Top PDF Influence of long-term fertilization on soil enzyme activities

Influence of long-term fertilization on soil enzyme activities

Influence of long-term fertilization on soil enzyme activities

Our observation is in agreement with other studies. For example [1] observed that soil management influences soil microorganisms and soil microbial processes through changes in the quantity and quality of plant residues entering the soil, and its spatial distribution. Mulching, generally, increases enzymes activities in soils. With the increasing of mulch there is an increased of the supply of the readily available substrate for microorganisms as well as soil enzymes. While N fertilization in the no-till treatments slightly increased microbial populations and activities [3, 8] green manuring with crimson clover had a much greater impact on soil microbial properties. Microbial activity as measured by soil enzymes was significantly greater in the clover plots than the non-clover plots. Differences in enzyme activities between the two treatments were significant for alkaline phosphatase. While green-manuring with crimson clover significantly affected soil biological properties in the 0 to 7.5 cm zone, few significant differences were found between treatments in the 7.5 to 30 cm zone. Soil enzyme activities can be more influenced by type of organic matter than the quantity of organic matter [2, 7], once had been observed that mineralization of plant residue added to soil is controlled by C:N ratio. The larger and more active microbial biomass in the surface soil from the green manure plots results from the green manure providing a source of C and N for microbial growth. Cropping systems that increase inputs of C through green manures have been shown to have more microbes and greater microbial activity than that found in systems that utilize only fertilizer inputs [7, 9]. Green manuring increases soil organic matter levels, leading to improved soil structure, infiltration, fertility and water-holding capacity [4]. [12] compared the
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Long-term phosphate fertilization, mycorrhizal inoculation and historical land use influence on soybean growth and P uptake

Long-term phosphate fertilization, mycorrhizal inoculation and historical land use influence on soybean growth and P uptake

In the second cultivation (Table 3), inoculation increased soybean SDM in NC LAx, LVdfg and LVdft. In LVw, there was no response to inoculation regardless of land use history. Although there was colonization in the non- cultivated soils as well as in the cultivated, except for the cultivated LAx (Table 4), where there was no colonization due to higher P levels (Table 3), and there was no increase in SDM due to mycorrhizal colonization. In LVw and LVdft, there was no response to inoculation, whereas in LVdfg there was a similar response as in the first cultivation, i.e. there was an SDM increase at both P doses, this increase being greater, however, with the lower P dose. In LAd, in the first cultivation, there was also no response at the greater P dose, while in the second cultivation there was a 19% increase (Table 3). In the LVw, although there was response at the lower P dose in the first cultivation, this did not occur in the second. In the other soils, the response to inoculation in the absence of P was lesser in the second cultivation. The lowest response at the lower P dose (Table 3) is due to the reduction of the content of the nutrient in the soil by the first cultivation, which also reduced the effect of the mycorrhizal fungi. When comparing the SDM production in non- cultivated LAd and LVdf with the lowest P (7.97 and 6.56 g in the first cultivation and 2.94 and 4.91 g in the second), it was observed that although there was little difference between them in the first cultivation, the SDM reduction in the second cultivation (63 and 25%) was lesser in the LVdfg. Since the values of available P (Mehlich-1) of these soils were equal, around 5 mg dm -3 , it is concluded that the
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Rapid response of arbuscular mycorrhizal fungal communities to short-term fertilization in an alpine grassland on the Qinghai-Tibet Plateau

Rapid response of arbuscular mycorrhizal fungal communities to short-term fertilization in an alpine grassland on the Qinghai-Tibet Plateau

Zhang et al., 2011). Fertilization is known to alter successional trajectories (Tilman, 1987) and promote the establishment of invasive plant species (Huenneke et al., 1990). Nitrogen and phosphorus addition have significantly altered soil organic carbon in arctic tundra (Mack et al., 2004) and soil carbon fractions in an alpine meadow (Li et al., 2014). Long-term fertilization has been associated with significant decreases of soil microbial biomass and bacterial diversity, and is known to drive shifts in bacterial community composition in grassland ecosystems (Lovell, Jarvis & Bardgett, 1995; Ramirez et al., 2010; Allison et al., 2013) and agriculture soils (Enwall et al., 2007; Yuan et al., 2012; Sun et al., 2015). Soil fungal communities are also altered by fertilization in forest (Liu et al., 2012a), agricultural (Avio et al., 2013), and grassland ecosystems (Klabi et al., 2015). Arbuscular mycorrhizal fungal (AMF) communities were significantly altered by long-term
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Effects of Long-Term Fertilization Management Practices on Soil Microbial Carbon and Microbial Biomass in Paddy Soil at Various Stages of Rice Growth

