The fate of residual nitrogen fertiliser applied to a ryegrass (Lolium perenne L.) seed crop

2000 ◽  
Vol 51 (2) ◽  
pp. 287 ◽  
Author(s):  
W. R. Cookson ◽  
J. S. Rowarth ◽  
K. C. Cameron
Keyword(s):  
Microbial Biomass ◽  
Microbial Biomass N ◽  
Root Mass ◽  
N Mineralisation ◽  
Pasture Production ◽  
Total N ◽  
Leaching Losses ◽  
Seed Harvest ◽  
Fertiliser Application ◽  
Seed Crops

Large amounts of the nitrogen (N) fertiliser applied to ryegrass seed crops remain within the soil at seed harvest and can potentially affect subsequent pasture production and environmental contamination. The fate of residual urea-15N-labelled fertiliser and the effect of previous fertiliser application on subsequent leaching losses and pasture production was assessed during a 9-month period after seed harvest using monolith lysimeters (diameter, 180 mm; length, 300 mm) in Canterbury, New Zealand. Results indicated that leaching losses and pasture uptake of residual 15N-labelled fertiliser were largely restricted by the immobilisation of 15N-labelled fertiliser into soil organic pools and the expanding root mass. Most of the 15N-labelled fertiliser remaining in the soil 9 months after the seed harvest was present within the humified organic matter (50%) and microbial biomass (40%) pools; the majority (62%) was anaerobically mineralisable. The 15N-labelled fertiliser that became available was largely recovered in rapidly expanding ryegrass roots, which increased 3–4-fold between seed harvest (December 1997) and pasture harvest (September 1998). Root mass, soil mineral N, and soil microbial biomass N were significantly (P < 0.05) greater in fertilised treatments than in controls at pasture harvest; clay-fixed N, anaerobically mineralisable N, and total N were not affected. The results indicated that, in the short term, N mineralisation rates were increased by previous fertiliser application but there was little evidence of a longer term effect on N mineralisation rates.

scholarly journals Maturity indices of composting plant materials with Trichoderma asperellum as activator

2020 ◽  
Vol 53 (1) ◽  
pp. 19-27
Author(s):  
Adenike Fisayo Komolafe ◽  
Christopher Olu Adejuyigbe ◽  
Adeniyi Adebowale Soretire ◽  
Isaac OreOluwa Olatokunbo Aiyelaagbe
Keyword(s):  
Microbial Biomass ◽  
Microbial Biomass N ◽  
Cow Dung ◽  
Trichoderma Asperellum ◽  
Plant Materials ◽  
Total N ◽  
Compost Maturity ◽  
Randomized Design ◽  
Maturity Indices ◽  
Biomass N

AbstractCompost maturity is a major factor in its use for nutrient supply without adverse effect on crop germination. Composting may be accelerated with inclusion of some microorganisms as activators. This study was conducted to determine the effect of Trichoderma asperellum and length of composting of different plant materials and cattle manure on compost maturity in Ibadan, Nigeria. Composting of two plant materials with cow dung at ratio 3:1 was done in triplicate with or without Trichoderma activation to obtain twelve heaps of four different types of composts; Panicum-based compost with Trichoderma, Tridax-based compost with Trichoderma, Panicum-based compost without Trichoderma and Tridax-based compost without Trichoderma. The process was a 2×2 factorial experiment, laid out a completely randomized design. The Trichoderma activated compost (TAC) at four weeks of composting (4WC) had 56% total N, 21% organic matter, 38% total K, 51% total P and 66.6% microbial biomass N increase over non-activated compost (NAC). Carbon to nitrogen ratio was within the ideal range (10–20) in TAC while it was greater than it in NAC. Microbial biomass and lignin contents had a 56% and 41% increase, respectively, in NAC over TAC. Trichorderma-activated compost has a potential to hasten maturation and makes the compost ready for field on or before four weeks without posing a threat to crop germination.

