993 resultados para Agricultural growth


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In crop-livestock integration systems the presence of both grass roots in the soil and straw on the surface can temporarily immobilize nitrogen. This study examined the persistence of grass residues in the system as well as their effects on cotton response to N when grown after Congo grass (Brachiaria ruziziensis, Syn. Urochloa ruziziensis). Congo grass was grown in pots with soil. Next, cotton was grown in the same pots without residues, with whole plant residues (Congo grass roots and shoots) or root residues (grass roots) and fertilized with N as ammonium nitrate. Congo grass and cotton roots were separated using stable carbon isotope fractioning. Congo grass roots showed higher C/N ratio than shoots, losing 14% of its mass after 45 days and increasing soil N immobilization. The lower N availability resulted in N deficient and shorter cotton plants with lower dry matter yields. Nevertheless, the application of 80 to 120 mg kg-1 of N compensated the immobilization by the soil microorganisms, allowing cotton to show normal growth. When Congo grass is present in the cropping system, the effects of the decaying roots on soil N dynamics and availability are more important than those of the straw left on the soil surface.

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Mycelial growth strains of POS 98/38, POS 09/100, POS 09/101, and POS 09/102 of Pleurotus ostreatus were evaluated in culture media with various compositions based on extracts of substrates formulated with sugar cane bagasse together with straws and grasses, and with or without nitrogen supplementation. The evaluation was performed during incubation regularly with a ruler graduated in millimeters until total colonization of the culture medium contained in Petri dishes. The statistical model explaining the kinetics of mycelial growth of mushroom strains of P. ostreatus as a deterministic component has an exponential Gompertz function. The results show that the culture medium with sugar cane straw and brizantha grass (supplemented) showed the highest rates of mycelial growth, regardless of strain used compared to wheat straw-based culture media with had the lowest velocities of growth, regardless of supplementation and strains studied.

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According to estimates released by the Bureau of the Census in August, 2009, Nebraska’s total housing stock increased by 5,529 units between July 1, 2007 and July 1, 2008, an increase of 0.7 percent for the year. This represented an estimated rate of growth in housing stock slightly below the state’s estimated rate of population growth, which was 0.8 percent for the same time period.

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Purpose--The paper theoretically and empirically investigates the impact on human capital investment decisions and income growth of lowered life expectancy as a result of HIV/AIDS and other diseases. Design/methodology/approach--The theoretical model is a three-period overlapping generations model where individuals go through three stages in their life, namely, young, adult and old. The model extends existing theoretical models by allowing the probability of premature death to differ for individuals at different life stage, and by allowing for stochastic technological advances. The empirical investigation focuses on the effect of HIV/AIDS on life expectancy and on the role of health on educational investments and growth. We address potential endogeneity by using various strategies, such as controlling for country specific time-invariant unobservables and by using the male circumcision rate as an instrumental variable for HIV/AIDS prevalence. Findings--We show theoretically that an increased probability of premature death leads to less investment in human capital, and consequently slower growth. Empirically we show that HIV/AIDS has resulted in a substantial decline in life expectancy in African countries and these falling life expectancies are indeed associated with lower educational attainment and slower economic growth world wide. Originality/value--The theoretical and empirical findings reveal a causal link flowing from health to growth, which has been largely overlooked by the existing literature. The main implication is that health investments, that decrease the incidence of diseases like HIV/AIDS resulting on increases in life expectancy, through its complementarity with human capital investments lead to long run growth..

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Scientists predict that global agricultural lands will expand over the next few decades due to increasing demands for food production and an exponential increase in crop-based biofuel production. These changes in land use will greatly impact biogeochemical and biogeophysical cycles across the globe. It is therefore important to develop models that can accurately simulate the interactions between the atmosphere and important crops. In this study, we develop and validate a new process-based sugarcane model (included as a module within the Agro-IBIS dynamic agro-ecosystem model) which can be applied at multiple spatial scales. At site level, the model systematically under/overestimated the daily sensible/latent heat flux (by -10.5% and 14.8%, H and E, respectively) when compared against the micrometeorological observations from southeast Brazil. The model underestimated ET (relative bias between -10.1% and 12.5%) when compared against an agro-meteorological field experiment from northeast Australia. At the regional level, the model accurately simulated average yield for the four largest mesoregions (clusters of municipalities) in the state of Sao Paulo, Brazil, over a period of 16 years, with a yield relative bias of -0.68% to 1.08%. Finally, the simulated annual average sugarcane yield over 31 years for the state of Louisiana (US) had a low relative bias (-2.67%), but exhibited a lower interannual variability than the observed yields.

