Climate risk to peanut cultivation in Brazil across different planting seasons.

BACKGROUND: Peanuts are widely grown in Brazil because of their great importance in the domestic vegetable oil industry and the succession of sugarcane, soybean and maize crops, contributing to soil conservation and improvement in agricultural areas. Thus, the present study aimed to determine the zoning of peanuts' climatic risk by estimating the water requirement satisfaction index (WRSI) for the crop in Brazil. We used a historical series of data on average air temperature and rainfall between 1980 and 2016. Reference evapotranspiration was estimated using the method of Thornthwaite, and we subsequently calculated crop evapotranspiration and maximum evapotranspiration. Water balances for all stations were calculated using the method of Thornthwaite and Mather, with an available water capacity in the soil of 15, 30 and 45 mm. The definitions of suitable, unfit and restricted areas and the planting season were performed using the WRSI. RESULTS: Brazil has low climatic risk areas for growing peanuts throughout the year, except for winter. The country reveals that 88.19%, 97.93%, 99.16% and 39.25% of its area is suitable for planting peanuts on planting dates in spring, summer, autumn and winter, respectively. CONCLUSION: Brazil has a large part of the areas favorable to the planting of peanuts. The maximum availability of soil water at a depth of 15, 30 and 45 mm does not influence regions with respect to peanut growing in Brazil. The states of Piauí, Ceará and Bahia are the most unsuitable on the winter planting date, with an average WRSI of 0.22. © 2021 Society of Chemical Industry.

Early Holocene crop cultivation and landscape modification in Amazonia.

The onset of plant cultivation is one of the most important cultural transitions in human history1-4. Southwestern Amazonia has previously been proposed as an early centre of plant domestication, on the basis of molecular markers that show genetic similarities between domesticated plants and wild relatives4-6. However, the nature of the early human occupation of southwestern Amazonia, and the history of plant cultivation in this region, are poorly understood. Here we document the cultivation of squash (Cucurbita sp.) at about 10,250 calibrated years before present (cal. yr BP), manioc (Manihot sp.) at about 10,350 cal. yr BP and maize (Zea mays) at about 6,850 cal. yr BP, in the Llanos de Moxos (Bolivia). We show that, starting at around 10,850 cal. yr BP, inhabitants of this region began to create a landscape that ultimately comprised approximately 4,700 artificial forest islands within a treeless, seasonally flooded savannah. Our results confirm that the Llanos de Moxos is a hotspot for early plant cultivation and demonstrate that-ever since their arrival in Amazonia-humans have markedly altered the landscape, with lasting repercussions for habitat heterogeneity and species conservation.

Genetic and phenotypic diversity in 2000 years old maize (Zea mays L.) samples from the Tarapacá region, Atacama Desert, Chile.

The evolution of maize (Zea mays L.) is highly controversial given the discrepancies related to the phenotypic and genetic changes suffered by the species, the incidence of human groups and the times in which these changes occurred. Also, morphological and genetic traits of crops are difficult to evaluate in the absence of fossils macro-botanical remains. In contrast in the Tarapacá region (18-21° S), Atacama Desert of Chile, prehispanic settlements (ca. 2500-400 yr BP) displayed extensive maize agriculture. The presence of archaeological macro-botanical remains of maize provided a unique opportunity to study the evolution of this crop, covering a temporal sequence of at least 2000 years. Thus, in this study, we ask how the morphological and genetic diversity of maize has varied since its introduction during prehispanic times in the Tarapacá region. To answer this, we measured and compared morphological traits of size and shape between archaeological cobs and kernels and 95 ears from landraces. To established genetic diversity eight microsatellite markers (SSR) were analyzed in archaeological and modern kernels. Genetic diversity was estimated by allelic frequency rates, the average number of alleles per locus, observed heterozygosity (Ho) and expected heterozygosity (He). Differences between populations and genetic structure were estimated by fixation index FST and STRUCTURE analysis. Our results indicate significant phenotypic differences and genetic distance between archaeological maize and landraces. This result is suggestive of an introduction of new varieties or drastic selective changes in modern times in Tarapacá. Additionally, archaeological maize shows a low genetic diversity and a progressive increase in the size of ears and kernels. These results suggest a human selection during prehispanic times and establish that prehispanic farmers played an important role in maize development. They also provide new clues for understanding the evolutionary history of maize in hyperarid conditions.

Greater post-Neolithic wealth disparities in Eurasia than in North America and Mesoamerica.

