Infestação da broca-do-café em agroecossistemas convencional, organo-mineral e orgânico na região sul de Minas Gerais.

2009

Produtividade de cana-de-açúcar sob adubação com torta de filtro enriquecida com fosfato solúvel

Phosphorus is considered an essential element for plants and it is found in small amounts in Brazilian soils. The filter cake residue, composed of a mixture of bagasse and decanting sludge, has high levels of organic matter, phosphorus and calcium. The phosphorus present in the filter cake is organic, and its release, as it happens to the nitrogen, occurs gradually by mineralization and by microorganisms attack in the soil. This study aimed to evaluate sugarcane vegetative growth and yield under fertilization with filter cake enriched with soluble phosphate. The experiment was carried out in Presidente Prudente, São Paulo State, Brazil, by using a randomized complete block design, in a 5x4 factorial scheme, where the first factor consisted of filter cake doses (0 t ha-1, 0.5 t ha-1, 1.0 t ha-1, 2.0 t ha-1, and 4.0 t ha-1) and the second of phosphorus fertilizer doses (0 kg ha-1, 50 kg ha -1, 100 kg ha-1, and 200 kg ha-1 of P 2O5), with 4 repetitions, totalizing 80 plots. The experiment evaluated the tiller number, at 30, 60, 90, and 120 days after planting, oBrix, and yield. The stalk yield and tillering were influenced by the filter cake rates applied to the soil. Filter cake doses and their combination with phosphate did not change the juice quality (Brix) at harvest.

Produtividade de cana-de-açúcar sob adubação com torta de filtro enriquecida com fosfato solúvel

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The effect of filter cakes enriched with soluble phosphorus used as a fertilizer on the sugarcane ratoons

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fontes de matéria orgânica para a formulação de fertilizantes organominerais peletizados no desenvolvimento da cultura do sorgo

Organo-mineral fertilizers have been used to both meet plants’ nutritional needs and reduce producers’ reliance on mineral fertilizers. This practice improves both the use of nutrients by plants and the soil structure due to the organic matter in these fertilizers. This study aimed to determine the effect of organic matter sources in the composition of organomineral fertilizers and compare it to the effect of traditional mineral fertilizers when it comes to the initial development of sorghum. Research was carried out in a greenhouse at the Federal University of Uberlandia, in Uberlandia, Minas Gerais, Brazil. Sorghum seeds of grain-bearing simple hybrid 1G100 were used in the seeding process. The experiment followed a randomized complete block design in a 4 x 3 + 2 factorial arrangement. Factors included four levels (50, 75, 100 and 125% of 450 kg ha-1, which is the recommended dose for sorghum crops), three organic matter sources in the composition of the organomineral fertilizers (sewage sludge, filter cake, and peat), a control (100% mineral fertilizer), and an untreated check (no fertilizers). Each experimental plot consisted of four plants divided into two pots. Oxisol was used in all pots. Analyses were performed at 30 and 60 days after seeding (DAS) and targeted: plant height, stem diameter, chlorophyll A, chlorophyll B, and leaf area. After this period, plants were removed from the soil, and had their aerial parts isolated to be dried in an air-forced oven before measurement of their dry mass. Means of the organomineral fertilizers outperformed those of both control and untreated check plots in almost all variables at 30 DAS. The only exception was variable stem diameter, in which organomineral fertilizers outperformed untreated check plots only. Sorghum fertilized with organomineral fertilizers also showed positive results in the variables analyzed at 60 DAS: even with dose reduction, their means were similar to those found in control plots. Organomineral fertilizers had higher means in some variables, such as diameter and dry mass of the aerial part, than both control and untreated check plots. In the conditions set in this study and considering the variables herein reported, organomineral fertilizers can substitute mineral fertilizers in the initial development of sorghum, even with some dose reductions.

