The production of mineral nitrogen by soil samples, contained in polyethylene bags, under field conditions and in the laboratory

1968 ◽  
Vol 29 (1) ◽  
pp. 170-183 ◽  
Author(s):  
D. A. van Schreven
Keyword(s):  
Soil Samples ◽  
Mineral Nitrogen ◽  
Field Conditions ◽  
Polyethylene Bags

Breakdown and Movement of 2,4-D in the Soil Under Field Conditions

Weed Science ◽  
1976 ◽  
Vol 24 (5) ◽  
pp. 461-466 ◽  
Author(s):  
R. G. Wilson ◽  
H. H. Cheng
Keyword(s):  
Triticum Aestivum ◽  
Acetic Acid ◽  
Soil Profile ◽  
Soil Surface ◽  
Application Rate ◽  
Soil Samples ◽  
Field Conditions ◽  
Herbicide Application ◽  
Eastern Washington ◽  
Dichlorophenoxy Acetic Acid

The fate of 2,4-D [(2,4-dichlorophenoxy)acetic acid] in the soil under winter wheat (Triticum aestivumL. ‘Nugaines’) and fallow cropping schemes was studied under the field conditions of eastern Washington in 1973 and 1974 using formulated dimethylamine salt and isooctyl ester of 2,4-D. Soil samples taken 1 hour after herbicide application showed that amine-treated plots retained considerably more applied 2,4-D than ester-treated plots. The rapidity of 2,4-D breakdown decreased gradually with time, and at the end of 6 months, an average of 0.04 ppm of 2,4-D remained in the sampled soil profile regardless of formulation, application rate, or cropping scheme. Loss of 2,4-D from the soil surface in runoff occurred when the plots were irrigated heavily one day after the herbicide application. The herbicide was also leached into the soil profile by both irrigation and natural precipitation. Herbicide concentrations in the sampled portion of the upper soil profile decreased during the summer and then increased slightly in the fall.

Broomrape (Orobanche cumana Wallr.) can Influence the Microbial Cenosis in Sunflower Rhizosphere

Helia ◽  
2019 ◽  
Vol 42 (71) ◽  
pp. 145-159
Author(s):  
V. A. Lyakh ◽  
N. I. Kostyuchenko ◽  
I. A. Shevchenko
Keyword(s):  
Species Composition ◽  
Infected Plant ◽  
Soil Samples ◽  
Mineral Nitrogen ◽  
Plant Residues ◽  
Acidic Ph ◽  
Microscopic Fungi ◽  
Orobanche Cumana ◽  
Agar Media ◽  
Number Of Bacteria

Abstract The bacterial and micromycete complexes in the rhizosphere of sunflower plants non-infected and infected with broomrape (Orobanche cumana Wallr.) have been compared. The investigations were carried out in the conditions of a stationary infectious field which was annually enriched with infected plant residues and broomrape seeds collected in different regions of Ukraine. Soil is leached, low-humic chernozem with acidic pH. The soil samples selected at the end of vegetation from the rhizosphere of healthy and infected with broomrape plants of sunflower breeding samples. The total number of bacteria found in the rhizosphere of sunflower plants infected by the parasite did not differ significantly from the control and was 11.7 and 12.1 million CFU / g of soil, respectively. The numbers of ammonifiers as well as bacterial microflora, using for its life mineral nitrogen, and pedotrophs and oligotrophs in the compared soil samples did not differ significantly, and generally corresponded to this type of soil. Although in general, both tested samples of soil were characterized by a low content of bacteria of the genus Azotobacter, the number of representatives of this genus in the rhizosphere of parasite-infected plants was somewhat less than in control (35 % and 21 %, respectively). However, unlike most bacteria, the number of micromycetes detected on Czapek-Dox and starch-ammonia agar media, in the rhizosphere of plants infected by broomrape almost twice exceeded the number of these microorganisms in the rhizosphere of healthy plants. Analysis of the generic and species composition of microscopic fungi showed that in the rhizosphere of sunflower plants infected by the parasite a very specific mycocenosis was formed that differ from a mycocenosis of healthy plants. This mycocenosis was characterized by a much smaller number of genera and species of micromycetes. At the same time for the structure of the fungal cenosis of diseased plants there was a characteristic increase in the proportion of toxin-forming fungi of the Aspergillus and Penicillium genera with active conidiogenesis. The obtained data testify not only to the differences in the microbial complexes in the rhizosphere of sunflower plants non-infected and infected by broomrape, but also indicate the direction of action of this parasite.

