Submitted by Michele Mologni (mologni@unoeste.br) on 2018-05-11T14:33:01Z No. of bitstreams: 1 Ricardo Augusto da Silva.pdf: 1884085 bytes, checksum: e146cbd401e4e50cee2228e675dbd8fa (MD5) / Made available in DSpace on 2018-05-11T14:33:01Z (GMT). No. of bitstreams: 1 Ricardo Augusto da Silva.pdf: 1884085 bytes, checksum: e146cbd401e4e50cee2228e675dbd8fa (MD5) Previous issue date: 2017-11-17 / Brazil has an area of 715,580 thousand hectares of citrus fruits (Orange and Lemon), resulting in a production in the year 2015 of 17,926,518.00 million tons, of which 47,391 thousand ha are of Lemon and ‘Tahiti’ Lime (IBGE, 2017), which demonstrates the importance of the activity for the country. In the state of Paraná, the Lemon / ‘Tahiti’ Lime area occupies an area of 1034 hectares, resulting in a production of 30,141 tons, generating a Gross Production Value (VBP) of R$ 50,637,384.00 million (1,8% of state fruit production), showing the importance of the crop to the state. The work was carried out between February 2015 and July 2016 (2014/2015, 2015/2016), in rural properties located in the municipalities of Santa Fé, Ângulo, Iguaraçu, Nova Esperança and Altônia, both in the state of Paraná . It was obtained the establishment of the DRIS norms for the nutritional diagnosis of Tahiti Lime (Citrus latifolia Tanaka) for the State of Paraná, using as standard the productivity of 32.5 t ha-1 (2014/2015 and 2015/2016 crops). It was observed in the data of the samples of the selected cut point (above 32.5 t ha-1) that in the agricultural year 2014/2015 the major deficiency was nutrient B (40%), followed by Mg (26%). As for nutrient contents, nutrients S (25%), Ca (20%) and K (18%) were observed. Already, in the results with the data of the agricultural year 2015/2016, deficiency of P (21%) was verified, followed by the nutrients B and Fe (20% both). In relation to the contents of excessive nutrients, one can observe K (21%), followed by nutrients N (16%) and Mn (14%). It is possible to define a criterion for choosing which matrix generated by the DRIS system to use at the field level, since the higher the productivity, the lower the IBN was obtained by calculating and analyzing the correlation (r) between the Nutritional Balance Index IBN) and DRIS matrices for the different productive levels. it was obtained the establishment of the DRIS standards for Tahiti Lime (Citrus latifolia Tanaka) for the state of Paraná, using as standard, productivity above 32.5 t ha-1. / O Brasil possuí uma área de 715.580 mil hectares de frutas cítricas (Laranja e Limão), resultando em uma produção no ano de 2015 de 17.926.518,00 milhões de toneladas, sendo que desse montante 47.391 mil ha são de Limão e Lima Ácida (IBGE, 2017), o que demonstra a importância da atividade para o país. No Paraná, o Limão/Lima Ácida Tahiti ocupa uma área de 1034 hectares, resultando em uma produção de 30.141 toneladas, gerando um Valor Bruto de Produção (VBP) de R$ 50.637.384,00 milhões (1,8% da produção da fruticultura estadual), mostrando a importância da cultura para o estado. O trabalho foi realizado entre os meses de Fevereiro de 2015 à Julho de 2016 (safras 2014/2015, 2015/2016), em propriedades rurais situadas nos municípios de Santa Fé, Ângulo, Iguaraçu, Nova Esperança e Altônia, ambos no estado do Paraná. Obteve-se o estabelecimento das normas DRIS para a diagnose nutricional da Lima Ácida Tahiti (Citrus latifolia Tanaka) para o Estado do Paraná, utilizando como padrão a produtividade de 32,5 t ha-1 (safras 2014/2015 e 2015/2016). Observou-se nos dados das amostras do ponto de corte escolhido (acima de 32,5 t ha-1) que, no ano agrícola 2014/2015 a deficiência maior foi do nutriente B (40%), seguido do Mg (26%). Quanto aos teores dos nutrientes excessivos, verificou-se nos nutrientes S (25%), seguidos do Ca (20%) e K (18%). Já, nos resultados com os dados do ano agrícola 2015/2016, verificou-se deficiência de P (21%), seguido dos nutrientes B e Fe (20% ambos). Em relação aos teores de nutrientes excessivos, pode-se observar o K (21%), seguido dos nutrientes N (16%) e Mn (14%). Pode-se definir um critério para escolha de qual matriz gerada pelo sistema DRIS utilizar à nível de campo, haja vista que quanto maior a produtividade menor foi o IBN, através do cálculo e análise da correlação (r) entre o Índice de Balanço Nutricional (IBN) e matrizes DRIS para os diferentes níveis produtivos. obteve-se o estabelecimento das normas DRIS para a Lima Ácida Tahiti (Citrus latifolia Tanaka) para o estado do Paraná, utilizando como padrão, a produtividade acima de 32,5 t ha-1.

