scholarly journals Relationship between mineral N content and N mineralization rate in disturbed and undisturbed soil samples incubated under field and laboratory conditions

Soil Research ◽  
1992 ◽  
Vol 30 (4) ◽  
pp. 477 ◽  
Author(s):  
J Sierra
Keyword(s):  
N Mineralization ◽  
Negative Relationship ◽  
Feedback Mechanism ◽  
Soil Samples ◽  
Mineralization Rate ◽  
Mineral N ◽  
Undisturbed Soil ◽  
N Content ◽  
Undisturbed Samples

An investigation of in situ N mineralization, using undisturbed soil samples, indicated a negative relationship between the mineral N content [(NO3+NH4)-N] at the beginning of the experiment and the mineral N produced during it. This suggests that a maximum value of mineral N accumulation in intact soil cores could be calculated from the relationship between mineral N content and N mineralization rate. This value would be related to the size of the mineralizable N pool. If this hypothesis is true, the amount of mineralizable N could be estimated from in situ incubations and utilized in the modelling of N mineralization in the field. The aim of this work was to verify this hypothesis. The relationship between the mineral N content and the N mineralization rate was analysed for in situ and laboratory incubations of disturbed and undisturbed soil samples. A negative relationship between the two variables was only obtained for the experiments carried out with undisturbed samples (in the field and laboratory incubations) when the soil moisture content was not limiting for N mineralization. Futhermore, in undisturbed samples, a negative relationship between mineralization rates of consecutive incubation periods was observed, i.e. the soil sample producing relatively more, during a given period, produced relatively less in the following period. This relationship suggests a feedback mechanism operating in N mineralization which would be related to a mineralization-immobilization process in soil microsites. Thus, the N mineralization pattern was more complex than that described by initial hypothesis. The possible consequence of this feedback mechanism on in situ N dynamics is discussed.

scholarly journals Calibration of a soil moisture sensor with disturbed and undisturbed soil samples from Bahia

2018 ◽  
Vol 22 (10) ◽  
pp. 696-701
Author(s):  
João G. A. Lima ◽  
Aureo S. de Oliveira ◽  
Luciano da S. Souza ◽  
Neilon D. da Silva ◽  
Paula C. Viana
Keyword(s):  
Soil Moisture ◽  
Soil Samples ◽  
Calibration Data ◽  
Undisturbed Soil ◽  
Moisture Sensor ◽  
Soil Moisture Sensor ◽  
Disturbed Soil ◽  
Undisturbed Samples ◽  
Three Samples ◽  
Quadratic Models

ABSTRACT The objective of this study was to evaluate the models proposed by manufacturers and in the literature with respect to soil moisture measurement and to evaluate the performance of the CS616 sensor in the calibration of disturbed and undisturbed soil samples. These calibrations were performed using linear and quadratic models. Disturbed samples were collected in São Gabriel/BA, six samples placed in pots, whereas undisturbed samples were collected in Cruz das Almas/BA, three samples directly collected in the area and placed in a container. A calibration was performed between 21/12/2016 and 08/01/2017. The models proposed in the literature and by manufacturers differed in the estimation of volumetric soil moisture. Disturbed soil samples had higher data dispersion than undisturbed samples, due to factors such as grain size and bulk density, which influence the calibration data. The CS616 sensor had satisfactory performance in the calibration of disturbed and undisturbed samples, with excellent fit of the soil moisture data. Using soil moisture contents obtained by the CS616 sensor, without a previous calibration, may lead to errors in the results, confirming the need for a specific calibration for each type of soil.

scholarly journals Novel rapid measurement system of undisturbed soils water characteristics curve utilizing the continuous pressurization method

2019 ◽  
Vol 92 ◽  
pp. 07008 ◽  
Author(s):  
Adel Alowaisy ◽  
Noriyuki Yasufuku ◽  
Ryohei Ishikura ◽  
Masanori Hatakeyama ◽  
Shuu Kyono
Keyword(s):  
Soil Water ◽  
Unsaturated Soils ◽  
Natural Soil ◽  
Undisturbed Soil ◽  
Water Characteristics ◽  
Undisturbed Samples ◽  
In Situ Conditions ◽  
Undisturbed Soils ◽  
Short Time

