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A root system is an important factor to increase soil resistance to detachment of soil particles. However, due to the large number of species, there is a need for studying the impacts of native plant species on soil quality and soil erodibility. This investigation did flume experiments at various soil slopes (9.2%, 18.1%, 25.1%, and 32.5%) and different water flow rates (0.56, 0.67, 0.74, 0.81, and 0.94 L/(m·s)), to evaluate sediment detachment capacity caused by rills (D c) and rill erodibility (K r) as well as the soil quality of hillslopes with three common species including Carpinus betulus (as a natural tree species), Alnus glutinosa (as a planted tree species) and Mespilus germanica (as a shrub species) in forestland of northern Iran. The variability of D c has been associated with soil properties and root characteristics of Carpinus betulus. D c was significantly lower (average, −45%) for soils under Carpinus betulus compared to soils with the two other plant species (p < 0.01). This was due to the higher values of soil properties including medium weight diameter of soil aggregates (MWD), organic carbon (OC), total nitrogen (TN), total phosphorous (TP), potassium (K), calcium (Ca), magnesium (Mg) as well as to the more extended root system, as confirmed by the negative correlations between D c and the studied variables. K r also was different among the studied soils and plant species. The root system of Carpinus betulus also played a useful role for increasing soil resistance to rill erosion yielding a safety factor (1.61) in the studied forest ecosystem. Overall, the current study supports a broader use of native species (such as Carpinus betulus) in areas exposed to surface erosion and instability, as an effective eco-engineering conservation technique and an alternative technology instead of utilizing artificial and expensive management practices. [Display omitted] • Sediment detachment capacity (D c) has been estimated by flume experiments for vegetated soils. • A natural species had lower D c compared to the planted and shrub species. • This reduction was due to higher soil quality and more extended plant roots. • Carpinus betulus species played a beneficial role for increasing slope stability. • The rill erodibility (K r) was the lowest in soils under Carpinus betulus species. [ABSTRACT FROM AUTHOR]

Heracleum dissectum Ledeb. (HD) with high edible and medicinal values is distributed in Northeast Asia. To provide a reference for selecting appropriate parts and periods to harvest HD, the nutrient contents in different parts of HD at three growth stages were determined. The nutrients being determined are essential nutrients closely related to human needs, and the crude protein content of HD was 3.58-28.43 g • 100 g-1 DW (dry weight), sugar content was 2.33-30.92 g • 100 g-1 DW, and soluble dietary fiber content was 9.71-26.09 g • 100 g-1 DW. Crude protein was mainly distributed in leaf blades and inflorescences, sugar was primarily found in roots, and dietary fiber was predominantly located in leaves. From the leaf development stage to the flowering stage and then to the late seed harvest stage, the content of moisture, crude protein and soluble sugar first decreased and then increased. In contrast, the content of dietary fiber and crude fat first increased and then decreased. Key words: nutrient content, vegetable, plant organ, developmental stage [ABSTRACT FROM AUTHOR]

Soil stoichiometric ratios serve as valuable indicators for the composition and quality of soil organic matter. While available studies predominantly examine the soil stoichiometric ratios of carbon ( C), nitrogen ( N), and phosphorus ( P), limited attention has been paid on the influence of forest restoration on soil stoichiometric ratios of potassium (K), calcium (Ca), and magnesium (Mg). We analyzed soil K, Ca, and Mg content, as well as elemental stoichiometric ratios, in secondary forests with varying restoration periods (5, 8, 21, 27 and 40 years) and a natural forest, in order to examine the impact of forest restoration on soil stoichiometry. The results showed that soil C and N contents decreased significantly with increasing soil layers. Soil stoichiometric ratios decreased significantly with increasing soil layers except for K:P, Mg: P, and P : Ca. With the increases of forest restoration years, soil C and N contents significantly increased in 0-10 cm soil layer, Ca content in 10-20 cm soil layer significantly increased, and total P content in 20-40 cm layer significantly decreased. However, soil K and Mg contents in each soil layer did not differ among five restoration ages. With the increases of restoration years, C :Ca, N:Ca and P :Ca in 0-10 cm soil layer significantly increased, and C:P, N:P, and K:P in 20-40 cm soil layer significantly increased, while P:Ca in 20-40 cm soil layer significantly decreased. In all soil layers, K:P and Mg:P were significantly and negatively correlated with soil total P content, and C: Ca and N: Ca were significantly and positively correlated with soil mineral N, available P, and available K content. With the increases of the restoration ages of secondary forests, soils are gradually P-limited and progressively restricted by Ca element in the later years, leading to the limitation of multiple nutrients. [ABSTRACT FROM AUTHOR]

This article discusses a study conducted in Himachal Pradesh, India, to compare the nutrient content of crops grown in different production systems. The study found that the conventional system had the highest macronutrient content, while the organic system had the highest sulfur and micronutrient content. Among the crops, black gram had the highest nutrient content, while okra had the lowest. The study emphasizes the importance of nutrient management for food and nutritional security. The findings have implications for sustainable agriculture and food security. [Extracted from the article]

Background: Non-Dairy (ND) food consumption is rapidly increasing in the UK and for many consumers plant-based diets are presumed to be healthier than standard diets. ND alternatives have different nutritional compositions, and their consumption could present challenges on a public-health level. Aim: To compare the price and nutritional composition of dairy and ND milks and cheeses in UK supermarkets. Methods: Macro and micronutrient data was recorded from Alpro's website and the 6 leading UK grocers for their own-label ND milks and cheeses. For missing micronutrient values the McCance & Widdowson's dataset was used. 99 total products were extracted: 57 ND milks, 7 dairy milks, 10 dairy cheeses and 25 ND cheeses. Dairy milk and cheese were used as control against which all ND products were compared. Results: Soya and coconut milks had lower values of carbohydrates, sugars, calcium, iodine, and potassium (p < 0.01) than dairy. Almond milk had lower values of carbohydrates (p = 0.01), sugars, calcium, iodine, and potassium (p < 0.01) compared to dairy milk. Protein was significantly (p < 0.01) lower for all ND except soya. Dairy cheeses had higher values for energy, protein, iodine, potassium, riboflavin, vitamin B12 and calcium (p < 0.01) than ND. Median prices were similar between dairy and ND milks, whereas ND cheeses were significantly more expensive compared to dairy (p < 0.01). Conclusions: ND alternatives fall short in several key nutrients compared to dairy. Fortification, accurate labelling and nutrition education are needed to help consumers make healthy and informed choices. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article presents the findings of a study on the effects of integrated nutrient management on the nutrient content and uptake of okra plants. The study found that a specific treatment involving the use of 75% recommended dose of fertilizers, along with organic amendments and beneficial bacteria, significantly increased the nitrogen, phosphorus, and potassium content in the okra pods and plants. This treatment also showed higher overall nutrient uptake compared to other treatments. The research suggests that combining inorganic and organic sources of nutrients can enhance nutrient uptake in okra plants, which can be valuable for improving okra production and nutrient management practices. These findings align with previous research on okra. [Extracted from the article]