A contaminação do solo é crescente no mundo. Há grandes extensões de áreas contaminadas com elementos traço, compostos orgânicos, organometálicos e elementos radioativos, que ocorrem em concentrações que podem representar perigo ambiental. O comportamento dos elementos traço em solos e sua fitodisponibilidade com conseqüente passagem para a cadeia alimentar tem sido extensivo objeto de estudos mundialmente. Com o objetivo de avaliar o comportamento dos elementos traço, essenciais e não essenciais, num solo contaminado avaliou-se a absorção pelas plantas, a fitodisponibilidade por extratores e a fração do solo na qual os elementos encontram-se ligados em maior quantidade. O presente trabalho constou de dois experimentos, ambos realizados em casa de vegetação do Departamento de Ciência do Solo da ESALQ/USP com delineamento inteiramente casualizados, nos quais se utilizaram amostras de solo contaminado acidentalmente com elementos traço e espécies de plantas de interesse econômico. Os experimentos foram conduzidos de Novembro de 2004 a Abril de 2005, utilizando 7 níveis de contaminação por elementos traço e duas culturas, arroz e soja. Foi realizada adubação NPK de modo a atender as necessidades básicas de cada cultura. As plantas foram conduzidas até maturação. As variáveis avaliadas foram: desenvolvimento e produção vegetal; quantidade absorvida e acumulada de Cd, Cu, Fe, Mn, Pb e Zn; teores totais (água régia) e teores disponível dos elementos traço pelo uso das soluções Mehlich-1, HCl 0,1 mol L-1, DTPA e Ácidos Orgânicos no solo e a disponibilidade desses elementos através da correlação dos teores disponível no solo com os teores em folha diagnóstico, folha em final de ciclo e sementes de arroz e soja; e os teores de elementos traço nas frações do solo. A soja e o arroz foram sensíveis aos níveis de contaminação por elementos traço disponíveis no solo, exibindo sintomas de fitotoxidez, principalmente pelo Zn, manifestados por clorose e inibição do crescimento das plantas, sendo que o arroz mostrou-se mais sensível do que a soja à presença desses elementos. Para a soja, os quatro extratores foram eficientes para Cd, Cu, Pb e Zn, tanto ao correlacioná-los com teor na folha diagnóstico quanto na folha no final do ciclo enquanto que para o arroz, os mais eficientes foram o Mehlich-1, HCl 0,1 mol L-1 e o DTPA para o Cd, Cu, Fe e Zn. Para o Mn apenas o DTPA foi eficiente. Para o Fe, os extratores se mostraram pouco eficientes. O extrator Ácidos Orgânicos foi mais eficiente na avaliação da fitodisponibilidade de Cd, Cu, Pb e Zn para soja. Os maiores teores de Cd, Cu, Mn e Zn no solo encontram-se nas frações com ligações químicas mais estáveis (ligados a óxidos e residual) sendo as frações trocável + solúvel e orgânica de menor representatividade em relação ao total encontrado. O Pb, apesar de predominar nas frações ligadas a óxidos e residual, oferece grande potencial de contaminação ambiental por também apresentar-se nas frações trocável + solúvel e orgânica em teores consideráveis. O mesmo ocorre com o Zn, para o qual os teores totais foram mais elevados. / The contamination of the soil is growing in the world. There are great expanses of soil polluted with trace elements, organic compounds, organometals and radioactive elements that appear in concentrations that can endanger the environment. The behavior of trace elements in soils and its phytoavailability with subsequent transport to the alimentary chain has been quite intensive object of studies worldwide. With the objective of evaluating the behavior of essentials and non essential trace elements in a polluted soil, it was evaluated the absorption of trace elements by plants, its phytoavailability by extractors and in which fraction of the soil the elements are present in larger amount. The present work consisted of two experiments, both done entirely in a greenhouse of the Department of Soil Science of ESALQ/USP, with experimental design entirely randomized, in which samples of soil accidentally contaminated with trace elements and species of plants of economical interest were used. The experiments were conducted from November, 2004 to April, 2005, using seven levels of contamination for each trace elements and two cultures, rice and soybean. Fertilization with NPK was done in order to assist the basic needs of each culture. The plants were grown until maturation. The variables evaluated were: development and vegetable production; absorbed and accumulated amount of Cd, Cu, Fe, Mn, Pb and Zn; In the soil were determined total concentrations (HNO3/ HCl 1:3) and concentrations available of the trace elements by the use of the solutions Mehlich-1, HCl 0,1 mol L-1, DTPA and Organic Acids and the availability of those elements through the correlation of the available concentrations in the soil with the concentrations in diagnostic leaf, leafs in end of the cycle and seeds of rice and soybean; and the concentrations of trace elements in fractions of soil. The soybean and the rice were sensitive to the levels of trace elements available in the soil, exhibiting phytotoxicity symptoms, mainly for Zn, manifested as chlorosis and inhibition of growth. The rice was more sensitive than the soybean to the presence those elements. For soybean, the four extractors were efficient for Cd, Cu, Pb and Zn, both for the correlation with concentrations in the leaf diagnosis and in the leaf in the end of the cycle, while for rice, the most efficient were Mehlich-1, HCl 0,1 mol L-1 and DTPA for the Cd, Cu, Fe and Zn. For Mn, only DTPA was efficient. For Fe, the extractors were not efficient. The extractor Organic Acids was more efficient in the evaluation of the phytoavailability of Cd, Cu, Pb and Zn for soybean. The largest concentrations of Cd, Cu, Mn and Zn in the soil are found in the fractions with stable chemical bounds (attached to oxides and residue) being the exchangeable fractions + soluble and organic of smaller representativeness in relation to the total found. The Pb, in spite of prevailing in the fractions liked to oxides and residue, offers great potential of environmental contamination since it is also present in the exchangeable + soluble and organic fractions in considerable concentrations. The same happens for Zn, for which the total concentration was higher.

A cana-de-açúcar têm despertado o interesse mundial como fonte alternativa de energia renovável. Para que a cultura se estabeleça globalmente como alternativa à produção de bioenergia, questões de sustentabilidade devem ser consideradas. Nesse sentido, a fertilização nitrogenada desempenha papel fundamental, pois influencia a produtividade do canavial e, por outro lado, pode ocasionar impactos ao ambiente se manejada inadequadamente. O objetivo deste estudo foi elucidar questões recentemente levantadas a respeito do manejo da cana-de-açúcar em áreas colhidas sem queima, tais como (i) a colheita mecanizada sucessiva poderá ocasionar degradação física do solo que comprometerá o desenvolvimento do sistema radicular da cultura? (ii) a aplicação de elevadas doses de N sobre a palha e sem o cultivo das soqueiras irá alterar a arquitetura radicular da cana-de-açúcar? e (iii) é possível desenvolver métodos diagnósticos de N do solo para dar suporte ao manejo da adubação nitrogenada da cana-de-açúcar? Três estudos foram desenvolvidos para elucidar as questões acima descritas. Do primeiro capítulo conclui-se que a colheita mecanizada sucessiva do canavial, sem o cultivo da soqueira, altera as propriedades físicas da camada superficial do solo, com efeito negativo na densidade radicular da cultura. Valores