Tiago Santos Telles

The costs of soil erosion

The aim of this study was a survey of the estimated costs of soil erosion, an issue of fundamental importance in view of the current worldwide discussions on sustainability. A list was drawn up of research papers on erosion (on-site and offsite effects) and their respective costs. The estimates indicate the amount of resources spent in the process of soil degradation, raising a general awareness of the need for soil conservation. On-site costs affect the production units directly, while off-site costs create a burden borne by the environment, economy and society. In addition, estimating the costs of soil erosion should be effective to alert the agricultural producers, society and government for the need for measures that can be implemented to bring erosion under control. Among the various estimates of soil erosion costs between 1933 a 2010, the highest figure was 45.5 billion dollars a year for the European Union. In the United States, the highest figure was 44 billion dollars a year. In Brazil, estimates for the state of Parana indicate a value of 242 million dollars a year, and for the state of Sao Paulo, 212 million dollars a year. These figures show, above all, that conservation measures must be implemented if crop and livestock farming production are to be sustainable.

Valuation and assessment of soil erosion costs

Soil is an essential natural resource for humans and an important part of the environment. However, soil is often used and managed inappropriately, causing its erosion and degradation, with concomitantly negative social, political and economic impacts. This study aimed to discuss sustainable development; and losses and problems caused by soil erosion, and to suggest a model for assessing erosion costs. The relevance of economic models for costing soil erosion is stressed. Based on an economic theory, it presents a procedure for assessing economic costs of soil erosion, centered on the on-site and off-site costs that are generated. The physical processes of soil erosion are described and their economic effects reviewed, drawing on theoretical and empirical sources. Limited data and information is available on the economic losses resulting from erosion, which hampers assessment and valuation.

Physical properties of a rhodic haplustox under two sugarcane harvesting systems

SUMMARY This study had the purpose of evaluating the effects of two management types of sugarcane: harvesting of burnt cane (BCH) and mechanized harvesting of unburnt green cane (MCH), on some soil physical properties of a dystrophic Rhodic Haplustox. The data were then compared with results for the same soil type under native forest. A completely randomized design was used, with three treatments and 20 replications. The following characteristics were determined: organic matter, aggregate stability, soil bulk density, and porosity at depths of 0–0.20 m and soil penetration resistance. After 15 years of cultivation, there were some alterations in the soil under cane burnt before harvesting, evidenced by a drop in the weighted average diameter of stable aggregates in water and increased soil bulk density. Significant changes were also detected in total porosity and pore distribution under both harvesting systems. Critical values for penetration resistance were observed in the area under mechanized sugar cane harvesting, with a value of 4.5 MPa in the 40–55 cm layer. This value is considered high and could indicate compaction and restriction of root growth. Soil properties under the green cane (unburned) management system were closest to those of the soil under native forest.

Perdas e custos associados à erosão hídrica em função de taxas de cobertura do solo

O objetivo deste estudo e estimar custos da erosao hidrica associados as perdas de nutrientes em quatro taxas de cobertura artificial do solo. O experimento foi conduzido de 1987 a 1996, em talhoes coletores de perdas por erosao, em Campinas (SP), em Latossolo Vermelho distroferrico, sob chuva natural. O delineamento experimental foi inteiramente ao acaso, com quatro tratamentos (taxas de cobertura do solo: 0%, 24%, 40% e 90%) e tres repeticoes. Para estimar os custos, os teores de P, K+, Ca2+ e Mg2+ na agua da enxurrada e na terra carreada pela erosao foram somados, convertidos em superfosfato triplo, cloreto de potassio e calcario dolomitico, e multiplicados pelos seus precos de mercado. Os resultados indicam, para as condicoes experimentais, que quanto maior o percentual de cobertura do solo, menores as perdas de agua, terra, materia orgânica e nutrientes. O solo com 90% de cobertura, em comparacao aquele com 0%, reduziu as perdas medias de agua em 51,97%, de terra em 54,44% e de materia orgânica em 54,91%. Em solo sem cobertura, foram estimadas perdas de 16% de P2O5 e 8% de KCl em relacao a quantidade de fertilizantes recomendada. Os custos variaram de US

Institutional landmarks in Brazilian research on soil erosion: a historical overview

107,76 ha–1 ano–1 no solo com 0% de cobertura a US

Evolução da Ocupação e do Rendimento das Pessoas no Espaço Rural Brasileiro no Período de 2001 a 2009

18,15 ha–1 ano–1 no solo com 90%. A partir desses valores, estimaram-se para o Brasil perdas de 616,5 milhoes de toneladas de terra ao ano, decorrentes do processo de erosao do solo em lavouras anuais, e custos da ordem de US

Indicators of soil quality in the implantation of no-till system with winter crops

1,3 bilhao ao ano.