Soil-plant nitrogen dynamics following incorporation of a mature rye cover crop in a lettuce production system

1995 ◽  
Vol 124 (1) ◽  
pp. 17-25 ◽  
Author(s):  
L. J. Wyland ◽  
L. E. Jackson ◽  
K. F. Schulbach
Keyword(s):  
Microbial Biomass ◽  
Cover Crop ◽  
Microbial Biomass N ◽  
N Availability ◽  
N Content ◽  
N Transformations ◽  
Total N ◽  
Mineralizable N ◽  
Biomass N ◽  
Bare Soils

SUMMARYWinter non-leguminous cover crops are included in crop rotations to decrease nitrate (NO3-N) leaching and increase soil organic matter. This study examined the effect of incorporating a mature cover crop on subsequent N transformations. A field trial containing a winter cover crop of Merced rye and a fallow control was established in December 1991 in Salinas, California. The rye was grown for 16 weeks, so that plants had headed and were senescing, resulting in residue which was difficult to incorporate and slow to decompose. Frequent sampling of the surface soil (0–15 cm) showed that net mineralizable N (anaerobic incubation) rapidly increased, then decreased shortly after tillage in both treatments, but that sustained increases in net mineralizable N and microbial biomass N in the cover-cropped soils did not occur until after irrigation, 20 days after incorporation. Soil NO3-N was significantly reduced compared to winter-fallow soil at that time. A 15N experiment examined the fate of N fertilizer, applied in cylinders at a rate of 12 kg 15N/ha at lettuce planting, and measured in the soil, microbial biomass and lettuce plants after 32 days. In the cover-cropped soil, 59% of the 15N was recovered in the microbial biomass, compared to 21% in the winter-bare soil. The dry weight, total N and 15N content of the lettuce in the cover-cropped cylinders were significantly lower; 28 v. 39% of applied 15N was recovered in the lettuce in the cover-cropped and winter-bare soils, respectively. At harvest, the N content of the lettuce in the cover-cropped soil remained lower, and microbial biomass N was higher than in winter-bare soils. These data indicate that delayed cover crop incorporation resulted in net microbial immobilization which extended into the period of high crop demand and reduced N availability to the crop.

scholarly journals A comparative account of the microbial biomass-N and N-mineralization of soils under natural forest, grassland and crop field from dry tropical region, India

2009 ◽  
Vol 55 (No. 6) ◽  
pp. 223-230 ◽  
Author(s):  
S. Singh Jay ◽  
D.P. Singh ◽  
A.K. Kashyap
Keyword(s):  
Soil Moisture ◽  
Microbial Biomass ◽  
N Mineralization ◽  
Mixed Forest ◽  
Microbial Biomass N ◽  
Tropical Region ◽  
Net N Mineralization ◽  
Inorganic N ◽  
Total N ◽  
Biomass N

This study investigated microbial biomass-N (MB-N) and N-mineralization in soils of four different vegetation systems including forest (sal), mixed forest, savanna and cropland ecosystems in the Vindhyan region, India. A change was noted in the above region due to physiographic differences and anthropogenic disturbances. Annually the soil moisture (SM) content across the different study sites ranged from 7.5 to 24.3% being maximum in forest sites compared to savanna and cropland sites. The NH<sub>4</sub><sup>+</sup>-N, NO <sup>-</sup><sub>3</sub> -N and MB-N concentrations varied from 4.3 to 10.2 &mu;g/g, 1.1 to 5.8 &mu;g/g and 21.3 to 90.2 &mu;g/g dry soil, respectively, with minimum values in the wet and maximum values in the dry season. The trend of seasonal variation in net N-mineralization was similar to that of moisture content but counter to the concentrations of inorganic-N and MB-N. The net N-mineralization rates at different investigated sites ranged from 4.5 to 37.6 &mu;g/g month. Cultivation reduced the N-mineralization and MB-N by 58.5% and 63.5%, respectively. Experiments showed that the percentage contribution of MB-N to total-N was 8.01 to 19.15%. MB-N was positively correlated with the inorganic-N (<i>n</i> = 180,<i>r</i>.80,<i>P</I> < 0.001) but negatively with soil moisture (<i>n</i> = 180, <i>r</i> = 0.79, <i>P</I> < 0.001) and net N-mineralization rates (<i>n</i> = 180, <i>r</i> = 0.92, <i>P</I> < 0.0001). The higher N-mineralization and MB-N in the soil of forest ecosystem was reported compared to savanna and cropland and the order of soil MB-N levels and net N-mineralization followed the sequence: forest (sal) > mixed forest > savanna > cropland.