de resistência à penetração (RP) inferiores a 0,75 MPa não comprometem o crescimento radicular da cana, porém RP entre 0,75 a 2,0 MPa diminui a densidade radicular e, a partir de 2,0 MPa, há restrição severa ao crescimento radicular. O segundo capítulo apresentou a variação no crescimeno radicular da cana-de-açúcar no ciclo de primeira soqueira, em duas áreas (Usina Santa Adélia, USA e São Martinho, USM) e em função de doses de N aplicadas no plantio (0 ou 120 kg ha-1 N) e na soqueira (0 e 150 kg ha-1 N). O efeito da adubação nitrogenada no crescimento de raízes da cana-de-açúcar variou entre as áreas. Em ambos experimentos, a variação na biomassa de raízes durante o ciclo foi mais influenciada pelas propriedades dos solos do que pelas doses de N. Na área da USM a adubação nitrogenada de soqueira aumentou a densidade de raízes na camada superficial (0-0,2 m) e próximo às plantas (<0,3 m), enquanto que no experimento da USA nenhum efeito foi observado. Não houve efeito residual da adubação nitrogenada de plantio na biomassa e no acúmulo de N nas raízes e na parte aérea. A aplicação de altas doses de N na superfície do solo e sobre a palha não alterou significativamente a arquitetura do sistema radicular da cultura. O terceiro capítulo avaliou a resposta à adubação nitrogenada de soqueira em dez experimentos de campo no Estado de São Paulo. Os solos foram divididos em altamente responsivo, moderadamente responsivos e não responsivos. Estudos subsequentes em laboratório mostraram que os solos diferiram quanto à capacidade de fornecimento de N. A mineralização bruta separou adequadamente os solos quanto à responsividade ao N, enquanto o testes químicos Illinois Soil Nitrogen Test e Destilação a Vapor Direta apresentaram resultados promissores, podendo ser realizados em laboratórios de rotina de análise de solo em um dia de serviço. Estudos adicionais devem ser realizados para verificar a viabilidade de testes de N no solo para melhorar o manejo da adubação nitrogenada da cana-de-açúcar. / Sugarcane has been a promissing crop for renewable energy production around the world. In order to establish sugarcane as a globally alternative for bioenergy production, sustainability issues should be considered. Synthetic nitrogen (N) fertilizers plays a key role in sugarcane production but, if used improperly, causes environmental threats. The goal of this study was to elucidate current questions about sugarcane management in unburned areas, as follows (i) the sucessive mechanical harvesting could decrease the soil physical quality and thus compromise root system development? (ii) applying high N rates over the sugarcane straw, without further cultivation would modify the sugarcane root architecture? and (iii) is it possible to use soil N mineralization indexes in order to improve the N management of sugarcane? Three studies were carried out in order to elucidate the aforementioned issues. The findings of the first study is that successive mechanical harvesting without further soil cultivation modify the physical properties of the superficial soil layer, with negative effects on root density. No limitations on root growth occurs when penetration resistance (PR) is lower than 0,75 MPa, but PR from 0,75 to 2,0 MPa decreases root density and PR higher than 2,0 MPa causes severe restriction to root growth. The second study shows the variation in sugarcane root growth over the first ratoon cycle in two trials (Santa Adelia Mill, USA and Sao Martinho Mill, USM) as related to N rates applied at planting (0 or 120 kg ha-1 N) and to the ratoon (0 and 150 kg ha-1N). The effect of N fertilizer addition in sugarcane rooting varied between sites. In both trials, the variation in root biomass was more influencied by soil properties than by N supply. At USM site, ratoon N fertilization increased root density in the superficial soil layer (0-0,2 m) and close to the plants (<0,3 m), while at the SA site no effect of N was observed. There was no carry over effect from N applied at planting in the evaluated parameters (root and shoot biomass and N accumullation). Applying high N rates over the sugarcane straw does not affect significantly the sugarcane root architecture. The third study assess the N fertilizer response of sugarcane in ten field trials at Sao Paulo State. The soils were categorized in highly responsive, moderately responsive and non-responsives to N fertilization. Further studies developed under laboratory conditions showed differences in the soil\'s N supplying power. The gross mineralization succesfully identified the soils responsiveness to N, and the chemical tests Illinois Soil Nitrogen Test and Direct Steam Distilation showed promising results and can be performed in routine soil analysis in one work day. Further studies are warranted to assess the feasibility in using soil N tests to improve N fertilizer management in sugarcane.

A colheita de cana-de-açúcar, sem despalha a fogo, vem crescendo no Brasil. Nesse sistema de cultivo, existem muitas dúvidas em relação ao manejo da palha, e das quantidades de nitrogênio e potássio a serem utilizadas. Objetivou-se avaliar o manejo da palha, adubação nitrogenada, potássica e uso do inoculante em área comercial de cana-de-açúcar. Para isso, instalou-se experimento na região de Piracicaba - SP, num Latossolo Vermelho Amarelo Distrófico, cultivado com a variedade de cana-de-açúcar CTC 9, em delineamento de blocos casualizados em esquema fatorial incompleto 3x6x4, totalizando 153 parcelas, sendo três manejos da palha-MP (distribuição da palha da cana em toda área-MPT, retirada da palha apenas nas linhas da cana-de-açúcar-MPRL e enleiramento da palha a cada duas linhas-MP2:1), seis doses de N (aplicação de 0, 60, 120 e 180 kg ha-1 de N, aplicação na linha da cana de solução contendo cinco espécies de bactérias fixadoras de nitrogênio na ausência de adubação nitrogenada e aplicação na linha da cana de solução contendo cinco espécies de bactérias fixadoras de nitrogênio mais 30 kg ha-1 de N mineral), quatro doses de K (0, 50, 100 e 150 kg de K2O ha-1) e três repetições. As variáveis analisadas ao longo das duas socas foram: análises químicas do solo, emissão de CO2, diagnose foliar, avaliações biológicas e tecnológicas e produção de colmos da cana-de-açúcar. A aplicação de nitrogênio e potássio afetou a fertilidade do solo, teor foliar de N, açúcar teórico recuperável e crescimento da cana-de-açúcar. A aplicação de 80 kg ha-1 de K2O é suficiente para apresentar alta produtividade da primeira (87 t ha-1) e da segunda soca de cana-deaçúcar (141 t ha-1) e não houve resposta a aplicação de nitrogênio mineral. A aplicação de inoculante não aumentou a produtividade da cana-de-açúcar. O MPRL se mostrou como o mais promissor em relação ao crescimento e produtividade da cana-de-açúcar. O MPRL apresentou maior emissão de carbono se comparado ao MP2:1 na 2a soca. Na 1ª soca, no MPT, MPRL e MP2:1, a emissão de CO2 foi de 1,7; 2,0 e 1,7 ?mol m-2 s-1, a temperatura foi de 21,7; 21,7; 21,2 ºC e a umidade foi de 11,1; 6,6 e 9,5%, respectivamente. Na 2ª soca, no MPT, MPRL e MP2:1, o CO2 foi de 1,8; 2,1 e 1,6 ?mol m-2 s-1, a temperatura foi de 21,4; 22,9; 22,4 ºC e a umidade foi de 16,9; 12,3 e 11,5%, respectivamente. A emissão de CO2 aumentou com o crescimento das plantas de cana-de-açúcar e oscilou de 6 a 12,4 ?mol m-2. / The harvesting of sugarcane, straw removal without fire, is growing in Brazil. In this culture system, there are many questions about the management of residue, and the amounts of nitrogen and potassium to be used. This study aimed to evaluate the straw management