Background: In 1995, Remer and Manz reported potential renal acid load (PRAL) values of various foods, quantifying their estimated impact on acid–base balance. Their estimation considered ionic dissociation, sulphur metabolism and intestinal absorption rates for several micronutrients and proteins. Notably, PRAL values are based on food content data from the early 1990s and may nowadays no longer adequately reflect accurate estimates. Some foods' macronutrient and mineral content has declined over the past three decades due to changes in soil mineral health. Aim: We hypothesize that the 1995 PRAL values no longer adequately reflect reliable estimates of the current acid–base impact of some foods. Methods: Based on specific examples, we argue that these values overestimate the alkalizing effects of various fruits and vegetables. Conclusion: Discussing evidence in favour of (and against) our hypothesis, we conclude that the 1995 PRAL estimates should nowadays rather be used as a relative guidance and reviewed carefully. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fish markets are key to supporting the availability and accessibility of nutritious food but are often overlooked in food and nutrition research and policy. This study investigated fish markets in coastal Kenya, using data from 223 semi-structured interviews collected through market surveys, and analyzed their potential to meet recommendations for consumption and alleviate malnutrition in a vulnerable coastal population (children under five years). Findings reveal that women small-scale traders dealt in lower quantities of fish per trader than the other traders, yet sold more nutritious fish. Fish shop traders sold enough fish to meet 129% of the recommended intake of fish (10.4 kg cap−1 yr−1) for all people within the assessed towns, whereas women small-scale traders sold enough to meet 84% of the intake. All market traders were key to making nutrient-dense fish available, with a 100 g portion of fish providing at least 25% of required intakes, across five nutrients, and women small-scale traders providing over 25% of required intakes across six nutrients for a child under five years. The average cost of a nutritious portion of fish was KES 31 (USD 0.22), ranging from KES 12 (USD 0.08) to 49 (USD (0.34), which provide 33.3% of the required nutrients (averaged across six nutrients), with nutrient-dense fish being notably cheaper. This study contributes empirical evidence on how territorial fish markets support nutrition, which is important for food policy interventions that promote nutritional literacy, address nutrient gaps, and improve postharvest practices and infrastructure for fish quality and safety in Kenya. • Fish markets mediate the availability of and access to nutritious fish for health. • Traded fish diversity important for diverse nutrient profiles and consumer choices. • Traded fish has the potential to address child malnutrition in a coastal context. • Most nutrient-dense fish were also the cheapest by portion size required for needs. • Represent fish markets in policy to foster nutrition-sensitive trade in Kenya. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A pot experiment was conducted at the Shaoyang University test base in May 2020, with Xudou 18 as the research object. We investigated the growth and development as well as the agronomic traits and nutrient content across a gradient of 0 (CK), 5, 10, 20, and 40 g · kg-1 of biochar addition. The results showed that compared with CK, the biochar application significantly affected growth dynamic, plant height, number of effective pods per plant, 100-grain weight, and leaf and stem dry weights of soybean plants, and the contents of protein, crude fat and isoflavone in soybean seeds. At the application rate of 20 g · kg-1, the germination rate of soybean was the highest, the growth period was the shortest, the number of effective pods per plant was the highest, the 100-grain weight was the largest, and the contents of protein, crude fat, and isoflavone were the highest in the seeds. When biochar application reached 40 g · kg-1, the plant height of soybean was the highest with extended vegetative growth and delayed maturity, whereas the effective pods per plant and 100-grain weight was reduced compared to that with 20 g · kg-1 application. In conclusion, the effects of biochar addition on agronomic traits and nutrient content of soybean varied with application amount, with 20 g · kg-1 being the optimal under the test condition. [ABSTRACT FROM AUTHOR]

This study was designed to clarify the effects of different fertilizer types and their mutual application on improving peanut yield, to determine the appropriate type of topdressing fertilizer and mutual application, and provide theoretical basis and technical guidance for scientific fertilization of peanut. Nitrogen (N), calcium (Ca), and boron (B) fertilizer were applied at the pod-pin stage under the condition of mulching drip irrigation in the field and the effects of different types of drip irrigation top-dressing on dry matter weight, mineral nutrient absorption and yield of peanut in pod-bearing stage were analyzed. The results showed that the dry matter weight, nitrogen content and accumulation, calcium content and accumulation, and pod yield of peanut stems and leaves were significantly increased by topdressing of N, B, and Ca fertilizer in the pod-pin stage, however, the effect of topdressing of N, B, and Ca fertilizer alone was not as good as that of the combination of N, B, and Ca fertilizer, and the effect of topdressing of N, B, and Ca fertilizer on stem and leaf dry matter weight, nitrogen content and accumulation, calcium content and accumulation, and pod yield was better. Topdressing boron fertilizer could improve the boron content and its accumulation in peanut stems and leaves, while the combination of nitrogen and calcium fertilizer could promote the absorption and accumulation of boron in peanut. Peanut yield and stem (matter weight, nitrogen accumulation, calcium accumulation and leaf boron accumulation) were significantly positively related, stem (stem leaf nitrogen accumulation and leaf weight and the calcium accumulation) were significantly positive correlation, stem leaf nitrogen accumulation and stem leaf nitrogen content were significantly positive correlation, the calcium content in the stem leaf calcium accumulation and leaf were significantly positive correlation, stem leaf boron accumulation with stem and leaf boron content were significantly positive correlation. These results suggest that the application of N, B, and Ca promoted the absorption and accumulation of N, B, and Ca, increased the quality of dry matter, and consequently increased the yield of peanut. [ABSTRACT FROM AUTHOR]

