Effects of phosphate fertilizer applications on microorganisms in pastoral soil

Soil Research ◽  
1993 ◽  
Vol 31 (3) ◽  
pp. 299 ◽  
Author(s):  
SU Sarathchandra ◽  
A Lee ◽  
KW Perrott ◽  
SSS Rajan ◽  
EHA Oliver ◽  
...  

Microbial and earthworm populations and some soil chemical characteristics were measured in soil samples collected from an existing fertilizer trial that had been in progress for 3 years. The samples were collected two weeks before and two weeks after the annual applications of single superphosphate (SSP) or North Carolina phosphate rock (NCPR). There were no significant long-term fertilizer effects on any of the characteristics measured but there were some significant changes between the two samplings. Total bacterial count (69 x 106 to 6 x 106 g-1 soil) and the fungal count (l3 x 105to 5.2 x 105 g-1 of soil) declined significantly in all treatments between the two samplings. This decline was significantly smaller for fungi in fertilized plots. There were significant increases in populations of gram negative bacteria (28 x 105 to 52 x 105 bacteria g-1 of soil) and phosphate rock (PR) dissolving bacteria (7 6 x 105 to l3 x 105 bacteria g-1 of soil) two weeks after fertilizer application. Populations of these bacteria did not change significantly in unfertilized plots. The water-extractable carbon declined significantly in unfertilized and SSP-treated plots but not in NCPR-treated plots. The levels of ammonium oxidizing bacteria, PR-dissolving fungi, fluorescent Pseudomonas spp. and microbial P were unaffected by fertilizer. Two groups of earthworms were examined once before the fertilizer application. There were no significant fertilizer effects on adult or juvenile populations of Lumbricus rubellus or Aporrectodea caliginosa.

1968 ◽  
Vol 48 (1) ◽  
pp. 75-84 ◽  
Author(s):  
T. Lawrence ◽  
D. H. Heinrichs

A study was conducted from 1947 to 1966 to determine the long-term effects of row spacings and applications of ammonium phosphate fertilizer (16–20–0) on the productivity and persistence of Russian wild ryegrass, Elymus junceus Fisch.The optimum row spacing for highest seed production was 0.9 m, whereas for highest forage production it was 0.6 m. The 280-kg/ha rate of fertilizer significantly increased the seed and forage yield over the 151-kg/ha rate, which in turn significantly increased the yield over the zero fertilizer treatment.Increases in precipitation in August and September increased the seed yield of Russian wild ryegrass the following year. Significant positive correlations were found between forage yields and precipitation during March, April, May, and the previous September for practically all treatments.Width of row increased with age of stand. During the 19-year period there was still bare ground between the grass rows seeded 0.9 and 1.2 m apart. These areas of bare ground were slightly narrower when fertilizer was used, indicating that fertilizer application tended to accelerate row-width development.Russian wild ryegrass was found to have excellent cold tolerance, drought tolerance and persistence. It survived through a long drought period and resisted invasion by weeds and volunteer grass seedlings after the third crop year.


Soil Research ◽  
1996 ◽  
Vol 34 (6) ◽  
pp. 985 ◽  
Author(s):  
V Manoharan ◽  
P Loganathan ◽  
RL Parfitt ◽  
RW Tillman

This study describes some of the effects of 8 years of annual application of 6 types of phosphatic fertilisers on the chemical composition and aluminium (Al) speciation in soil solution extracted from a soil under pasture. Soil samples at 2 depths, 0-30 and 30-75 mm, were collected at the end of 8 years. Soil solutions were extracted by centrifuging at 12 000 RCF and analysed for Al, Na, K, Ca, Mg, F, NO3, Cl, and SO4, as well as pH and ionic strength. Soil and soil solution pH were significantly increased at both depths by application of North Carolina phosphate rock (NCPR) compared with the control. In contrast, diammonium phosphate (DAP) significantly decreased the soil and solution pH. Single superphosphate (SSP) did not have any significant effect on soil or solution pH compared with the untreated control. The surface soil (0-30 mm) solution pH was on average 0.6 of a unit higher than the subsurface soil (30-75 mm) solution pH. Total monomeric Al concentration [Al], measured by the pyrocatecol violet (PCV; 4 min) method, ranged from 1.5 to 4.8 �M in the surface soil and 2.5 to 12.2 �M in the subsurface soil. The DAP and higher rates of SSP application resulted in a large increase in total and inorganic monomeric [Al] in the soil solution extracted from the subsurface soil. Total soluble [F] ranged from 2.7 to 23.5 �M and 3.2 to 25.6 �M in the surface and subsurface soils, respectively, and was significantly increased by the application of NCPR and by higher rates of SSP. The predominant forms of inorganic monomeric Al present in the soil solution were estimated to be the non-phytotoxic Al-F complexes, AlF2+, and AlF2+. There was a marked decrease in toxic Al species (Al3+, Al(OH)2+, Al(OH)2+) in soil solution following NCPR and SSP application. This was due primarily to complexation of Al with F derived from these fertilisers forming non-toxic AI-F complexes. The results suggest that the long-term application of reactive phosphate rock such as NCPR may contribute to amelioration of soil acidity and Al toxicity under legume-based pastures. In contrast ammonium-containing phosphate fertilisers such as DAP probably decrease soil pH and increase the formation of toxic Al species in the soil solution.