scholarly journals Seed Meals from Brassicaceae Oilseed Crops as Soil Amendments: Influence on Carrot Growth, Microbial Biomass Nitrogen, and Nitrogen Mineralization

HortScience ◽  
2009 ◽  
Vol 44 (2) ◽  
pp. 354-361 ◽  
Author(s):  
André Snyder ◽  
Matthew J. Morra ◽  
Jodi Johnson-Maynard ◽  
Donald C. Thill
Keyword(s):  
Microbial Biomass ◽  
Degradation Products ◽  
N Uptake ◽  
Biologically Active ◽  
Microbial Biomass N ◽  
Glucosinolate Content ◽  
N Availability ◽  
Fresh Market ◽  
Microbial Biomass Nitrogen ◽  
Total N

Brassicaceae seed meals (BSMs) average 6% nitrogen (N) by weight and contain glucosinolates (GLSs) that produce biologically active compounds. A two-season field study was initiated to determine how Brassica juncea L., Brassica napus L., and Sinapis alba L. seed meals, each with different glucosinolate profiles, alter carrot (Daucus carota L. subsp. sativus) growth, microbial biomass N (MBN), and soil N mineralization. BSM applications of 1 and 2 t·ha−1 36 days before planting did not influence carrot emergence, whereas carrot emergence decreased up to 40% in S. alba treatments seeded 15 days after BSM application. Crop quality was unaffected by BSM treatments and total fresh market yields were equal to or higher than the unamended controls in both years. At 4 and 8 days after seed meal application, MBN in the high-GLS B. juncea and S. alba treatments was 48% to 67% lower than in the low-GLS B. napus treatment. Seasonal apparent net N mineralized expressed as a percentage of the total N applied in the seed meals was unaffected by glucosinolate concentration and ranged from 30% to 81% across both years. BSMs can be used to increase soil inorganic N and carrot yields, but crop phytotoxicity is possible depending on the meal and its respective glucosinolate content. GLS degradation products inhibit microbial N uptake in the short term, but longer-term N availability is not compromised.

scholarly journals Climatic, Edaphic and Biotic Controls over Soil δ13C and δ15N in Temperate Grasslands

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 433
Author(s):  
Xing Zhao ◽  
Xingliang Xu ◽  
Fang Wang ◽  
Isabel Greenberg ◽  
Min Liu ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Large Scale ◽  
Microbial Biomass C ◽  
Microbial Biomass N ◽  
Temperate Grasslands ◽  
Total N ◽  
Δ13c And Δ15n ◽  
Biomass N ◽  
Soil Δ15n ◽  
Total P

Soils δ13C and δ15N are now regarded as useful indicators of nitrogen (N) status and dynamics of soil organic carbon (SOC). Numerous studies have explored the effects of various factors on soils δ13C and δ15N in terrestrial ecosystems on different scales, but it remains unclear how co-varying climatic, edaphic and biotic factors independently contribute to the variation in soil δ13C and δ15N in temperate grasslands on a large scale. To answer the above question, a large-scale soil collection was carried out along a vegetation transect across the temperate grasslands of Inner Mongolia. We found that mean annual precipitation (MAP) and mean annual temperature (MAT) do not correlate with soil δ15N along the transect, while soil δ13C linearly decreased with MAP and MAT. Soil δ15N logarithmically increased with concentrations of SOC, total N and total P. By comparison, soil δ13C linearly decreased with SOC, total N and total P. Soil δ15N logarithmically increased with microbial biomass C and microbial biomass N, while soil δ13C linearly decreased with microbial biomass C and microbial biomass N. Plant belowground biomass linearly increased with soil δ15N but decreased with soil δ13C. Soil δ15N decreased with soil δ13C along the transect. Multiple linear regressions showed that biotic and edaphic factors such as microbial biomass C and total N exert more effect on soil δ15N, whereas climatic and edaphic factors such as MAT and total P have more impact on soil δ13C. These findings show that soil C and N cycles in temperate grasslands are, to some extent, decoupled and dominantly controlled by different factors. Further investigations should focus on those ecological processes leading to decoupling of C and N cycles in temperate grassland soils.