Kashmir traditionally known as heaven on earth for its beauty is gifted with water resources comprising rivers, lakes, streams and springs. Lakes provide a multitude of uses and are prime regions of human settlement and habitat. One such water body is Khushalsar Lake located in the downtown area of Srinagar city. It is noticed that Khushalsar at present has fallen victim to extensive encroachment, garbage dumping and the release of untreated sewage. Taking the pathetic condition of this lake and dynamic nature of water bodies in general into consideration this study was taken up to analyse the different physicochemical parameters and the rotifer abundance of this water body since rotifers are considered to be important indicators of trophic conditions of any aquatic habitat. The data collected was analysed using standard tools, statistical software's SPSS (version 20) and PAST3. Nutrient content of this water body was found to be high and only sixteen species of Rotifera were observed. Statistically different physico-chemical parameters were compared at inlet, middle and outlet of the study lake. Only few parameters showed significant differences. Shannon-Wiener index of rotifer signifies the water body to be moderately diverse as the values lies below 5.00 while as values of Simpson diversity index indicate accelerated eutrophication. [ABSTRACT FROM AUTHOR]

The determination of the nutritional and mineral composition of tomato and cucumber wastes would provide perspectives for further investigation with a view to possible utilization. Accordingly, the aim of the present research was to evaluate the nutritional and mineral content in these wastes. The tomato and cucumber wastes were characterized with <0.01% free fat, and respectively 0.96% and 1.02% crude protein, 1.18% and 0.16% total dietary fibre, 3.5% and 4.0% digestible carbohydrates, 3.20% and 1.62% total sugars, 3.03% and 1.44% reducing sugars, 94.0% and 94.4% water content, 6.1% and 5.6% dry matter, 0.37% and 0.47% total ash. In both wastes tested, the potassium element had the highest amount (2510 mg/kg in cucumber waste and 2238 mg/kg in tomato waste). Sodium was the only element in which tomato waste was richer than cucumber waste: Na was contained four times more in tomato waste (132 mg/kg) than in cucumber waste (33 mg/kg). Cucumber waste was almost five times richer in element Ca (493 mg/kg) than tomato waste (99. 7 mg/kg). While in tomato waste Al was below the detectable minimum (<0.05 mg/kg), cucumber waste contained 4.59 mg/kg aluminum. In addition, cucumber waste was richer in the following elements than tomato waste: Mg (244 mg/kg in cucumber waste vs. 134 mg/kg in tomato waste), P (397 mg/kg in cucumber waste vs. 264 mg/kg in tomato waste), S (302 mg/kg in cucumber waste vs. 135 mg/kg in tomato waste), Mn (1.44 mg/kg in cucumber waste and 0. 79 mg/kg in tomato waste), Fe (6.28 mg/kg in cucumber waste and 2.63 mg/kg in tomato waste), Cu (1.00 mg/kg in cucumber waste and 0.67 mg/kg in tomato waste), and Zn (2.31 mg/kg in cucumber waste vs. 1.60 mg/kg in tomato waste). [ABSTRACT FROM AUTHOR]

• Some components of forest nutrient cycles are measured others are calculated. • Reliable estimates of soil weathering, N fixation, and nutrient export remain elusive. • Nutrient cycling depictions do not include the effects of catastrophic events. • Predictions from these traditional models have had mixed results. • New information requires revision of traditional models. In this review, we consider a traditional conceptual model of nutrient cycling in forests and evaluate (1) assumptions and issues with existing methods for measuring and calculating nutrient pools and fluxes, including the estimation of errors; (2) how various elements of the conceptual model vary with geographic and climatic region, and gaps in knowledge about certain regions; (3) predictions from nutrient cycling data for the effects of harvesting, burning, fertilization, and elevated CO 2 , including the effects of nutrient cycling on productivity and the effects of productivity on nutrient cycling. As is true of all models, traditional models of forest nutrient cycling are all incorrect in the sense that they are approximations and do not capture all features the real world. For example, none of these traditional models include the important effects of catastrophic events such as wildfire, insect attack, hurricanes, etc. Nonetheless, traditional nutrient cycling models have allowed us to explore the collective implications of our current understanding of nutrient cycling processes. While the methods apply to plantations the focus of this review has been on natural forest studies. Despite much effort, reliable estimates of some transfers such as soil weathering and nitrogen fixation remain elusive. Soluble exports on a watershed level are not reliable representatives of exports from terrestrial nutrient cycles because correct conditions for such measurements are relatively rare and also because such estimates are subject to deep soil weathering and stream spiraling beyond the rooting zone. Soluble exports by lysimetery are subject to errors in the estimation of water flux and the delineation of the depth of rooting. The current versions of these traditional models will no doubt require modifications in the future to account for new information becomes available, for example, the delays between root uptake and the appearance of nutrients in aboveground biomass, the importance of soil nutrient hotpots for uptake, and the unforeseen ability of nitrogen-limited trees to extract additional nitrogen from soils when root growth in stimulated by elevated CO 2. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An investigation was carried out in the years 2006-2008 in order to compare the chemical composition of sweet sorghum stems. Two varieties of sweet sorghum: Sucrosorgo G-1990 (photoperiodically sensitive -- headless) and Sucrosorgo 506 (photoperiodically insensitive -- headed) were tested. Samples of large and small diameter stems were collected from both types of sorghum, from different parts of stem (lower, medium and top internodes). Each internode was fractionated into three stem part: leaves, the outer (rind) and the inner part (pith). The effect of the part of a stem and the place from which internodes were collected on the chemical composition was determined. The content of crude fibre and its fractions: neutral detergent fibre (NDF), acid detergent fibre (ADF), hemicellulose, crude proteins, carbohydrates: total carbohydrates, sucrose, reducing sugars and macroelements was determined in the plant material. The largest diversity in proportions of the chemical compounds was observed in the pith. Amounts of the NDF fraction in the rind depended on a stem's diameter. The site from where an internode sample was collected had the greatest effect on the chemical composition, mostly the concentrations of macroelements (N, P -- in all three stem parts, K and Mg -- in the pith, Ca -- in leaves and the rind, Na -- in leaves). The diameter of a stem had a negative effect on the chemical composition and deteriorated the technological value of sorghum, since the content of crude fibre and its fraction increased. [ABSTRACT FROM AUTHOR]