sugarcane, nitrogen, potassium and use of inoculants in commercial sugarcane. For this experiment was installed in Piracicaba - SP, in the Oxissol cultivated with the variety of sugarcane CTC 9, in a randomized block design in a incomplete factorial 3x6x4, totaling 153 plots, three management of stubble-MP (distribution of sugarcane trash in every area-MPT, removal of straw only rows of sugarcane MPRL and windrowing straw every two lines-MP2:1) six doses of N (application of 0, 60, 120 and 180 kg ha-1 of N, applied in line with the cane solution containing five species of nitrogen-fixing bacteria in the absence of nitrogen fertilizer application on line and cane solution containing five species of nitrogen-fixing bacteria plus 30 kg ha-1 of mineral N), four doses of K (0, 50 , 100 and 150 kg ha-1 of K2O) and three replications. The variables analyzed along the two years were: soil chemical analysis, CO2 emission, foliar diagnosis, biological and technological evaluations and straw yield of sugarcane. The application of nitrogen and potassium affect soil fertility, leaf N content, theoretical recoverable sugar and growth of sugarcane. The application of 80 kg ha-1 of K2O is sufficient to present the first high productivity (87 t ha-1) and second ratoon sugarcane (141 t ha-1) and there was no response from the application nitrogen mineral. The inoculant application did not increase productivity of sugarcane. The MPRL proved as the most promising in relation to growth and productivity of sugarcane. The MPRL had lower moisture and higher carbon footprint compared to MPT and MP2:1. In the 1st ratoon, the MPT, MPRL and MP2:1, the emission of CO2 was 1.7, 2.0 and 1.7 ?mol m-2 s-1, the temperature was 21.7, 21.7; 21.2 ºC and humidity was 11.1, 6.6 and 9.5%, respectively. In the 2nd ratoon in MPT, MPRL and MP2:1 first, the CO2 was 1.8, 2.1 and 1.6 ?mol m-2 s-1, the temperature was 21.4, 22.9; 22, 4 ºC and the humidity was 16.9, 12.3 and 11.5%, respectively. The emission of CO2 increased with the growth of plants sugarcane and oscillated 6 to 12.4 ?mol m-2 s-1.

Orientador: Rafael Montanari / Resumo: Na busca por soluções que otimizem as operações, auxiliem no planejamento e reduzam os custos operacionais no manejo do solo, a geoestatística tem sido aplicada em diversas áreas. Utilizando a geoestatística como ferramenta e forma de planejamento de manejo, o presente trabalho objetivou-se analisar economicamente a recuperação da fertilidade do solo de uma pastagem potencialmente degradada no cerrado brasileiro em dois sistemas de intervenção: convencional (SC) e agricultura de precisão (AP) e gerar informações por meio da análise de variabilidade e estabelecimento da estrutura de dependência espacial, a fim de auxiliar no planejamento de atividades agrícolas em seis cidades na província de El Oro, Equador. O trabalho foi realizado no ano agrícola de 2015/2016 na área experimental de sistemas de produção em bovinocultura de corte pertencente à Faculdade de Engenharia – UNESP, Campus de Ilha Solteira, São Paulo, Brasil e na Universidade Técnica de Machala (UTMACH), Machala, Equador. A recuperação no SC apresentou índice de lucratividade negativa (-1,32%) e no AP positiva (0,26%) proporcionando um preço de custo @-1 de R$ 155,52 e R$ 153,10 para o SC e AP, respectivamente. Comparando-se áreas cultivadas com AP e SC, é provável que se obtenha resultados mais confiáveis e com melhores perspectivas em maiores áreas de cultivo de forma a aumentar a rentabilidade do sistema. Na província de El Oro, o teor de Zinco obteve o maior coeficiente de determinação espacial. O pH se destaco... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: A demand for solutions that optimize operations, support planning and reduce operational costs in soil management, geostatistics has been applied in several areas. Using geostatistics as a tool and management planning method, the present work aimed to economically analyze the soil fertility recovery of a potentially degraded pasture in the Brazilian cerrado in two intervention systems: conventional (CS) and precision agriculture (PA) and generate information through variability analysis and establishment of spatial dependence structure to assist in the planning of agricultural activities in six cities in El Oro province, Ecuador. The work was carried out in the 2015/2016 agricultural year in the experimental area of beef cattle production systems belonging to the Faculty of Engineering - UNESP, Ilha Solteira Campus, São Paulo, Brazil and the Technical University of Machala, Machala, Ecuador. The recovery in CS presented negative profitability index (-1,32%) and positive in PA (0,26%) providing a cost @ -1 price of R$ 155,52 and R$ 153,10 for CS and PA, respectively. Comparing cultivated areas with PA and CS, it is likely that more reliable results and better prospects will be obtained in larger cultivated areas in order to increase the profitability of the system. In El Oro province, the Zinc content obtained the highest coefficient of special determination, but low range, which may be influence by the numbers of pairs in the first Lag. The pH stood out as the major influence... (Complete abstract click electronic access below) / Doutor

L’introduzione di agro-ecosistemi conservativi viene indicata come strategia per aumentare il sequestro del carbonio organico nel suolo (SOC) e migliorarne la fertilità. La continua applicazione di concimi organici, come il compost e il sovescio, favorisce il sequestro di SOC (+ 1.3 ÷ 2.5 Mg C ha-1 anno-1) e l'accumulo di azoto totale del suolo (STN) (+ ~ 1 Mg N ha-1 anno-1). Tuttavia, quando le fertilizzazioni organiche vengono interrotte, il SOC diminuisce rapidamente. Negli agro-ecosistemi intensivi, il no till (NT) garantisce rese comparabili a quelle dei sistemi convenzionali (CT) immediatamente dopo la transizione. Il NT aumenta la sostanza organica (SOM) e il STN principalmente nei primi 5 cm di terreno, sebbene la cover crop di segale assicuri l'accumulo di SOM fino a 30 cm di profondità (+ 30% rispetto alla CT). Il NT e la minima lavorazione (MT) portano ad un aumento del SOC e del STN nei primi 30 cm di suolo, rispetto al CT. Gran parte di tale aumento è dovuto ai macroaggregati, all'interno dei quali, i pool di C e N associati ai microaggregati (mM) rappresentano tra il 41 e il 65% del contenuto totale di C e N nei sistemi NT e MT. / The introduction of conservation agro-ecosystems has been suggested for increasing soil organic carbon (SOC) sequestration and enhancing soil fertility. Continuous organic fertilization such as compost distribution and cover crops incorporation promotes SOC sequestration (+1.3÷2.5 Mg C ha-1 yr-1) and soil total nitrogen (STN) accumulation (+~1 Mg N ha-1 yr-1). However, when the organic fertilization is stopped, SOC rapidly decreases. In intensive agro-ecosystems, no till (NT) can ensure yields comparable to conventional tillage (CT) immediately after transition. The major contribution of NT to soil organic matter (SOM) and STN increase is detected in the top 5 cm of soil, although the cultivation of rye as cover crop ensures SOM accumulation down to 30 cm depth (+30% than CT). No till and minimum tillage (MT) may increase SOC and STN levels in the 0-30 cm soil layer, both as concentration and as mass, compared with CT. Most of such a SOC and STN increase is due to C- and N-rich macroaggregates. Within macroaggregates, microaggregates (mM) are of primary importance for soil organic matter stabilization since C and N pools associated to mM account for between 41 and 65% of total C and N content in the NT and MT systems.