scholarly journals Warming and Nitrogen Addition Change the Soil and Soil Microbial Biomass C:N:P Stoichiometry of a Meadow Steppe

2019 ◽  
Vol 16 (15) ◽  
pp. 2705
Author(s):  
Gong ◽  
Zhang ◽  
Guo
Keyword(s):  
Microbial Biomass ◽  
Soil Microbial Biomass ◽  
Field Experiments ◽  
Microbial Biomass C ◽  
Nutrient Ratios ◽  
Microbial Biomass N ◽  
N Addition ◽  
Total N ◽  
C:N:P Stoichiometry ◽  
Soil Microbial

: Soil and soil microbial biomass (SMB) carbon: nitrogen: phosphorus (C:N:P) stoichiometry are important parameters to determine soil balance of nutrients and circulation of materials, but how soil and SMB C:N:P stoichiometry is affected by climate change remains unclear. Field experiments with warming and N addition had been implemented since April 2007. Infrared radiators were used to manipulate temperature, and aqueous ammonium nitrate (10 g m-2 yr-1) was added to simulate nitrogen deposition. We found that molar nutrient ratios in the soil averaged 60:11:1, warming and warming plus N addition reduced soil C:N by 14.1% and 20% (P < 0.01), and reduced soil C:P ratios by 14.5% and 14.8% (P < 0.01). N addition reduced soil C:N significantly by 17.6% (P < 0.001) (Figs. 2B, 2D). N addition and warming plus N addition increased soil N:P significantly by 24.6% and 7.7% (P < 0.01). The SMB C:N, C:P and N:P ratios increased significantly with warming, N addition and warming plus N addition. Warming and N addition increased the correlations between SOC and soil microbial biomass C (SMBC), soil total P and soil microbial biomass P (SMBP), warming increased the correlation between the soil total N and soil microbial biomass N (SMBN). After four years’ treatment, our results demonstrated that the combined effects of warming and N fertilization could change the C, N, P cycling by affecting soil and SMB C:N:P ratios significantly and differently. At the same time, our results suggested SMB might have weak homeostasis in Sonnen Grassland and warming and N addition would ease N-limitation but aggravate P-limitation in northeastern China. Furthermore, these results further the current demonstration of the relationships between the soil and SMB C:N:P stoichiometry in response to global change in temperate grassland ecosystems.

scholarly journals Responses of Soil and Microbial C:N:P Stoichiometry to Vegetation Succession in a Karst Region of Southwest China

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 755 ◽  
Author(s):  
Min Song ◽  
Wanxia Peng ◽  
Hu Du ◽  
Qingguo Xu
Keyword(s):  
Microbial Biomass ◽  
Vegetation Succession ◽  
Karst Region ◽  
Microbial Biomass N ◽  
Agricultural Abandonment ◽  
Total N ◽  
C:N:P Stoichiometry ◽  
Organic C ◽  
Successional Stages ◽  
Time Substitution

