Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “soil nutrient”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

Shoot development and extension of Quercus serrata saplings in response to insect damage and nutrient conditions.

BACKGROUND AND AIMS: Plants have the ability to compensate for damage caused by herbivores. This is important to plant growth, because a plant cannot always avoid damage, even if it has developed defence mechanisms against herbivores. In previous work, we elucidated the herbivory-induced compensatory response of Quercus (at both the individual shoot and whole sapling levels) in both low- and high-nutrient conditions throughout one growing season. In this study, we determine how the compensatory growth of Quercus serrata saplings is achieved at different nutrient levels. METHODS: Quercus serrata saplings were grown under controlled conditions. Length, number of leaves and percentage of leaf area lost on all extension units (EUs) were measured. KEY RESULTS: Both the probability of flushing and the length of subsequent EUs significantly increased with an increase in the length of the parent EU. The probability of flushing increased with an increase in leaf damage of the parent EU, but the length of subsequent EUs decreased. This indicates that EU growth is fundamentally regulated at the individual EU level. The probabilities of a second and third flush were significantly higher in plants in high-nutrient soil than those in low-nutrient soil. The subsequent EUs of damaged saplings were also significantly longer at high-nutrient conditions. CONCLUSIONS: An increase in the probability of flushes in response to herbivore damage is important for damaged saplings to produce new EUs; further, shortening the length of EUs helps to effectively reproduce foliage lost by herbivory. The probability of flushing also varied according to soil nutrient levels, suggesting that the compensatory growth of individual EUs in response to local damage levels is affected by the nutrients available to the whole sapling.

Animals↗

Hardwood seeding root and nutrient parameters for a model of nutrient uptake.

Use of mechanistic models is an increasingly accepted way to evaluate complex processes. The Barber-Cushman model provides a means to simulate nutrient uptake once information on root system characteristics, nutrient uptake, and soil nutrient supply are developed. Objectives of this study were to determine during a growing season: (i) root growth for 1-yr-old black cherry (Prunus serotina Ehrh.), northern red oak (Quercus rubra L.), and red maple (Acer rubrum L.) seedlings; (ii) net plant increase in N, P, K, Ca, and Mg; (iii) soil solution and solid phase nutrient concentrations; and (iv) the influence of root growth and soil nutrient supply changes on nutrient uptake using the Barber-Cushman model. Seedlings were grown in pots containing A horizon soil from two forest sites. Measurements were made on five occasions during the growing season. Root growth averaged 41.5 cm d-1 for red maple compared with 28.0 and 16.7 cm d-1 for cherry and oak, respectively. Seventy-five percent of root growth occurred at the end of the growing season. Total plant N showed the greatest change (25-58%) due to soil source. Model simulations underestimated observed uptake by 31 to 99%. A clear relationship between soil solution nutrient concentration and plant uptake, an important assumption of the model, was not observed. Results indicate care will need to be exercised in the development and use of root growth and nutrient supply values in mechanistic models.

Calcium↗

[A long-term field trial on fertilization and on use of recycled nutrients in farming systems IV. Soil fertility changes].

The fertility changes of soil under different fertilization treatments of a twelve years field trial indicated that the application of compost recycled in a farming system with appropriate amount of fertilizer applied to balance the soil nutrient budget, could not only produce higher crop yields and less surplus of nutrients into environment, but also improved soil fertility with significant increase of soil organic carbon and nitrogen in cultivated layer. However, maintaine higher soil available phosphorus, it was not sufficient just to balance the budget of soil phosphorus, and more phosphorus fertilizer application was needed.

Agriculture↗

Rapid development of phosphorus limitation in temperate rainforest along the Franz Josef soil chronosequence.

