EFFECT OF PLANT ROOTS ON CHEMICAL AND BIOCHEMICAL PROPERTIES OF SURROUNDING DISCRETE SOIL ZONES

1988 ◽  
Vol 68 (2) ◽  
pp. 233-242 ◽  
Author(s):  
J. F. DORMAAR

The chemical and biochemical properties within and immediately adjacent to the root zone of two grass species were studied over a 5-wk period. The experiment utilized a simple container comprising five sandwiched compartments giving a center or "rhizosphere" zone, two intermediate zones, and two outer zones. Soil samples were taken from an Orthic Brown, Dark Brown, and Black Chernozemic Ah horizon and from the Orthic Dark Brown Chernozemic Ap horizons of the unfertilized part of a continuous wheat field and the fallow field of a wheat-fallow rotation, both under cultivation for 70 yr. The two grasses were blue grama (Bouteloua gracilis (H.B.K.) Lag.) and rye (Secale céréale L. 'Frontier'). High root densities were achieved by the end of the study, especially with the blue grama. Changes in pH over time were slight but consistent; they decreased in the Black Chernozemic soil and increased in the other soils. A redistribution of labile phosphorus was caused by the presence of the plant roots. The Orthic Dark Brown Ah and Ap horizon soils reacted differently to the conditions of the study. Monosaccharides always increased in the rhizosphere zone and generally decreased in the zone adjacent to the rhizosphere zone in the case of rye and in the outside zone in the case of blue grama. The ratio galactose + mannose/arabinose + xylose always increased towards the outer zone. Although the presence of roots influenced the measured chemical properties of the soil surrounding them, there were no overall common trends. The results, even in this simplified system, demonstrated complex and interrelated effects (P < 0.01) of soil type, plant species, and time on the biochemical dynamics in and near the rhizosphere. The properties of rhizosphere soil are system specific. To interpret the processes within the system, detailed knowledge of the soil organic matter, the physiology of the species root, and the effect on each other is obligatory. Key words: Rhizosphere, Chernozemic Ah/Ap horizons, blue grama, rye, monosaccharides

1968 ◽  
Vol 48 (2) ◽  
pp. 119-127 ◽  
Author(s):  
S. Smoliak ◽  
A. Johnston

Six native grass species, Bouteloua gracilis, Stipa comata, Koeleria cristata, Festuca scabrella, Andropogon scoparius, and Danthonia parryi, and six introduced grass species, Elymus junceus, Bromus inermis, Agropyron cristatum, Agropyron tricophorum, Festuca rubra, and Dactylis glomerata, were germinated and grown for 90 days at root-zone temperatures of 7, 13, 18, and 27 °C. In general, the introduced species were superior to the native species in percentage germination and speed of germination and germinated, emerged and grew more readily at lower root-zone temperatures. Introduced species produced about 10 times as much weight of leaf and about eight times as much weight of root as did the native species at comparable growth stages. The chances of establishment and successful early growth of seeded stands appeared to be better with introduced grass species than with native grass species.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Pedro Jurado-Guerra ◽  
Miguel Luna-Luna ◽  
Ernesto Flores-Ancira ◽  
Ruben Saucedo-Teran

Single application of biosolids increases forage production on semiarid grasslands. Residual effects of biosolids on forage production have been scarcely measured in semiarid grasslands. The objective was to evaluate the residual effects of biosolids application on forage production of blue grama (Bouteloua gracilis(Willd. ex Kunth) Lag. ex Griffiths) and other grasses at a semiarid grassland in Jalisco, Mexico. The study was performed at shortgrass prairie in northeast Jalisco. Field plots were selected to include blue grama plants before rainy season in 2002. Aerobic biosolids were applied at 0 (control), 15, 30, 45, 60, 75, or 90 dry Mg ha−1under a completely random design with five replications. Forage production was estimated by clipping at the end of the growing season during five years. Data analysis was performed with linear mixed model and repeated measures. Forage production was influenced by a rate × year × species interaction (P=0.0001). Blue grama forage production increased with increasing biosolids rates during all years, with the magnitude of this response varying among years. Forage production of other grass species slightly decreased with biosolids application. Single biosolids application had a residual effect on forage production throughout five years in semiarid grasslands.