Effects of Long-Term Fertilization Management Practices on Soil Microbial Carbon and Microbial Biomass in Paddy Soil at Various Stages of Rice Growth

Soil microbial biomass is often used as an early indicator of soil quality changes (Liu et al., 2014). Some results have indicated that soil microbial biomass was greater with application of animal manure fertilizer than with application of rice straw residues. This is due to the wide range of C/N ratios in rice straw residues, and the rice straw residue decomposition rate is relatively slow (Paustian et al., 1997). In contrast, application of animal manure fertilizer promotes soil microorganism growth because it contains a large number of soluble available organic substrates. Therefore, incorporation of organic matter into paddy soils increases the supply of valuable soil nutrients, SOC, and soil microbial biomass contents. Data from this study revealed that throughout the rice growth period, the SMBC and SMBN contents increased along with the advance in rice growth stages. The SMBC and SMBN contents were higher under the MF, RF, LOM, and HOM treatments at the heading stage of rice. This could be due to organic matter decomposing and providing a large amount of available substrates for soil microbial growth. Compared with early growth stages, the SMBC and SMBN contents were lower at the mature stage of rice; the reason may be that plant root exudation decreased along with the soil drainage practiced at mature rice stages (Aulakh et al., 2001).
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Clay Mineralogy of Subtropical Soils under Long-Term Organic Fertilization in No-Tillage Systems

Clay Mineralogy of Subtropical Soils under Long-Term Organic Fertilization in No-Tillage Systems

with pig slurry, for six years. Soil samples from the layers 0.00-0.04, 0.04-0.08, and 0.16-0.20 m were collected and subjected to chemical extractions with DCB and oxalate, X-ray diffractometry, and thermal analysis. No mineralogical changes in the clay fraction were observed in either the Alfisol or Oxisol. The chemical dissolution data indicated no significant differences among the tested treatments with regard to the re-precipitation of low-crystallinity oxides. However, the increase in zinc extracted by DCB and zinc extracted by oxalate in the treatments with residue application was clear. The crystallinity data efficiently indicated the effects of residue rates on soil mineralogy only in the Alfisol; the increasing slurry rates induced a reduction in the percentage of hematite, increase in the percentage of goethite, increase in the Gt/Gt+Hm ratio and decreased the mean crystal diameter of goethite and hematite.
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Differential long-term effects of climate change and management on stocks and distribution of soil organic carbon in productive grasslands

Differential long-term effects of climate change and management on stocks and distribution of soil organic carbon in productive grasslands

Abstract. We studied the impact of climate change on the dynamics of soil organic carbon (SOC) stocks in produc- tive grassland systems undergoing two types of management, an intensive type with frequent harvests and fertilizer ap- plications and an extensive system without fertilization and fewer harvests. Simulations were conducted with a dedicated newly developed model, the Oensingen Grassland Model. It was calibrated using measurements taken in a recently estab- lished permanent sward in Central Switzerland, and run to simulate SOC dynamics over 2001–2100 under various cli- mate change scenarios assuming different elements of IPCC A2 emission scenarios. We found that: (1) management in- tensity dominates SOC until approximately 20 years after grassland establishment. Differences in SOC between cli- mate scenarios become significant after 20 years and cli- mate effects dominate SOC dynamics from approximately 50 years after establishment. (2) Carbon supplied through ma- nure contributes about 60 % to measured organic C increase in fertilized grassland. (3) Soil C accumulates particularly in the top 10 cm of the soil until 5 years after establishment. In the long-term, C accumulation takes place in the top 15 cm of the soil profile, while C content decreases below this depth. The transitional depth between gains and losses of C mainly depends on the vertical distribution of root senescence and root biomass. We discuss the importance of previous land use on carbon sequestration potentials that are much lower at the Oensingen site under ley-arable rotation with much higher SOC stocks than most soils under arable crops. We further discuss the importance of biomass senescence rates, because C balance estimations indicate that these may differ considerably between the two management systems.
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INFLUENCE OF ORGANIC-MINERAL FERTILIZATION OF AN OXISOL ON SOIL CHEMICAL PROPERTIES AND Bracharia brizantha PRODUCTION