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The use of sewage sludge is a highly promising practice for the development of sustainable agricultural systems. The objective of this study was to evaluate doses of sewage sludge composted with and without Rhizobium inoculation in leaf N content, nodule number, nodule dry weight and plant during flowering. The experiment was conducted in the greenhouse of the Department of Soil Science and Natural Resources College of Agricultural Sciences of Botucatu, using as substrate used in vessels of 30 liters a Red Yelow Latosol sandy texture with experimental design adopted was randomized blocks constituted for 10 treatments and five doses of composted sewage sludge (0, 10, 20, 30, 40 t ha(-1)) with or without inoculation Bradyrhizobium japonic with three replications. There was an increase in the number and dry weight of nodules and shoot dry mass of soybeans due to the increase of the dose of sludge up to a dose of 20 t ha(-1) and after this dose there was a decrease of these parameters. At a dose of 10 t ha(-1) sludge compost inoculated seeds showed higher for foliar concentrations of N and number of nodules compared with uninoculated seeds. At a dose of 30 t ha(-1) inoculated seeds were higher compared to uninoculated in all parameters.

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We employ the case of USAID's Linking Agricultural Markets with Producers (LAMP) project to address opportunities and obstacles to development assistance. Framed within LAMP's identification of constraints to growth within Bosnia's agricultural market, we explore the complex interorganizational linkages required for success. We identify three distinct linkage types inherent to development situations. Relationships exist (1) within the international community, (2) within the local Bosnian community and (3) between international and local organizations.

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While bryophytes greatly contribute to plant diversity of semi-natural grasslands, little is known about the relationships between land-use intensity, productivity, and bryophyte diversity in these habitats. We recorded vascular plant and bryophyte vegetation in 85 agricultural used grasslands in two regions in northern and central Germany and gathered information on land-use intensity. To assess grassland productivity, we harvested aboveground vascular plant biomass and analyzed nutrient concentrations of N, P, K, Ca and Mg. Further we calculated mean Ellenberg indicator values of vascular plant vegetation. We tested for effects of land-use intensity and productivity on total bryophyte species richness and on the species richness of acrocarpous (small & erect) and pleurocarpous (creeping, including liverworts) growth forms separately. Bryophyte species were found in almost all studied grasslands, but species richness differed considerably between study regions in northern Germany (2.8 species per 16 m2) and central Germany (6.4 species per 16 m2) due environmental differences as well as land-use history. Increased fertilizer application, coinciding with high mowing frequency, reduced bryophyte species richness significantly. Accordingly, productivity estimates such as plant biomass and nitrogen concentration were strongly negatively related to bryophyte species richness, although productivity decreased only pleurocarpous species. Ellenberg indicator values for nutrients proved to be useful indicators of species richness and productivity. In conclusion, bryophyte composition was strongly dependent on productivity, with smaller bryophytes that were likely negatively affected by greater competition for light. Intensive land-use, however, can also indirectly decrease bryophyte species richness by promoting grassland productivity. Thus, increasing productivity is likely to cause a loss of bryophyte species and a decrease in species diversity.

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Current nutrient deposition shows episodic variations which likely may impact the local nutrient cycle at the RBSF. Comparing analyses of deposition data during present-day atmospheric circulation and phases of high biomass burning in the Amazon, characteristic relationships between remote emissions and local deposition are determined. By using projections drawn from the special report on emission scenarios (SRES) in combination with a trajectory modeling tool, future nutrient deposition conditions of the mountain ecosystem are assessed. Observations of relations between climatic variables, current time series of nutrient deposition, and tree growth point to an impact of the remote fertilization effect of atmospheric matters, emitted primarily by human activities like biomass burning and agricultural and industrial sources. The increasing emissions in the future may have adverse effects on the ecosystem in the long run.