Author(s):  
ERLINA HASRIATI ◽  
HARU SETYO ANGGANI ◽  
MARIA PURBIATI ◽  
ENDANG WINIATI BACHTIAR

Objective: Inflammation is one of the most common complications observed when using orthodontic miniscrews. Chlorhexidine mouthwash can beused to prevent and reduce the degree of inflammation, but long-term use of this solution may lead to some side effects. This study sought to evaluatethe peri-miniscrew antibacterial effect of 1% chitosan, a biomaterial with antibacterial properties, relative to 0.2% chlorhexidine mouthwash.Methods: A randomized, double-blind clinical trial was conducted at the Dental Teaching Hospital and Oral Biology Research Laboratory at theUniversity of Indonesia from February to June 2019. Thirty subjects (25 females and five males) were randomly assigned to rinse with 1% chitosan(n=10), 0.2% chlorhexidine digluconate (n=10), and Aquadest (n=10) in addition to their usual oral hygiene procedure for 4 days. Peri-miniscrewclinical inflammation signs were recorded and peri-miniscrew plaque collected before and after 4 days of rinsing. The total bacterial and red-complexbacteria count in plaque samples were evaluated by a real-time polymerase chain reaction.Results: Chitosan and chlorhexidine showed antibacterial activity, reducing total bacterial count around orthodontic miniscrews (p<0.05). Theantibacterial activity of chitosan on total bacteria was not significantly different from that of chlorhexidine (p≥0.05). Regarding the antibacterialactivity of chitosan on red-complex bacteria, the best result seen was a 58% bacteria count reduction in Tannerella denticola.Conclusion: Chitosan has potential antibacterial activity and could be used in mouthwash to maintain peri-miniscrew hygiene.


Author(s):  
S.F. Ledgard ◽  
B.S. Thorrold ◽  
A.G. Sinclair ◽  
S.S.S. Rajan ◽  
D.C. Edmeades

Longlife' phosphatic fertiliser is manufactured in New Zealand by mixing reactive phosphate rock (RPR) with single superphosphate (SSP) when the SSP is at an ex-den stage. Commercially produced Longlife (70:30 SSP:RPR) was evaluated in 6 field mowing trials in the North Island over 3 or4 years. Also, a 5050 (SSP:RPR) Longlife-type product was examined in 5 field trials throughout New Zealand over 5 or 6 years. Longlife was compared against SSP and/or triple superphosphate (TSP) in all trials, and RPR treatments were included in 7 trials. In all trials with commercially produced Longlife, the pasture response to Longlife tended to be less than that to SSP or TSP in the first 2 years and was significantly different (P 6.0 and/or rainfall ~800 mm/year). Keywords field trials, Longlife, phosphate, reactive phosphate rock, superphosphate


2021 ◽  
Vol 17 (2) ◽  
pp. 455-461
Author(s):  
Jagdish Parshad ◽  
Dharam Bir Yadav ◽  
Satbir Singh Punia ◽  
Kuldeep Singh ◽  
Baljeet Singh

A long term experiment was conducted at CCS Haryana Agricultural University, Regional Research Station, Uchani (Karnal), India. Assessment of fix and rotational herbicides with and without green manure on the microbial population were studied in wheat crop during 2017-18. The treatments included fix/continuous herbicide (Clodinafop) and rotational herbicide (Sulfosulfuron) to control weeds along with weed free and weedy checks. Rhizosphere samples of wheat were collected from different plots of fixed and rotational herbicides treated soil to assess the total bacterial count, phosphate solubilizing microorganisms, actinobacteria, fungi and free-living diazotrophs. Weed free and weedy check served as check (control) for total microbial populations in the soil. Initially, herbicidal application showed negative effect on the soil microbes but retain the number later on as compared to weedy check under both conditions. But the effects of the herbicides on the micro flora in soil could be nullified through green manure.


2021 ◽  
Vol 309 ◽  
pp. 107285
Author(s):  
Mengyu Gao ◽  
Jinfeng Yang ◽  
Chunmei Liu ◽  
Bowen Gu ◽  
Meng Han ◽  
...  

Author(s):  
Hashmath Inayath Hussain ◽  
Naga Kasinadhuni ◽  
Tony Arioli

AbstractThis study investigated the effects of seaweed extract (SWE) made from the brown algae Durvillaea potatorum and Ascophyllum nodosum on plants and soil. The application of SWE to soil growing tomato plants showed dual effects. SWE comprehensively improved tomato plant growth (flower clusters, flower number, fruit number, root length, root and shoot dry weight, SPAD) and increased plant productivity (yield and quality). Similarly, SWE application effected soil biology at the soil root zone by increasing total bacterial count and available soil nitrogen and impacting bacterial community diversity with an increase in certain bacterial families linked to soil health. A broader understanding of the effects of SWE on the plant-soil ecosystem may offer breakthrough approaches for sustainable food production.


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