, which is a hygienic and sanitary management adopted by Brazilian pig farms. In comparison to other agricultural activities, the swine production is considered the most polluting agricultural activity of surface water and groundwater (Novaes, 2001). For many years, untreated swine wastes were applied in agricultural soils next to swine farms, causing the contamination of these areas.…”

Section: Introductionmentioning

confidence: 99%

Carbon Mineralization in Soils Irrigated with Treated Swine Wastewater

Moretti¹,

Bertoncini²,

Abreu-Junior³

2017

JAS

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Treated swine wastewater agricultural use can promote environmental and agronomical improvements, however, the inappropiate management of this organic load added on soil can cause unbalances in soil fertility and in availability of nutrients and/or contaminants. Thus, this study aim was evaluate the organic matter biodegradation of treated swine wastewater (WB) and diluted swine wastewater (WBD) applied in Oxisol clayey texture (CS) and in Ultisol (SS) with medium-sandy texture. The treatments studied were: R1 -CS control; R2 -irrigation with WB on CS; R3 -irrigation with WBD on CS; R4 -SS control; R5 -irrigation with WBD on SS; R6 -irrigation with WBD on SS. Three applications were done in flasks containing 500 g of soils sampled from depth of 0-20 cm, the C-CO 2 evolutions and degradation fractions were quantified after each application. The results obtained were adjusted to first-order chemical kinetics model. More than half organic matter was biodegraded between 4 and 10 days of incubation, when higher WB amount was applied (33.3 mm). Sucessive WBD use caused degradation of organic matter remaning of previous application. Higher CO 2 evolutions were obtained for Oxisol treatments due to higher carbon contents of this soil. SW use caused depletion of Ultisol native organic matter. However, the WB use in Oxisol provided accumulation of organic matter. Soon, the respirometry test evidenced the importance of evaluate the soil depuration capacity before agricultural use, since that this process can affect the contents of organic matter native of these soils and the availabity of nutrient/contaminant for soil-water-plant system.

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Dilemas do desenvolvimento agrário

Cited by 7 publications

References 0 publications

Low genetic diversity and intrapopulation spatial genetic structure of the Atlantic Forest tree, Esenbeckia leiocarpa Engl. (Rutaceae)

Low genetic diversity and intrapopulation spatial genetic structure of the Atlantic Forest tree, Esenbeckia leiocarpa Engl. (Rutaceae)

Procedimentos e ferramentas de suporte à sustentabilidade agropecuária

Carbon Mineralization in Soils Irrigated with Treated Swine Wastewater

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