Copyright of Animal Biodiversity & Conservation is the property of Museu de Ciencies Naturals de Barcelona and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present study investigated the macro-micro nutrient, sugar and vitamin C content and some yield parameters in 3 miniature tomato cultivars (Black Zebra Cherry, Window Box Yellow and Sweet Pea Currant) grown with three different fertilizer applications: Application 1 (App. 1): Base fertilization with DAP; Application 2 (App. 2): Base fertilization with DAP + chemical fertilizer; Application 3 (App. 3): Base fertilization with DAP + organic fertilizer + biochemical fertilizer on a farmer's field. The study was conducted with a factorial design comprised of 9 treatments, with 4 replications of 40 plants per treatment. Study findings demonstrated that there were significant differences among the cultivar yields and fertilizer applications, where applications 2 and 3 led to significant increases in yield parameters. Furthermore, especially the fertilizer applications 2 and 3 provided the best results in most studied parameters. [ABSTRACT FROM AUTHOR]

In Nordic and Baltic countries short-rotation management of various tree species for pulpwood and energy is gaining increased interest. The sprouting, biomass production, nutrient uptake and heating value of coppiced hybrid aspen were studied over three years in southern Finland. The 26-year old mother stand was clearcut and coppiced. Half of the 12 study plots were fertilized with nitrogen. Allometric equations relating the dry weight of wood and bark to tree height were developed to estimate bark and wood biomass. After the first growing season, 99% of the sprouts were root suckers. The 833 mother trees produced 182,100 sprouts ha −1 . The number of living sprouts decreased to 41,400 ha −1 at the end of the third growing season. After the third growing season, nitrogen fertilization had increased biomass by 20% to 28.6 Mg ha −1 . The mean annual increment (MAI) on N-fertilized plots was 9.5 Mg ha −1 . The nitrogen fertilized stands had 133 kg N, 17 kg P, 113 kg K, 117 kg Ca and 18 kg Mg bound in their leafless above-ground biomass per ha. Fertilization had increased the amount of N, P, K, Ca and Mg bound in the stands by 52, 4, 28, 7 and 2 kg ha −1 respectively. The amount of micronutrients bound in the stand per ha was much smaller (259 g B, 380 g Fe, 830 g Mn, 1512 g Zn, 63 g Cu, 13 g Cd). The effective heating value of hybrid aspen bark was higher than that of wood and the heating value of shoots decreased with age. The heating value of three-year-old shoots was 18.608 MJ kg −1 . [ABSTRACT FROM AUTHOR]

The distribution and cycling of carbon and nutrients of a small, calibrated research catchment vegetated with regrowth eucalypt forest was studied over a 30 year period. The vegetation is mixed species, dry Eucalyptus woodland with an average age of 64 years at the commencement. Study plots were established within land unit strata and used to estimate mean weighted averages for the catchment. Biomass equations for each aboveground component of each species were developed and each component was analyzed for N, P, K, Ca and Mg. In 1977 the mean weighted average carbon content of the catchment was 113.2 Mg C ha −1 of which 43.3% was in the vegetation and litter and in 2011 it was 149.6 Mg C ha −1 with 55.1% in the vegetation and litter, an accretion rate of 1.1 Mg C ha −1 yr −1 . The nitrogen quantity was 3900 kg ha −1 of which 4.7% was in the vegetation increasing to 4188 kg N ha −1 in 2011 with 6.7% in vegetation, an apparent increase of 8.5 kg N ha −1 yr −1 . The initial phosphorus quantity, using soil available P, was 25.6 kg P ha −1 , with 45.8% in vegetation and in 2011 this changed to 33.0 kg P ha −1 of which 57.1% in litter and vegetation. When soil total P was estimated there was 1486 kg P ha −1 of which 0.8% was in the vegetation. The calcium quantity in 1977 was estimated at 1163 kg Ca ha −1 of which 51% was in vegetation and this had increased to 59% in 2011. There was 1066 kg K ha −1 of which 13.9% was in vegetation rising to 21% in 2011. Magnesium in 1977 was 624 kg Mg ha −1 with little change in 2011. Such quantities in the vegetation make the sites very vulnerable to nutrient loss when vegetation is removed in land use changes. Nutrient turnover was estimated including litterfall and throughfall and, using growth increments, annual uptake. The overall pattern shows long term transfers from the soil to vegetation and cycling is mainly in the soil A horizon. The net losses from the system are small and appear to be related to bedrock chemistry rather than the vegetation. Small catchments do not present an efficient method for studying biogeochemical cycling. [ABSTRACT FROM AUTHOR]

Pistacia vera L., whose edible fruit is the pistachio, is an economically important crop. It is cultivated worldwide and over 50 different varieties have been described attending to morphological and phenological characteristics. The selection of a suitable cultivar may affect the profitability of the orchards, and thus requires careful consideration for any given region. The type and concentration of nutrients taken up by the plant affect its development and eventually the quality and quantity of the fruits. It is a matter of discussion whether all varieties have the same capacity to absorb nutrients. In order to clarify this aspect, in this study the efficiency of nutrient uptake has been assessed for five pistachio varieties: three males (M38, G1, and Mateur), and two females (Batoury, and Joley), by measuring the concentration of 30 chemical elements in leaves by Inductively Coupled Plasma (ICP) and C/N micro-elemental analyses. Data were subjected to a non-parametric Friedman test, using a series of Wilcoxon Rank Sum test with a Bonferroni correction as post hocs. Our findings demonstrate that all these varieties have an equal uptake capacity for Al, Cr, Cu, K, Li, Mn, Ni, Pb, S, Sr, Ti, Tl, Zn, N, B, Fe, Mg, Na, and V. No differences related to the gender of the plants were detected. Only Mateur exhibited significantly higher levels of Ca and lower levels of C. Stock plants from an experimental plot were used as material. These plants are not used for productive purposes, and flowering and fruiting are partially restricted by removing potential nutrient-demanding structures. These findings support the contention that the presence/absence of such organs has more influence on the nutrient uptake than does the variety itself. [ABSTRACT FROM AUTHOR]

