Nitrogen washing from C3 and C4 cover grasses residues by rain

Crop species with the C-4 photosynthetic pathway are more efficient in assimilating N than C-3 plants, which results in different N amounts prone to be washed from its straw by rain water. Such differences may affect N recycling in agricultural systems where these species are grown as cover crops. In this experiment, phytomass production and N leaching from the straw of grasses with different photosynthetic pathways were studied in response to N application. Pearl millet (Pennisetum glaucum) and congo grass (Brachiaria ruziziensis) with the C-4 photosynthetic pathway, and black oat (Arena Strigosa) and triticale (X Triticosecale), with the C-3 photosynthetic pathway, were grown for 47 days. After determining dry matter yields and N and C contents, a 30 mm rainfall was simulated over 8 t ha(-1) of dry matter of each plant residue and the leached amounts of ammonium and nitrate were determined. C-4 grasses responded to higher fertilizer rates, whereas N contents in plant tissue were lower. The amount of N leached from C-4 grass residues was lower, probably because the C/N ratio is higher and N is more tightly bound to organic compounds. When planning a crop rotation system it is important to take into account the difference in N release of different plant residues which may affect N nutrition of the subsequent crop.

Carbon isotope composition as a tool for quality control of herbs, spices and medicinal plants

Isotope screening is a simple and cheap test for determining the photosynthetic pathway used by plants. The scope of this work was to classify the photosynthetic type of Melissa officinalis L. and Cymbopogon citratus [DC.] Stapf, through studies of the carbon isotope composition (δ13 C), and we are proposing the use of carbon isotope composition results as a tool to control the quality of medicinal plants. For studies of δ 13C (13 C% = [R (sample)/R (standard) - 1] × 10 -3), dried, powdered leaves were analyzed in a mass spectrometer coupled with an elemental analyzer for determining the ratio R (R = 13CO2/12CO2). As results, M. officinalis presented a C3 photosynthetic type, and C. citratus presented a C4 photosynthetic type. The carbon isotope composition from this study can be used as quality control of M. officinalis adulterants.

Caracterização sistêmica de alterações em redes fisiológicas de plantas C3 e C4 submetidas à deficiência hídrica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação metabólica de dietas de C3 e C4 na formação do ovo (gema e albúmen) pelo uso da técnica dos isótopos estáveis do carbono

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Carbon isotope composition and leaf anatomy as a tool to characterize the photosynthetic mechanism of Artemisia annua L.

Leaves of Artemisia annua L. are a plentiful source of artemisinin, a drug with proven effectiveness against malaria. The aim of this study was to classify the photosynthetic mechanism of A. annua through studies of the carbon isotope composition (δ 13C) and the leaf anatomy. A. annua presented a δ 13C value of - 31.76 ± 0.07, which characterizes the plants as a typical species of the C3 photosynthethic mechanism, considering that the average δ 13C values for C3 and C4 species are -28 and -14, respectively. The leaf anatomy studies were consistent with the δ 13C results, where, in spite of the existence of parenchymatic cells forming a sheath surrounding the vascular tissue, the cells do not contain chloroplasts or starch. This characteristic is clearly different from that of the Kranz anatomy found in C4 species.

Turnover de carbono e a preferência alimentar de ovelhas por isótopos estáveis

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

Turnover do δ¹³C na substituição de dietas com ingredientes de diferentes ciclos fotossintéticos em ovos de codornas japonesas (Coturnix coturnix japonica)

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

Carbon isotope composition as a tool to control the quality of herbs and medicinal plants

Isotope screening is a simple test for determining the photosynthetic pathway used by plants. The scope of this work was to classify the photosynthetic type of some herbs and medicinal plants through studies of the carbon isotope composition (δ13C). Also, we propose the use of carbon isotope composition as a tool to control the quality of herbs and medicinal plants. For studies of δ13C, δ 13C‰ = [R (sample)/R (standard) - 1] × 10-3, dry leaves powdered in cryogenic mill were analyzed in a mass spectrometer coupled with an elemental analyzer for determining the ratio R = 13CO2/12CO2. In investigation of δ13C of 55 species, 23 botanical families, and 44 species possessed a C3 photosynthetic type. Six species found among the botanical families Euphorbiaceae and Poaceae were C4 plants, and 5 species found among the botanical families Agavaceae, Euphorbiaceae, and Liliaceae possessed CAM-type photosynthesis. Carbon isotope composition of plants can be used as quality control of herbs and medicinal plants, allowing the identification of frauds or contaminations. Also, the information about the photosynthetic type found for these plants can help in introducing and cultivating exotic and wild herbs and medicinal plants.

