scholarly journals Soil nitrification increases with elevated phosphorus or soil pH in an acidic mixed mesophytic deciduous forest

2020 ◽  
Vol 142 ◽  
pp. 107716 ◽  
Author(s):  
Jared L. DeForest ◽  
Rael K. Otuya
1975 ◽  
Vol 55 (1) ◽  
pp. 15-21 ◽  
Author(s):  
P. C. PANG ◽  
C. M. CHO ◽  
R. A. HEDLIN

Two soils, Keld silty clay loam (pH 5.4) and Wellwood clay loam (pH 6.6), were used to investigate the effects of modifying soil pH upon the nitrification of band-applied urea at 20 C. The pH of the Keld soil was adjusted to 6.5 and 7.3 with Ca (OH)2, whereas the Wellwood soil was adjusted to 5.6 with H2SO4. In addition, nitrification of nitrogen in a homogeneously mixed soil–urea suspension at 20 C was studied using the two soils mentioned and also Morton very fine sandy loam (pH 8.2). There were marked differences in the rate of oxidation of NH4 between the natural Keld and acidified Wellwood soils at comparable soil pH values. The oxidation was found to be very slow in the Keld soil at all pH values and no appreciable nitrite was formed. In the Wellwood soil, nitrification was more rapid and was accompanied by nitrite formation. However, the rate of oxidation was temporarily retarded by decreasing the pH of the Wellwood soil, but the oxidation of band-applied urea in the Keld soil remained unchanged with modified pH of 6.5 and 7.3. Increase in nitrification and nitrate accumulation occurred when the limed Keld soils (pH 7.3) was inoculated with Nitrosomonas europaea. Soil suspension studies confirmed that the difference in nitrifying capacity among the soils was related to the initial nitrifier numbers whose activities were affected by the initial soil pH.


2015 ◽  
Vol 10 (1) ◽  
Author(s):  
M. Sagova-Mareckova ◽  
L. Cermak ◽  
M. Omelka ◽  
M. Kyselkova ◽  
J. Kopecky

AbstractThe effect of environmental factors on bacterial and actinobacterial communities was assessed to predict microbial community structure in natural gradients. Bacterial and actinobacterial communities were studied at four sites differing in vegetation and water regime: creek sediment, wet meadow, dry meadow and deciduous forest located in a shallow valley. The vegetation structure was assessed by phytocoenological releves. T-RFLP and quantitative PCR were used to determine community composition and abundances. Significant relationships between bacterial community structure and selected soil traits at sites located relatively close to each other (within 200 m) were demonstrated. Both the quantity and structure of bacterial communities were significantly influenced by organic matter content, soil moisture and pH. Bacterial diversity was higher in summer, while that of actinobacteria increased in winter. The Simpson’s evenness E was significantly correlated with soil organic matter content. Soil pH had the greatest influence on bacterial community structure showing higher within-site variability in summer than in winter.


Author(s):  
N.A. Thomson

In a four year grazing trial with dairy cows the application of 5000 kg lime/ ha (applied in two applications of 2500 kg/ha in winter of the first two years) significantly increased annual pasture production in two of the four years and dairy production in one year. In three of the four years lime significantly increased pasture growth over summer/autumn with concurrent increases in milk production. In the last year of the trial lime had little effect on pasture growth but a relatively large increase in milkfat production resulted. A higher incidence of grass staggers was recorded on the limed farmlets in spring for each of the four years. In the second spring immediately following the second application of lime significant depressions in both pasture and plasma magnesium levels were recorded. By the third spring differences in plasma magnesium levels were negligible but small depressions in herbage magnesium resulting from lime continued to the end of the trial. Lime significantly raised soil pH, Ca and Mg levels but had no effect on either soil K or P. As pH levels of the unlimed paddocks were low (5.2-5.4) in each autumn and soil moisture levels were increased by liming, these factors may suggest possible causes for the seasonality of the pasture response to lime