INFLUENCE OF ORGANIC-MINERAL FERTILIZATION OF AN OXISOL ON SOIL CHEMICAL PROPERTIES AND Bracharia brizantha PRODUCTION

Livestock farming is one of the most important economic activities in the Cerrado (savannah-like vegetation) region. More than half of an estimated total of 48 million hectares in the region are Brachiaria decumbens pastures (Soares et al., 2000). However, approximately 80 % of the pastures in the Cerrado are partially degraded, as indicated by the low productivity and low support capacity (Lima et al., 2000). The low productivity can be explained by the lack of fertilization and liming at recommended quantities and the degradation of the physical soil quality. The recovery of these areas is fundamental for environmental, technical, and economical reasons. To recover these areas, it is essential to improve soil fertility and manage forage plants properly (Oliveira et al., 2005).
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EFFECT OF CROP ROTATION AND LONG TERM FERTILIZATION ON THE CARBON AND GLOMALIN CONTENT IN THE SOIL

EFFECT OF CROP ROTATION AND LONG TERM FERTILIZATION ON THE CARBON AND GLOMALIN CONTENT IN THE SOIL

The potential fertility of the soil is determined on the base of the general content of soil organic matter (SOM). In the agricultural practice, it is important to determine the contribution of fractions responsible for the progressive transformation associated with the different susceptibility to degradation. Apart from the most labile faction, which is a source of nutrients, fractions resistant to degradation that decide on the preserving and reconstructing of humus resources are important. The example of such substance is glomalin, which was shown to account for 25 and 52% of the total C in the mineral soils and organic soils, respectively (Schindler, at al., 2007).
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LONG-TERM EFFECTS OF SWINE WASTEWATER AND MINERAL FERTILIZER ASSOCIATION ON SOIL MICROBIOTA

LONG-TERM EFFECTS OF SWINE WASTEWATER AND MINERAL FERTILIZER ASSOCIATION ON SOIL MICROBIOTA

ABSTRACT: Swine wastewater (SW) application in agricultural soils may affect its microbial community in a long term. The objective of this study was to evaluate prospective changes in soil bacterial community after eight years continuous application of swine wastewater. The wastewater doses tested were 0; 100; 200 and 300 m 3 ha -1 , being applied from the beginning of the experiment and with or without recommended fertilization. Three soil samples were taken from each plot for determinations of basal respiration, microbial biomass and metabolic quotient. We also performed DGGE analysis and made a correlation between soil chemical conditions and microbial activity. Microbial community underwent significant structural changes from swine wastewater applications. Higher SW doses (200 and 300 m 3 ha -1 ) influenced significantly (p <0.05) and benefitted certain bacteria groups.
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SOME MACROASPECTS OF FDI IN ROMANIA

SOME MACROASPECTS OF FDI IN ROMANIA

The paper studies the macroeconomic aspects and influence of FDI on banking sector, foreign external debt on medium and long term, labour market and relevant macro indicators of economic growth. The main conclusion is that the comparison of FDI advantages and disadvantages presupposes a complex methodological approach, particularised on types of activities and effects. The corroboration at local, regional and national levels of favourable and unfavourable effects, as a rule, leads to a net favourable result, yet without eliminating also the existence of some non favourable punctual results.
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Influence of exercise on the activity and the distribution between free and bound forms of glycolytic and associated enzymes in tissues of horse mackerel

Influence of exercise on the activity and the distribution between free and bound forms of glycolytic and associated enzymes in tissues of horse mackerel

The effect of exercise on intermediary metabolism and energetics of organisms has been well studied (31), including numerous studies of metabolic responses to exercise by fish species (4,5,8). Two areas of exercise metabolism in fish that are still not fully resolved, however, are the effects of exer- cise on enzyme activities and on the distribu- tion of enzymes between free and bound states. Therefore, in this study we focused on these two phenomena, monitoring the ef- fects of burst high-speed swimming (5 min at 1.8 m/s) and of sustained moderate-speed swimming (60 min at 1.2 m/s) on the maxi- mal activities of enzymes in four organs and on the subcellular distribution of enzymes between free and bound states. Short-term burst exercise is typically powered by white muscle in fish, whereas long-term cruiser exercise is primarily a function of red muscle. Previous work from our Karadag laboratory has analyzed the different modes of swim- ming and their effects on metabolite levels in horse mackerel tissues. These fish can swim
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Long-term effects of irrigation with waste water on soil AM fungi diversity and microbial activities: the implications for agro-ecosystem resilience.

Long-term effects of irrigation with waste water on soil AM fungi diversity and microbial activities: the implications for agro-ecosystem resilience.