Metabolism of mineral-sorbed organic matter depends upon microbial lifestyle in fluvial ecosystems

In fluvial ecosystems mineral erosion, carbon (C) and nitrogen (N) fluxes are linked via organo-mineral complexation, where dissolved organic molecules bind to mineral surfaces. Biofilms and suspended aggregates represent major aquatic microbial lifestyles whose relative importance changes predictably through fluvial networks. We tested how organo-mineral sorption affects aquatic microbial metabolism, using organo-mineral particles containing a mix of ¹³C, ¹⁵N-labelled amino acids. We traced ¹³C and ¹⁵N retention within biofilm and suspended aggregate biomass and its mineralisation. Organo-mineral complexation restricted C and N retention within biofilms and aggregates and also their mineralisation. This reduced the efficiency with which biofilms mineralise C and N by 30 % and 6 %. By contrast, organo-minerals reduced the C and N mineralisation efficiency of suspended aggregates by 41 % and 93 %. Our findings show how organo-mineral complexation affects microbial C:N stoichiometry, potentially altering the biogeochemical fate of C and N within fluvial ecosystems.

Application of biogas slurries from energy crops to arable soils and their impact on carbon and nitrogen dynamics

The use of renewable primary products as co-substrate or single substrate for biogas production has increased consistently over the last few years. Maize silage is the preferential energy crop used for fermentation due to its high methane (CH4) yield per hectare. Equally, the by-product, namely biogas slurry (BS), is used with increasing frequency as organic fertilizer to return nutrients to the soil and to maintain or increase the organic matter stocks and soil fertility. Studies concerning the application of energy crop-derived BS on the carbon (C) and nitrogen (N) mineralization dynamics are scarce. Thus, this thesis focused on the following objectives: I) The determination of the effects caused by rainfall patterns on the C and N dynamics from two contrasting organic fertilizers, namely BS from maize silage and composted cattle manure (CM), by monitoring emissions of nitrous oxide (N2O), carbon dioxide (CO2) and CH4 as well as leaching losses of C and N. II) The investigation of the impact of differences in soil moisture content after the application of BS and temperature on gaseous emissions (CO2, N2O and CH4) and leaching of C and N compounds. III) A comparison of BS properties obtained from biogas plants with different substrate inputs and operating parameters and their effect on C and N dynamics after application to differently textured soils with varying application rates and water contents. For the objectives I) and II) two experiments (experiment I and II) using undisturbed soil cores of a Haplic Luvisol were carried out. Objective III) was studied on a third experiment (experiment III) with disturbed soil samples. During experiment I three rainfall patterns were implemented including constant irrigation, continuous irrigation with periodic heavy rainfall events, and partial drying with rewetting periods. Biogas slurry and CM were applied at a rate of 100 kg N ha-1. During experiment II constant irrigation and an irrigation pattern with partial drying with rewetting periods were carried out at 13.5°C and 23.5°C. The application of BS took place either directly before a rewetting period or one week after the rewetting period stopped. Experiment III included two soils of different texture which were mixed with ten BS’s originating from ten different biogas plants. Treatments included low, medium and high BS-N application rates and water contents ranging from 50% to 100% of water holding capacity (WHC). Experiment I and II showed that after the application of BS cumulative N2O emissions were 4 times (162 mg N2O-N m-2) higher compared to the application of CM caused by a higher content of mineral N (Nmin) in the form of ammonium (NH4+) in the BS. The cumulative emissions of CO2, however, were on the same level for both fertilizers indicating similar amounts of readily available C after composting and fermentation of organic material. Leaching losses occurred predominantly in the mineral form of nitrate (NO3-) and were higher in BS amended soils (9 mg NO3--N m-2) compared to CM amended soils (5 mg NO3--N m-2). The rainfall pattern in experiment I and II merely affected the temporal production of C and N emissions resulting in reduced CO2 and enhanced N2O emissions during stronger irrigation events, but showed no effect on the cumulative emissions. Overall, a significant increase of CH4 consumption under inconstant irrigation was found. The time of fertilization had no effect on the overall C and N dynamics. Increasing temperature from 13.5°C to 23.5°C enhanced the CO2 and N2O emissions by a factor of 1.7 and 3.7, respectively. Due to the increased microbial activity with increasing temperature soil respiration was enhanced. This led to decreasing oxygen (O2) contents which in turn promoted denitrification in soil due to the extension of anaerobic microsites. Leaching losses of NO3- were also significantly affected by increasing temperature whereas the consumption of CH4 was not affected. The third experiment showed that the input materials of biogas plants affected the properties of the resulting BS. In particular the contents of DM and NH4+ were determined by the amount of added plant biomass and excrement-based biomass, respectively. Correlations between BS properties and CO2 or N2O emissions were not detected. Solely the ammonia (NH3) emissions showed a positive correlation with NH4+ content in BS as well as a negative correlation with the total C (Ct) content. The BS-N application rates affected the relative CO2 emissions (% of C supplied with BS) when applied to silty soil as well as the relative N2O emissions (% of N supplied with BS) when applied to sandy soil. The impacts on the C and N dynamics induced by BS application were exceeded by the differences induced by soil texture. Presumably, due to the higher clay content in silty soils, organic matter was stabilized by organo-mineral interactions and NH4+ was adsorbed at the cation exchange sites. Different water contents induced highest CO2 emissions and therefore optimal conditions for microbial activity at 75% of WHC in both soils. Cumulative nitrification was also highest at 75% and 50% of WHC whereas the relative N2O emissions increased with water content and showed higher N2O losses in sandy soils. In summary it can be stated that the findings of the present thesis confirmed the high fertilizer value of BS’s, caused by high concentrations of NH4+ and labile organic compounds such as readily available carbon. These attributes of BS’s are to a great extent independent of the input materials of biogas plants. However, considerably gaseous and leaching losses of N may occur especially at high moisture contents. The emissions of N2O after field application corresponded with those of animal slurries.