In the studied Kagera region (NW Tanzania), smallholder banana-coffee-based farming systems developed over hundreds of years. To this day, they traditionally consist of four components: the older and younger homegardens (kibanja and kikamba in the local Bantu language), woodland (kabira), and grassland (rweya). The management of organic farm waste has played an essential role in maintaining soil fertility, diversity, and agricultural productivity in these agroforestry systems. However, rapid population growth since Tanzania’s independence in the 1960s, an influx of refugees in the 1990s, and accompanying environmental degradation have shaped large parts of the study region. As a result, farm sizes, crop yields, and food security have declined, soils and farming systems have degraded, and impoverishment has increased. The overall objective of this study was to investigate whether degraded homegardens can be transformed back into multifunctional, sustainable, and fertile agroforestry systems through sustainable organic farm waste management. Organic farm waste embraced crop and tree residues, kitchen and food waste including cooking ash (as inorganic residue), livestock manure and urine, animal bones, as well as human faeces and urine. The objective was subdivided into three targets and related research foci: (1) to understand the status quo of organic farm waste management in the research area, (2) to evaluate modification options for sustainable banana-coffee-based systems, and (3) to evaluate an optimisation of organic farm waste management to increase agricultural production. An interview of 150 smallholder households on the current availability and uses of organic farm waste was conducted (1). The survey encompassed geographical variables, economic data, and household and agricultural information relating to the Water-Soil-Waste Nexus and the Water-Energy-Food Nexus. A farm household typology was constructed to categorise the farm households according to their biomass production and use of organic farm waste. Five focus group discussions were held in a local farmer field school to evaluate training on sustainable land use management (2). The farmer field school had trained about 750 farm households in de-graded banana-coffee-based farming systems in the last two decades. Also here, a typology construction of trained farm households was created. Both typologies were compared to each other. Nutrient cycles of the homegardens of trained and untrained farm house-holds were calculated (3) using the following scenarios: S0: business as usual; S1: the use of 80% of the available human urine; S2: the incorporation of 0.5 t yr-1 of the herbaceous legume species Crotalaria grahamiana into the soil; S3: the production of 5 m3 yr-1 of CaSa-compost (human excreta and biochar) and its application on 600 m2 of land; and S4: a combination of S1, S2, and S3. Results revealed that integrated organic farm waste management still plays a key role in farm nutrient and soil fertility management in these farming systems, but to a lower extent than in the past (status quo). Smallholder farmers that apply organic farm waste to their fields – using in situ, pit, ring-hole, and mixed composting techniques – have higher yields. However, the knowledge on waste management – traditionally passed on from generation to generation – has declined. Today, only one-third of these households earn a reasonable living from their agricultural products. Female-led households with a high age-dependency ratio and farmers with problematic socio-economic backgrounds continue to be the most vulnerable to food insecurity. In comparison, the implementation of training on sustainable land-use management has considerably improved farmers’ livelihoods. Successfully implemented knowledge on sustainable soil and farm nutrient management, including the modification of composting techniques, afforestation, selection of appropriate crop and tree species, improved labour allocation and time management, agricultural record-keeping, as well as gender-responsive communication and decision-making, has led to a transition: from degraded agricultural to multifunctional agroforestry systems. However, also here, one-third of the trained farmers has hardly transformed at all and has remained vulnerable to difficulties with food security, income diversification, and access to education. Comparing the nutrient balance between the homegardens of untrained and trained households, the homegardens of trained households are more likely to have a positive nutrient balance than those of untrained ones. Although untrained households would improve the nutrient balance under all management scenarios, their nutrient balances do not actually turn positive, especially not for nitrogen. Besides, nutrient cycles in the homegardens of all households remain ‘open’ because farmers currently import nutrients from the surrounding area, e.g., through fodder from the grassland. To overcome this dependency, short-term nutrient deficiencies might be alleviated with a precise application of mineral fertiliser and by fostering zero grazing. However, limited access to mineral fertiliser, labour-intensive manure collection and compost production against a background of land scarcity, labour shortage, prolonged dry seasons, and socio-economic imbalances, remain major challenges. To conclude, action needs to be taken and supporting policies and regulations need to be developed, e.g., on the safe use of organic farm waste and wastewater in smallholder agriculture to contribute towards achieving key Sustainable Development Goals of the United Nations. The relevant goals are Goal 2 (Zero hunger), Goal 7 (Affordable and clean energy), and Goal 15 (Life on land). None of the un-trained smallholder households lives under the conditions that these goals intend to prescribe. Only one-third