Growth Resource Use Research Articles

Yield and Nutrient Demand and Efficiency of Eucalyptus under Coppicing Regime

Eucalyptus stands can be managed by coppicing, however, in several Brazilian regions reduced yield has been observed with harvesting successions. This reduction can be attributed to reduced nutrient availability, among other factors. This study aimed to: to assess the nutritional demand of the Eucalyptus stand under a coppice regime; the effect of fertilization on the production of wood, distribution and compartmentalization of nutrients in eucalyptus stands managed by coppice; the effect of the height and number of shoots, on the occasion of the sprouting, in the production of eucalyptus managed by coppice and to compare the productivity of high eucalyptus wood with coppice management regime. The trial was conducted for clone GG157 (Eucalyptus urophylla hybrid), in Latossolo Vermelho-Amarelo (Oxisol), of the Cerrado region in Minas Gerais State, Brazil. Trees were originally planted at the 3.8 × 2.4 m spacing and, after the first harvesting, at age 84 months, the stand was managed by coppicing. Treatments consisted of: (a) fertilization or not; (b) one, two or four poles per stump; and (c) selection of 1-, 2- or 4-m-high poles and repeated three times. Sixty months after treatment application, plots of 80 trees were used for the assessments. The gain in trunk yield with fertilization and the combination between the height of poles at the time of pole selection and number of poles left varies between 140.2% for thinning when the pole is 2 m high and maintains 1 pole per strain and 128.6% when the plants are 1 m high and maintain 1 pole per strain. Not supplying nutrients in the coppicing system leads to lower accumulation of nutrients in the tree and reductions in both wood and trunk yields. Trees in the coppicing system use nutrients for trunk production more efficiently than those in high forest. Earlier pole selection enables the best use of growth resources, resulting in increased yield. Adequate nutritional management of coppiced stands results in the maintenance or increase of yield compared to the first rotation.

Accumulation of macronutrients in cowpea and weeds in competition and under soil water deficit

The ability of a plant species to succeed in colonization of agroecosystem depends on its efficiency in the use of growth resources even in deficient conditions. The present study aimed to evaluate the effects of competition and water deficit in the soil on the accumulation of macronutrients of Vigna unguiculata L. Walp., Commelina benghalensis L. and Waltheria indica L. The study was conducted in a greenhouse, in randomized block design, with four replications. The treatments were arranged in a 5 × 2 factorial, with the first factor corresponding to types of interaction among species (V. unguiculata + C. benghalensis; V. unguiculata + W. indica; V. unguiculata in monoculture, C. benghalensis in monoculture and W. indica in monoculture), and the second of water regimes (irrigated and water deficit). The water deficit differently affects macronutrient content on the species, with decreased of K, Ca and Mg in cowpea, and N, P, K and Ca in W. indica. For C. benghalensis, the water deficit does not reduce the macronutrient contents on the plant. The competition between plants intensifies the effects of water deficit only on C. benghalensis, with a decreased on the content of all macronutrients studied. Under irrigated conditions, competition between plants was more damaging the weeds compared to cowpea. The C. benghalensis specie, free from interference, has a high potential for nutrient extraction under irrigated and water deficit regimes.

Resource efficiency and green economic sustainability transition evaluation of green growth productivity gap and governance challenges in Cambodia

AbstractThis study provides an analysis of Cambodian socio‐economic and environmental development. The analysis applies the Sustainable Society Index—database and uses Sustainability Window analyses linked to the green growth strategy in Cambodia. The novel analyses provide criteria for weak and strong sustainability and are further developed to evaluate the green growth productivity gap.We have carried out empirical analyses using indicators of the different dimensions of sustainability—economic, social, and environmental. The Sustainability Window defines the minimum economic development for social sustainability and the maximum economic development for environmental criterion for sustainability.This study demonstrates methodological usefulness of the Sustainability Window analysis in the fields of development studies and green growth. The methodological novelty of this study is to use Sustainability Window approach and to provide a novel empirical testbed for strong and weak sustainability analyses as well as for the analysis of the green growth resource use productivity gap.