The aim of this study was to examine how shifts in soil nutrient availability along a soil chronosequence affected temperate rainforest vegetation. Soil nutrient availability, woody plant diversity, composition and structure, and woody species leaf and litter nutrient concentrations were quantified along the sequence through ecosystem progression and retrogression. In this super-wet, high leaching environment, the chronosequence exhibited rapid soil development and decline within 120000 years. There were strong gradients of soil pH, N, P and C, and these had a profound effect on vegetation. N:P(leaf) increased along the chronosequence as vegetation shifted from being N- to P- limited. However, high N:P(leaf) ratios, which indicate P-limitation, were obtained on soils with both high and low soil P availability. This was because the high N-inputs from an N-fixing shrub caused vegetation to be P-limited in spite of high soil P availability. Woody species nutrient resorption increased with site age, as availability of N and P declined. Soil P declined 8-fold along the sequence and P resorption proficiency decreased from 0.07 to 0.01%, correspondingly. N resorption proficiency decreased from 1.54 to 0.26%, corresponding to shifts in mineralisable N. Woody plant species richness, vegetation cover and tree height increased through ecosystem progression and then declined. During retrogression, the forest became shorter, more open and less diverse, and there were compositional shifts towards stress-tolerant species. Conifers (of the Podocarpaceae) were the only group to increase in richness along the sequence. Conifers maintained a lower N:P(leaf) than other groups, suggesting superior acquisition of P on poor soils. In conclusion, there was evidence that P limitation and retrogressive forests developed on old soils, but N limitation on very young soils was not apparent because of inputs from an abundant N-fixing shrub.

Ecology↗

[Significance of senescence study on tree roots and its advances].

Root system is one of the important components of trees, and has some important physiological functions such as nutrient and water absorption, transport and storage, anchoring, and supporting. After tree root systems formed, roots often suffer from nutrient- and water-deficient stress, and thus, their absorption of nutrients and water appears more important. Soil nutrient and water have a great spatiotemporal heterogeneity. As the heterogeneity occurs, trees regulate carbon partitioning to roots, resulting in the senescence or death of some roots of the whole root system. In forestry, the senescence of tree roots is closely related to tree productivity, because there is a close relationship between the senescence of tree roots and the absorption of soil nutrient and water. At ecosystem and global scale, the senescence of tree roots influences the cycling of carbon and nutrients, because roots exhaust a great deal of carbon fixed by source leaves through photosynthesis, and there are great amounts of nutrients in tree roots. The senescence of tree roots is influenced by many environmental factors, biotic (e.g., fungi, bacteria, viruses, small edaphic animals) and abiotic (e.g., water, temperature, soil nutrients, heavy metals). These factors affect the senescence of tree roots by different mechanisms. Although we have much knowledge on the senescence of tree roots and some hypotheses have been proposed, some problems still remain to be resolved, and further experiments are needed to test these hypotheses. Interdisciplinary studies integrating cytology, biochemistry, soil science, and genetics are the prerequisite for rapid advances in understanding the essence of tree root senescence.

Biological Transport↗

[Effects of land use and vegetation restoration on soil quality in a small catchment of the Loess Plateau].

Soil quality improvement plays an important role in sustaining global biosphere. This paper studied the changes of soil quality after 25 years' land use and vegetation restoration at the Anjiapo catchment of western Loess Plateau. The analyses of soil characteristics of wasteland, almond land, farmland, pineland, shrub land and fallow land showed that different land use and vegetation restoration had different effects on soil integrated fertility index. Soil organic matter content was increased due to planting shrubs and forests. Both vegetation restoration and fallow could improve soil quality. Cultivation practice could decrease soil nutrient levels, and cropland soil was degraded. Shrub soil formed "fertile island" in the semi-arid region. Fallow could improve soil fertility to some extent. Human activities and vegetation restoration could affect soil nutrient contents after land use pattern was changed. With the launch out into the "Grand development of Western China", "Grain for Green Project" and ecological restoration, both shrub planting and fallow (natural restoration) should be the optional choices to restore soil fertility, as they could decrease soil erosion and improve soil condition at catchment scale, especially in the hilly and gully loess area. Integrative control of small catchment may be the best way for the sustainable development of the semi-arid hilly area of Loess Plateau.

China↗

[Effects of vegetation types and landscape features on soil properties at the plateau in the upper reaches of Minjiang River].