of the trained farming households is one step closer to achieving these targets. To counteract this, a roadmap may serve as a starting point for future initiatives to develop coherent policies and science-based guidelines.:List of figures 7 List of tables 13 Abbreviations and acronyms 17 Units 20 Abstract 21 Zusammenfassung 23 1 Introduction 29 1.1 Problem identification and structure of this thesis 29 1.2 Study area 31 1.2.1 Environment 31 1.2.2 History and development of agriculture 37 1.2.3 Social, economic, and ecological challenges 44 1.3 Objectives 46 1.4 Research questions 47 1.4.1 The status quo of organic farm waste management 48 1.4.2 The transition towards multifunctionality 49 1.4.3 The optimisation of farm waste management 50 1.5 List of publications 53 2 Status quo of organic farm waste management 55 Highlights 55 Graphical abstract 56 Abstract 56 Keywords 57 2.1 Introduction 57 2.2 Background 59 2.2.1 The development of banana-coffee-based farming systems in Karagwe 59 2.2.2 The traditional role of organic farm waste 62 2.3 Materials and methods 63 2.3.1 Study area 63 2.3.2 Methods 65 2.4 Results 67 2.4.1 Farm household typology 67 2.4.2 Status quo of the farm waste management 72 2.4.3 Today's gender roles in agriculture 75 2.5 Discussion 78 2.6 Conclusions and recommendations 81 2.7 Declaration of competing interest 82 2.8 Acknowledgements 82 2.9 References 83 3 Traditional and adapted composting practices 91 Abstract 91 3.1 Introduction 92 3.1.1 Banana-coffee-based farming systems in the highlands of Tanzania 95 3.1.2 Composting practices 98 3.1.3 Traditional: In-situ and pit composting 100 3.1.4 Adapted: On-surface composting 101 3.2 Case studies 102 3.2.1 Traditional composting in the Kagera region 102 3.2.2 On-surface composting in the Morogoro region 104 3.3 Discussion 107 3.4 Conclusion 109 3.5 References 110 4 Transition towards multifunctional farming systems 115 Graphical abstract 115 Highlights 116 Abstract 116 Keywords 117 4.1 Introduction 117 4.2 Materials and methods 120 4.2.1 Study area 120 4.2.2 CaSa-compost 120 4.2.3 Data collection 121 4.2.4 Data analysis 124  4.3 Results 125 4.3.1 Group A: Successful farm households 126 4.3.2 Group B: Moderate successful farm households 134 4.3.3 Group C: Failing farm households 136 4.3.4 Remaining challenges and bottlenecks 138 4.4 Discussion 139 4.5 Conclusions and recommendations 143 4.6 Acknowledgements 144 4.7 References 145 5 Optimised nutrient management 155 Abstract 155 Keywords 156 5.1 Introduction 157 5.2 Materials and methods 158 5.2.1 Study area 158 5.2.2 Data 160 5.3 Results 175 5.4 Discussion 181 5.4.1 Methodology 181 5.4.2 Results 181 5.5 Conclusions and recommendations 186 5.6 Appendix A 188 5.7 References 192 6 Synthesis 199 6.1 Summary and discussion of the results 199 6.1.1 The status quo of organic farm waste management 199 6.1.2 The modification of traditional farm waste management 203 6.1.3 The optimisation of farm waste management 206 6.2 Relevance to the Sustainable Development Goals (SDGs) 208 6.3 Outline of a roadmap for the implementation of the SDG target 2.4 211 6.4 Limitations 215 6.5 Concluding discussion and recommendations 215 7 References 221 8 Appendix 233 8.1 Data set of smallholder farm households 233 Abstract 234 Keywords 235 8.1.1 Specifications table 235 8.1.2 Value of the data 237 8.1.3 Data description 237 8.1.4 Experimental design, materials, and methods 238 Ethics statement 240 Declaration of competing interest 240 Acknowledgments 240 References 240 8.2 Survey data 243 8.2.1 Meta data 243 8.2.2 Geographical data 245 8.2.3 Household information 251 8.2.4 Agricultural information 257 8.2.5 Economic data and Water-Energy-Food (WEF) Nexus 285 8.2.6 Gender-specific distribution of tasks within the farming family 298 / Bananen-Kaffee-basierte Anbausysteme haben eine lange Tradition in Ostafrika. In der Kagera-Region im Nordwesten Tansanias entwickelten sich über Jahrhunderte hinweg ertragreiche Bananen-Kaffee-basierte Anbausysteme in kleinbäuerlicher Landwirtschaft. Die Böden der Hausgärten waren durch die kontinuierliche Zugabe von kompostierten organischen Abfällen dunkel, humusreich und fruchtbar. Jedoch verlor dieses nachhaltige Agroforstsystem in der Kagera-Region in den letzten 50 Jahren zunehmend an Bedeutung. Die Gründe dafür waren in erster Linie der rasche Anstieg der Bevölkerung seit der Unabhängigkeit Tansanias in den 1960er-Jahren sowie der Zustrom von Flüchtlingen in den 1990er-Jahren. Beides führte zu einer Erhöhung der Nachfrage nach Nahrungsmitteln, Baumaterial und Brennholz, die noch immer wichtigste Energiequelle zum Kochen mit einhergehender Degradierung, massiver Entwaldung sowie nachlassender Erhaltung der Bodenfruchtbarkeit und das Auslassen notwendiger Brachzeiten und Gründungen. Infolgedessen wurden den Böden über fünf Jahrzehnte mehr Nährstoffe entzogen als zugefügt, was zu einer Abnahme der Bodenfruchtbarkeit führte. Die Ernteerträge aller ein- und mehrjährigen Kulturpflanzen sind zurückgegangen und die Böden sowie die Vegetation der Hausgärten sind teilweise stark degradiert. Seitdem sind die Ernährungssicherheit und der Wohlstand der lokalen Bevölkerung sowie die für Tansanias Wirtschaft wichtigen Exporte von Bananen (Musa L.) und Kaffee (Coffea canephora L. var. robusta) aus der Kagera-Region gefährdet. Ziel dieser Dissertation war es, zu untersuchen, ob der jetzigen Degradierung der Hausgärten, die für die Ernährungssicherung der Bevölkerung entscheidend sind, durch eine erneute, stärkere und nachhaltige Einbindung organischer Abfälle entgegengewirkt werden kann und so wie einst multifunktionale, nachhaltige und fruchtbare Agroforstsysteme entstehen können. Dieses Ziel wurde in drei untergeordnete Ziele unterteilt: (1) das Verständnis des Ist-Zustandes des organischen Abfallmanagements im Forschungsgebiet, (2) die Untersuchung von Modifikationsmöglichkeiten