scholarly journals Nitrogen mineralization in soils cultivated with plantain (Musa AAB Subgroup plátano cv. Hartón), Zulia state, Venezuela

2021 ◽  
Vol 38 (3) ◽  
pp. 525-547
Author(s):  
Ana González-Pedraza ◽  
Juan Escalante
Keyword(s):  
Multiple Comparisons ◽  
Soil Characteristics ◽  
Soil Samples ◽  
Mineralization Rate ◽  
Total N ◽  
Available N ◽  
Tukey Test ◽  
Nitrate N ◽  
Ammonium N ◽  
Potentially Mineralizable N

The main source of N in the soil is organic matter; therefore, its availability depends on its quantity and quality, microbial activity, soil characteristics and management. An efficient way to quantify available N is by mineralizing it as ammonium (N-NH ) and nitrate (N-NO ). Therefore, in this study, the total and available N was determined in soil samples 0-20 cm deep from two plots with plantain plants (Musa AAB plantain subgroup cv. Hartón) with high and low vigor (AV and BV, respectively), in the South of Lake Maracaibo. Total N was determined by the Kjeldalh method and the mineralization of available N by incubation under laboratory conditions for 10 weeks. The accumulated mineralized N (Nm), the constant mineralization rate of (k) and the potentially mineralizable N (N0) were calculated. A one-way analysis of variance was applied, when it was significant (p<0.05), a Tukey test was applied for multiple comparisons of means. Total N was low (<0.025 %) and did not present statistical differences (p<0.05) between AV and BV. The accumulated mineralized N-NO was statistically (p<0.05) higher (524.47 mg.kg-1) in BV, while the N-NH did not present differences between AV and BV. Only k was statistically higher (0.07 ± 0.03; p<0.05) in BV. Nitrification was the process that prevailed especially in BV where organic carbon was higher and presented a higher percentage of sand.

Nutrient release from decomposing crop residues in soil: A laboratory experiment

1997 ◽  
Vol 12 (1) ◽  
pp. 10-13 ◽  
Author(s):  
A. Scagnozzi ◽  
A. Saviozzi ◽  
R. Levi-Minzi ◽  
R. Riffaldi
Keyword(s):  
Laboratory Experiment ◽  
Crop Residues ◽  
Nutrient Release ◽  
Soil Samples ◽  
Water Soluble ◽  
Microbial Immobilization ◽  
Total N ◽  
Available N ◽  
Treated Soil ◽  
Quantitative Changes

AbstractIn a 400-day laboratory experiment, soil was amended with rape, sunflower and soybean residues to monitor the quantitative changes in the main inorganic nutrients. Total N, available P, exchangeable K+, Ca2+, and Mg2+ in all the amended samples increased significantly. Generally, the increase in the amounts of these nutrients was maintained until the end of the incubation period, suggesting that the mineralization of the three crop residues enhanced soil fertility. In amended soil samples, disappeared within 14 days, while available N was released as after 60 days in soybean-treated and after 120 days in rape- and sunflower-treated soil, respectively. Water-soluble P was completely lacking in each treatment because of microbial immobilization and adsorption or precipitation processes in soil.

Nitrogen-mineralization potential of meadow soils

1993 ◽  
Vol 73 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Régis R. Simard ◽  
Adrien N'dayegamiye
Keyword(s):  
Organic Matter ◽  
Soil Quality ◽  
N Mineralization ◽  
Mineralization Rate ◽  
Total N ◽  
Available N ◽  
Gompertz Equation ◽  
Mineralizable N ◽  
Mineralization Potential ◽  
Potential Mineralization

An understanding of the mineralization factors in contrasting cultivated soils is necessary for accurate predictions of plant-available N. The objective of this work was to determine the N-mineralization potential and mathematical models that can properly describe the dynamics of the mineralization process in 20 meadow soils from Quebec. The mineralization was monitored over 55.4 wk in a laboratory incubation at 20 °C with intermittent leaching. The cumulative mineralization curves in most soils were characterized by definite lags or a sigmoidal pattern and near-linear release with time after 20 wk. The data were best described by the Gompertz equation; first-order models were inadequate. The total amount of mineralizable N and the potential mineralization rate were very closely correlated with the total amounts of C or N (r > 0.73; P < 0.01). The clay content was also correlated with these mineralization parameters and significantly improved the prediction of the cumulative and potential N-mineralization rate estimated from the total N or C content of soils. The relationships with other soil characteristics such as soil pH and available nutrient contents were weak but significant. The results of this study suggest that textural classes be added in the correction for organic matter content to improve the precision in N-fertilizer recommendation and in soil-quality classifications based on potential mineralization rate. Key words: Soil quality, potentially mineralizable N, Gompertz equation, soil organic matter, soil texture, C, N