Spatial heterogeneity is one of the important properties of oil. In this paper, the classical statistics method and the principles of geostatistics were used to study the spatial heterogeneity of soil properties on the Tibet plateau in the upper reaches of Minjiang River, and the relationship between vegetation type, landscape position and soil factors. Semivariogram analyses showed that there existed high degrees of spatial heterogeneity in soil moisture and soil nutrients. The test quadrats were assorted into three groups according to the landscape position and vegetation types, and then statistical analyses were made. The taxon results showed that different vegetation types had great effects on soil nutrients, and elevation was also an important factor influencing soil properties. A comprehensive index of soil properties showed that shrubs had the highest soil quality. The same trend of soil nutrients was found in the category of landscape positions. The soil nutrient contents decreased in the order of lower slope > upper slope > middle slope for the lower altitude hill, and lower slope > middle slope > upper slope for the high altitude hill. The results elucidated that the spatial heterogeneity of soil property was the result of the interaction between landscape factors and vegetation types.

Ecosystem↗

Effect of land-use and land-cover change on nutrients in soil in Bashang area, China.

The Bashang area is a water-source area and ecological barrier zone for Beijing and Tianjin. The area is located at 200 km from Beijing and Tianjin and is a typical agriculture-pasture-interlacing zone, in which the eco-environment is vulnerable and hence it is sensitive to environmental change. The area is relatively lagged in social and economic development, where the traditional cultivation mode is predominated in agriculture and animal husbandry, but the disturbance by human activity is relatively small. Therefore, in order to reveal the interrelation between eco-environmental change in the area and environmental change in Beijing and Tianjin area, it is fairly necessary to study the effect of land-use and land-cover change on nutrients in soil in this area. According to the actual situation of changed land use for the limited time period, five series of changed land plots were selected and 4 samples were collected from each series for the study. The samples were collected from different soil-forming levels at the same site in different time. Analysis of the collected samples indicates that in the process of change of land use and land cover, the nutrients in soil, such as organic matter, total N, total P, total K, and available N, P, K, and B, Mo, Mn, Zn, Cu, and Fe, have regularly changed. When the land had changed from grassland and non-irrigated farmland into woodland, and from non-irrigated farmland into irrigated field, the nutrients in soil totally increased. But there exists some exception, i.e. quick-acting N, P, K, and some microelements have appeared to be inconsistent with the mentioned above regularity in some cases.

Agriculture↗

Effects of acid rain on growth and nutrient concentrations in Scots pine and Norway spruce seedlings grown in a nutrient-rich soil.

The effects of artificially applied acid precipitation on growth and nutrient concentrations of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies [L.] Karst.) seedlings were investigated in a long-term acid irrigation experiment in field conditions. Seedlings of northern and southern origin were planted in boxes containing peat and composted soil rich in nutrients, and sprinkler irrigated with water acidified with nitric and sulphuric acids to pH 3 or pH 4 for periods varying from two to three and a half growing seasons during 1986-1989. Water irrigated (pH 5.4-7.6) and non-irrigated groups of seedlings were also included in the experiment. At the end of the experiment needles, main and lateral shoots and roots were collected from the seedlings for the determination of height growth and biomass partitioning, and for the analysis of S, N, Mg, P, K, Ca, Mn and Fe concentrations. The treatment effects compared to the irrigated control were studied using multivariate analyses of variance and covariance. In the pine seedlings the total dry matter production increased by 25-70% compared with the irrigated controls when the total wet deposition to the seedlings exceeded 67 kg S ha(-1) and 36 kg N ha(-1) (e.g. after two growing seasons' exposure of the pH 3 treatment). The increase was mainly due to an increase in needle dry weight (54-72% greater at pH 3) and root weight (20-65% greater at pH 3), whereas the height growth or shoot weight growth were less affected. The northern provenance pine seedlings responded more clearly to the pH 3 irrigation than the southern ones. The treatments had no consistent effects on any of the growth variables studied in the spruce seedlings, however. The pines had higher root and foliage Ca concentrations as a result of the acid irrigation, whereas in spruce, acid rain decreased the Ca concentration in needles and shoots. Root Mn and Fe concentrations were higher in both species as a result of the pH 3 treatment. A higher soil conductivity and Ca concentration resulted from the prolonged pH 3 treatment. The results strongly support the hypothesis that the long-term growth and nutrient allocation response of conifers to acid precipitation is dependent both on the tree species and on the nutritional status of the soil.

Journal Article↗

Accumulation of nutrients in soils affected by perennial colonies of piscivorous birds with reference to biogeochemical cycles of elements.