für nachhaltige Bananen-Kaffee-basierte Agrarforstsysteme sowie (3) die Evaluierung der Optimierungsmöglichkeiten des organischen Abfallmanagements zur Steigerung der landwirtschaftlichen Produktion. Für jedes Ziel wurde eine Forschungsfrage entwickelt: (1) Inwieweit werden die organischen Abfälle bereits genutzt (Ist-Zustand) und kann abgeschätzt werden, ob das momentane Abfallmanagement ausreicht, um die Bodenfruchtbarkeit und die Produktion von Nahrungsmitteln und Energieträgern zu erhöhen und damit die Armut zu reduzieren; (2) Ob und wie das derzeitige Management organischer Abfälle verbessert werden könnte, um die Bodenfruchtbarkeit und die Biomasseproduktion zu erhöhen; (3) Ob und wie negative Nährstoffbilanzen in positive umgewandelt werden können, wenn das organische Abfallmanagement in den Anbausystemen optimiert und verbessert in den landwirtschaftlichen Stoffkreislauf integriert werden würde. Zur Beantwortung der ersten Frage wurden 150 kleinbäuerliche Haushalte zu ihrer aktuellen landwirtschaftlichen Produktion, der Verfügbarkeit und Aufbereitung von organischen Abfällen sowie deren Verwendung im Anbau der wichtigsten ein- und mehrjährigen Kulturpflanzen befragt. Die Befragung umfasste geografische und ökonomische Daten sowie haushaltsbezogene und landwirtschaftliche Informationen in Bezug auf den Wasser-Boden-Abfall-Nexus und den Wasser-Energie-Nahrungsmittel-Nexus. Mit den erhobenen Daten wurde eine expertenbasierte Typologie der befragten Haushalte erstellt, um diese nach ihrer Biomasseproduktion sowie der Nutzung von organischen Abfällen zu kategorisieren. Bezüglich der zweiten Frage wurden fünf Fokusgruppendiskussionen mit den Ausbildern und Ausbilderinnen einer lokalen Bauernschule durchgeführt, die in den vergangenen zwei Jahrzehnten mehr als 700 kleinbäuerliche Haushalte in nachhaltiger Landwirtschaft schulten. Dabei wurde ebenfalls eine expertenbasierte Typologie der geschulten Haushalte erstellt. Beide Haushaltstypologien wurden hingehend ihrer Biomasseproduktion, organischen Abfallnutzung und Wohlstandes miteinander verglichen. Im Rahmen der dritten Fragestellung wurden die Nährstoffkreisläufe der Hausgärten von geschulten und nicht geschulten Bauernhaushalten analysiert. Dabei wurden folgende Szenarien berücksichtigt: S0: der normale Betrieb ohne Änderungen (Ist-Zustand); S1: die Nutzung von 80 % des verfügbaren menschlichen Urins; S2: die Einarbeitung von 0,5 Tonnen pro Jahr der krautigen Leguminosenart Crotalaria grahamiana in den Boden; S3: die Produktion von jährlich 5 Kubikmetern CaSa-Kompost, bestehend aus menschlichen Ausscheidungen und Biokohle, und dessen Ausbringung auf 600 Quadratmetern in den Hausgärten; und S4: eine Kombination aus S1, S2 und S3. Entsprechende Daten wurden der Literatur entnommen. Die Ergebnisse zeigten, dass die Einbindung organischer Abfälle auch in degradierten Bananen-Kaffee-basierten Anbausystemen noch immer eine Schlüsselrolle im Nährstoff- und Bodenfruchtbarkeitsmanagement spielt, jedoch zu einem niedrigeren Ausmaß als noch vor 50 Jahren. An Bedeutung verlor dabei auch die traditionelle Weitergabe des Wissens über Kompostierung durch erschwerte sozio-ökonomische Bedingungen. Generell wurde festgestellt, dass Kleinbauernfamilien, die organische Abfälle auf ihren Feldern ausbringen, höhere landwirtschaftliche Erträge erzielen. Das Potenzial zur Erhaltung der Bodenfruchtbarkeit wird dabei jedoch aktuell nicht vollständig ausgeschöpft, und nur ein Drittel der herkömmlichen kleinbäuerlichen Haushalte erzielt einen den Lebensumständen annähernd angemessenen Lebensunterhalt (Ist-Zustand). Ein weiteres Drittel der ungeschulten Haushalte nutzt organische Dünger zu einem geringeren Ausmaß und erzielt deswegen und wegen weiterer Schwächen im landwirtschaftlichen Management geringere Ernteerträge. Sie sind damit stärker armutsgefährdet als die erstgenannte Gruppe. Jedoch sind v. a. Haushalte, die von alleinerziehenden Frauen geführt werden (ebenfalls ein Drittel der befragten Haushalte), am stärksten von Ernährungsunsicherheit und Armut betroffen. Dabei spielen problematische, sozio-ökonomische Hintergründe eine erschwerende Rolle. Um das Ausmaß dieser Armutsspirale zu verringern, entwickelte eine lokale Bauernschule eine umfangreiche Ausbildung im Bereich nachhaltiger Landwirtschaft. Die erfolgreiche Implementierung der Ausbildung in die eigene Produktion hat die Lebensgrundlage von mindestens einem Drittel der geschulten Bauernhaushalte deutlich verbessert. Erfolgreich umgesetztes Wissen haben dazu geführt, dass degradierte Bananen-Kaffee-basierte Anbausysteme sich zunehmend zu multifunktionalen Agroforstsystemen entwickeln. Hierdurch hat sich nur für ein Drittel der ausgebildeten Bauern bereits die Lage signifikant verbessert. Ein weiteres Drittel befindet sich noch in dem Transformationsprozess. Ihre Erträge bleiben jedoch unter denen der ersten Gruppe. Die dritte Gruppe innerhalb der geschulten Bauernhaushalte konnte das erworbene Wissen wiederum nicht oder nur kaum in die Praxis umsetzen. Diese Gruppe bleibt in Bezug auf Ernährungssicherheit, Einkommens-diversifizierung und Zugang zu Bildung stark vulnerabel. Im Vergleich der Nährstoffbilanzen der Hausgärten zwischen den geschulten und den ungeschulten Bauernhaushalten zeigen erstere eher eine positive Nährstoffbilanz als letztere. Obwohl sich die Nährstoffbilanzen der Felder ungeschulter Haushalte unter allen Managementszenarien verbessern würden, würden sie jedoch noch negativ bleiben, insbesondere für Stickstoff. Darüber hinaus sind die Nährstoffkreisläufe in den Hausgärten aller Familien nicht geschlossen, da ein Großteil der Nährstoffe aus der Umgebung importiert wird, z. B. durch die Verwendung von Futtermittel aus dem umliegenden Grasland.:List of figures 7 List of tables 13 Abbreviations and acronyms 17 Units 20 Abstract 21 Zusammenfassung 23 1 Introduction 29 1.1 Problem