The Relation of Soil Acidity to the Decomposition of Organic Residues 1

1933 ◽  
Vol 25 (6) ◽  
pp. 392-396 ◽  
Author(s):  
Charles Thom ◽  
N. R. Smith
Author(s):  
V. N. Suleimanova ◽  
N. Yu. Egorova

The object of our research was one of the most common orchids in the world – Cypripedium calceolus L. As a rare species, it is listed in the Red book of the Russian Federation (3 category of rarity) [8], the Kirov region (3 category of rarity) [9], as well as in the Red books of 59 regions of the Russian Federation [2]. Limiting factors in the Kirov region are the violation of habitats as a result of anthropogenic impacts – deforestation, recreation, collection for bouquets, digging, reducing the number of species. Studies on the study of C. calceolus in the Kirov region are isolated [10–12]. The purpose of this work is to identify phytocenotic parameters and environmental conditions of C. calceolus habitats within the southern taiga fragment of the range. Studies of ecological and cenotic conditions of C. calceolus habitats were conducted in southern taiga forest ecosystems within the Kirov region (Slobodskaya, Afanasyevsky districts) (See table 1) in the period from 2012 to 2019. The studied habitats of C. calceolus are confined to non-morally-boreal-small-grass and grass spruce forests (Melico nutantis-Piceetum abietis subass. typicum, Maianthemo-Piceetum subass. typicum var. typical) (See fig. 1), pine trees with fir and spruce of various grasses (Melico nutantis-Pinetum sylvestris var. Lathyrus vernus). The growth of C. calceolus on the technogenically disturbed substrate of an old spent limestone quarry overgrown with coniferous rocks and various grasses was also noted. All the studied biotopes are characterized by a large constancy of non-moral species with not significant coverage of mosses. The stand of spruce forest types is dominated by Picea abies, pine-Pinus sylvestris. Abies sibirica occurs as an impurity. The undergrowth layer has a diverse species composition: Sorbus aucuparia, Frangula alnus, Lonicera xylosteum, Yuniperus communis, Daphne mezereum. In this tier of most studied phytocenoses there is a Atragene sibirica. The grass-shrub layer is also very diverse, which determines the high specificity of these communities. In addition to species of boreal small grass (Maianthemum bifolium, Orthilia secunda, Luzula pilosa, Rubus saxatilis), the presence of non – morals is characteristic-Lathyrus vernus, Melica nutans, Stellaria holostea, Asarum europaeum. Moss-lichen layer is fragmentary (covering up to 45 %), Pleurozium schreberi and Hylocomium splendens act as sodominants. Phyto-indication of the studied C. calceolus habitats according to ten ecological scales of D. N. Tsyganov (See table 2, Fig. 2) showed that in relation to the complex of all environmental factors, the studied species is mesovalent (MV) (It total = 0.54) and has an average level of lability in relation to the studied environmental factors. In relation to the complex of all environmental factors, C. calceolus is a mesobiont species. On a scale of soil acidity, the species is semistarvation at termokhimicheskie and apolitically scale and dial illumination-shading – metavalent on the scale of the wealth of the soil nitrogen – hemimillennial at createmotions scale and the scale of continentality of the climate avivamento. Only on the scale of soil moisture and the scale of soil salt regime, C. calceolus is stenovalent, which indicates a very limited range of possible habitats for this factor. The species, in the studied habitats, realizes from 4.61 to 23.84 % of its potential according to the studied factors. For C. calceolus, the results obtained allow us to extend the scale of soil acidity by 0.75 degrees to the right. According to the other scales, the values of the ecological space of the studied CP are placed in the ranges given by D. N. Tsyganov for this type Edaphic conditions of C. calceolus on the scale of soil moisture correspond to regimes from dry-saline to wet-forest-saline; on the factor of soil salt regime-poor soils; soil acidity – acidic-slightly acidic soils; soil richness in nitrogen – nitrogen – poor soils; moisture variability-soils with relatively stable and poorly variable moisture.


1997 ◽  
Vol 62 ◽  
Author(s):  
A. De Schrijver ◽  
L. Nachtergale ◽  
L. De Temmerman ◽  
J. M.F. Frechilla ◽  
S. Mussche ◽  
...  