Author(s):  
G.G. Cossens ◽  
M.F. Hawke

During the first 20 years of a Pinus radiata tree rotation, tree growth and pasture yield were assessed under a range of tree spacings at Invermay and Akatore, two coastal sites in Eastern Otago. Pasture yield in association with trees thinned to 100 stems per hectare (sph) was comparable to that from open pasture up to a tree age of 12 years. By the 19th year, however, pasture production declined to 63% of open pasture yield at Invermay and to 42% at Akatore. At 200 and 400 sph at Akatore, pasture yield was similar to that from open pasture at tree age 12 years but declined to 27% and 0% of open pasture yield respectively by year 20. At both Invermay and Akatore, the ryegrass and clover content of open pasture was relatively constant throughout the term of the trial. However, both the ryegrass and clover content of pasture beneath trees began to decline by tree age 12 years with a very rapid decline at Akatore in the number of pasture species at 200 sph by the 19th year. No pasture remained at 400 sph, after 19 years. Livestock carrying capacity with sheep on tree treatments at Invermay decreased from 100% of open pasture at year 6 to 60% by year 10. At Akatore, livestock carrying capacity averaged over the 20-year life of the trial was 4.1 stock units per hectare with a maximum of 8.1 stock units at a tree age of 8 years. Tree growth at both sites was similar, averaging between 1 and 1.1 m/year in height over 20 years, with trees at Invermay at 100 sph averaging 9% greater height and diameter growth than at Akatore. Increasing tree stocking from 100 to 200 to 400 sph at Akatore, resulted in increased tree height, but decreased diameter at breast height. A comparison of the East Otago trees with those in a similar trial at Tikitere (Rotorua) 900 km further north indicated that the southern trees were about 6 years later in their growth pattern by tree age 20 years. On both sites, soil pH tended to be lower in the presence of trees and was significantly lower than in open pasture by year 20. The results and comparisons with the Tikitere data suggest that, in an integrated agroforestry regime, there will be livestock grazing under the trees further into the tree rotation in Otago than in North Island sites. However, slower tree growth would result in a longer rotation time to harvest. Current recommendations to farmers are to plant trees on the less productive areas of the farm and adopt a tree stocking rate which fully utilises the site. Keywords: agroforestry, livestock, pasture, Pinus radiata, soil pH, tree stocking


2017 ◽  
Vol 28 (1-2) ◽  
pp. 28-35 ◽  
Author(s):  
B. A. Baranovski

Nowadays, bioecological characteristics of species are the basis for flora and vegetation studying on the different levels. Bioecological characteristics of species is required in process of flora studying on the different levels such as biotopes or phytocenoses, floras of particular areas (floras of ecologically homogeneous habitats), and floras of certain territories. Ramensky scale is the one of first detailed ecological scales on plant species ordination in relation to various environmental factors; it developed in 1938 (Ramensky, 1971). A little later (1941), Pogrebnyak’s scale of forest stands was proposed. Ellenberg’s system developed in 1950 (Ellenberg, 1979) and Tsyganov’s system (Tsyganov, 1975) are best known as the systems of ecological scales on vascular plant species; these systems represent of habitat detection by ecotopic ecomorphs of plant species (phytoindication). Basically, the system proposed by Alexander Lyutsianovich Belgard was the one of first system of plant species that identiified ectomorphs in relation to environmental factors. As early as 1950, Belgard developed the tabulated system of ecomorphs using the Latin ecomorphs abbreviation; he also used the terminology proposed in the late 19th century by Dekandol (1956) and Warming (1903), as well as terminology of other authors. The article analyzes the features of Belgard’s system of ecomorphs on vascular plants. It has certain significance and advantages over other systems of ecomorphs. The use of abbreviated Latin names of ecomorphs in tabular form enables the use shortened form of ones. In the working scheme of Belgard’s system of ecomorphs relation of species to environmental factors are represented in the abbreviated Latin alphabetic version (Belgard, 1950). Combined into table, the ecomorphic analysis of plant species within association (ecological certification of species), biotope or area site (water area) gives an explicit pattern on ecological structure of flora within surveyed community, biotope or landscape, and on environmental conditions. Development and application by Belgrard the cenomorphs as «species’ adaptation to phytocenosis as a whole» were completely new in the development of systems of ecomorphs and, in this connection, different coenomorphs were distinguished. Like any concept, the system of ecomorphs by Belgard has the possibility and necessity to be developed and added. Long-time researches and analysis of literature sources allow to propose a new coenomorph in the context of Belgard’s system of ecomorphs development: silvomargoant (species of forest margin, from the Latin words margo – edge, boundary (Dvoretsky, 1976), margo – margin, ad margins silvarum – along the deciduous forest margins). As an example of ecomorphic characterization of species according to the system of ecomorphs by Belgard (when the abbreviated Latin ecomorph names are used in tabular form and the proposed cenomorph is used), it was given the part of the table on vascular plants ecomorphs in the National Nature Park «Orelsky» (Baranovsky et al). The Belgard’s system of ecomorphs is particularly convenient and can be successfully applied to data processing in the ecological analysis of the flora on wide areas with significant species richness, and the proposed ecomorph will be another necessary element in the Belgard’s system of ecomorphs. 


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