Opportunities for Industry 4.0 to Support Remanufacturing

Remanufacturing is the process of bringing end-of-life products back to good-as-new. It plays a critical role in decoupling economic growth from growth in resource use, and in accelerating the circular economy. However, the uptake of remanufacturing activities faces obstacles. This paper reviews the challenges encountered by the remanufacturing sector and discusses how the Industry 4.0 revolution could help to effectively address these issues and unlock the potential of remanufacturing. Two case studies are included in this paper to exemplify how technology enablers from Industry 4.0 can increase efficiency, reliability, and digitization of the remanufacturing process.

Psychiatric Disorders and Trends in Resource Use in Pediatric Hospitals

To describe recent, 10-year trends in pediatric hospital resource use with and without a psychiatric diagnosis and examine how these trends vary by type of psychiatric and medical diagnosis cooccurrence. A retrospective, longitudinal cohort analysis using hospital discharge data from 33 tertiary care US children's hospitals of patients ages 3 to 17 years from January 1, 2005 through December 31, 2014. The trends in hospital discharges, hospital days, and total aggregate costs for each psychiatric comorbid group were assessed by using multivariate generalized estimating equations. From 2005 to 2014, the cumulative percent growth in resource use was significantly (all P < .001) greater for children hospitalized with versus without a psychiatric diagnosis (hospitalizations: +137.7% vs +26.0%; hospital days: +92.9% vs 5.9%; and costs: +142.7% vs + 18.9%). During this time period, the most substantial growth was observed in children admitted with a medical condition who also had a cooccurring psychiatric diagnosis (hospitalizations: +160.5%; hospital days: +112.4%; costs: +156.2%). In 2014, these children accounted for 77.8% of all hospitalizations for children with a psychiatric diagnosis; their most common psychiatric diagnoses were developmental disorders (22.3%), attention-deficit/hyperactivity disorder (18.1%), and anxiety disorders (14.2%). The 10-year rise in pediatric hospitalizations in US children's hospitals is 5 times greater for children with versus without a psychiatric diagnosis. Strategic planning to meet the rising demand for psychiatric care in tertiary care children's hospitals should place high priority on the needs of children with a primary medical condition and cooccurring psychiatric disorders.

CRESCIMENTO INICIAL E CONCENTRAÇÃO DE NUTRIENTES EM CLONES DE&lt;i&gt; Eucalyptus urophylla&lt;/i&gt; x &lt;i&gt;Eucalyptus grandis&lt;/i&gt; SOB INTERFERÊNCIA DE PLANTAS DANINHAS

http://dx.doi.org/10.5902/1980509821099A presença de plantas daninhas em plantios de eucalipto, especialmente nos dois primeiros anos, pode acarretar grandes prejuízos à produtividade, pois reduz a eficiência de aproveitamento dos recursos de crescimento pela cultura. Assim, objetivou-se com este trabalho avaliar os efeitos da interferência de plantas daninhas sobre o crescimento inicial de dois clones de Eucalyptus urophylla x Eucalyptus grandis e sobre a concentração foliar de nutrientes na cultura e nas plantas daninhas. O experimento foi instalado em esquema fatorial 2 x 5 + 7, sendo dois clones de híbridos de Eucalyptus urophylla x Eucalyptus grandis, identificados como CNB001 e CNB016, em competição com cinco espécies de plantas daninhas Urochloa decumbens (capim-braquiária), Ipomoea nil (corda-de-viola), Commelina diffusa (trapoeraba), Spermacoce latifolia (erva-quente) e Panicum maximum (capim-colonião). Adicionalmente foram cultivados os dois clones de eucalipto e as cinco plantas daninhas em monocultivo como padrão de comparação, no delineamento inteiramente casualizado, com quatro repetições. Foram avaliados o crescimento inicial de mudas de eucalipto através da altura de plantas, o diâmetro do coleto, o número de ramos, a área foliar e matéria seca, o teor foliar de nutrientes do eucalipto, bem como o teor de nutrientes nas folhas das plantas daninhas. O clone CNB001 apresentou crescimento inicial superior ao clone CNB016, no entanto, livre da interferência de plantas daninhas, verificaram-se teores foliares semelhantes para a maioria dos nutrientes em ambos os genótipos. O clone CNB016 mostrou maior sensibilidade à interferência negativa das plantas daninhas que o clone CNB001, sendo seu crescimento inicial mais afetado por Ipomoea nil e a concentração de nutrientes reduzida pelas espécies Panicum maximum, Urochloa decumbens e Commelina diffusa. Panicum maximum apresentou maior interferência com o clone CNB001, enquanto Ipomoea nil pouco influenciou o crescimento e o teor de nutrientes deste híbrido. As plantas daninhas apresentaram elevada capacidade de extrair nutrientes do solo, mesmo em convivência com os clones de Eucalyptus urophylla x Eucalyptus grandis. A interferência imposta à cultura é dependente da espécie infestante e do genótipo de eucalipto.