Through this paper, a sampling methodology and a novel full automatic system adopting the continuous pressurization method which is capable of determining the Soil Water Characteristics Curve (SWCC) for both remoulded and undisturbed samples in a very short time were developed. The proposed system was validated by comparing the SWCCs of standard testing soils obtained using the developed system to the SWCCs obtained using a conventional method. Remoulded and undisturbed natural soil samples were tested, where the degree of disturbance influence on the obtained SWCC was discussed. In addition, the undisturbed samples containing moulds material influence on the obtained SWCC was investigated. It was found that remoulded samples do not properly represent the in-situ conditions with significant error that should be carefully considered when conducting analysis and proposing countermeasures against unsaturated soils related Geo-disasters. In addition, the material which the containing mould is made from has minor influence on the obtained SWCC which can be neglected. Finally, it can be concluded that the developed undisturbed soil water characteristics curve obtaining system is direct, rapid, reliable and simple. In addition, the proposed undisturbed sampling and testing methodology can be used to accurately evaluate the spatial variations of the SWCC regardless the heterogeneity of the soil profile.

The Nitrogen Mineralization of Five Forest Types Soil in Eastern Slope of Gaoligongshan Mountains

2014 ◽  
Vol 1073-1076 ◽  
pp. 222-228
Author(s):  
Ming Qian Yu ◽  
Guang Tao Meng ◽  
Li Ping He ◽  
Ning Yun Li ◽  
Gui Xiang Li ◽  
...  
Keyword(s):  
Nitrogen Mineralization ◽  
Rain Forest ◽  
Inorganic Nitrogen ◽  
Forest Types ◽  
Undisturbed Soil ◽  
N Content ◽  
Montane Rain Forest ◽  
Broad Leaved Forest ◽  
Leaved Forest

Sequential soil coring and in situ exposure of largely undisturbed soil columns technique was used to study the nitrogen mineralization of five forest types soils in the east side of Gaoligongshan mountains, which were Dry-Hot Vally (D), Montane Rain Forest (MR), Monsoon Evergreen Broad-leaved Forest (M), the Mid-Montane Humid Evergreen Broad-leaved Forest (H), Tsuga Forest (Ts). The results indicated that NH4+-N content decreased for all the forest types soil after four months training, the order of decrease proportion is monsoon evergreen broad-leaved forest (84.1%)> montane rain forest (69.3%)> the mid-montane humid evergreen broad-leaved forest (34.7%)> dry-hot vally (8.7%)> tsuga forest (7.3%). And NO3--N content increased for the soils, the increasing multiples is tsuga forest (39.0 times)> dry-hot vally (18.8 times)> the mid-montane humid evergreen broad-leaved forest (4.7 times)> monsoon evergreen broadleaf forest (4.0 times) > montane rainforest (2.8 times). We conclude that NH4+-N is the main form of inorganic nitrogen in forest soil, which is the main reason of changing the soil nitrogen mineralization and mineralization rate.

INCREASE IN MINERAL N IN SOILS DURING WINTER AND LOSS OF MINERAL N DURING EARLY SPRING IN NORTH-CENTRAL ALBERTA

1986 ◽  
Vol 66 (3) ◽  
pp. 397-409 ◽  
Author(s):  
S. S. MALHI ◽  
M. NYBORG
Keyword(s):  
Field Experiments ◽  
Early Spring ◽  
Soil Samples ◽  
Frozen Soil ◽  
Late Winter ◽  
Mineral N ◽  
N Accumulation ◽  
N Content ◽  
North Central ◽  
Cultivated Soils

Ten field experiments were conducted on cultivated soils in north-central Alberta to determine any change in mineral N content of soils during winter, and during early spring after the soils had thawed. Soil samples were taken periodically from fall to spring to a depth of 120 (or 90) cm and were analyzed for NH4-N and for NO3-N. Mineral N changes occurred primarily in the top 60 cm. Between fall and late winter, there was an increase of 48 kg N ha−1 of mineral N (range of 27–83) in the 60-cm depth of eight experiments set on stubble and the value increased only to 55 kg N ha−1 when the sampling depth was extended to 120 (or 90) cm. Considering only the values from soil samples taken when soils were frozen, the increase in mineral N was 31 kg N ha−1 (range of 14–54) in the 120-cm depth, and the average net mineral N accumulation was 0.35 kg N ha−1 d−1 (range of 0.26–0.43). There was a loss of mineral N during early spring of 44 kg N ha−1 (range of 18–71). The two experiments on summerfallow had more over-winter accumulation of mineral N and more loss in early spring compared to the stubble experiments. This study showed large increases in the mineral N content when the soil was frozen and large decreases in the early spring. The mechanism of increase in mineral N in frozen soil was not determined. The cause of the decrease in early spring was most likely denitrification, and was not leaching of nitrate. The results of the investigation may have implications for the time of soil test sampling and for the loss of native N from cultivated soils. Key words: Ammonium N, frozen soil, mineral N, nitrate N, early spring loss