Soil aggregation and carbon stabilization in burn and no-burn sugarcane management systems

A percepcao do problema da erosao do solo, nas pesquisas brasileiras em ciencias agrarias, vem sendo relatada desde o seculo XIX. Nesse contexto, o objetivo deste trabalho foi realizar uma revisao historica dos marcos institucionais que fomentaram as pesquisas em erosao do solo no Brasil e deram inicio as pesquisas agricolas no pais. Ao longo do seculo XIX e inicio do seculo XX, observaram-se a criacao de jardins botânicos, instituicoes executivas, institutos de pesquisa, estacoes experimentais e instituicoes de ensino e a elaboracao e diversificacao de periodicos de comunicacao tecnico-cientifica. Esses estabelecimentos atuaram, cada qual a sua maneira, nas pesquisas em erosao do solo no Brasil. No periodo Imperial (1808-1889), as discussoes se concentravam no esgotamento do solo e na manutencao da fertilidade das terras agricolas. Na Primeira Republica (1889-1930), com a criacao de varias instituicoes de ensino e com a consolidacao do Instituto Agronomico nas pesquisas sobre a degradacao dos solos, os estudos se pautaram na discussao sobre o depauperamento do solo, na identificacao dos principais fatores geradores do processo de erosao e nas medidas necessarias para o seu controle. No Estado Novo (1930-1945), foram desenvolvidas e disseminadas inumeras praticas de conservacao do solo para combater a erosao, implantando-se experimentos para medir o volume das perdas, principalmente de terra e agua por erosao hidrica. Na Republica Nova (1945-1964), experimentos foram instalados em praticamente todas as regioes do pais. A conservacao do solo e a da agua se consolidaram como uma das principais areas da Ciencia do Solo no Brasil. Eventos cientificos comecaram a ser realizados sobre a tematica. A pos-graduacao foi instituida no pais. No Regime Militar (1964-1985), muitas instituicoes de pesquisa e ensino foram criadas e os trabalhos experimentais foram intensificados. Nesse periodo, o processo de erosao do solo atingiu patamares alarmantes e o sistema de Plantio Direto foi desenvolvido no pais.

Effects of sugarcane harvesting with burning on the chemical and microbiological properties of the soil

In the last decade of the 20th century it was observed an increasing diversification in the composition of the agricultural occupation and a slow increasing of Brazilian rural population in productive age. The aim of this study was to report the main tendencies on occupation and income of population in the rural space of Brazil in the 2001-2009 period. From the data of National Household Sample Survey (PNAD) and based in a log-linear regression model, an analysis on variation in population, income, average income and Gini index was made. It was identified that, despite the continuous decline of the total economically active population (EAP) occupied in the mercantile agriculture, the Brazilian rural population remained stable, mainly due to the expansion of EAP with off-agricultural occupation. The change on the profile of Brazilian rural space was more evident in the population income. These tendencies are associated with the diversification of the occupational composition, the increase of the acquisitive power, the reduction of the access to income inequality and the decrease of informal employment in the rural space. The continuity of these trends may lead to, in the rural area, both occupation and income from agricultural activities are surpassed by those originated from off-agricultural activities. Therefore, the readjustment of the rural development initiatives, which are mainly focused in the agricultural activities, is necessary.

Performance of elite cultivars of industrial cassava in savannah area of Mato Grosso do Sul State, Brazil

We assessed the effect of different winter crops on indicators of soil quality related to C and N cycling and C fractions in a Rhodic Kandiudult under no-till system at implantation, during two growing seasons, in Londrina PR Brazil. The experimental design was randomized blocks with split-plot in time arrangement, with four replications. The parcels were the winter crops: multicropping of cover crops with black oat (Avena strigosa), hairy vetch (Vicia villosa) and fodder radish (Raphanus sativus); sunflower (Heliantus annuus) intercropped with Urochloa ruziziensis; corn (Zea mays) intercropped with Urochloa; and corn; fodder radish; or wheat (Triticum aestivum) as sole crops. The subplots were the years: 2008 and 2009. Determinations consisted of total organic C, labile and resistant C, total N, microbial biomass C and N, the C/N ratio of soil organic matter, and the microbial quotient (qMic), besides microbiological and biochemical attributes, assessed only in 2009. The attributes significantly changed with the winter crops, especially the multicropping of cover crops and fodder radish, as well as effect of years. Despite stimulating the microbiological/biochemical activity, fodder radish cropping decreased the soil C in the second year, likewise the wheat cropping. The multicropping of cover crops in winter is an option for management in the establishment of no-till system, which contributes to increase the concentrations of C and stimulate the soil microbiological/biochemical activity.