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2019 ◽  
Vol 286 (1894) ◽  
pp. 20182347 ◽  
Author(s):  
Lucy J. E. Cramp ◽  
Jonathan Ethier ◽  
Dushka Urem-Kotsou ◽  
Clive Bonsall ◽  
Dušan Borić ◽  
...  

The spread of early farming across Europe from its origins in Southwest Asia was a culturally transformative process which took place over millennia. Within regions, the pace of the transition was probably related to the particular climatic and environmental conditions encountered, as well as the nature of localized hunter–gatherer and farmer interactions. The establishment of farming in the interior of the Balkans represents the first movement of Southwest Asian livestock beyond their natural climatic range, and widespread evidence now exists for early pottery being used extensively for dairying. However, pottery lipid residues from sites in the Iron Gates region of the Danube in the northern Balkans show that here, Neolithic pottery was being used predominantly for processing aquatic resources. This stands out not only within the surrounding region but also contrasts markedly with Neolithic pottery use across wider Europe. These findings provide evidence for the strategic diversity within the wider cultural and economic practices during the Neolithic, with this exceptional environmental and cultural setting offering alternative opportunities despite the dominance of farming in the wider region.


1977 ◽  
Vol 57 (2) ◽  
pp. 197-203 ◽  
Author(s):  
W. A. RICE ◽  
D. C. PENNEY ◽  
M. NYBORG

The effects of soil acidity on nitrogen fixation by alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) were investigated in field experiments at 28 locations, and in greenhouse experiments using soils from these locations. The pH of the soils (limed and unlimed) varied from 4.5 to 7.2. Rhizobia populations in the soil, nodulation, and relative forage yields (yield without N/yield with N) were measured in both the field and greenhouse experiments. Rhizobium meliloti numbers, nodulation scores, and relative yields of alfalfa decreased sharply as the pH of the soils decreased below 6.0. For soils with pH 6.0 or greater, there was very little effect of pH on any of the above factors for alfalfa. Soil pH in the range studied had no effect on nodulation scores and relative yields of red clover. However, R. trifolii numbers were reduced when the pH of the soil was less than 4.9. These results demonstrate that hydrogen ion concentration is an important factor limiting alfalfa growth on acid soils of Alberta and northeastern British Columbia, but it is less important for red clover. This supports the continued use of measurements of soil pH, as well as plant-available Al and Mn for predicting crop response to lime.


CATENA ◽  
2021 ◽  
Vol 198 ◽  
pp. 105021
Author(s):  
Mauro De Feudis ◽  
Gloria Falsone ◽  
Livia Vittori Antisari

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 248
Author(s):  
Tanabhat-Sakorn Sukitprapanon ◽  
Metawee Jantamenchai ◽  
Duangsamorn Tulaphitak ◽  
Nattaporn Prakongkep ◽  
Robert John Gilkes ◽  
...  

Understanding phosphorus (P) dynamics in tropical sandy soil treated with organic residues of contrasting quality is crucial for P management using organic amendments. This research determined P fractions in a tropical sandy soil under the application of organic residues of different quality, including groundnut stover (GN), tamarind leaf litter (TM), dipterocarp leaf litter (DP), and rice straw (RS). The organic residues were applied at the rate of 10 t DM ha−1 year−1. The P fractions were examined by a sequential extraction procedure. Organic residue application, regardless of residue quality, resulted in P accumulation in soils. For unamended soil, 55% of total P was mainly associated with Al (hydr)oxides. Organic residue application, regardless of residue quality, diminished the NH4F-extractable P (Al-P) fraction, but it had a nonsignificant effect on NaOH-extractable P (Fe-P). The majority of Al-P and Fe-P fractions were associated with crystalline Al and Fe (hydr)oxides. NH4Cl-extractable P (labile P), NaHCO3-extractable P (exchangeable P and mineralizable organic P), HCl-extractable P (Ca-P), and residual P fractions in soil were significantly increased as a result of the incorporation of organic residues. The application of organic residues, particularly those high in ash alkalinity, increase soil pH, labile P, and Ca-P fractions. In contrast, applications of residues high in lignin and polyphenols increase residual P fraction, which is associated with organo-mineral complexes and clay mineral kaolinite.


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