Greenhouse gas emissions and the technical efficiency of dairy farmers

Agriculture in Scotland is facing immense challenges for the future. Scottish policy now promotes sustainable economic growth, which to many implies both a growth in resource use and the requirement to meet targets for reducing greenhouse gas emissions. Attempts to increase economic gains can be in conflict with environmental aims and the question arises how both objectives can be met simultaneously.This paper examines the relationship between the technical and environmental efficiency of dairy farms in Scotland with respect to greenhouse gas emissions. It estimates the technical efficiency of a sample of dairy farms based on survey data, applying a number of approaches based on the non-parametric Data Envelopment Analysis (DEA) method. The farms’ greenhouse gas emissions are calculated using a variety of sources and were used to estimate environmental efficiency. This paper finds that, within the study sample, farms which are more technically efficient, are bigger or have higher yields are also more efficient in their emissions of GHG emissions.These results suggest that the potential exists for, Scottish dairying to improve its competitiveness and lower greenhouse gas emissions by increasing efficiency, though the extent of the environmental benefits achieved largely depends on how efficiency is increased.

Effect of pea and spring cereals intercropping on grain yield and crude protein content

The advantage of intercropping is beneficial biological interactions between crops and their different use of growth resources. Our experiment aimed at investigating the effects of pea intercropping with cereals on the improvement of cereal supply with nitrogen and protein content in grain on a loamy soil in organic farming conditions. It was carried out during 2007-2009 at the Lithuanian Institute of Agriculture in Dotnuva. Pea (Pisum sativum L) and spring wheat (Triticum aestivum L), spring barley (Hordeum vulgare L) oats (Avena sativa L), and triticale (x Triticosecale Wittm) were sown as intercrops 50:50 or as a sole crop. The results obtained during the experimental years showed that the productivity and quality of spring cereal sole crops or intercrops depended on the species of cereals and varied between different year's cultivation conditions. Grain productivity in some cases was estimated to be higher in the intercrops, however it was not stable in three experimental years. The protein content and yield in the grain of cereals grown in intercrops was positively affected by pea intercrops.

Maize hybrids less dependent on high plant densities improve resource-use efficiency in rainfed and irrigated conditions

Density-dependent maize hybrids have a number of disadvantages such as the strong dependence of the crop yield on the seeding rate, the high hybrid by density interaction, and the difficulty to exploit drought-prone environments. Density-neutral cultivars are defined as those able to optimize crop yield over a wide range of plant densities. In this study we used two sets of maize hybrids, seven Romanian and seven Greek hybrids, and examine two main objectives. To evaluate under rainfed and irrigated conditions density-dependent and partially bred for density independence hybrids, in order to assess the advantages and disadvantages of the two categories. The other is to assess the reliability of a novel selection and evaluation equation in predicting the crop yield genetic potential of maize hybrids evaluated at the ultra-low plant density of 0.74 plants/m 2. The equation enables to broaden the density range for optimum productivity because it selects jointly for two attributes. One, for yield potential per plant which extends the lower limit of the optimum density range and second, for stability of performance that extends the higher limit of the optimum density range. The results of this study suggest that the optimum plant density for maize hybrids grown under drought-prone conditions is much lower than when they grow under favorable conditions, meaning that the drought-prone environments require lower plant densities for efficient use of growth resources. The advantage of breeding for density-neutral maize hybrids is that these hybrids have the potential to attain higher productivity in the drought-prone environments where the environmental resources cannot support a high plant density population and medium plant densities are most favorable. Moreover, our results show that the mean crop yield across years of the top maize Romanian and Greek hybrids evaluated at commercial plant densities could be predicted from the crop yield potential (CYP) values assessed in honeycomb trials at the low plant density.