Relationships between yield and mineral concentrations in potato tubers

There is concern that modern cultivars and/or agronomic practices have resulted in reduced concentrations of mineral elements essential to human nutrition in edible crops. Increased yields are often associated with reduced concentrations of mineral elements in produce, and a number of recent studies have indicated that, when grown under identical conditions, the concentrations of several mineral elements are lower in genotypes yielding more grain or shoot biomass than in older, lower-yielding genotypes. Potato is a significant crop, grown worldwide, yet few studies have investigated whether increasing yields, through agronomy or breeding, affects the concentrations of mineral elements in tubers. This article examines the hypothesis that increasing yields, either by the application of mineral fertilizers and/or by growing higher-yielding varieties, leads to decreased concentrations of mineral elements in tubers. It reports that the application of fertilizers influences tuber elemental composition in a complex manner, presumably as a consequence of soil chemistry and interactions between mineral elements within the plant, that considerable variation exists between potato genotypes in the concentrations of mineral elements in their tubers, and that, like in other crops, higher-yielding genotypes occasionally have lower concentrations of some mineral elements in their edible tissues than lower-yielding genotypes.

Comportamento do meloeiro em cultivo sem solo com a utilização de biofertilizante

O reaproveitamento de nutrientes após a fermentação de resíduos orgânicos em biodigestor, associado à técnica do cultivo hidropônico, é uma alternativa para reduzir custos na agricultura, além de contribuir no menor consumo das reservas naturais de nutrientes do planeta. Com esse enfoque, estudou-se o comportamento da cultura do meloeiro usando a técnica hidropônica e efluente de biodigestor proveniente da fermentação anaeróbica de estrume bovino. Cultivou-se o meloeiro (Cucumis melo L. 'Bônus 2') em condições de ambiente protegido. O delineamento estatístico utilizado foi de blocos casualizados, com 4 tratamentos (cultivo hidropônico em sistema fechado tipo NFT com uso de solução nutritiva organo-mineral; cultivo hidropônico em sistema fechado tipo NFT com uso de solução nutritiva 100% mineral; cultivo em sistema aberto, com substrato e solução nutritiva organo-mineral e cultivo em sistema aberto, com substrato e solução nutritiva 100% mineral) e 6 repetições. Foram realizadas avaliações quanto a altura de plantas aos 50; 56; 63; 70 e 77 dias após a semeadura; tempo de colheita; peso de frutos e produtividade. As melhores respostas foram observadas no cultivo hidropônico em sistema fechado tipo NFT com uso de solução nutritiva 100% mineral. A substituição parcial de adubos minerais por biofertilizante, se mostrou viável para os tratamentos em sistema aberto (com substrato), constituindo-se em masi uma alternativa aos horticultores.