Comparative Persistence and Mobility of Pyridine and Phenoxy Herbicides in Soil

1989 ◽  
Vol 3 (1) ◽  
pp. 155-161 ◽  
Author(s):  
James R. Jotcham ◽  
David W. Smith ◽  
Gerald R. Stephenson
Keyword(s):  
Biological Activity ◽  
Thin Layer ◽  
Soil Samples ◽  
Biologically Active ◽  
Field Conditions ◽  
Growth Room ◽  
Phenoxy Herbicides

Bioassays with soybeans and lentils were used to compare the persistence of 2,4,5-T, triclopyr, and picloram in soil after applying 0.038, 0.38, and 3.8 kg ae/ha under field conditions. Soil samples were collected from 1 to 269 days after spraying and were kept frozen until growth room bioassays were conducted. Triclopyr was slightly less persistent than 2,4,5-T, but neither herbicide was biologically active during the next season. At least 90% of picloram disappeared within 7 months, but its biological activity was more persistent than that of either triclopyr or 2,4,5-T. Nine months after treatment, neither lentils nor soybeans could be grown in soil treated with picloram at 3.8 kg/ka. Triclopyr and 2,4-D had smiilar soil thin layer chromatographic mobilities in four different scils. Picloram was significantly more mobile than either triclopyr or 2,4,5-T, primarily due to its lower adsorption in the soils examined.

Leaching of Seven s-Triazines

Weed Science ◽  
1968 ◽  
Vol 16 (2) ◽  
pp. 117-120 ◽  
Author(s):  
E. G. Rodgers
Keyword(s):  
Sandy Soil ◽  
Avena Sativa ◽  
Soil Samples ◽  
Field Conditions ◽  
Soil Concentration ◽  
Treated Soil ◽  
Growing Period ◽  
Leaf Chlorosis

Leaching of seven s-triazines in Lakeland fine sandy soil under greenhouse and field conditions was demonstrated by use of oats (Avena sativa L., var Seminole) and cucumber (Cucumis sativis L., var. Palomar) for bioassay. Depth of leaching was determined by abnormalities of these species grown in soil samples from the surface of treated soil to a depth of 22 in in the field and to 36 in in columns. Symptoms of injury by the different materials were similar and included primarily leaf chlorosis of both species and bending and breaking of cucumber stems within 7 to 10 days after planting; plants that failed to survive usually died 12 to 14 days after planting. Leaching of 2-methoxy-4-ethylamino-6-isopropylamino-s-triazine (atratone) was greatest, followed in decreasing order by 2-chloro-4,6-bis(isopropylamino)-s-triazine (propazine), 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine), 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine), 2-chloro-4-diethylamino-6-isopropylamino-s-triazine (ipazine), 2-ethylamino-4-isopropylamino-6-methylmercapto-s-triazine (ametryne), and 2,4-bis(isopropylamino)-6-methylmercapto-s-triazine (prometryne). Oats did not significantly reduce the soil concentration of ametryne and prometryne during a growing period of 56 days.

The Azotobacter Test of Soil Fertility Applied to the Classical Fields at Rothamsted.

1932 ◽  
Vol 22 (4) ◽  
pp. 797-810 ◽  
Author(s):  
Jadwiga Ziemięcka
Keyword(s):  
Calcium Carbonate ◽  
Soil Fertility ◽  
Soil Samples ◽  
Mineral Nitrogen ◽  
Nitrogen Compounds ◽  
Phosphate Content ◽  
Plate Test ◽  
Classical Fields ◽  
Available Phosphate

Summary and abstract1. The kneaded plate (plaque moulée) method of detecting deficiency in lime and available phosphate was applied to seventy-nine soil samples taken from the classical Rothamsted arable plots, and the Azotobacter population from some of these samples was estimated by counts on silica jelly.2. The silica jelly counts showed that Azotobacter cells were very much reduced in number, or even absent in soil receiving 86 lb. per acre or more of mineral nitrogen. It is suggested that this is due to competition with other organisms whose growth is stimulated by added nitrogen compounds.3. The kneaded-plate test correctly indicaṫed whether phosphate had been applied in soils receiving little or no nitrogen manures.4. In those soils receiving 86 lb. or more of mineral nitrogen, the kneaded-plate test usually showed little or no Azotobacter growth even in the presence of phosphate and calcium carbonate. This failure was probably due to the paucity of Azotobacter cells originally present in such soil samples. In some cases the test was modified by inoculating the sample with a culture of Azotobacter and it then gave correct indications as to phosphate content.