Plant uptake of nitrogen from the organic nitrogen fraction of animal manures: a laboratory experiment

2000 ◽  
Vol 134 (2) ◽  
pp. 159-168 ◽  
Author(s):  
D. R. CHADWICK ◽  
F. JOHN ◽  
B. F. PAIN ◽  
B. J. CHAMBERS ◽  
J. WILLIAMS
Keyword(s):  
N Mineralization ◽  
Organic N ◽  
Pig Slurry ◽  
Mineral N ◽  
N Content ◽  
Total N ◽  
N Supply ◽  
Ammonium N ◽  
Cow Slurry ◽  
N Fractions

Twenty slurries, 20 farmyard manures (FYM) and 10 poultry manures were chemically analysed to characterize their nitrogen (N) fractions and to assess their potential organic N supply. The organic N fraction varied between manure types and represented from 14% to 99% of the total N content. The readily mineralizable N fraction, measured by refluxing with KCl, was largest in the pig FYMs and broiler litters, but on average only represented 7–8% of the total N content. A pot experiment was undertaken to measure N mineralization from the organic N fraction of 17 of these manures. The ammonium-N content of the manures was removed and the remaining organic N mixed with a low mineral N status sandy soil, which was sown with perennial ryegrass (Lolium perenne L.). N offtake was used as a measure of mineralization throughout the 199 day experiment. The greatest N mineralization was measured from a layer manure and a pig slurry, where N offtake represented 56% and 37% of the organic N added, respectively. Lowest (%) N mineralization was measured from a dairy cow slurry (< 2%) and a beef FYM (6%). The mineralization rate was negatively related to the C[ratio ]organic N ratio of the ammonium-N stripped manures (P < 0·01, r = −0·63).

Influence of soil texture on protozoa-induced mineralization of bacterial carbon and nitrogen

1992 ◽  
Vol 72 (3) ◽  
pp. 183-200 ◽  
Author(s):  
P. M. Rutherford ◽  
N. G. Juma
Keyword(s):  
N Mineralization ◽  
Pore Space ◽  
Mineralization Rate ◽  
Microcosm Experiment ◽  
Carbon And Nitrogen ◽  
Protozoan Grazing ◽  
C And N ◽  
Typic Cryoboroll ◽  
Bacterial C

Texture affects pore space, bacterial and protozoan populations and their activity in soil. The objective of this study was to test the hypothesis that protozoa grazing on bacteria increase the mineralization of bacterial C and N more in coarse-textured soils than in fine-textured soils. The microcosm experiment consisted of samples from three sterilized Orthic Black Chernozemic soils (SiC, CL and SL) inoculated with Pseudomonos bacteria, two treatments (with and without protozoa), and five sampling dates. The Pseudomonas population was labelled in situ by adding glucose- 14C and KNO3-15N (day 0). A species of Acanthamoeba was added to the microcosms on Day 2. On Day 4 bacterial numbers in all three soils were approximately 3 × 109 g−1 soil. The greatest reduction of bacteria due to protozoan grazing occurred between day 4 and day 7. All soils showed increased CO2-14C evolution and NH4-15N mineralization due to protozoan grazing but the mineralization rate of labelled N in the SL soil was much greater than in the fine-textured soils. The effect of texture on protozoan grazing was not as marked between day 12 and day 37 as earlier in the incubation. Protozoan-induced effects were transient in the soils studied and were most apparent in the coarse-textured soil. Key words: 14C, 15N, N mineralization-immobilization, bacteria, organic matter, Typic Cryoboroll, porosity, protozoa