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Growing evidence suggests environmental change to be most severe across the semi-arid subtropics, with past, present and projected drying of the Mediterranean Basin posing a key multidisciplinary challenge. Consideration of a single climatic factor, however, often fails to explain spatiotemporal growth dynamics of drought-prone ecosystems. Here, we present annually resolved and absolutely dated ring width measurements of 871 Scots pines (Pinus sylvestris) from 18 individual plot sites in the Central Spanish Pinar Grande forest reserve. Although comprising tree ages from 6 to 175 years, this network correlates surprisingly well with the inverse May–July diurnal temperature range (r = 0.84; p < 0.00011956–2011). Ring width extremes were triggered by pressure anomalies of the North Atlantic Oscillation, and the long-term growth decline coincided with Iberian-wide drying since the mid-1970s. Climate model simulations not only confirm this negative trend over the last decades but also project drought to continuously increase over the 21st century. Associated ecological effects and socio-economic consequences should be considered to improve adaptation strategies of agricultural and forest management, as well as biodiversity conservation and ecosystem service.

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Plants generally respond to herbivore attack by increasing resistance and decreasing growth. This prioritization is achieved through the regulation of phytohormonal signaling networks. However, it remains unknown how this prioritization affects resistance against non-target herbivores. In this study, we identify WRKY70 as a specific herbivore-induced, mitogen-activated protein kinase-regulated rice transcription factor that physically interacts with W-box motifs and prioritizes defence over growth by positively regulating jasmonic acid (JA) and negatively regulating gibberellin (GA) biosynthesis upon attack by the chewing herbivore Chilo suppressalis. WRKY70-dependent JA biosynthesis is required for proteinase inhibitor activation and resistance against C. suppressalis. In contrast, WRKY70 induction increases plant susceptibility against the rice brown planthopper Nilaparvata lugens. Experiments with GA-deficient rice lines identify WRKY70-dependent GA signaling as the causal factor in N. lugens susceptibility. Our study shows that prioritizing defence over growth leads to a significant resistance trade-off with important implications for the evolution and agricultural exploitation of plant immunity.

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Foresters frequently lack sufficient information about thinning intensity effects to optimize semi-natural forest management and their effects and interaction with climate are still poorly understood. In an Abies pinsapo–Pinus pinaster–Pinus sylvestris forest with three thinning intensities, a dendrochronologial approach was used to evaluate the short-term responses of basal area increment (BAI), carbon isotope (δ13C) and water use efficiency (iWUE) to thinning intensity and climate. Thinning generally increased BAI in all species, except for the heavy thinning in P. sylvestris. Across all the plots, thinning increased 13C-derived water-use efficiency on average by 14.49% for A. pinsapo, 9.78% for P. sylvestris and 6.68% for P. pinaster, but through different ecophysiological mechanisms. Our findings provide a robust mean of predicting water use efficiency responses from three coniferous species exposed to different thinning strategies which have been modulated by climatic conditions over time.

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This paper reviews the development of the agricultural sector in Myanmar after the transition to an open economy in 1988 and analyzes the nature as well as the performance of the agricultural sector. The avoidance of social unrest and the maintenance of control by the regime are identified as the two key factors that have determined the nature of agricultural policy after 1988. A major consequence of agricultural policy has been a clear difference in development paths among the major crops. Production of crops that had a potential for development showed sluggish growth due to policy constraints, whereas there has been a self-sustaining increase in the output of those crops that have fallen outside the remit of agricultural policy.

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Japanese ODA, especially that undertaken by JICA, has targeted South Sulawesi Province as a core area of development in eastern Indonesia, with hope that the economic growth of South Sulawesi will bring about spillover effects in other regions. This paper tests the validity of the strategy using a framework of Vector Autoregressive model. The results show that South Sulawesi’s economy Granger causes other regions in eastern Indonesia, but not vice versa, implying that South Sulawesi drives the development of other regions in eastern Indonesia. Further analysis shows that the development of the agricultural sector in South Sulawesi potentially has the highest spillover effects than other sectors and that the magnitude of spillover effect from South Sulawesi on eastern Indonesia is higher than other economically important regions, such as Eastern Java and Kalimantan.

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The development of agriculture is a main pillar of Myanmar’s growth strategies. It is natural for the Myanmar government to prioritize agriculture as a source of economic growth, since it accounted for 36% of GDP, employs a majority of labor force, and generates nearly 30% of exports as of 2010. Although the agricultural share in GDP and employment usually declines as an economy grows, it is not a sunset industry in Myanmar. Methods exist for increasing agriculture’s value added other than the growth of labor and land inputs. The key is to enhance three productivity measures: labor, land, and total productivity. We call this strategy "Agriculture Plus Plus."