Variation in the Relative Distribution of Amino Sugars with Depth in Some Soil Profiles

1968 ◽  
Vol 32 (4) ◽  
pp. 598-600 ◽  
Author(s):  
F. J. Stevenson ◽  
O. C. Braids
2020 ◽  
Vol 143 ◽  
pp. 107762 ◽  
Author(s):  
Xiangyin Ni ◽  
Shu Liao ◽  
Siyi Tan ◽  
Dingyi Wang ◽  
Yan Peng ◽  
...  

2015 ◽  
Vol 2 (2) ◽  
pp. 148-158
Author(s):  
Surianto

Spodosol soil of Typic Placorthod sub-group of East Barito District is one of the problem soils with the presence of hardpan layer, low fertility, low water holding capacity, acid reaction and it is not suitable for oil palm cultivation without any properly specific management of land preparation and implemented best agronomic practices. A study was carried out to evaluate the soil characteristic of a big hole (A profile) and no big hole (B profile) system and comparative oil palm productivity among two planting systems. This study was conducted in Spodosol soil at oil palm plantation (coordinate X = 0281843 and Y = 9764116), East Barito District, Central Kalimantan Province on February 2014, by surveying of placic and ortstein depth and observing soil texture and chemical properties of 2 (two) oil palm's soil profiles that have been planted in five years. Big hole system of commercial oil palm field planting on the Spodosol soil area was designed for the specific purpose of minimizing the potential of a negative effect of shallow effective planting depth for oil palms growing due to the hardpan layer (placic and ortstein) presence as deep as 0.25 - 0.50 m. The big hole system is a planting hole type which was vertical-sided with 2.00 m x 1.50 m on top and bottom side and 3.00 m depth meanwhile the 2:1 drain was vertical-sided also with 1.50 m depth and 300 m length. Oil palm production was recorded from the year 2012 up to 2014. Results indicated that the fractions both big hole profile (A profile) and no big hole profile (B profile) were dominated by sands ranged from 60% to 92% and the highest sands content of non-big hole soil profile were found in A and E horizons (92%). Better distribution of sand and clay fractions content in between layers of big hole soil profiles of A profile sample is more uniform compared to the B profile sample. The mechanical holing and material mixing of soil materials of A soil profile among the upper and lower horizons i.e. A, E, B and C horizons before planting that resulted a better distribution of both soil texture (sands and clay) and chemical properties such as acidity value (pH), C-organic, N, C/N ratio, CEC, P-available and Exchangeable Bases. Investigation showed that exchangeable cations (Ca, Mg, K), were very low in soil layers (A profile) and horizons (B profile) investigated. The low exchangeable cations due to highly leached of bases to the lower layers and horizons. Besides, the palm which was planted on the big hole system showed good adaptation and response positively by growing well of tertiary and quaternary roots that the roots were penetrable into deeper rooting zone as much as >1.00 m depth. The roots can grow well and penetrate much deeper in A profile compared to the undisturbed hardpan layer (B profile). The FFB (fresh fruit bunches) production of the non-big hole block was higher than the big hole block for the first three years of production. This might be due to the high variation of monthly rainfall in-between years of observation from 2009 to 2014. Therefore, the hardness of placic and ortstein as unpenetrable agents by roots and water to prevent water loss and retain the water in the rhizosphere especially in the drier weather. In the high rainfall condition, the 2:1 drain to prevent water saturation in the oil palm rhizosphere by moving some water into the drain. Meanwhile, the disturbed soil horizon (big hole area) was drier than un disturbance immediately due to water removal to deeper layers. We concluded that both big hole and 2:1 drain are a suitable technology for Spodosol soil land especially in preparing palms planting to minimize the negative effect of the hardpan layer for oil palm growth.


1978 ◽  
Vol 88 (2) ◽  
pp. 298-305 ◽  
Author(s):  
Peter Laurberg

ABSTRACT Thyroglobulin fractions rich and poor in new thyroglobulin were separated by means of DEAE-cellulose chromatography of dog thyroid extracts and by zonal ultracentrifugation in a sucrose gradient of guinea pig thyroid extract incubated at low temperature. The distribution of thyroxine, triiodothyronine and 3,3′,5′-(reverse)-triiodothyronine in hydrolysates of the different fractions was estimated by radioimmunoassays. Following DEAE-cellulose chromatography there was a small but statistically significant increase in the T4/T3 ratio in thyroglobulin fractions eluted at high ionic strength - that is fractions relatively rich in stable iodine but poor in fresh thyroglobulin. There were no differences in the T4/rT3 ratios between the different fractions. The ratios between iodothyronines were almost identical in the various thyroglobulin fractions following zonal ultracentrifugation in a sucrose gradient of cold treated guinea pig thyroid extract. These findings lend no support to the possibility that a relatively high content of triiodothyronines in freshly synthesized thyroglobulin modulates the thyroid secretion towards a preferential secretion of triiodothyronine and 3,3′,5′-(reverse)-triiodothyronine at the expense of the secretion of thyroxine.


2012 ◽  
Vol 63 (4) ◽  
pp. 41-45 ◽  
Author(s):  
Iwona Makuch

Abstract In order to determine the influence of intensive horticulture on the amount of lead and its fraction contents, there were selected soil profiles from following objects to be researched: house gardens and allotment gardens from town areas and arable field on the outskirts of the town. It has not been determined that there is any influence of manner usage on total lead content as well as its distribution in soil profiles. The fractionation composition has created the following series: fraction IV > fraction III > fraction II > fraction I. The manner of usage has influenced the content and distribution the III fraction of lead connected with organic matter. Humus horizons of garden soils is characterized as the highest in its content.


2020 ◽  
Vol 48 (1) ◽  
pp. 62-72
Author(s):  
E. A. Ershova

Сalanoid copepods of the genus Pseudocalanus play an important role in the plankton communities of the Arctic and boreal seas, often dominating in numbers and constituting a significant proportion of the biomass of zooplankton. Despite their high presence and significance in the shelf plankton communities, species-specific studies of the biology of these are significantly hampered by extremely small morphological differences between them, especially at the juvenile stages, at which they are virtually indistinguishable. In this paper, we describe a new, routine and low-cost molecular method for identifying all Pseudocalanus species found in the Atlantic sector of the Arctic: the Arctic P. acuspes, P. minutus and the boreal P. moultoni and P. elongatus, and apply it to describe the relative distribution of these species in four locations of the Arctic and sub-Arctic. With this method, species-specific polymerase chain reaction (ssPCR), mass identification of individuals of any developmental stage, including nauplii, is possible. This method can serve as an excellent tool for studying the species-specific biology of this group, describing their life cycles, as well as monitoring changes in Arctic marine ecosystems under the influence of changing climate.


1976 ◽  
Vol 5 (1) ◽  
pp. 9-16
Author(s):  
Donald F. Post ◽  
Kenneth A. Barbarick ◽  
James L. Ahlrichs
Keyword(s):  

1975 ◽  
Vol 39 (6) ◽  
pp. 1220-1223
Author(s):  
K. M. Holtzclaw ◽  
J. M. Rible ◽  
P. F. Pratt
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document