CHANGES IN NATURAL 15N ABUNDANCE ASSOCIATED WITH PEDOGENIC PROCESSES IN SOIL. II. CHANGES ON DIFFERENT SLOPE POSITIONS

1980 ◽  
Vol 60 (2) ◽  
pp. 365-372 ◽  
Author(s):  
R. E. KARAMANOS ◽  
D. A. RENNIE
Keyword(s):  
Total Nitrogen ◽  
Organic N ◽  
Total N ◽  
Nitrate N ◽  
Ammonium N ◽  
Soil Forming Processes ◽  
Pedogenic Processes ◽  
15N Abundance ◽  
Upper Slope

Rather marked variations in δa15N values were obtained in a study carried out on samples taken from four soils belonging to the Weyburn soil association. The δa15N of the total N of well-drained depressional profiles dropped sharply with depth and, in contrast, for upper slope positions was relatively constant to a depth of approximately 5 m. This characteristic enrichment in the heavier isotope of total nitrogen of surface horizons may represent long-term immobilization of partially oxidized ammonium N into the organic N fraction; δa15N of the total N more closely represents past soil-forming processes while that of the nitrate N appears to reflect, in addition, recent N cycle stresses.

scholarly journals Variations in Soil Chemical Properties, Bacteria and Fungi Populations Along Slope Positions and Profile Depths in Terraced and Non-terraced Lands of Rwanda highlands

2019 ◽  
Vol 39 (03) ◽  
Author(s):  
A Fashaho ◽  
G M Ndegwa ◽  
J J Lelei ◽  
A O Musandu ◽  
S M Mwonga
Keyword(s):  
Organic Carbon ◽  
High Altitude ◽  
Soil Ph ◽  
Chemical Properties ◽  
Soil Characteristics ◽  
Biological Properties ◽  
Soil Samples ◽  
High Altitudes ◽  
Total N ◽  
Bacteria And Fungi

The objective of the current study was to evaluate effect of terracing on soil chemical and biological properties in the Rwanda highlands. The study was done in March 2017. Composite soil samples were collected from the top, middle and bottom slopes of four-year-terraced and non-terraced lands, in three profile depths, in medium and high altitudes. Results showed that, levels of organic carbon (1.3, 1.04%) were significantly (p less than 0.05) higher in non-terraced than terraced land, and populations of bacteria (3.59, 2.61 CFU*106g-1) and fungi (2.51, 1.57 CFU*104g-1) were significantly higher in terraced than non-terraced land, in the medium altitude, with no significant differences observed in the high altitude. Soil pH, total N, available P, CEC, exchangeable K+, Mg2+ and Ca2+ levels in terraced and non-terraced lands were not significantly different in both altitudes. Thus, soil characteristics and fertility of the study areas showed slight changes after four years of terracing.

scholarly journals Soil inorganic nitrogen in spatially distinct areas within a commercial dairy farm in Canterbury, New Zealand

2017 ◽  
Vol 79 ◽  
pp. 83-88
Author(s):  
D.C. Ekanayake ◽  
J.L. Owens ◽  
S. Hodge ◽  
J.A.K. Trethewey ◽  
R.L. Roten ◽  
...  
Keyword(s):  
New Zealand ◽  
Surface Soil ◽  
Inorganic Nitrogen ◽  
Dairy Farm ◽  
Soil Samples ◽  
Inorganic N ◽  
N Distribution ◽  
Nitrate N ◽  
Ammonium N ◽  
Grazing Behaviour

For precision nitrogen (N) fertilisation of grazed dairy paddocks, soil N distribution needs to be quantified. It is expected that farm infrastructure will affect inorganic-N distribution due to its influence on cow grazing behaviour. Surface soil from four spatially distinct areas (main gate, water troughs, non-irrigated and the remaining pasture) was analysed for soil ammonium-N (NH4 +-N) and nitrate-N (NO3 --N) from three paddocks (180 soil samples) on an irrigated commercial dairy farm in Canterbury, New Zealand. Variation between paddocks was higher for NO3 - (P

scholarly journals Long term trends in fertility of soils under continuous cultivation and cereal cropping in southern Queensland .VIII. Available nitrogen indexes and their relationships to crop yield and N uptake

Soil Research ◽  
1990 ◽  
Vol 28 (4) ◽  
pp. 563 ◽  
Author(s):  
RC Dalal ◽  
RJ Mayer
Keyword(s):  
N Uptake ◽  
Continuous Cultivation ◽  
Annual Rainfall ◽  
Soil Series ◽  
Total N ◽  
Available N ◽  
Organic C ◽  
Winter Cereals ◽  
Nitrate N ◽  
Mineralizable N