The study, carried out in 2012-2013, intended to determine effects of different cultivation systems on the uptake and content of macronutrients (nitrogen, phosphorus, potassium, magnesium, calcium and sodium) in sugar beets at the technological maturity stage. A conventional tillage system (SO) was compared to simplified technologies of soil cultivation. The following conservation tillage systems were analyzed: (2) tillage to a depth of 35 cm and sowing into stubble mulch (MS35); (3) shallow tillage to a depth of 15 cm and sowing into stubble mulch (MS15); (4) tillage to a depth of 15 cm and sowing into white mustard mulch; (5) strip-till on stubble mulch to a depth of 25 cm and instantaneous beet seed sowing (STS); (6) strip-till to a depth of 25 cm on white mustard mulch and instantaneous beet seed sowing (STG). Mineral nutrient concentrations in beets varied depending on the cultivation system applied and the plant organ analyzed. The experimental factor significantly differentiated the content of P, K, Ca, Mg and Na in both beet leaves and roots, having no effect on the nitrogen content. When compared to the conventional tillage system, a decreasing trend for phosphorus and calcium in beet leaves and a significant increase of sodium both in beet leaves and roots was observed in the simplified cultivation systems. Cultivation simplifications provided some equivocal evidence implicating differences in the nutrient content between the study years. The analysis of correlations between root yields and the total accumulation of nutrients indicated significant relationships for N, P, K, Ca, Mg only in the conventional tillage system and in the treatment with 35 cm deep tillage (soil ripping) along with sowing into stubble mulch (MS35). In the other treatments, strong relationships were observed only for individual nutrients. [ABSTRACT FROM AUTHOR]

[Display omitted] • The production and quality of the leaf-litter are closely linked to the genotype. • Black locust and willow were the ones with the highest decomposition rate. • Poplar and plane tree showed the greatest retranslocation as a conservation strategy. • Species with high decomposition rate are more recommended to preserve soil fertility. • An advantageous strategy could be to mix species with different decomposition dynamics. Quantifying leaf-litter and the potential contribution of essential nutrients to the soil is key to guaranteeing the sustainability of forest systems, especially in plantations under short rotation coppice, insofar as it can condition crop management such as the requirement for nutritional amendments. Nutrient cycling is dependent on production as well as litter decomposition, so to compare the different strategies of the species in nutrient recycling it is important not only to determine the quality and quantity of leaf litter, but also the decomposition rate dynamics and the consequent potential incorporation of organic matter and nutrients into the soil. Therefore, this work aims to quantify and analyze the dynamics of leaf-litter as well as the retranslocation rate, to assess the decomposition rate of the foliar biomass and its nutrient concentrations, and finally, to assess the evolution of leaf-litter quality. For these purposes, eight genotypes were considered in this study: Populus deltoides ('Baldo'), Populus × canadensis ('Ballottino', 'I-214′, 'Orion' and 'Oudenberg'); Platanus × hispanica ('Girona'), Salix matsudana × Salix spp. ('Levante') and Robinia pseudoacacia ('Nyirsegi'). The plantation was established in central Spain with a density of 10,000 cuttings ha−1. Three rotations of 3 years each were applied, this study being carried out during the first growing season of the second rotation. Although the leaf fall dynamics were similar among the different species, the production and quality of the leaf-litter were highly species specific. Different strategies were identified; greater retranslocation of N and P being found in poplar, plane tree or only of P in the case of black locust as a conservation strategy, although lower retranslocation of all nutrients was observed in willow, which means that the leaf litter of the latter is very rich in nutrients. While willow, black locust or even some genotypes of poplar are capable of releasing many of the nutrients to the soil during decomposition, plane tree released a smaller variety of nutrients, N, P and Mg being immobilized in the leaf-litter. From the perspective of conserving the soil fertility resulting from the decomposition of leaf-litter, the plantations of species with the highest decomposition rates, such as black locust and willow, were found to be the most recommendable. However, the immobilization of some nutrients in the leaf-litter during the decomposition process could satisfy the nutritional requirements of these species in the medium and long term, thus an advantageous strategy could be to mix species with different decomposition dynamics. [ABSTRACT FROM AUTHOR]

One of the strategies adopted to introduce fruits to youngsters is achieved by delivering pineapple chellies containing soy milk. This study, therefore, aims to determine the differences in nutrient content, antioxidant activity, physical properties, and organoleptic quality of pineapple chellies with the addition of suitable soy milk as a complementary alternative to children's nutritious snacks. Based on the weights and considerations, P 3 was selected as the best formulation, in terms of the nutrient content and contribution level of the chellies with adequate snack standards. • The addition of soy milk in the producing of pineapple chellies increases the levels of protein, fat, calcium, and antioxidant activity. • The chellies carbohydrate and vitamin C levels decreased as the amount of soy milk added increased. • The acceptance of pineapple chellies decreasing as the amount of soy milk added increases. [ABSTRACT FROM AUTHOR]

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Liming is a common technique used to restore forest health in acidified areas but little is known on the remanence of this amendment in forest ecosystems. We thus investigated how calcareous amendments impact internal biogeochemical cycling of beech stands ( Fagus sylvatica ), especially the chemistry and traits of leaves and leaf litter and the subsequent rate of litter decomposition 25 years after applications. We also wanted to know if leaf features provide easy predictive tools of litter quality. In both limed and unlimed stands, we compared functional traits (SLA, LDMC, stomatal density), nutrients and fiber contents (hemicellulose, cellulose and lignin) of green and senescent leaves. Additionally, litter bags were used to infer litter decomposition rate. Our results clearly showed that liming impacts leaf chemistry but not morphological leaf traits many years after treatment. In limed stands, green leaves had significantly higher content of Ca and lignin, but lower Mg and cellulose. For senescent leaves, limed stands had greater Ca, Na and cellulose, but lower K, Mn, and N. Resorption rates of K, Na and Mg, in senescent leaves were also affected by limed treatment. We also found a higher litter decomposition rate in limed stands than in unlimed stands. We thus demonstrated that the effect of liming on soil nutrient availability was weak but that changes in beech leaf quality could be recorded 25 years after treatment. These mid-term liming effects on leaf litter quality likely alter soil properties, soil biota and their interactions and thus litter decomposition rate. Lastly, the use of functional leaf traits as a proxy of ecosystem functioning (such as litter decay) is not sufficiently sensitive to detect changes in sites with smooth environmental stress variation. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Improved knowledge concerning nutrient removals through harvesting in former coppice forests is crucial for the sustainable management of these forests. This is especially true if the resumption of coppicing is being considered to serve increasing fuel wood demands. In this study the nutrient contents of various tree compartments of sessile oak ( Quercus petraea (Mattuschka) Liebl.) and hornbeam ( Carpinus betulus L.) from two sites differing in soil fertility were determined using allometric equations to calculate nutrient removal associated with different harvesting intensities. Stand level nutrient contents in tree compartments were comparable between both study sites. The results for exchangeable base cations, plant available P, and total N indicate that coppicing is not a priori an unsustainable forest management system. On sites with large soil nutrient pools, even whole trees may be harvested without substantial reductions in ecosystem nutrient pools. However, on sites with a low nutrient capital, current harvesting practices would result in relatively high rates of nutrient export. In these stands, harvesting intensity should be based on careful selection of the tree compartments removed, e.g. stem only, to conserve nutrients on site. This study describes the impact of simulated tree harvesting on soil nutrient pools in aged coppice forest for the first time. Based on our findings, general assumptions related to soil sustainability of coppicing are replaced by clear recommendations regarding silvicultural nutrient management. Considering the large areas of aged coppice forests in Europe this study provides a methodological template which is needed to enhance their sustainable management. [ABSTRACT FROM AUTHOR]