scholarly journals Observations on the effect of organic materila upon aggregation and nitrate-nitrogen content of soil

1952 ◽  
Vol 24 (3) ◽  
pp. 127-134
Author(s):  
Armi Kaila ◽  
Pertti Kivinen
Keyword(s):  
Nitrogen Content ◽  
Soil Nitrogen ◽  
Nitrate Nitrogen ◽  
Soil Samples ◽  
Mineral Nitrogen ◽  
Aggregation State ◽  
Water Stable Aggregates ◽  
Mineral Soils ◽  
Simultaneous Immobilization ◽  
Properties Of Soil

In the experiments reported above the effect of organic material upon the aggregation of soil particles and the simultaneous immobilization of mineral nitrogen by microorganisms were studied. The relative amount of water-stable aggregates larger than 0.5 mm in diameter was considered to indicate the aggregation state of the soil samples. Probably, somewhat different results were obtained if the crumb formation had been determined by some other method, but it is not sure that these would have been more reliable. Since the incubation of soil samples were performed under aerobic conditions, and all the samples were mineral soils, it seemed justifiable to take the nitrate-nitrogen content of the soil samples to characterize the amount of mineral nitrogen in them. On the basis of the results the general conclusion may be drawn that the more favourable the conditions are for the development of an active and large microflora in the soil, the more intensively the crumb formation and the immobilization of nitrogen takes place, but also the destruction of aggregates begins the more rapidlv. This appeared to be true with regard to the indigenous fertility of soil as well as to the fertilization. Liming, however, did not improve the conditions in these experiment, probably due to the rather slight acidity of the soil samples used. Under otherwise similar conditions the larger amount of straw produced larger amount of aggregates, but the differences in the nitrate-nitrogen content of soil in the presence of various amounts of straw were neglibigle. Generally, the degree of immobilization of soil nitrogen seemed largely to depend on the properties of soil and on other environmental conditions, and nitrogen applications, theoretically enough for the needs of microorganisms that decomposed the straw, could not always prevent an intensive absorption of soil nitrogen. The crumb formation appeared to need mere energy-yielding material than the immobilization of nitrogen, or the destruction of crumbs occurred more rapidly than the nitrification of microbiologically bound nitrogen.

scholarly journals Characterizing rhizosphere microbiota of peanut (Arachis hypogaea L.) from pre-sowing to post-harvest of crop under field conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ankit T. Hinsu ◽  
Ketankumar J. Panchal ◽  
Ramesh J. Pandit ◽  
Prakash G. Koringa ◽  
Ramesh K. Kothari
Keyword(s):  
Developmental Stages ◽  
Hot Spot ◽  
Soil Samples ◽  
Field Conditions ◽  
Bulk Soil ◽  
Design Stage ◽  
Post Harvest ◽  
Arachis Hypogaea L ◽  
Crop Development ◽  
Plant Growth Promoting

AbstractThe rhizosphere, a narrow zone of soil near plant roots, is a hot spot for microbial activity. Rhizosphere microbiota directly or indirectly benefit plants by supplementing nutrients, producing beneficial chemicals, or suppressing pathogens. Plants attract and modulate bacteria within the rhizosphere by releasing exudates. Plants also tend to select the rhizosphere microbiota based on their needs; a phenomenon termed as “rhizosphere effect”. In this study, we characterized the rhizosphere microbiota of peanut plants across the crop development cycle from pre-sowing of seeds to post-harvest of crop under field conditions. The rhizosphere and bulk soil samples from different crop developmental stages were also compared. The composition of bulk soil microbiota resembled microbiota of pre-sowing and post-harvest soil and was markedly different from rhizosphere soil samples. Rhizosphere samples were enriched with multiple organisms mostly from the Proteobacteria, Firmicutes and Bacteroidota phyla. Differences in diversity were observed among the rhizosphere samples but not in bulk soil across different crop development stages. Pseudomonas_M indica was highly enriched during the germination of seeds. Furthermore, Plant Growth Promoting (PGP) bacteria like Bacillus were enriched during the middle stages of crop development but there was a decline in PGP organisms in the matured crop stage. We also observed a significant association of pH and Electrical Conductivity (EC) with the profiles of microbial community. Overall, this study portrayed the changes in rhizosphere microbiota of peanut during different developmental stages of crop and may help to design stage specific bio-strategies such as bio-fertilizer to improve crop yield.