PLoS ONE ◽  
2015 ◽  
Vol 10 (12) ◽  
pp. e0144115 ◽  
Author(s):  
Guopeng Liang ◽  
Albert A. Houssou ◽  
Huijun Wu ◽  
Dianxiong Cai ◽  
Xueping Wu ◽  
...  

2004 ◽  
Vol 94 (5) ◽  
pp. 433-439 ◽  
Author(s):  
S.N. Johnson ◽  
P.J. Gregory ◽  
P.J. Murray ◽  
X Zhang ◽  
I.M. Young

AbstractThis study investigated the ability of neonatal larvae of the root-feeding weevil, Sitona lepidus Gyllenhal, to locate white clover Trifolium repens L. (Fabaceae) roots growing in soil and to distinguish them from the roots of other species of clover and a co-occurring grass species. Choice experiments used a combination of invasive techniques and the novel technique of high resolution X-ray microtomography to non-invasively track larval movement in the soil towards plant roots. Burrowing distances towards roots of different plant species were also examined. Newly hatched S. lepidus recognized T. repens roots and moved preferentially towards them when given a choice of roots of subterranean clover, Trifolium subterraneum L. (Fabaceae), strawberry clover Trifolium fragiferum L. (Fabaceae), or perennial ryegrass Lolium perenneL. (Poaceae). Larvae recognized T. repens roots, whether released in groups of five or singly, when released 25 mm (meso-scale recognition) or 60 mm (macro-scale recognition) away from plant roots. There was no statistically significant difference in movement rates of larvae.


2015 ◽  
Vol 2 (3) ◽  
pp. 395-410 ◽  
Author(s):  
Shah Md Yusuf Ali ◽  
Md Ahiduzzaman ◽  
Sharmin Akhter ◽  
M Abdul Matin Biswas ◽  
Nafis Iqbal ◽  
...  

Pineapple is considered as one of the most wanted tropical fruits and it is widely taken for fresh consumption as well as their flesh and juice are used for preparation of different product in Agro-processing industries. For such industrial processes, it is important to know the information of characteristics changes of pineapple during day after storage. Four varieties of pineapple were collected from different areas of Bangladesh named Honey Queen (H.Q), Giant Kew (G.K), Asshini and Ghorasal. Some Physico-chemical properties (weight loss, moisture content, ash and edible portion, pH, TSS, titrable acidity (TA), total sugar, reducing sugar) biochemical properties (ascorbic acid) and sensorial attributes (color, odor, firmness, appearances, sweetness and overall acceptability) of pineapple juice were studied during day after storage. This study examined the Comparison of different varieties of pineapple fruit characteristics and sensory quality of the pineapple fruits during storage. It was shown that there was a significant changes between the storage periods in relation to different varieties of fruits. The firmness of pineapple fruits were in outside and inside to be 0.21 to 0.27 N/m2 and 0.06 to 0.10 N/m2, respectively. The pH values of different varieties were found to be in the range of 4.30 to 4.36. The highest and lowest sweetness index were estimated to be 36.30 and 22.15 for Honey Queen and Asshini respectively. The highest and lowest magnitude of sugar contents of four pineapple varieties were found to be in the range of 14.16 to 15.8 mg/100g.The average TSS values were found to be 15.12%, 12.33%, 13.14% and 12.95% for H.Q., G.K., Asshini and Ghorashal, respectively. The comparative study indicated the characteristics of different varieties of pineapple changes during after storage.Res. Agric., Livest. Fish.2(3): 395-410, December 2015


2014 ◽  
Vol 56 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Ewa Błońska ◽  
Jarosław Lasota

Abstract The aim of this study was to assess the possibility of using biological and biochemical parameters in the evaluation of forest soil quality and changes caused by land use. The study attempted to determine a relationship between the enzymatic activity of soil, the number of earthworms and soil physico-chemical properties. The study was carried out in central Poland in adjoining Forest Districts (Przedbórz and Smardzewice). In soil samples taken from 12 research plots, basic physico-chemical properties, enzyme activity (dehydrogenase, urease) and density and biomass of earthworms were examined. Enzyme activity showed a large diversity within the forest site types studied. The correlations between the activity of the enzymes studied and C/N ratio indicated considerable importance of these enzymes in metabolism of essential elements of organic matter of forest soils. Urease and dehydrogenase activity and earthworm number showed susceptibility to soil pH, which confirmed relationships between enzyme activity and abundance of earthworms and soil pH in H2O and KCl.