Six major soil series of southern Queensland were studied for the changes in the levels of available N indices (determined by both biological and chemical methods) and nitrate-N, with continuous cultivation and cereal cropping for up to 70 years. The biological N indices, measured in soil collected at planting of winter cereals, were anaerobic mineralizable N, aerobic mineralizable N and nitrate-N down to 1.2 m depth. The chemical indices were autoclave N and oven N. The predictive capabilities of various available N indices, and total N and organic C, were assessed from dry matter and N uptake of winter cereals in the field in 1983 as well as in the glasshouse. Anaerobic mineralizable N levels increased with mean annual rainfall but decreased with mean annual temperatures of the sampling sites of the six soil series. Therefore, it was possible to predict closely anaerobic mineralizable N from soil total N, and mean annual rainfall and temperature. Autoclave N showed no such trends. Anaerobic mineralizable N declined with period of cultivation, exponentially in Waco, Langlands-Logie and Cecilvale soils (0.112, 0.111 and 0.247 year-1, respectively) and linearly in the other three soil series. No consistent trends were discerned in autoclave N and oven N in four of the soil series with period of cultivation. Generally, nitrate-N (measured at planting) declined with period of cultivation. However, in Billa Billa soil, it increased in the soil profile (0-1.2 m) during the initial 7 years of cultivation and declined rapidly after 12 years. Although a number of available N indices, including total N and organic C, were significantly correlated with crop dry matter yield and N uptake, the best prediction of crop performance was provided by a combination of anaerobic mineralizable N (0-0.3 m) and nitrate-N (0-0 6 m) in the six soil series.

Soil nitrogen availability in the cereal zone of South Australia .2. Buffer-extractable nitrogen, mineralisable nitrogen, and mineral nitrogen in soil profile under different land uses

Soil Research ◽  
1996 ◽  
Vol 34 (6) ◽  
pp. 949 ◽  
Author(s):  
ZH Xu ◽  
M Amato ◽  
JN Ladd ◽  
DE Elliott
Keyword(s):  
Soil Profile ◽  
South Australia ◽  
Mineral Nitrogen ◽  
Soil Profiles ◽  
Land Uses ◽  
Mineral N ◽  
Total N ◽  
Growing Seasons ◽  
Nitrate N ◽  
Ammonium N

Mineral nitrogen (nitrate-N+ammonium-N) and its distribution in soil profiles to 60 cm depth at sowing in 3 growing seasons, 1990-1992, were assessed for 123 field experimental sites in South Australia. The sites were used to test N fertiliser responses with cereal crops following different land uses. More than 90% of the variation in mineral N at cereal sowing was attributable to nitrate-N in the 60-cm soil profiles. Coefficients of variation (CV) for nitrate-N ranged from 37 to 45%, less than half of the CV values (88-113%) for ammonium-N. More than 70% of mineral N in soil to 60 cm depth was accounted for by mineral N in the top 20 cm of soil, and 49% by mineral N in the top 10 cm of soil. The amounts of mineral N in the 60-cm soil profiles at sowing ranged from 24 to 180 kg N/ha (median 75) at sites following pastures, and from 22 to 113 kg N/ha (median 69) following grain legumes, significantly higher than 17 to 116 kg N/ha (median 47) following cereals. Only 26% of the variation in mineral N of soils (0-60 cm depth) could be predicted by soil total N, mineralisable N assessed by the aerobic incubation method, and previous land use. Ammonium-N extracted by phosphate-borate buffer from soils sampled at 0-10 and 10-20 cm depths was directly related to soil total N and N mineralised after soil incubation, but not to mineral N accumulating at sowing in the soil profiles to 60 cm depth. Utilisation of a soil containing 15N-labelled organic residues, and sampled to 100 cm depth at sowing in 5 successive growing seasons, revealed a positive relationship between the 15N atom% enrichments of soil profile mineral N, mineralisable N from soil incubations, and plant N. Enrichments of soil profile mineral N and plant N were almost identical. However, the enrichment of buffer-extractable ammonium-N was comparatively low and unresponsive to the time of soil sampling, and unrelated to the other soil and plant N pools. Thus, buffer-extractable N was unrepresentative of plant-available N.

scholarly journals Response of Soil Respiration to Grazing in an Alpine Meadow at Three Elevations in Tibet