Biomass production, symbiotic nitrogen fixation and inorganic N use in dual and tri-component annual intercrops

The interspecific complementary and competitive interactions between pea (Pisum sativum L.), barley (Hordeum vulgare L.) and oilseed rape (Brassica napus L.), grown as dual and tri-component intercrops were assessed in a field study in Denmark. Total biomass production and N use at two levels of N fertilisation (0.5 and 4.0 g N/m2), were measured at five harvests throughout a growing season. All intercrops displayed land equivalent ratio values close to or exceeding unity, indicating complementary use of growth resources. Whereas both rape and barley responded positively to increased N fertilisation, irrespective of whether they were grown as sole- or intercrops, pea was strongly suppressed when grown in intercrop. Of the three crops barley was the strongest competitor for both soil and fertiliser N, rape intermediate and pea the weakest. Faster initial growth of barley than pea and rape gave barley an initial competitive advantage, an advantage that in the two dual intercrops was strengthened by the addition of N. Apparently the competitive superiority of barley was less strong in the tri-component intercrop, indicating that the impact of the dominantmay, through improved growth of both rape and pea, have been diminished through indirect facilitation. Interspecific competition had a promoting effect on the percent of nitrogen derived from N2 fixation of pea, and most so at the low N fertilisation level. Results indicate that the benefits achieved from the association of a legume and nonlegume, in terms of N2 fixed were greatest when pea was grown in association with rape as opposed to barley which could indicate that the benefits achieved from the association of a legume and nonlegume are partly lost if the nonlegume is too strong a competitor.

Ecological interactions, management lessons and design tools in tropical agroforestry systems

During the 1980s, land- and labor-intensive simultaneous agroforestry systems (SAFS) were promoted in the tropics, based on the optimism on tree-crop niche differentiation and its potential for designing tree-crop mixtures using high tree-densities. In the 1990s it became clearer that although trees would yield crucial products and facilitate simultaneous growing of crops, they would also exert strong competitive effects on crops. In the meanwhile, a number of instruments for measuring the use of growth resources, exploratory and predictive models, and production assessment tools were developed to aid in understanding the opportunities and biophysical limits of SAFS. Following a review of the basic concepts of interspecific competition and facilitation between plants in general, this chapter synthesizes positive and negative effects of trees on crops, and discusses how these effects interact under different environmental resource conditions and how this imposes tradeoffs, biophysical limitations and management requirements in SAFS. The scope and limits of some of the research methods and tools, such as analytical and simulation models, that are available for assessing and predicting to a certain extent the productive outcome of SAFS are also discussed. The review brings out clearly the need for looking beyond yield performance in order to secure long-term management of farms and landscapes, by considering the environmental impacts and functions of SAFS.

Sustainable Growth and Chemical Engineering

Growth is needed. Connected with economic growth is the concern about our resources, environment, and the effects on human health. Our economy and wealth depend on material resources. Chemistry transforms the resources into the materials and products we need: energy, housing, clothing, food, transport, appliance, and clean water. Economic growth presently implies growth in use of resources what cannot be sustained on the long run – a challenge for society as a whole, industry, and chemical engineering in particular.

Adaptation of the timing of bud burst of Norway spruce to temperate and boreal climates

The adaptation of the annual cycle of development of boreal and temperate trees to climatic conditions has been seen as a result of stabilizing selection caused by two opposite driving forces of natural selection, i.e. the tolerance of unfavorable conditions during the frost exposed season (survival adaptation) and the effective use of growth resources during the growing season (capacity adaptation). In this study, two theories of the effects of climate on the adaptation of the timing of bud burst of trees were evaluated. This was done with computer simulations by applying a temperature sum model for predicting the timing of bud burst of different Norway spruce genotypes on the basis of air temperature data from various climatic conditions. High geographical variation in the temperature response of bud burst, typical for Norway spruce, was included in the theoretical analyses. The average timing of bud burst and the corresponding risk of occurrence of damaging frost during the susceptible period after bud burst were calculated for each genotype in each climate. Two contrasting theories of the stabilizing selection were evaluated, i.e. the overall adaptedness of each genotype was evaluated either 1) by assuming a fixed threshold for the risk of frost damage, or 2) by assuming a tradeoff between the risk of frost damage and the length of the growing season. The tradeoff assumption produced predictions of between provenance variation in bud burst which correspond more closely with empirical observations available in literature, compared to the fixed threshold assumption.