Nickel in soil and maize plants grown on an oxisol treated over a long time with sewage sludge

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

Resposta da alface à adubação nitrogenada com diferentes compostos orgânicos em dois ciclos sucessivos

Os objetivos deste trabalho foram avaliar a produção de alface em ambiente protegido, utilizando diferentes compostos orgânicos como fonte de nitrogênio, e seu efeito residual em dois ciclos sucessivos. O experimento foi conduzido entre os meses de fevereiro e maio de 2005, em casa-de-vegetação com ventilação e temperatura controlados, utilizando vasos de 3,5 L e solo classificado como Latossolo Vermelho Escuro. Foram utilizados compostos orgânicos produzidos a partir da mistura de resíduos do processamento de quatro plantas medicinais e esterco bovino. Os compostos C1, C2, C3 e C4 nas doses 30, 60, 90 e 120 t ha-1 constituíram os tratamentos dispostos em delineamento inteiramente casualizado, com quatro repetições e uma testemunha (adicional). Foram determinados: matéria fresca da parte aérea (MFPA); massa de matéria seca da parte aérea (MSPA). Os compostos aplicados supriram satisfatoriamente as necessidades de nitrogênio da cultura, no primeiro ciclo, dispensando o uso de fertilizante mineral. A composição dos materiais aplicados influenciou significativamente a produção de alface no primeiro ciclo, promovendo efeito residual no segundo ciclo, porém em menores proporções.

Environmental management in ethanol and sugarcane plants in Brazil

There has been much discussion on the importance of Brazilian ethanol in promoting a more sustainable society. However, there is a lack of analysis of whether sugarcane plants/factories that produce this ethanol are environmentally suitable. Thus, the objective of this study was to analyse stages of environmental management at four Brazilian ethanol-producing plants, examining the management practices adopted and the factors behind this adoption. The results indicate that (1) only one of the four plants is in the environmentally proactive stage; (2) all plants are adopting operational and organisational environmental management practices; (3) all plants have problems in communicating environmental management practices; and (4) the plant with the most advanced environmental management makes intense use of communication practices and is strongly oriented towards a more environmentally aware international market. This paper is an attempt to explain the complex relationship between the evolution of environmental management, environmental practices and motivation using a framework. The implications for society, plant directors and scholars are described, as well as the study's limitations.

Time-dependent alterations of soluble and cellular components in human milk

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

Diabetes induced immunological and biochemical changes in human colostrum

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

Muscle delta C-13 change in nile tilapia (Oreochromis niloticus) fingerlings fed lants grain-based diets

The effects of grain-based diets from C3 or C4-cycle plants on muscle delta C-13 change process in Nile tilapia (Oreochromis niloticus) fingerlings were investigated. Two groups of sex reversal males Nile tilapia fingerlings were fed with isoproteic (32.0% DP) and isocaloric (3200 kcal DE/kg) diets, differing from each other by their delta C-13. Muscle samples were collected and the carbon isotopic composition was measured. For C4 diet, the formula for the muscle delta C-13 change related to the intake time of a new diet was delta C-13=- 14.88 - 9.2 1 e(-0.0209t) and the half-life (T) of the muscle carbon was 33.2 days. For C3 diet, the formula was delta C-13 = - 25.43 + 8.59e(-0.0533), with T = 13 days. The C3 diet was considered more appropriate based on its palatability and consequent larger food intake than the C4 diet, resulting in an increased muscle delta C-13 change rate. However, for future studies, would be necessary to mix both the C3 and C4 feedstuffs to formulate diets nutritionally appropriated, with contrasting stable isotopes signatures. Tissue delta C-13 change rate is therefore indicated as a promising tool to better understand the biotic and abiotic factors that influence nutrients utilization from the diet and animal growth. (c) 2006 Elsevier B.V. All rights reserved.