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Gang Fu ◽  
Xianzhou Zhang ◽  
Chengqun Yu ◽  
Peili Shi ◽  
Yuting Zhou ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Soil Respiration ◽  
Alpine Meadow ◽  
Elevation Gradient ◽  
Major Type ◽  
The Tibetan Plateau ◽  
Total N ◽  
Organic C ◽  
Nitrate N ◽  
Ammonium N

Alpine meadows are one major type of pastureland on the Tibetan Plateau. However, few studies have evaluated the response of soil respiration (Rs) to grazing along an elevation gradient in an alpine meadow on the Tibetan Plateau. Here three fenced enclosures were established in an alpine meadow at three elevations (i.e., 4313 m, 4513 m, and 4693 m) in July 2008. We measuredRsinside and outside the three fenced enclosures in July–September, 2010-2011. Topsoil (0–20 cm) samples were gathered in July, August, and September, 2011. There were no significant differences forRs, dissolved organic C (DOC), and belowground root biomass (BGB) between the grazed and ungrazed soils. Soil respiration was positively correlated with soil organic C (SOC), microbial biomass (MBC), DOC, and BGB. In addition, bothRsand BGB increased with total N (TN), the ratio of SOC to TN, ammonium N (NH4+-N), and the ratio ofNH4+-N to nitrate N. Our findings suggested that the negligible response ofRsto grazing could be directly attributed to that of respiration substrate and that soil N may indirectly affectRsby its effect on BGB.

scholarly journals Effects of Short-term Tillage of a Long-term No-Till Land on Available N and P in Two Contrasting Soil Types

2015 ◽  
Vol 4 (4) ◽  
pp. 27 ◽  
Author(s):  
Miles Dyck ◽  
Sukhdev. S. Malhi ◽  
Marvin Nyborg ◽  
Dick Puurveen
Keyword(s):  
N Fertilizer ◽  
Short Term ◽  
Available N ◽  
Straw Management ◽  
Nitrate N ◽  
No Till ◽  
Ammonium N ◽  
Extractable P ◽  
Fertilizer Rates

The effects of short-term (4 years) tillage (hereafter called reverse tillage [RT]) of land previously under long-term (29 or 30 years) no-till (NT), with straw management (straw removed [SRem] and straw retained [SRet]) and N fertilizer rate (0, 50 and 100 kg N ha-1 in SRet, and 0 kg N ha-1 in SRem plots) were determined in autumn 2011 on ammonium-N, nitrate-N and extractable P in the 0-7.5, 7.5-15 and 15-20 cm soil layers at Breton (Gray Luvisol [Typic Cryoboralf] loam) and Ellerslie (Black Chernozem [Albic Argicryoll] loam), Alberta, Canada. There was no significant effect of RT and straw on ammonium-N, nitrate-N and extractable P in soil. Ammonium-N in soil increased significantly (but small) with N rate in many cases at both sites. Nitrate-N in soil increased with increasing N rate from 0 to 100 kg N ha-1 rate at Ellerslie, and up to 50 kg N ha-1 rate at Breton. Etractable P in soil decreased markedly with increasing N rate up to 100 kg N ha-1 at Breton and up to 50 kg N ha-1 at Ellerslie. In summary, increased N fertilizer rates were usually associated with decreased extractable P and increased nitrate-N in soil, but RT and straw had no effect on these nutrients in soil.

Total nitrogen removal in an aerobic/anoxic membrane biofilm reactor system

2005 ◽  
Vol 52 (7) ◽  
pp. 115-120 ◽  
Author(s):  
J. Cowman ◽  
C.I. Torres ◽  
B.E. Rittmann
Keyword(s):  
Nitrogen Removal ◽  
Hydrogen Pressure ◽  
Biofilm Reactor ◽  
Total N ◽  
Nitrate N ◽  
Membrane Biofilm Reactor ◽  
N Removal ◽  
Ammonium N ◽  
High O2 ◽  
Total Nitrogen Removal

The hydrogen-based membrane biofilm reactor (MBfR) is effective for reducing nitrate-N to N2 gas, but most wastewaters contain ammonium-N. Here, we document that an aerobic/anoxic MBfR system achieves nearly total N removal (&lt;2 mgN/L) when the influent N is ammonium. The aerobic/anoxic MBfR couples two MBfR modules. The aerobic MBfR is supplied O2 and brings about nitrification of ammonium to nitrate or nitrite. The anoxic MBfR is supplied H2 and brings about denitrification to N2 gas. Total N removal is most strongly influenced by the O2 pressure in the aerobic module: too low O2 caused poor nitrification, while too high O2 inhibited denitrification in the anoxic module. Hydrogen pressure does not strongly affect total-N removal, and the best total-N removal occurs when the H2 and O2 pressures are similar.

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