Nitrogen mineralization, nitrate leaching and crop growth after ploughing-in leguminous and non-leguminous grain crop residues

1994 ◽  
Vol 123 (1) ◽  
pp. 81-87 ◽  
Author(s):  
G. S. Francis ◽  
R. J. Haynes ◽  
P. H. Williams
Keyword(s):  
N Mineralization ◽  
Growing Season ◽  
Net N Mineralization ◽  
Soil N ◽  
Mineral N ◽  
N Content ◽  
Leaching Losses ◽  
N Yield ◽  
Leguminous Crops ◽  
N Fertility

SummaryA field experiment was conducted in Canterbury, New Zealand to investigate the effect of six leguminous and non-leguminous grain crops on soil N fertility over a 12 month period (March 1989 to March 1990). All crops had an overall negative N balance during their growing season. A greater amount of soil N was removed by barley, rape and lupins (104–119 kg N/ha) than by field beans, field peas or lentils (50–74 kg N/ha).Net N mineralization was measured in all treatments between residue incorporation and the start of winter. With the exception of the lupins, accumulation of mineral N in the soil profile before the start of winter drainage was greater following leguminous (mean 124 kg N/ha) than non-leguminous crops (mean 80 kg N/ha).Cumulative apparent leaching losses over the autumn/winter were largely a reflection of the mineral N content of the profile before the start of drainage. Excluding lupins, leaching losses declined in the order fallow > legumes > non-legumes (110 > 72 > 37 kg N/ha respectively). The anomalous results for the lupins were attributed to the incorporation of a large amount of woody residues after harvest which may well have resulted in extensive net N mineralization occurring later in the autumn.Over a 12 month period, all treatments showed a decline in N fertility (110–160 kg N/ha), although compared with barley, the total loss of soil N was 10–40 kg N/ha less following leguminous crops.Growth of the following spring wheat test crop was affected by the preceding crop. Grain yield, grain N yield and total N yield were significantly related to the mineral N content of the soil at the end of leaching, and to a measure of net N mineralization during the growing season of the test crop.

scholarly journals Nitrogen Sources for Organic Vegetable Crops

2007 ◽  
Vol 17 (4) ◽  
pp. 431-441 ◽  
Author(s):  
Mark Gaskell ◽  
Richard Smith
Keyword(s):  
Cover Crops ◽  
N Mineralization ◽  
Cultural Practice ◽  
Organic N ◽  
Mineralization Rate ◽  
Vegetable Crops ◽  
Feather Meal ◽  
N Content ◽  
N Sources ◽  
Seabird Guano

Fertilization is the most expensive cultural practice for the increasing numbers of organic vegetable growers in the United States. Nitrogen (N) is the most important and costly nutrient to manage, and cost-effective N management practices are needed for efficient organic vegetable production. There is a wide array of organic N sources available, but they vary in cost, N content, and N availability. Compost and cover crops are commonly used sources of N for vegetables because they are relatively inexpensive and offer additional nutrients or soil improvement qualities in addition to N. Studies have shown that compost quality factors that affect N mineralization vary by source and among different batches from the same source. Compost carbon to N ratio should be equal to or less than 20:1 to assure net short-term mineralization. Cover crops also vary in N content and mineralization rate after incorporation. Leguminous cover crops decompose and release N more rapidly than grass or cereal cover crops at the preheading stage typically incorporated. Even the most efficient N-supplying composts, cover crops, or other organic N sources do not release appreciable N to a subsequent crop beyond 6 to 8 weeks from incorporation, and this burst of early N may not synchronize with N requirements for many vegetable crops. Other potential organic fertilizer N sources have been evaluated for vegetables, and they vary in N cost and N mineralization rate. Materials evaluated include seabird guano, liquid fish, feather meal, corn meal (Zea mays), blood meal, and liquid soybean meal (Glycine max) among others. Of those evaluated, feather meal, seabird guano, and liquid fish stand out as more economical organic sources of available N. Organic sources generally lack uniformity and are bulky, unstable, and inconsistent as a group, and this contributes to additional hidden management costs for organic growers. Liquid organic N sources for use in microirrigation systems may have additional disadvantages caused by loss of valuable nutrient N that is removed by filters.