Currently, insects are considered as a potential substitute for fishmeal and soybean meal in feeding mixtures for farm animals. However, detailed information regarding insects’ nutritional values is available only for some species. We suggested criteria for insect suitability to mass production and found 15 species from 5 orders which meet our requirements: Blattaria: Blaptica dubia, Blatta lateralis, Eublaberus distanti, Coleoptera: Alphitobius diaperinus, Tenebrio molitor, Zophobas morio, Diptera: Hermetia illucens, Musca domestica, Lepidoptera: Antheraea assamensis, Bombyx mori, Galleria mellonela, Samia riciini, Orthoptera: Acheta domestica, Locusta migratoria, Zonocerus variegates. We have collected available information about their nutritional composition and compared it to soybean meal and fishmeal. Protein content was found to be similar to (or slightly higher than in) soybean and fish meals. In terms of protein quality, it was found that insect protein composition is more similar to soybean protein or fishmeal with low protein concentration, than to that of high concentration fishmeal or casein. Due to highest lysine and metionin contents, we recommend Musca domestica and Samia riciini as most suitable protein sources for poultry and pigs feeding. [ABSTRACT FROM AUTHOR]

Highlights: [•] We examined bioindicators of the seagrass Thalassia hemprichii to nutrient loading. [•] Apparent two nutrient gradients were found in the Xincun Bay seagrass meadow. [•] The P% of the plant almost mirrored the two nutrient gradients in the meadow. [•] The epiphytic algae biomass and N% reflected one of the two nutrient gradients. [•] The P% of T. hemprichii may be the most useful indicator of nutrient loading. [Copyright &y& Elsevier]

Abstract: The inhibitory effects of alfalfa (Medicago sativa L.) residues on seed germination, nutrient uptake and growth of broad beans (Vicia faba L.) grown in two soil types (clay and sandy soil) were investigated. An 8% aqueous extract of M. sativa strongly inhibited (41.2%) the seed germination index and the plumule and radicle lengths (by 8.6 and 4.1cm, respectively) as compared with controls. The phytotoxicity of the aqueous extract increased from 9.9% to 59% when the concentration was increased from 1% to 8%. Addition of M. sativa crude powder significantly reduced the accumulation of total stem, leaf and root dry matter when applied at the maximum concentration (8%) in both clay and sandy soil, with greater inhibition in plants grown in clay than in sandy soil. The maximum concentration of the crude powder had a greater negative effect on N, P and K uptake when applied to clay soil than when applied to sandy soil. The study indicates that soil type is an important factor in the allelopathic effects of alfalfa on broad beans. [Copyright &y& Elsevier]

Introduction: The objective of this study was to determine antioxidant potential of Garcinia atroviridis leaves and fruits extracts in vitro. Methods: Antioxidant activity was assessed using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Total phenolic content (TPC) of the extracts was estimated as gallic acid equivalent by Folin-Ciocalteau method. Proximate analysis was determined based on the Association of Official Analytical Chemists (AOAC) procedures. Results: Garcinia atroviridis leaves extracted at 100°C/15 min demonstrated the highest TPC value (21.21 ± 0.28 mg GAE/mg) and was significantly different (p<0.05) from that of leaves extracted at 60°C/6 h and 40°C/12 h. On the other hand, the fruit extracted at 60°C/6 h showed the highest TPC value (16.23 ± 0.18 mg GAE/mg) (p<0.05) compared to the fruit extracted at 40°C/12 h and 100°C/15 h respectively. The antioxidant activities of both samples were positively correlated with the TPC values based on DPPH-radical-scavenging activity and ferric reducing power estimation. Garcinia atroviridis leaf extract contained significantly higher proteins, carbohydrate and ash contents (2.16% ± 0.08; 15.98% ± 0.12 and 0.72% ± 0.07 respectively) than its fruit extract (0.46% ± 0.08, 8.64% ± 0.06 and 0.15% ± 0.06) respectively). The energy content was also found to be higher in the leaf (73.64% ± 2.15) compared to the fruit (38.38% ± 1.72) (p<0.05). Conclusion: The findings indicate that G. atroviridis leaves and fruits have potential for use as a source of natural antioxidants and nutrients for therapeutic purposes against free radical mediated health conditions. [ABSTRACT FROM AUTHOR]

Background. Food-based approaches have been advocated as the best strategies to curb hunger and malnutrition in developing countries. The use of low-cost, locally available, nutritious foods in the development of supplementary foods has been recommended. Objective. To develop low-cost food supplements using different traditionally processed local foods, consisting of cereals, legumes, nuts, fish, and vegetables, to meet the nutrient requirements for vulnerable groups in Kenya. Methods. Four food supplements were developed and evaluated by taste panel procedures. The product containing amaranth grain, pigeon pea, sweet potato, groundnuts, and brown sugar was found to be the most acceptable supplement. Evaluation of nutritional composition, shelf-life, and cost analysis of the acceptable supplement was carried out to assess if it could satisfactorily provide more than 50% of the Recommended Dietary Allowances (RDAs) of the basic nutrients for vulnerable groups. Results. The acceptable supplement contained 453.2 kcal energy, 12.7 g crude protein, 54.3 g soluble carbohydrates, 20.8 g crude fat, and 10.1 g crude fiber per 110 g. The micronutrient contents were 93.0 mg calcium, 172.4 mg magnesium, 2.7 mg zinc, 5.7 mg iron, 0.8 mg vitamin B1, 0.2 mg vitamin B2, 7.9 mg niacin, 100 µg folic acid, and 140 µg retinol equivalent per 110 g. The supplement also contained 21% total essential amino acid in addition to appreciable levels of palmitic, stearic, oleic, linoleic, and α-linolenic fatty acids. The shelf-life study showed that it could be stored in different packaging materials (polythene bags, gunny bags, and kraft paper) at 26°C without deleterious effects on its chemical composition for up to 4 months. Cost analysis of the supplement indicated that the product could be competitively sold at US$0.812/kg (KES 65.50/kg). Conclusions. Locally available indigenous foods can be used in the formulation of acceptable, low-cost, shelfstable, nutritious supplementary foods for vulnerable groups. [ABSTRACT FROM AUTHOR]