The accumulation of selected N, K, and P forms in soils within three perennial colonies of black cormorant (Phalacrocorax carbo sinensis) and grey heron (Ardea cinerea) located in northern and eastern Poland were investigated. Soil samples were collected beneath the nests from the most representative for each colony plots. Control samples were taken outside the colonies within sites adjacent to the nesting areas but not affected by bird excrement. From each genetic horizon (20 horizons) in soil profiles, a cumulative sample of about 25-30 kg of soil was taken for analysis. Nitrogen by Kjeldahl, ammonium ions (N(NH(4))), nitrates (N(NO(3))), exchangeable potassium (K(ex)), available potassium (K(av)), and available phosphorus (P(av)) were determined. The soils affected by birds demonstrated a very strong enrichment with N, K, and P in comparison to the control sites, especially in the topsoil horizons. The content of N(NH(4)) in individual soil horizons from the colonies was from 1.7 to 10.1 times higher than the respective control, N(NO(3)) from 2.9 to 215.7, K(ex) from 2.0 to 35.1, K(av) from 1.1 to 48.1, and P(av) in the range from 2.4 to 53.0 times. The highest increment of chemical elements was noticeable in the soils of territories inhabited by cormorants and the least in forest occupied by herons. Some relationships between soil texture and accumulation of biogenic nutrients were determined. Clay loam soil showed the greatest enrichment with analysed forms of elements with the exception of N(NH(4)).

Animals↗

[Effect of long-term fertilization on crop yield and soil fertility of upland red soil].

The studies on the influence of long-term fertilization on crop yield and soil fertility of upland red soil showed that P was the most deficient in this soil, and hence, phosphorus fertilizer had the best effect on crop yield. Applying lime and microelements could not significantly increase the crop yield. The concentration of P and K in peanut could be increased if fertilizer was applied, indicating that the supply level of soil nutrients decided the nutrient concentration in plants. The reconstructive efficiency of soil available nutrient pool was dependent on the surplus or deficit of soil nutrients. When the surplus of nutrients was 1 kg x hm(-2), N was increased by 0.6-6.2 mg x kg(-1), P was increased by 0.20-0.28 mg x kg(-1), and K was increased by 1.1-8.5 mg x kg(-1). The changing in results was due to the loss of N and K from soil. The nutrient bupplying capability of soil was the quantity of the nutrients which soil could provide by weathering to satisfy the plant growth. The amount of P fixed by soil was 43.5 kg x hm(-2) x yr(-1), and that of N and K provided by soil was 40.5 and 55 x kg x hm(-2) x yr(-1), respectively.

Biomass↗

Evaluating the Role of Plantations as Carbon Sinks: An Example of an Integrative Approach from the Humid Tropics

/ Despite their fast growth, tropical plantations are a small sink of atmospheric carbon because they occupy only a small area in relation to other land uses worldwide. Proper design and management of plantations can increase biomass accumulation rates, making them more effective C sinks. However, fast-growing plantations can extract large amounts of nutrients from the soil, and site fertility declines may limit sustained plantation forestry after a few rotations. We measured aboveground biomass accumulation, carbon sequestration, and soil chemistry in three young plantations of 12 indigenous tree species in pure and mixed designs in the humid lowlands of Costa Rica. Annual biomass increments for the three mixed plantations ranged from 10-13 Mg/ha. The mixtures of four species gave higher biomass per hectare than that obtained by the sum of one fourth hectare of each species in pure plots. At this early age of the plantations, estimated annual C sequestration values were comparable to other reports from young plantations of exotic species commonly grown in the tropics. Four years after planting, decreases in soil nutrients were apparent in pure plots of some of the fastest growing species, while beneficial effects on soils were noted under other species. The mixed plots showed intermediate values for the nutrients examined and, sometimes, improved soil conditions. A mixture of fast and slower growing species yields products at different times, with the slower growing species constituting a longer term sink for fixed carbon. Examination of the role of tropical plantations as C sinks necessitates integrative approaches that consider rates of C sequestration, potential deleterious effects on ecosystem nutrients, and economic, social, and environmental constraints.KEY WORDS: Native trees; Aboveground biomass; Stem increments; Rotation length; Soil nutrients; Economics

Journal Article↗

Effects of genotype, nutrient availability, and defoliation on aspen phytochemistry and insect performance.

