Interaction of plant genotype and management in the persistence of a perennial grass exposed to grazing and soil fertility stresses

2015 ◽  
Vol 71 (4) ◽  
pp. 540-558 ◽  
Author(s):  
R. A. Culvenor ◽  
R. J. Simpson
Keyword(s):  
Soil Fertility ◽  
Perennial Grass ◽  
Plant Genotype

Correlations between environmental factors, the biomass of exotic annual grasses and the frequency of native perennial grasses

2006 ◽  
Vol 54 (7) ◽  
pp. 655 ◽  
Author(s):  
Tanja I. Lenz ◽  
José M. Facelli
Keyword(s):  
Species Composition ◽  
Soil Fertility ◽  
Perennial Grass ◽  
Perennial Grasses ◽  
Annual Rainfall ◽  
Grass Species ◽  
Soil Factors ◽  
Annual Grasses ◽  
Exotic Annual Grasses ◽  
Native Perennial Grass

The species composition of temperate grasslands in the mid-north of South Australia has been radically altered from a system dominated by native perennial grasses to a system dominated by Mediterranean annual grasses. This study investigated the importance of chemical and physical soil characteristics, topographical features and climatic variables on the abundance of native and exotic grass species in nine ungrazed grasslands. Overall, climatic and other abiotic factors were highly variable. In addition, past management practices and original species composition are generally unknown, leading to further unexplained variation in the data. On a large spatial scale (among sites), the abundance of exotic annual grasses was positively correlated with mean annual rainfall, and on any scale, with finer soil textures and higher soil organic carbon levels. The most abundant annual grass, Avena barbata (Pott ex Link), was generally associated with soil factors denoting higher soil fertility. The abundance of native perennial grass species was not correlated with any environmental variables at any scale. The various native perennial grass species did not show clear associations with soil factors, although they tended to be associated with factors denoting lower soil fertility. However, at small spatial scales (within some sites) and among sites, the abundances of exotic annual and native perennial grasses were strongly negatively correlated. The results suggest that at the present time, rainfall and soil properties are important variables determining the abundance of annual grasses. The driving variables for the abundance of perennial grasses are less clear. They may be controlled by other factors or extreme rainfall events, which were not surveyed. In addition, they are likely to be controlled by competitive interactions with the annual grasses.

Restoring soil fertility of degraded hardsetting soils in semi-arid areas with different pastures

2001 ◽  
Vol 41 (4) ◽  
pp. 507 ◽  
Author(s):  
K. Y. Chan ◽  
A. M. Bowman ◽  
W. Smith ◽  
R. Ashley
Keyword(s):  
Organic Carbon ◽  
Soil Fertility ◽  
Perennial Grass ◽  
Chemical Properties ◽  
Cropping System ◽  
Annual Grass ◽  
Stubble Retention ◽  
South Wales ◽  
Perennial Legume ◽  
Semi Arid

To evaluate the effectiveness of a pasture phase in restoring soil fertility, changes in concentration of organic carbon, physical and chemical properties of degraded hardsetting red soils (Alfisols) were assessed at 3 sites in the semi-arid central western region of New South Wales 3–4 years after conversion to different pastures. The pasture species included an annual grass, ryegrass (Lolium rigidum cv. Wimmera), an annual legume, barrel medic (Medicago truncatulata cv. Sephi) as well as a perennial grass, Consol lovegrass (Eragrostis curvula), and a perennial legume, lucerne (Medicago sativa cv. Trifecta). Significant differences in concentration of organic carbon in soils were found only in the top 0–2.5 cm even after 3–4 years under perennial pastures. The concentration of organic carbon under annual grass pasture did not differ from that in the fallow. Corresponding to the organic carbon concentrations, significant changes in water-stable aggregation (detectable to 20 cm depth) and hydraulic properties (up to a 5-fold difference in sorptivity, namely 0.29 mm/h 0.5 under fallow to 1.42 mm/h 0.5 under lucerne) were observed under perennial pastures when compared with that of the fallow. Of the 2 perennial pastures, Consol lovegrass and lucerne were both effective in promoting soil friability as well as water-stable aggregation. However, lucerne increased mineralisable nitrogen more than Consol lovegrass (by up to 4.6 times more, equivalent to 11.6 mg/kg in the 0–10-cm layer). Our results highlight the potential benefits of perennial pastures in maintaining the quality of the fragile hardsetting soils in the low rainfall areas. However, due to the slow rate and the restricted depth of improvement (0–2.5 cm), apart from incorporation of a pasture phase in the cropping system, soil management that maintains soil organic matter level and soil structure, namely reduced tillage and stubble retention, should also be adopted. These findings should be relevant to the management of the hardsetting soils that occupy 12% of the land area of Australia, particularly those in the lower rainfall areas.

scholarly journals Effect of Epichloë gansuensis endophyte on rhizosphere bacterial communities and nutrient concentrations and ratios in the perennial grass species Achnatherum inebrians during three growth seasons