Effect of superphosphate addition on N mineralization in some Australian forest soils

Soil Research ◽  
1993 ◽  
Vol 31 (3) ◽  
pp. 285 ◽  
Author(s):  
RA Falkiner ◽  
PK Khanna ◽  
RJ Raison
Keyword(s):  
Pinus Radiata ◽  
Forest Soils ◽  
N Mineralization ◽  
Net N Mineralization ◽  
Mineral N ◽  
Undisturbed Soil ◽  
Total N ◽  
Organic C ◽  
Forest Sites ◽  
P Content

Pinus radiata stands are reported to accumulate increased N on addition of phosphatic fertilizers. Field and laboratory studies were initiated to determine if addition of superphoshate increases soil N mineralization in forest soils. In a field experiment, application of 200 kg P ha-1 as superphosphate to trenched plots in a Pinus radiata stand increased accumulated soil mineral-N contents by 122% and 82% above the control on two occasions. Application of 500 kg P ha-1 as superphosphate either alone or in combination with lime (10 Mg ha-1) increased in situ soil net N mineralization in a dry sclerophyll eucalypt forest from 20.7 (control) to 28.3 (+P) and 30.2 (+P+lime) kg N ha-1 yr-1 20 cm-1. Uptake by the vegetation accounted for all of the mineralized nitrogen. In a 180 day laboratory incubation using undisturbed soil columns (0-20 cm) from nine forest sites, seven soils showed a positive response to superphosphate (100 kg P ha-1) addition, with increases in N mineralization ranging from 14% to 117%. The response of N mineralization to superphosphate addition was not related to initial soil organic C, total N or P content in the 0-20 cm layer. However, soil pH and organic C combined to account for 76% of the variation in N mineralization response (P < 0.01). In the 0-5 cm layer of untreated soils, soil organic P content could explain 71% of the variation in net N mineralization. Addition of superphosphate appears to increase N mineralization in several Australian forest soils and the improved availability of N will enhance tree growth rates. The mechanisms underlying the response are still poorly understood and thus also our ability to predict its significance for tree nutrition on specific forest sites.

Net nitrogen mineralization from a Gray Luvisol under diverse cropping systems in the Peace River region of Alberta

1996 ◽  
Vol 76 (2) ◽  
pp. 117-123 ◽  
Author(s):  
K. Broersma ◽  
N. G. Juma ◽  
J. A. Robertson
Keyword(s):  
N Mineralization ◽  
Cropping Systems ◽  
Cropping System ◽  
Red Clover ◽  
Growing Season ◽  
Soil Samples ◽  
Net N Mineralization ◽  
Mineralization Rate ◽  
River Region ◽  
Gray Luvisol

Proper management of crops on Gray Luvisols requires knowledge of net soil N mineralization during the growing season. Soil samples from a long-term field experiment at Beaverlodge, Alberta, were used to determine the kinetics of net N mineralization in soil samples from different crop rotations. The cropping systems established in 1968 consisted of (i) continuous barley (Hordeum vulgare L.) (CB); (ii) barley–forage (BF) [bromegrass (Bromus inermis Leyss.) and red clover (Trifolium pratense L.)]; (iii) continuous bromegrass (CG); and (iv) continuous legume (red clover) (CL.). The BF rotation was generally alternated every 3 yr, and each phase of the rotation (BF and BF) was present in every year. Soil samples from each cropping system were sampled to a depth of 15 cm in 1984. Net N mineralized during a 20-wk laboratory incubation at 30 °C and optimum moisture ranged from 32 to 207 mg kg−1 soil and followed the trend BF < CB = CG = BF < CL. The potentially mineralizable N (N0) ranged from 29 to 364 mg kg−1 soil; the mineralization rate constant (k) ranged from 0.04 to 0.26 wk−1; and the ratio of N0 to total N (active fraction) ranged from 1.1 to 11.4%. The net N mineralization rate of CL soil was 10-fold greater than that of the other cropping systems at the end of 20 wk of incubation. This suggests that the CL cropping system provides more N than other cropping systems during the growing season. Results support the observation that forages improve the N-supplying power of Gray Luvisols. Key words: Gray Luvisol, Typic Cryoboralf, N mineralization potential, cropping rotations, active N fraction

Sign in / Sign up

Export Citation Format

Share Document