Arbuscular mycorrhizal fungi (AMF) form mutualistic associa- tions with most land plants. These fungi provide beneficial effects to plants, increasing their growth, uptake of nutrients, principally phosphorous and protection against biological and environmental stresses. The fungi in return receive plant carbon assimilates or carbohydrates [3]. It is evident that AMF play an important role in the edaphic system, contributing to the maintenance of terrestrial ecosystem functioning. Also, their occurrence, activity and efficency can be valuable indicators of soil quality [4]. It has been shown that the diversity of AMF in the soil can affect both productivity and ecosystem functioning [5,6]. Therefore, knowl- edge of the diversity of the AMF in the soil of crops is essential for better management, sustainability and productivity of these agricultural soils.
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Occasional soil tillage, liming, and nitrogen fertilization on long-term no-tillage system

Occasional soil tillage, liming, and nitrogen fertilization on long-term no-tillage system

the first corn crop in 2009/2010, harvested about four months after the application of treatments (Fidalski et al., 2015). These results are contrary to those reported by Debiasi et al. (2010), in which corn and soybean showed lower yields when the soil was subjected to mechanical scarification, since this practice lowered the final populations of the plants under water deficit. However, these authors also observed increases of soybean and corn yields with black oat and hairy vetch as winter crops, in comparison to fallow, and attributed this result to a better soil aggregation that resulted from greater soil organic matter content. Immediately after four months of the occasional soil tillage and liming, organic C contents increased 10.8% at the 0.1–0.2 m soil depth (Fidalski et al., 2015), and after about 30 months, this difference changed to 7.4% (1.9 g dm -3 C) (Table 1).
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Influence of long-term mineral fertilization on metal contents and properties of soil samples taken from different locations in Hesse, Germany

Influence of long-term mineral fertilization on metal contents and properties of soil samples taken from different locations in Hesse, Germany

avaca et al., 1999). In contrast to observations in other recent studies (Bationo et al., 2007), a significant negative linear- ity between soil pH and organic carbon content was found (Fig. 3). There are two possible explanations for these ad- verse observations: either organic matter accumulation does not necessarily result in pH decreases or other mechanisms causing pH change are more dominant (Ritchie and Dolling, 1985). In particular, accumulation of undecomposed soil or- ganic matter rich in organates and inputs of symbiotically fixed N and ammonium-based fertilizers with consequent ni- trate leaching are involved in the accelerated acidification of agricultural soils (Bolan and Hedley, 2003). Acidification from soil organic matter accumulation or the direct effects of fertilizers on the soil chemistry can, however, be of signifi- cant importance (de Klein et al., 1997). Schwab et al. (1990) determined a decrease in soil pH and an increase in soil or- ganic matter content due to applied high N rate.
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Long-term nitrogen fertilization in native pasture with Italian ryegrass introduction - Effects on soil health attribute indicators

Long-term nitrogen fertilization in native pasture with Italian ryegrass introduction - Effects on soil health attribute indicators

ABSTRACT: Native pastures are of great importance for cattle and sheep nutrition in the Pampa biome. However, due to its low productivity, the Italian ryegrass introduction and the nitrogen (N) fertilization are alternatives proposed to intensify livestock production in a sustainable manner. The objective of this study was to evaluate the effects of long-term N application on soil health indicators in a native pasture with Italian ryegrass introduction in southern Brazil. The experiment consists of a secondary native pasture under continuous grazing and constant herbage allowance. In 1996 experimental area was broadcast limed and the experiment was initiated, testing three N topdressing rates (0, 100 and 200kg N ha -1 year -1 ). In 2010 soil of experimental and
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Phosphorus Accumulation and Sorption in Calcareous Soil under Long-Term Fertilization.

Phosphorus Accumulation and Sorption in Calcareous Soil under Long-Term Fertilization.

(slope = 0.0251), which was about 7 times that below the change-point (slope = 0.0036). This clearly indicates that the risk of P losses, especially via runoff, will increased sharply when Olsen-P content is above the change point. Therefore, it is imperative to optimize soil P man- agement strategy to achieve optimal crop yield on one hand, and decrease soil P accumulation and losses on the other hand. The critical Olsen-P level for apple orchard in Loess Plateau is determined to be 15 mg kg −1 , below which apple trees may suffer from poor growth. In this

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Braz. J. Cardiovasc. Surg.  vol.24 número1 en v24n1a08

Braz. J. Cardiovasc. Surg. vol.24 número1 en v24n1a08

In a series of 54 patients restudied with one year of postoperative, there was also apparent vulnerability of the RA grafts under situations of “theft of flow.” The authors describe 50% of graft occlusion for preoperative obstructions less than 60% [26]. In postoperative angiographic restudy (mean 32 months) of 123 patients undergone surgery using ITA and RA grafts was observed patency of 99.2% and 92% respectively. The highest patency rates of RA were recorded in the “target coronary” with obstructions of 90% or more (98%) in relation to the less obstructive lesions (83.3%, P<0.05) [27]. Similar results were shown in retrospective assessment of 600 patients, where 93 (15.5%) were restudied, with 92.5% of RA grafts patency rate, and all occluded grafts were related to the coronary arteries with less severe obstructions, 56. 3% + 15.4 (P <0.001) [28].
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Characterization of thimet oligopeptidase and neurolysin activities in B16F10-Nex2 tumor cells and their involvement in angiogenesis and tumor growth