A slow infiltration experiment with different hydraulic loads (0, 3, 6, 9, 12, and 15 cm per week) of domestic wastewater was conducted in a 'Zhonglin 2001' poplar plantation to study the effects of the wastewater slow infiltration on the growth of the plantation. Comparing with the control (0 cm), the other five treatments increased the soil organic matter, total N, total P, total K, and Na+ contents in the plantation averagely by 1.940 g • kg-1, 0.115 g • kg-1, 0.029 g•kg-1, 1.454 g•kg-1 and 0.030 g•kg-1, respectively.At lower hydraulic loads (3- 12 cm per week), the poplar biomass growth and the N, P and Na+ contents in different poplar or- gans averagely increased by 17.583 t • hm-2 • a-1, 3.086 g • kg-1, 0.645 g • kg-1, and 0.121 g•kg-1, with the maximum (36.252 t•hm-2•a-1, 13.162 g•kg-1, 5.137 g•kg-1, and 0.361 g•kg-1, respectively) at hydraulic loads 6-12 cm per week. The further increase of the hy- draulic load decreased the poplar biomass growth and the N, P and Na+ contents in different poplar organs. The K content in different poplar organs decreased with increasing hydraulic load. Treating with domestic wastewater increased the leaf length, decreased the leaf asymmetry, and delayed leaf- falling. At high hydraulic load (15 cm per week), the higher soil Na+ and water contents would threat the poplar growth. The proper domestic wastewater hydraulic loads for the growth of poplar 'Zhonglin 2001' plantation would be 3-12 cm per week. [ABSTRACT FROM AUTHOR]

Abstract: Aqueous extract (MSAE) and crude powder (MSCP) of Medicago sativa demonstrated inhibitory effects on seed germination, growth and the nutrient uptake of Lycopersicon esculentum. The results showed that the extracts brought about considerable inhibition in the germination of tomato seeds and in plumule and radicle length. The allelopathic effect of Medicago sativa decreased the germination percentage (GP) of tomato seeds aggravating phytotoxicity (PT) or inhibition percentage with the increase in extract concentration. The extracts also reduced the phytomass of leaves, stems and roots of tomato seedling. The uptake of N, P and K was highly affected and varied drastically by MSCP application. This study revealed that the inhibitory effect of MSAE and MSCP might be due to the presence of some allelochemicals which need further investigation. [Copyright &y& Elsevier]

Abstract: The biomass and decomposition of coarse woody debris (CWD, ≥10cm in diameter) were studied in a monsoon evergreen broad-leaved old-growth forest in Dinghushan Nature Reserve, Southern China. The study examined the biomass of CWD from 1992 to 2008 and decomposition of three dominant tree species CWD (Castanopsis chinensis, Cryptocarya concinna, Schima superba) from 1999 to 2008. Changes in the wood density of three tree species’ CWD were used to estimate the decay rates with a single exponential model. The results showed that the biomass of CWD in the old-growth forest was increasing from 17.41tonnesha−1 (tha−1) in 1992 to 38.54tha−1 in 2008, and a higher decay constant was observed for C. concinna (0.1570 – 19 years for 95% mass loss); the decay rates of S. superba and C. chinensis were 0.1486 (20 years for 95% mass loss) and 0.1095 (27 years for 95% mass loss), respectively. The difference in decay constant rates may be due to their substrate quality and decomposers. The content of carbon (C) in three species declined after 9 years of decay. Nitrogen (N) content increased in all species with decay. The C/N ratio in the three species declined during the decay process. [Copyright &y& Elsevier]

Abstract: A large proportion of plantations of radiata pine (Pinus radiata D. Don) in southern Australia have been established on podzolized coastal sands with low nutrient reserves. Inter-rotational management of the forest floor and harvesting residues has been shown to be critical to maintain the productive capacity of these soils. In 1974 a study was initiated at the end of the first rotation to evaluate the long-term sustainability of fast-growing plantations on these podzolized sands. Growth was measured at 5, 10 and 20 years and prior to clear-felling at age 30. Soil sampling at the end of the first rotation in 1974 was repeated in 2004 prior to clear-felling to determine changes in carbon and nutrients in profiles after 30 years. Forest floor and tree biomass were measured to determine sequestration of carbon and nutrients in mature radiata pine. Productivity of radiata pine on infertile podzolized sands was either maintained at 26m3 ha−1 year−1 or improved from 21 to 27m3 ha−1 year−1 over two rotations from 1946 to 2005 and this was attributed to conservation of organic matter and nutrients through retention of litter and harvesting residues after the first rotation. Total carbon (23.4Mgha−1) and N (595kgha−1) remaining in residues and litter after harvesting compensated for losses of carbon (9.2Mgha−1) and N (582kgha−1) in soil (0–75cm) over the rotation. Total S, P, K, Ca and Mg remaining on site after conventional harvesting (stem wood and bark) increased during the second rotation (1975–2005). Accumulation of nutrients in the above-ground biomass and soil over 30 years exceeded deposition in rainfall indicating a redistribution of S, P, K, Ca and Mg from the sub-soil to tree biomass. The net accumulation of N in biomass (201kgha−1) also exceeded atmospheric deposition indicating significant inputs from nitrogen fixation during the rotation. Intensive harvesting including removal of log residues and branches for biofuels but leaving foliage on site increased nutrient exports by approximately 30% but did not exceed accession of nutrients over 30 years except for N. In contrast, whole-tree harvesting including foliage increased nutrient exports by 70–150% and fertilizers are likely to be required to compensate for the additional removal of nutrients and to maintain site productivity in the next rotation. [Copyright &y& Elsevier]