Desenvolvimento do feijoeiro sob o uso de biofertilizante e adubação mineral

A produção intensiva de alimentos exige manejo adequado do solo para garantir a produtividade e a sustentabilidade ambiental. Uma das alternativas é a utilização de resíduos orgânicos no desenvolvimento das culturas, diminuindo a dependência de adubos minerais. Com o objetivo de avaliar o desenvolvimento da cultura de feijão (Phaseolus vulgaris L.), utilizando biofertilizante e adubação mineral, conduziu-se o experimento com seis tratamentos dispostos ao acaso, em esquema fatorial, em quatro blocos, com parcelas de 8,0 x 5,0 m. Os tratamentos sob solo cultivado com a cultura de feijão caracterizaram-se como: com e sem biofertilizante (CB e SB, respectivamente) e para a adubação mineral foram utilizadas a dose recomendada no plantio, ½ dose de adubação e sem adubação mineral (AM, 1/2AM, SAM). Adotaram-se práticas culturais convencionais para o preparo inicial do solo, e em seguida foi efetuada a aplicação de biofertilizante de origem bovina na dosagem de 100 m³ ha-1, com antecedência de três meses da semeadura. Foram avaliados os parâmetros massa da matéria seca acumulada na parte aérea da planta, área foliar e produtividade da cultura. Os resultados mostraram semelhanças entre as características analisadas, obtendo-se melhor desenvolvimento à cultura que recebeu biofertilizante.

Comparação de custos de implantação de eucalipto com resíduo celulósico em substituição ao fertilizante mineral

A grande expansão das indústrias e do mercado consumidor tem provocado, nas últimas décadas, a geração de elevadas quantidades de resíduos, os quais têm constituído constante preocupação econômica e ambiental. Objetivou-se, neste trabalho, analisar a viabilidade econômica do uso de três doses de composto orgânico, oriundo da compostagem de resíduos da extração da celulose, em substituição à adubação mineral, na cultura do eucalipto, no município de Selvíria, MS. A metodologia de custos adotada foi a do custo operacional total e do custo total. Concluiu-se que, por causa do elevado custo de transporte e aplicação, a adubação orgânica mostrou-se mais onerosa em relação à mineral, sendo sua utilização viável, economicamente, apenas nas proximidades da indústria produtora.

Manejo de irrigação por aspersão com base no Kc e adubação mineral na cultura de arroz de terras altas

A irrigação por aspersão diminui bastante o risco de perda da lavoura por deficiência hídrica e aumenta a produtividade de grãos, incentivando maior uso de tecnologias como adubação mineral. Com o objetivo de avaliar o efeito de diferentes manejos da água da irrigação por aspersão com base no coeficiente de cultura (Kc) e da adubação mineral sobre a cultura do arroz cv. IAC 201, foram instalados dois experimentos em Latossolo Vermelho Distrófico, em Selvíria (MS). O delineamento foi em blocos casualizados, com quatro repetições. Os tratamentos constituíram-se de precipitação pluvial natural e três manejos de água fornecidos por aspersão. O manejo (M2) foi realizado com base no Kc do arroz de terras altas. Os manejos M1 e M3 foram definidos como 0,5 e 1,5 vezes os Kcs utilizados em M2 respectivamente. em 1995/96, utilizou-se o esquema de parcelas subdivididas, sendo as subparcelas constituídas por dois níveis de adubação: AD1 - 12 kg de N, 90 kg de P2O5 e 30 kg de K2O ha-1, e AD2 - 24 kg de N, 180 kg de P2O5 e 60 kg de K2O ha-1. A deficiência hídrica da emergência da plântula até a diferenciação do primórdio da panícula provocou aumento do ciclo e redução do porte da planta. A deficiência hídrica entre os estádios de diferenciação do primórdio da panícula e os de emborrachamento reduziu o número de espiguetas por panícula. A utilização de 1,5 vezes os valores de Kc recomendados, no manejo da irrigação por aspersão proporcionou maior produtividade de grãos. Os níveis de adubação utilizados não influenciaram a resposta da cultura ao manejo da irrigação por aspersão.

Adubação mineral, orgânica e biodinâmica de yacon (Polymnia sonchifolia Poep & Endl): rendimento, qualidade e armazenamento

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Impactos de sistemas de cultivo, extrato húmico e adubos orgânico e mineral sobre alguns atributos físicos e químicos de um latossolo, cultivado com cana-de-açúcar

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Lodo de esgoto e adubação mineral na recuperação de atributos químicos de solo degradado

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)