How wealth is distributed among households provides insight into the fundamental characters of societies and the opportunities they afford for social mobility. However, economic inequality has been hard to study in ancient societies for which we do not have written records, which adds to the challenge of placing current wealth disparities into a long-term perspective. Although various archaeological proxies for wealth, such as burial goods or exotic or expensive-to-manufacture goods in household assemblages, have been proposed, the first is not clearly connected with households, and the second is confounded by abandonment mode and other factors. As a result, numerous questions remain concerning the growth of wealth disparities, including their connection to the development of domesticated plants and animals and to increases in sociopolitical scale. Here we show that wealth disparities generally increased with the domestication of plants and animals and with increased sociopolitical scale, using Gini coefficients computed over the single consistent proxy of house-size distributions. However, unexpected differences in the responses of societies to these factors in North America and Mesoamerica, and in Eurasia, became evident after the end of the Neolithic period. We argue that the generally higher wealth disparities identified in post-Neolithic Eurasia were initially due to the greater availability of large mammals that could be domesticated, because they allowed more profitable agricultural extensification, and also eventually led to the development of a mounted warrior elite able to expand polities (political units that cohere via identity, ability to mobilize resources, or governance) to sizes that were not possible in North America and Mesoamerica before the arrival of Europeans. We anticipate that this analysis will stimulate other work to enlarge this sample to include societies in South America, Africa, South Asia and Oceania that were under-sampled or not included in this study.

[Health and environment in the rubber-tree plantations in the Bolivian Acre (1870-1903): the role of exogenous factors and processes]. / Saúde e ambiente nos seringais do Acre boliviano (1870-1903): o papel de fatores e processos exógenos.

A peculiar situation marks the conditions of human and environmental health in the first major cycle of rubber production in the Acre region of the Western Amazon, whereby the bulk of the boom (1870-1903) occurred in the territory that at that time still belonged to Bolivia. Based on this historical background, this work seeks to describe and comprehend how these factors and processes, which are exogenous to these two fields of analysis mediated the risks that originated in the environment, gave rise to sickness and death in the population of the "Brazilian" rubber-tree plantations established in Bolivian territory. In this manner, the inter-relations between health and environment linked to historically specific configurations of the physical-natural, socioeconomic, political, and cultural conditions, are examined. The work shows that these extrinsic factors and processes to the productive activities exerted an influence not only on its organizational but also functional aspects, while also resulting in the unhealthy conditions observed in the productive regions. It further highlights the fact that the extant infrastructure of the time was sufficient for extractive production and reproduction.

Saúde e ambiente nos seringais do Acre boliviano (1870-1903): o papel de fatores e processos exógenos / Health and environment in the rubber-tree plantations in the Bolivian Acre (1870-1903): the role of exogenous factors and processes

Situação particular marca as condições da saúde humana e do ambiente no primeiro surto da produção gomífera na Amazônia Ocidental, região do Acre, sendo que a maior parte dele (1870-1903) ocorreu em território ainda pertencente à Bolívia. Com base nesse quadro histórico, o trabalho busca descrever e compreender como fatores e processos exógenos a esses dois campos de análise mediavam os riscos, com origem no ambiente, para o adoecimento e a morte nas populações dos seringais "brasileiros" em território boliviano. Explora-se, assim, a inter-relação entre saúde e ambiente, a partir das configurações historicamente específicas das condições físico-naturais, socioeconômicas, políticas e culturais. O trabalho evidencia que esses fatores e processos extrínsecos às atividades produtivas exerceram não só influência, tanto em seu aspecto organizativo quanto funcional, como determinaram as condições insalubres que se observaram nas regiões produtoras. Aponta, ainda, que a infraestrutura então existente era suficiente para a produção e a reprodução extrativista.

A peculiar situation marks the conditions of human and environmental health in the first major cycle of rubber production in the Acre region of the Western Amazon, whereby the bulk of the boom (1870-1903) occurred in the territory that at that time still belonged to Bolivia. Based on this historical background, this work seeks to describe and comprehend how these factors and processes, which are exogenous to these two fields of analysis mediated the risks that originated in the environment, gave rise to sickness and death in the population of the "Brazilian" rubber-tree plantations established in Bolivian territory. In this manner, the inter-relations between health and environment linked to historically specific configurations of the physical-natural, socioeconomic, political, and cultural conditions, are examined. The work shows that these extrinsic factors and processes to the productive activities exerted an influence not only on its organizational but also functional aspects, while also resulting in the unhealthy conditions observed in the productive regions. It further highlights the fact that the extant infrastructure of the time was sufficient for extractive production and reproduction.