Genetic and environmental variability, and their interactions, influence phytochemical composition and, in turn, herbivore performance. We evaluated the independent and interactive effects of plant genotype, nutrient availability, and defoliation on the foliar chemistry of quaking aspen (Populus tremuloides) and consequences for performance of gypsy moths (Lymantria dispar). Saplings of four genotypes were grown under two conditions of nutrient availability and subjected to three levels of artificial defoliation. Concentrations of all secondary and primary metabolites evaluated responded to at least one or more of the experimental treatments. Of the secondary metabolites, phenolic glycosides were affected strongly by genotype, less so by nutrient availability, and not induced by defoliation. Condensed tannins were strongly dependent upon genotype, soil nutrient availability, and their interaction, and, in contrast to phenolic glycosides, were induced by artificial defoliation. Of the primary metabolites, foliar nitrogen was affected by genotype and soil nutrient availability. Starch concentrations were affected by genotype, nutrient availability, defoliation and interactions among these factors. Foliar water content responded to genotype, nutrient availability, and defoliation, and the effect of nutrient availability depended on genotype. Herbivore performance on these plants was strongly influenced by plant genotype and soil nutrient availability, but much less so by defoliation. Although several of the compound types (condensed tannins, starch, and water) responded to defoliation, quantitative variation in these compounds did not contribute to substantive changes in herbivore performance. Rather, the primary source of variation in insect performance was due to plant genotype (phenolic glycoside levels), while nutrient availability (foliar nitrogen levels) was of secondary importance. These results suggest that genetic variation in aspen plays a major role in determining patterns of insect performance, whereas environmental variation, such as was tested, here is of negligible importance.

Animals↗

Vegetation Composition Determines Microbial Activities in a Boreal Forest Soil.

Abstract Forest soil ecology was studied in Fennoscandinavian dry Scots pine forests grazed by reindeer to varying extents (ungrazed, lichen-dominated-sites; grazed sites; and bryophyte-dominated sites). We hypothesized that the productivity parameters of the site (i.e., tree growth and soil nutrient concentrations), the vegetation composition, and the microbial activities are directly correlated. Since the productivity of the lichen-dominated ecosystem is low, microbial activities are assumed to be naturally low. Grazing was expected to decrease both the amount of Scots pine fine roots and the soil microbial activities. Several variables on the characteristics of the soil microbial community, Scots pine fine roots, soil nutrients, and tree growth were studied in relation to vegetation composition by using non-metric multidimensional scaling (NMDS). Basal respiration (Bas), metabolic quotient of the microbial community (qCO2), and pine fine root parameters increased toward the ungrazed, nutrient-poor, lichen-dominated sites, which were grouped at one end of the first axis in the NMDS ordination. Soil nutrient and tree growth parameters and thickness of the humus layer increased toward bryophyte-dominated sites, which were grouped at the other end of the first axis in the ordination. The grazed sites fell between them. These were characterized by lower Bas and qCO2 values and longer lag, compared to ungrazed lichen- or bryophyte-dominated sites, probably due to decreased carbon input and microclimatic change (the soil without lichen carpet is exposed to direct sunlight and wind). Microbial biomass (Cmic), fungal biomass (ergosterol concentration), and the specific growth rate (µCO2) were not related to vegetation ordination. The high fine root production is the most plausible explanation for the high microbial activities at nutrient-poor, lichen-dominated sites, which produce qualitatively poor and slowly decomposing litter, as fine roots secrete considerable amounts of organic substances. At bryophyte-dominated sites, the higher soil nutrient concentrations and the higher production of easily decomposable substrates are likely to maintain the microbial activities.

Journal Article↗

[Mixing of Cunninghamia lanceolata with Michelia macclurei and restoration of self-sustaining mechanism in G. lanceolata plantation].