Characterization of thimet oligopeptidase and neurolysin activities in B16F10-Nex2 tumor cells and their involvement in angiogenesis and tumor growth

Results: Angiogenesis induced by B16F10-Nex2 melanoma cells was studied in a co-culture with HUVEC on Matrigel. A stimulating effect on angiogenesis was observed in the presence of B16F10- Nex2 lysate and plasma membrane. In contrast, the B16F10-Nex2 culture supernatant inhibited angiogenesis in a dose-dependent manner. This effect was abolished by the endo-oligopeptidase inhibitor, JA-2. Thimet oligopeptidase (TOP) and neurolysin activities were then investigated in B16F10-Nex2 melanoma cells aiming at gene sequencing, enzyme distribution and activity, influence on tumor development, substrate specificity, hydrolytic products and susceptibility to inhibitors. Fluorescence resonance energy transfer (FRET) peptides as well as neurotensin and bradykinin were used as substrates. The hydrolytic activities in B16F10-Nex2 culture supernatant were totally inhibited by o-phenanthrolin, JA-2 and partially by Pro-Ile. Leupeptin, PMSF, E-64, Z-Pro-Prolinal and captopril failed to inhibit these hydrolytic activities. Genes encoding M3A enzymes in melanoma cells were cloned and sequenced being highly similar to mouse genes. A decreased proliferation of B16F10-Nex2 cells was observed in vitro with specific inhibitors of these oligopeptidases. Active rTOP but not the inactive protein inhibited melanoma cell development in vivo increasing significantly the survival of mice challenged with the tumor cells. On Matrigel, rTOP inhibited the bradykinin – induced angiogenesis. A possible regulation of the homologous tumor
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STABILIZATION OF SOIL HYDRAULIC PROPERTIES UNDER A LONG TERM NO-TILL SYSTEM

STABILIZATION OF SOIL HYDRAULIC PROPERTIES UNDER A LONG TERM NO-TILL SYSTEM

The tension disc infiltrometer (Perroux & White, 1988) was used to determine the steady-state infiltration rate. Infiltration tests were carried out for three consecutive years during the fallow period (June 2008, June 2009, and June 2010) after harvest. The infiltrometer disc had a base radius of 6.25 cm. Infiltration measurements were conducted at ten randomly selected sites in each plot. To consider only the effects of tillage on soil water infiltration, crop residues were removed from the soil surface. To ensure good hydraulic contact between the device and the soil, the surface was flattened with a spatula and a thin dry sand layer was spread on it. Infiltration runs were performed at three values of water pressure heads, h (namely, -6, -3, and 0 cm, applied in this order and at the same place). This sequence of supply water pressure heads was adopted because a descending order may cause hysteresis, with progressive drainage occurring close to the disk while wetting continues at the infiltration front (Jarvis & Messing, 1995). Flow monitoring continued until steady-state flow from the disc was attained. Cumulative infiltration was recorded every min until 10 min, every 5 min until 30 min, and every 10 min until the end of the test. When the amount of water entering the soil did not change with time for four consecutive measurements taken at 10 min intervals, steady-state flow was assumed and the steady-state infiltration rate was calculated based on the last four measurements. The time necessary to reach the steady state was around 1.5 h for each tension.
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PDF EN Jornal Brasileiro de Pneumologia 1 16 english

PDF EN Jornal Brasileiro de Pneumologia 1 16 english

Neuromuscular diseases affect alveolar air exchange and therefore cause chronic respiratory failure. The onset of respiratory failure can be acute, as in traumas, or progressive (slow or rapid), as in amyotrophic lateral sclerosis, muscular dystrophies, diseases of the myoneural junction, etc. Respiratory muscle impairment also affects cough efficiency and, according to the current knowledge regarding the type of treatment available in Brazil to these patients, it can be said that the high rates of morbidity and mortality in these individuals are more often related to the fact that they cough inefficiently rather than to the fact that they ventilate poorly. In this review, with the objective of presenting the options of devices available to support and substitute for natural ventilation in patients with neuromuscular diseases, we have compiled a brief history of the evolution of orthoses and prostheses used to aid respiration since the end of the 19 th century. In addition, we
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