identification and structure of this thesis 29 1.2 Study area 31 1.2.1 Environment 31 1.2.2 History and development of agriculture 37 1.2.3 Social, economic, and ecological challenges 44 1.3 Objectives 46 1.4 Research questions 47 1.4.1 The status quo of organic farm waste management 48 1.4.2 The transition towards multifunctionality 49 1.4.3 The optimisation of farm waste management 50 1.5 List of publications 53 2 Status quo of organic farm waste management 55 Highlights 55 Graphical abstract 56 Abstract 56 Keywords 57 2.1 Introduction 57 2.2 Background 59 2.2.1 The development of banana-coffee-based farming systems in Karagwe 59 2.2.2 The traditional role of organic farm waste 62 2.3 Materials and methods 63 2.3.1 Study area 63 2.3.2 Methods 65 2.4 Results 67 2.4.1 Farm household typology 67 2.4.2 Status quo of the farm waste management 72 2.4.3 Today's gender roles in agriculture 75 2.5 Discussion 78 2.6 Conclusions and recommendations 81 2.7 Declaration of competing interest 82 2.8 Acknowledgements 82 2.9 References 83 3 Traditional and adapted composting practices 91 Abstract 91 3.1 Introduction 92 3.1.1 Banana-coffee-based farming systems in the highlands of Tanzania 95 3.1.2 Composting practices 98 3.1.3 Traditional: In-situ and pit composting 100 3.1.4 Adapted: On-surface composting 101 3.2 Case studies 102 3.2.1 Traditional composting in the Kagera region 102 3.2.2 On-surface composting in the Morogoro region 104 3.3 Discussion 107 3.4 Conclusion 109 3.5 References 110 4 Transition towards multifunctional farming systems 115 Graphical abstract 115 Highlights 116 Abstract 116 Keywords 117 4.1 Introduction 117 4.2 Materials and methods 120 4.2.1 Study area 120 4.2.2 CaSa-compost 120 4.2.3 Data collection 121 4.2.4 Data analysis 124  4.3 Results 125 4.3.1 Group A: Successful farm households 126 4.3.2 Group B: Moderate successful farm households 134 4.3.3 Group C: Failing farm households 136 4.3.4 Remaining challenges and bottlenecks 138 4.4 Discussion 139 4.5 Conclusions and recommendations 143 4.6 Acknowledgements 144 4.7 References 145 5 Optimised nutrient management 155 Abstract 155 Keywords 156 5.1 Introduction 157 5.2 Materials and methods 158 5.2.1 Study area 158 5.2.2 Data 160 5.3 Results 175 5.4 Discussion 181 5.4.1 Methodology 181 5.4.2 Results 181 5.5 Conclusions and recommendations 186 5.6 Appendix A 188 5.7 References 192 6 Synthesis 199 6.1 Summary and discussion of the results 199 6.1.1 The status quo of organic farm waste management 199 6.1.2 The modification of traditional farm waste management 203 6.1.3 The optimisation of farm waste management 206 6.2 Relevance to the Sustainable Development Goals (SDGs) 208 6.3 Outline of a roadmap for the implementation of the SDG target 2.4 211 6.4 Limitations 215 6.5 Concluding discussion and recommendations 215 7 References 221 8 Appendix 233 8.1 Data set of smallholder farm households 233 Abstract 234 Keywords 235 8.1.1 Specifications table 235 8.1.2 Value of the data 237 8.1.3 Data description 237 8.1.4 Experimental design, materials, and methods 238 Ethics statement 240 Declaration of competing interest 240 Acknowledgments 240 References 240 8.2 Survey data 243 8.2.1 Meta data 243 8.2.2 Geographical data 245 8.2.3 Household information 251 8.2.4 Agricultural information 257 8.2.5 Economic data and Water-Energy-Food (WEF) Nexus 285 8.2.6 Gender-specific distribution of tasks within the farming family 298

No description available.

Agricultural yields in Northwest Yucatán are constrained by climate, thin soils, and low fertility. Despite this, the ancient Maya city of Chunchucmil Yucatán, Mexico, boasted an immense, dense, and wealthy population during the Middle Classic period (ca A.D. 400-700). Soil physical and chemical properties were explored to determine how the ancient Maya of Chunchucmil fed themselves. Soil profiles were collected from various locations within ancient Chunchucmil's suspected sustaining area. The physical and chemical properties, carbon isotopes, black carbon, and coprostanols of soil profiles sampled were compared to ancient rural settlement and remotely sensed images, such as AIRSAR (airborne synthetic aperture radar). Our objectives were to geographically determine the areas of agricultural importance and determine whether evidence of ancient agricultural intensification could be observed in the surrounding soil resources of Chunchucmil. Indigenous Maya of the area identify three major soil classes, boxlu'um, saklu'um, and kancab. The ancient Maya likely preferred kancab because it provided some security with higher soil moisture, greater soil depth, and improved nutrient availability. The land use capability is severely limited in the swamp/estuary and tzekel. The lack of rural settlement within these zones suggests that they were not used for cultivation in ancient times; however, the wood resources likely provided Chunchucmil with vital raw materials. The carbon isotopic signature of ancient C4 crops was not detected suggesting that either maize was not extensively produced or that the mix of native C3 and C4 plants in the savanna hid the signature. There were no soil chemical or biomarker evidences of ancient agricultural intensification, suggesting that ancient agriculture was mainly based on shifting cultivation at Chunchucmil. Concentrations of black carbon, calcium, phosphorus, potassium (Olsen Method), magnesium, and organic carbon within urban and rural settlements were enhanced by incidental human activities. We determined that the land requirement would have been extensive to sustain the population of Chunchucmil during the Middle Classic based on traditional agricultural methods. The ancient Maya of Chunchucmil likely traded marine and estuary products from the Gulf coast and other high value trade items for agricultural products from the nearby Puuc Hills.

No description available.