The formation of self-sustaining mechanism is one of the major objectives for the sustainable management of plantations. In this study, the incorporation of different proportions of native Michelia macclurei into Cunninghamia lanceolata plantation was practiced to restore the degraded C. lanceolata plantation, and the comparison of nutrient cycling characteristics and soil nutrient concentrations was made among four types of plantation stand with different mixed rate of native M. macclurei representing four different restoration stages of degraded C. lanceolata plantations. With the increase of the proportion of M. macclurei in the plantation, the litterfall and returned nutrients N, P, K, Ca and Mg increased. The nutrient cycling efficiency increased significantly, e.g., that of N and Mg increased from about 0.1 for the degraded pure C. lanceolata plantation to above 0.5 for the pure M. macclurei plantation. Soil organic matter and nutrients also elevated. It is suggested that the self-sustaining mechanism of the C. lanceolata plantation forest gradually reformed as the proportion of native M. macclurei mixed in the plantation increased. The criteria to determine the proportion of native broad-leaved tree species mixed in C. lanceolata plantations for the purpose of sustainable management should be based on whether the self-sustaining mechanism was reformed and whether the soil nutrient status was improved.

Biomass↗

On the carrying capacity for large ungulates of African savanna ecosystems.

The effect of pastoral management on the standing crop biomass of large ungulates, an index of carrying capacity, is analysed at a regional level by using data compiled from published sources covering east and south Africa. The effect of primary production is controlled for by using two environmental factors, rainfall and soil nutrient availability, and the effect of species richness of the ungulate community is evaluated. The results confirm the dominant effect of rainfall, and demonstrate that soil nutrient levels also strongly affect the biomass of large ungulate communities. For a given level of rainfall, on rich soils (high nutrient availability) the biomass of large ungulates is about 20 times as great as on poor soils with low nutrient availability. The model based on rainfall and soil nutrient classes accounts for 87% of the variance in large ungulate biomass. Pastoral and natural ecosystems do not differ significantly in large ungulate biomass; there is therefore currently no evidence that extensive pastoral management increases carrying capacity for large ungulates above the levels observed in natural communities. Species richness, a measure of biodiversity, had a significant but very small effect on the biomass-rainfall relation in the complete data set. When analysed by pastoral management, the effect of this factor was significant for the set of natural ecosystems only. Pastoral management and species richness may therefore have compensatory effects. These results suggest that the carrying capacity is limited at the community, rather than the species, level.

Africa↗

Effects of Atmospheric CO(2) Enrichment on the Growth and Mineral Nutrition of Quercus alba Seedlings in Nutrient-Poor Soil.

One-year-old dormant white oak (Quercus alba L.) seedlings were planted in a nutrient-deficient forest soil and grown for 40 weeks in growth chambers at ambient (362 microliters per liter) or elevated (690 microliters per liter) levels of CO(2). Although all of the seedlings became severely N deficient, CO(2) enrichment enhanced growth by 85%, with the greatest enhancement in root systems. The growth enhancement did not increase the total water use per plant, so water-use efficiency was significantly greater in elevated CO(2). Total uptake of N, S, and B was not affected by CO(2), therefore, tissue concentrations of these nutrients were significantly lower in elevated CO(2). An increase in nutrient-use efficiency with respect to N was apparent in that a greater proportion of the limited N pool in the CO(2)-enriched plants was in fine roots and leaves. The uptake of other nutrients increased with CO(2) concentration, and P and K uptake increased in proportion to growth. Increased uptake of P by plants in elevated CO(2) may have been a result of greater proliferation of fine roots and associated mycorrhizae and rhizosphere bacteria stimulating P mineralization. The results demonstrate that a growth response to CO(2) enrichment is possible in nutrient-limited systems, and that the mechanisms of response may include either increased nutrient supply or decreased physiological demand.

Journal Article↗

[Changes of crop yield and soil fertility under long-term application of fertilizer and recycled nutrients in manure on a black soil III. Soil nutrient budget].

The nutrient budget of fertilization models under different treatments was calculated using data from a field experiment over the period of 1985-1999. The results indicated that application of nitrogen fertilizer accelerated a large deficit of soil phosphorus, and the use of nitrogen and phosphorus accelerated the deficit of potassium. The experimental data demonstrated the appearance of a large area of soil deficit of phosphorus from 1970s and of potassium from 1980s in China. Nutrient recycled in farming system improved soil nutrient budget, but could not meet the nutrient requirements from high-yield crops. The use of recycled nutrients with an appropriate use of fertilizers according to the soil fertility could produce higher crop yields, balance soil nutrient budget, and not cause surplus nutrients to emit into environment.

Agriculture↗