Abstract: The potential export of nutrients from Eucalyptus plantations harvested for pulp production may be high. However, depending on the harvest method, the nutrients from the residue can be recycled. The aims of this study were (i) to quantify the content and distribution of nutrients in different residue components at harvest for a Eucalyptus dunnii Maiden plantation; and (ii) to quantify the decomposition rates of the harvest residues, and the return of nutrients to the soil in the temperate climate conditions of Uruguay. Six trees of a 9-year-old E. dunnii plantation with average diameter at breast-height (DBH) were harvested, and the biomass produced and the N, P, K, Ca and Mg contents in commercial and non-commercial logs, leaves, branches, bark and litter were estimated. Decomposition of the remains of leaves, branches, non-commercial logs, bark and litter was studied in the field for 2 years. Although commercial logs accounted for 61% of the biomass produced, only 27% of the N, 35% of the P, 18% of the K, 16% of the Ca and 41% of the Mg present in the forest were exported with the product. When logs are exported without de-barking in the site, the nutrient export would increase to 41%, 55%, 46%, 68% and 66% of the total extraction of N, P, K, Ca and Mg, respectively. Residue decomposition showed that the leaves lost the highest proportion of biomass (half life 0.86 years), and bark was most resistant to decomposition in the field (half life 5.36 years). As regards the nutrients, K was lost most rapidly and Ca showed the slowest loss, while N, P and Mg losses were generally more gradual, and proportional to the decomposition rate. [Copyright &y& Elsevier]

Abstract: For 20 years, there has been 42,000ha estate of clonal Eucalyptus plantations around Pointe-Noire in Congo on sandy soils that have very low reserves of available nutrients. These plantations have been based on a natural hybrid (E. PF1). This hybrid is being replaced by E. urophylla × E. grandis (UG), a more productive hybrid developed by the breeding program of UR2PI. A study of biogeochemical cycles showed that nutrient removal by harvesting is the main nutrient output in the E. PF1 ecosystem. It is therefore important to quantify the nutrient content (NC) in both hybrids to compare corresponding nutrient removal values. The work dealt with four UG clones and the most planted clone of E. PF1. Twelve trees per clone were sampled at the logging age (8 years) in a clonal test for UG clones and in a nearby stand for E. PF1. Tables were established to predict, from girth at breast height (C 1.30m), the biomass and nutrient content of stemwood, bark, dead and living branches, leaves, and were applied to the inventory of the different stands to evaluate corresponding biomass, NC and nutrient use efficiency (NUE) on a per-hectare basis. Total biomass differed between the two hybrids and among UG clones: 109tha−1 for E. PF1 and 108–155tha−1 for UG clones. In E. PF1 trees, total NC was globally lower for N, K, and Mg, but greater for P and Ca. In stemwood, nitrogen content was similar for both hybrids. By contrast, in UG clones, NC was much lower for P (−72%) and Ca (−40% to −55%). The same trends were observed for NUE: equivalent for both hybrids for N, but higher in UG clones for P (+72%) and Ca (+43% to +59%). A marked variability among clones was observed for K and Mg. UG clones allocated proportionally more nutrients in leaves than E. PF1. These results show that clones should not be selected only on growth traits but also on NUE and on the concentration of nutrients in tree components removed by harvesting. It will be then possible to limit the cost of fertilising needed to maintain stand growth and soil fertility. [Copyright &y& Elsevier]

Information concerning sweetgum (Liquidambar styraciflua L.) genotypic variation and response to fertilization is needed for developing site-specific silvicultural techniques for plantation establishment. A pot experiment was conducted to investigate the effect of N and P application, and family on sweetgum growth and nutrient uptake. Two rates of N (0 vs. 100 kg N/ha equivalent) and P (0 vs. 50 kg P/ha equivalent), and two half-sib families (F10022 and F10023) were used in a split-plot experiment. Two months after the treatments were applied, N application increased height growth and total leaf area (LA) by 209 (P=0.002) and 138% (P=0.019), respectively, over the no N treatments, and P application increased basal diameter (BD) growth and total LA by 24 (P=0.002) and 23% (P=0.006), respectively, over the no P treatments. Genotypic effects were significant on BD growth and LA development and differences between the half-sib families in diameter growth response can be explained by differences in LA expansion. Both N and P additions increased foliar P, K, Ca and Mg content and the total uptake of these nutrients by the seedlings. The combined effect of N and P application was much greater than either N or P application alone in growth, LA and nutrient uptake responses, indicating that the proper balance of N and P nutrition is important for optimal sweetgum seedling growth. Seedling biomass production was significantly related to specific leaf area (SLA), total LA and foliar N concentration or content, and LA changes explained 90% of the growth responses. [Copyright &y& Elsevier]

Since 1978, 42,000 ha of clonal Eucalyptus plantations have been established around Pointe-Noire. These plantations are growing on sandy and acidic soils with small reserves of available nutrients; therefore, risks of nutrient deficiencies exist in the medium or long-term. The effects of slash and litter management practices on soil properties, tree nutrition and growth were quantified to evaluate harvesting methods with respect to sustainable management of the replanted sites. The experimental design was a randomized complete block with four replications and six treatments: R, all aboveground organic residues removed; WTH, whole-trees harvested and removed; SBH, stemwood and bark removed; SH, stemwood-only removed; DS, double slash retained; B, stemwood-only removed and all organic residues burned. After 12 months removal of all slash material (R) had a marked negative effect on total biomass (5.9 t ha−1 vs a mean of 7.2 t ha−1 for the other treatments). During the first 18 months of the study no significant differences among treatments were detected (P<0.05), but at 24 months, tree growth was significantly reduced where all organic residues were removed (R), compared to DS (12.9 m3 ha−1 per year vs 22.2 m3 ha−1 per year). The best growth was measured in plots with the highest organic residues (treatments DS and SH). Nutrient content in the aboveground biomass of the 1-year-old stand was strongly dependent on the type of slash and litter management. Differences in tree nutrient concentrations in various treatments demonstrated the ability of trees to store available nutrients in aboveground biomass. The rate of decomposition of organic residues during the first 8 months after harvesting ranged from 36% (WTH) to 56% (SH). Between 7 and 24 months, the annual production of inorganic nitrogen in the top soil (0–13 cm layer) was 71.6, 66.7, and 85.7 kg ha−1 per year for R, SH, and DS, respectively. The rate of soil nitrification was high, and therefore nitrogen leaching may have occurred in the early development stage when trees are not able to take up all the available nitrogen. [Copyright &y& Elsevier]