2012 ◽  
Vol 7 (3) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Zhanjie Xu ◽  
Peng Du ◽  
Peter Meiser ◽  
Claus Jacob

Proanthocyanidins represent a unique class of oligomeric and polymeric secondary metabolites found ubiquitously and in considerable amounts in plants and some algae. These substances exhibit a range of rather surprising physical and chemical properties which, once applied to living organisms, are translated into a multitude of biological activities. The latter include antioxidant properties, cancer chemoprevention, anti-inflammatory and anti-diabetic effects as well as some exceptional, yet highly interesting activities, such as anti-nutritional and antimicrobial activity. Despite the wide range of activities and possible medical/agricultural applications of proanthocyanidins, many questions still remain, including issues related to bioavailability, metabolism and the precise biochemical, extra- and intracellular targets and mode(s) of action of these highly potent materials. Among the various physical and chemical interactions of such substances, strong binding to proteins appears to form the basis of many of their biological activities. Once easy-to-use synthetic methods to produce appropriate quantities of pure proanthocyanidins are available, it will be possible to identify the prime biological targets of these oligomers, study oligomer-protein interactions in more detail and develop possible practical applications in medicine and agriculture.


1970 ◽  
Vol 19 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Mohammad Zabed Hossain ◽  
Mihir Lal Saha ◽  
Chaman Binta Aziz ◽  
Sirajul Hoque

This study examined the effect of deforestation on the soil properties (physico-chemical and bacterial) of the Sal (Shorea robusta Roxb. Ex Gaertn.) forests in Bangladesh. Physico-chemical properties and the bacterial colony counts of soil were studied by comparing a natural Sal forest site with deforested and planted with Menjium site, deforested and planted with Mahogoni site, as well as deforested but not planted but covered with profuse growth of Axonopus compressus grass species site. Moisture content was significantly lower in the deforested and planted with Menjium site and deforested and planted with Mahogoni site than the natural forest site and the deforested but not planted site. Total organic carbon, total nitrogen and available nitrogen contents were significantly lower in the natural forest site. Significantly higher number of bacterial colony and higher organic carbon and moisture contents were found in the deforested but not planted site indicating that both organic carbon and moisture content were important for microbial growth. The present study clearly showed that deforestation significantly altered the soil physico-chemical and bacterial communities of the Sal forests. It was also revealed that plantation with different exotic plants were found to be different in influencing soil properties. Key words: Bacterial colony; Deforestation effects; Sal forest; Soil physico-chemical properties DOI: http://dx.doi.org/10.3329/dujbs.v19i1.8945 DUJBS 2010; 19(1): 63-72


Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 773
Author(s):  
Sara Huerta ◽  
Víctor Fernández-García ◽  
Leonor Calvo ◽  
Elena Marcos

Recent changes in fire regimes, with more frequent, extensive, and severe fires, are modifying soil characteristics. The aim of this study was to evaluate the effect of burn severity on the resistance of some physical, chemical, and biochemical soil properties in three different forest ecosystems affected by a wildfire in the northwest of the Iberian Peninsula. We evaluated burn severity immediately after fire using the Composite Burn Index (CBI) in three different ecosystems: shrublands, heathlands, and oak forests. In the same field plots used to quantify CBI, we took a composite soil sample to analyse physical (mean weight diameter (MWD)), chemical (pH; total C; total organic C (TOC); total inorganic C (TIC); total N; available P; exchangeable cations Na+, K+, Mg2+, and Ca2+; and cation exchange capacity (CEC)), and biochemical (β-glucosidase, urease, and acid phosphatase enzyme activities) properties. The resistance index of each property was then calculated. Based on our results, the values of the soil chemical properties tended to increase immediately after fire. Among them, total C, TOC, and exchangeable Na+ showed higher resistance to change, with less variation concerning pre-fire status. The resistance of chemical properties was higher in the oak forest ecosystem. MWD decreased at high severity in all ecosystems, but soils in shrublands were more resistant. We found a high decrease in soil enzymatic activity with burn severity, with biochemical properties being the least resistant to change. Therefore, the enzymatic activity of soil could be a potential indicator of severity in forest ecosystems recently affected by wildfires.


1983 ◽  
Vol 36 (2) ◽  
pp. 232 ◽  
Author(s):  
E. M. White ◽  
F. R. Gartner ◽  
R. Butterfield

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