Impacts of growth in resource use and human population on the Nechako River: A major tributary of the Fraser River, British Columbia, Canada

Hydroelectric development, forest exploitation, agricultural land use and related human population numbers have increased rapidly during the last 40 years, in the basin of the Nechako River, a major tributary system of the Fraser River. The Kemano project of the Aluminum Company of Canada Ltd. begun in 1950, was the largest industrial scheme in the area. A key feature of the first stage of it was a dam which diverted about 40% of flow of the south branch of the Nechako River, through a tunnel in the mountains, to the Pacific Ocean. In 1987 an agreement for the Kemano Completion Project (KCP), which would have diverted 87% of the flow, was signed. This final phase of the project would have put important fisheries resources of the upper Fraser River at high risk. Mitigation for fisheries protection were inadequate or untested in the system at the time. Potential cumulative impacts of water abstraction, elevated pollution levels, increased water temperature and natural sediment were not addressed. In January 1995 KCP was cancelled but there remain at present no adequate measures to protect the fish and the river ecosystem. These measures are to be negotiated in the future. Future management of the whole Kemano development must provide biologically realistic flow and temperature regimes in the Nechako River, and must deal with cumulative impacts of population and industrial growth. To achieve ‘sustainability’ of fisheries in the Nechako River and upper Fraser watershed the present approach to the Kemano development must be changed fundamentally. The future of the Kemano development must be set in the context of the whole future of the upper Fraser system. Continued growth and development, as has occurred in the upper Fraser and total basin, can not go on without inimical changes to ecosystem conditions and loss of fisheries resources.

Environmental impact assessment: broadening the framework

Broadening the framework of environmental impact assessment (EIA) involves an examination of the principles and policies which should underline ecologically sustainable development. To work effectively, EIA procedures need to be located within a broad framework of policies and environmental objectives, standards and monitoring. This paper discusses the political and environmental context in Australia within which the debate on sustainable development is occuring. Some important principles which underlie an ecologically sustainable development policy framework are discussed. These include inter-generational equity, conservation of biological diversity and ecological integrity, maintenance of natural capital and a recognition of the biophysical limits on natural resource use. Economic policy needs to emphasise the qualitative aspects of development as opposed to the quantitative growth in resource use. Several key aspects of a broad Australian policy framework are discussed, including reform of Federal/State environmental arrangements and the establishment of a Federal Environment Protection Agency; development of a systematic means of measuring progress towards an ecologically sustainable development; materials resources, energy, waste, transport and urban development policies. The overall objective of these policy areas would be to bring the scale of human activity in Australia within the carrying capacity of the environment.

Sorghum-pigeonpea intercropping and the effects of plant population density

SummaryThe use of growth resources is examined in an intercropping combination of early sorghum (82 days) and later-maturing pigeonpea (173 days) in a row arrangement of 2 sorghum: 1 pigeonpea.Prior to sorghum harvest, light interception by the intercrop combination was almost as high as sole sorghum. After sorghum harvest, light interception by the remaining pigeonpea was very poor and it is suggested that pigeonpea yield could be increased with higher plant population density and better plant distribution. Soil water measurements indicated that this would increase the amount of water being transpired through the crop but would not increase the total evapotranspiration demand. Higher nutrient concentrations in the intercrop pigeonpea compared with sole pigeonpea during this post-sorghum period suggested that yield of intercrop pigeonpea was not limited by nutrient stress, though the total uptake of nutrients by both crops was much greater from intercropping than sole cropping.

Natural resource availability: Some economic aspects

This paper treats some of the more important aspects of natural resource availability. This includes a definition of real or opportunity costs in resource extraction as compared to money costs; some economics of secondary materials and recycling; energy resources; and a demonstration of the effect of exponential growth in resource use on the time to resource exhaustion. The paper concludes with a short note on econometrics and commodity models.