2020 ◽  
Vol 71 (12) ◽  
pp. 1050
Author(s):  
Wenpeng Hou ◽  
Chao Xia ◽  
Michael J. Christensen ◽  
Jianfeng Wang ◽  
Xiuzhang Li ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Soil Fertility ◽  
Host Plants ◽  
Perennial Grass ◽  
Rhizosphere Bacteria ◽  
Achnatherum Inebrians ◽  
Grass Endophyte ◽  
Different Seasons ◽  
Rhizosphere Bacterial Community ◽  
Grass Growth

Achnatherum inebrians is an invasive perennial grass widespread in natural grasslands of north-west China and plays an important role in grassland ecological restoration. The presence of the seed-borne endophytic fungus Epichloë gansuensis in A. inebrians promotes grass growth, increases resistance to abiotic stress, and affects the rhizosphere microbial community of host plants. However, the relationships among E. gansuensis, rhizosphere bacteria and plant contents of carbon (C), nitrogen (N), phosphorus (P) and potassium (K) during different growing seasons are not clear. We examined changes in the rhizosphere bacterial community and in nutrient contents and ratios in A. inebrians with (E+) and without (E−) E. gansuensis in May, August and December. The Shannon diversity index was higher for rhizosphere bacteria of E+ than E− plants in the three different seasons. Leaf C, N and P contents and root P and K contents were higher in E+ than E− plants in May, and leaf K and root C were higher in E+ than E− plants in August. Leaf C:N ratios were lower in E+ than E− plants in December, and leaf C:K ratios were lower in E+ than E− plants in August and December. In addition, our results indicate significant interactions among rhizosphere bacteria, C, N, P and K contents, and endophyte treatment in three different seasons. In conclusion, E. gansuensis enhanced the C, N, P and K contents of host plants, and affected nutrient ratios of A. inebrians probably by increasing rhizosphere bacterial diversity and altering rhizosphere bacterial community structure. This study provides new findings on the ecological function of the endophyte E. gansuensis, including its potential role in enhancing soil fertility. The improvements in soil fertility were utilised in extrapolating to forage grass–endophyte associations.

K-MEANS CLUSTERING ALGORITHM BASED CLASSIFICATION OF SOIL FERTILITY IN NORTH WEST NIGERIA

2020 ◽  
Vol 4 (2) ◽  
pp. 780-787
Author(s):  
Ibrahim Hassan Hayatu ◽  
Abdullahi Mohammed ◽  
Barroon Ahmad Isma’eel ◽  
Sahabi Yusuf Ali
Keyword(s):  
Soil Fertility ◽  
Crop Yield ◽  
Clustering Algorithm ◽  
Soil Samples ◽  
North West ◽  
R Programming ◽  
Available Information ◽  
Northwest Region ◽  
The Relationship

Soil fertility determines a plant's development process that guarantees food sufficiency and the security of lives and properties through bumper harvests. The fertility of soil varies according to regions, thereby determining the type of crops to be planted. However, there is no repository or any source of information about the fertility of the soil in any region in Nigeria especially the Northwest of the country. The only available information is soil samples with their attributes which gives little or no information to the average farmer. This has affected crop yield in all the regions, more particularly the Northwest region, thus resulting in lower food production.  Therefore, this study is aimed at classifying soil data based on their fertility in the Northwest region of Nigeria using R programming. Data were obtained from the department of soil science from Ahmadu Bello University, Zaria. The data contain 400 soil samples containing 13 attributes. The relationship between soil attributes was observed based on the data. K-means clustering algorithm was employed in analyzing soil fertility clusters. Four clusters were identified with cluster 1 having the highest fertility, followed by 2 and the fertility decreases with an increasing number of clusters. The identification of the most fertile clusters will guide farmers on where best to concentrate on when planting their crops in order to improve productivity and crop yield.

COUNTING TOTAL BACTERIA IN LAND ORGANIC WASTE HOUSEHOLD AND LAND INORGANIC WITH TOTAL PLATE COUNT METHOD (TPC)

2017 ◽  
Vol 4 (2) ◽  
pp. 87-91
Author(s):  
Ekamaida Ekamaida
Keyword(s):  
Soil Fertility ◽  
Bacterial Population ◽  
Organic Soil ◽  
Biological Properties ◽  
Plate Count ◽  
Bacterial Populations ◽  
Fertility Data ◽  
Plate Count Method ◽  
The Mean ◽  
Total Bacteria

The soil fertility aspect is characterized by the good biological properties of the soil. One important element of the soil biological properties is the bacterial population present in it. This research was conducted in the laboratory of Microbiology University of Malikussaleh in the May until June 2016. This study aims to determine the number of bacterial populations in soil organic and inorganic so that can be used as an indicator to know the level of soil fertility. Data analysis was done by T-Test that is by comparing the mean of observation parameter to each soil sample. The sampling method used is a composite method, which combines 9 of soil samples taken from 9 sample points on the same plot diagonally both on organic soil and inorganic soil. The results showed the highest bacterial population was found in total organic soil cfu 180500000 and total inorganic soil cfu 62.500.000

Strategies for Soil Fertility Improvement of Arable Land in China

2018 ◽  
Vol 20 (5) ◽  
pp. 84
Author(s):  
Yingjie Hu ◽  
Xiangbin Kong ◽  
Yuzhen Zhang
Keyword(s):  
Soil Fertility ◽  
Arable Land ◽  
Soil Fertility Improvement
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