Pretreatment and Storage of Soil Samples prior to Mineral Nitrogen Determination

1971 ◽  
Vol 21 (1) ◽  
pp. 57-63 ◽  
Author(s):  
A. R. Selmer-Olsen ◽  
A. Øien ◽  
R. Bæerug ◽  
I. Lyngstad
Keyword(s):  
Soil Samples ◽  
Mineral Nitrogen ◽  
Nitrogen Determination ◽  
And Storage

Suitability of felt traps to monitor oviposition by cabbage maggot (Diptera: Anthomyiidae)

2002 ◽  
Vol 134 (2) ◽  
pp. 205-214 ◽  
Author(s):  
P.L. Dixon ◽  
R.J. West ◽  
K.B. McRae ◽  
D. Spaner
Keyword(s):  
Brassica Napus ◽  
Soil Sample ◽  
Brassica Oleracea ◽  
Second Generation ◽  
Soil Samples ◽  
Delia Radicum ◽  
Field Conditions ◽  
Early Season ◽  
Cabbage Maggot

AbstractThe effectiveness of felt egg traps to detect oviposition by the cabbage maggot, Delia radicum (L.), was studied under field conditions for cabbage, Brassica oleracea L. var. capitata L. (Brassicaceae), and rutabaga, Brassica napus L. var. napobrassica (L.) Reichenb. (Brassicaceae), in 1994 and 1995. The numbers of eggs laid on traps were compared with the numbers deposited in the soil next to the plant. Also, the incidence of oviposition (i.e., the percentage of samples with eggs) on soil and traps was compared. A total of 5160 eggs was collected from 5208 samples, but just 16% of all samples had eggs. For cabbage, early in the 1994 season, the incidence of oviposition in soil samples was double that on traps, and the number of eggs per sample was greater also. Oviposition incidence and the number of eggs per sample during the rest of the summer were similar. In the 1995 cabbage trial, the incidence of oviposition early in the season was again higher in soil samples than on traps, and there were fewer eggs per trap than per soil sample. For rutabaga, the number of eggs was similar using both methods early in the second generation, but from mid-August there were more eggs per trap than per soil sample. The incidence of oviposition in the rutabaga trial was similar on traps and in soil through most of the experiment. In this study, felt traps did not adequately detect the timing of cabbage maggot oviposition in the critical early season.

scholarly journals Effect of superphosphate on the mobilization of nitrogen in a peat soil

1958 ◽  
Vol 30 (1) ◽  
pp. 114-124
Author(s):  
Armi Kaila
Keyword(s):  
Nitrogen Content ◽  
Peat Soil ◽  
Soil Samples ◽  
Mineral Nitrogen ◽  
Surface Layers ◽  
Untreated Soil ◽  
Slight Tendency ◽  
Treatment Comparison ◽  
Positive Effect ◽  
Previous Summer

The influence of superphosphate on the mobilization of nitrogen in a fen soil from Leteensuo Experiment Station in southern Finland was studied. Samples were used from a field trial in which superphosphate had been annually applied for 35 years in amounts of 0, 100, 200, and 300 kg/ha, resp. Analyses were performed on samples of four layers: 0 to 10 cm, 10 to 20 cm, 40 to 50 cm, and 60 to 70 cm. It was found that the mineral nitrogen (NH4-N + NO3-N) content of the soil samples collected late in the autumn was in all layers highest in the plots treated with the highest amount of superphosphate. The positive effect of the treatment with 200 kg/ha of superphosphate reached down to the layer of 40 to 50 cm. In the soil treated with 100 kg/ha the mineral nitrogen content was higher than in the untreated soil only in both surface layers. In the incubation experiment of five and ten weeks the differences in the mineral nitrogen content were equalized, particularly in the samples from deeper layers. In the top layers the superiority of the heaviest treatment was maintained. The amounts of nitrogen in the hay yields harvested in the previous summer appeared, generally, to be the higher the larger the amounts of superphosphate applied. It seemed to be probable that potassium was a minimum factor in the plots of the heaviest superphosphate treatment. Comparison of the present results with data obtained from the same experiment when it had been only run for five years indicated that, in regard to the availability of nitrogen in this peat soil, the slight tendency found thirty years ago had grown to the distinct superiority of the heavy superphosphate treatment.

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