Spontaneous vegetation succession after agricultural abandonment is a general phenomenon in many areas of the world. As important indicators of nutrient status and biogeochemical cycling in ecosystems, the stoichiometry of key elements such as carbon (C), nitrogen (N) and phosphorous (P) in soil and microbial biomass, and their responses to vegetation recolonization and succession after agricultural abandonment remain poorly understood. Here, based on a space-for-time substitution approach, surface soil samples (0–15 cm) were collected from four vegetation types, e.g., tussock grassland, shrubland, secondary forest, and primary forest, which represent four successional stages across this region. All samples were examined C, N and P concentrations and their ratios in soil and microbial biomass. The results showed that soil organic C and total N content increased synchronously but total soil P did not remarkably change along a progressive vegetation succession. Consequently, soil C:P and N:P ratios increased while C:N ratio stayed almost unchanged during vegetation succession. Soil microbial biomass C (SMBC) and microbial biomass N (SMBN) concentrations elevated while SMBP did not significantly change during vegetation succession. Unlike the soil C:N:P stoichiometry, however, microbial C:N and C:P ratios were significantly or marginally significantly greater in grassland than in the other three successional stages, while microbial N:P did not significantly vary across the four successional stages. Overall, the present study demonstrated that soil and microbial stoichiometry responded differently to secondary vegetation succession in a karst region of subtropical China.

Seasonal fluctuations in gross N mineralisation, ammonium consumption, and microbial biomass ina Western Australian soil under different land uses

1998 ◽  
Vol 49 (3) ◽  
pp. 523 ◽  
Author(s):  
D. V. Murphy ◽  
G. P. Sparling ◽  
I. R. P. Fillery
Keyword(s):  
Microbial Biomass ◽  
Empirical Relationship ◽  
Soil Layer ◽  
Subterranean Clover ◽  
Growing Season ◽  
Microbial Biomass N ◽  
N Mineralisation ◽  
Available N ◽  
Biomass N ◽  
Intact Soil Cores

A field experiment was conducted to study the seasonal variation in gross N mineralisation, NH4+ consumption (immobilisation and nitriflcation), potentially available N, and microbial biomass-N.Measurements were made during the wheat growing season in Western Australia under continuouswheat, during the wheat phase of a 1 year lupin : 1 year wheat rotation, during the wheat phaseof a 2 year pasture : 1 year wheat rotation, and under a subterranean clover pasture. The accuracyof gross N mineralisation and NH4+ consumption within intact soil cores was reduced by the largespatial variation in the size of the soil NH4+ pool. Calculated daily rates of gross N mineralisation inthe 0-5 cm soil layer ranged from 0·0 to 1·0 kg N/ha·day in the continuous wheat, 0·1 to 0·8 kgN/ha·day in the lupin{wheat rotation,- 0·1 to 1·3 kg N/ha·day in the pasture-wheat rotation, and-0·1 to 2·5 kg N/ha·day in the pasture treatment. Gross N mineralisation in the 5-10 cm soil layerunder wheat followed the same range observed in the 0-5 cm layer; in continuous pasture, lower rates were measured in the 5-10 cm layer compared with the 0-5 cm layer. The range in daily rates of NH4+ consumption in a given treatment was similar to the range in daily rates of gross N mineralisation,precluding accumulation of NH4+ in soil when considered over a season. Gross N mineralised in the0-10 cm soil layer was equivalent to 10-19% of the total soil N in this layer. Net N mineralised,determined from the difierence between gross N mineralisation and gross immobilisation, was estimatedto be about half of the gross N mineralised during the wheat growing season. Plant uptake wasestimated to be 13-37% of the total gross N mineralised (0-10 cm) during the field season and wasgreater in the wheat after legume compared with continuous wheat. Potentially available N, measured by anaerobic incubation, declined by about one-third during the season. At the beginning of the season, microbial biomass-N in the 0-5 cm soil layer contained 61 kg N/ha in continuous wheat, 68 kgN/ha in the lupin-wheat rotation, 73 kg N/ha in the pasture-wheat rotation, and 99 kg N/ha underpasture. Only half of these quantities of microbial biomass were detected by the end of the season. Microbial biomass-N was concentrated in the surface soil layer with <25 kg N/ha in the 5-10 cmsoil layer under each land use. A reasonable estimate of gross N mineralisation was obtained in the continuous wheat and legume-wheat rotations by using a simple empirical relationship based on thesize and activity of the microbial biomass, and functions to describe the efiect of temperature andwater on microbial activity. However, the pattern of gross N mineralisation in the pasture treatment could not be explained using this approach.

scholarly journals Dynamics of C and N in a clay loam soil amended with biochar and corn straw

2019 ◽  
Author(s):  
George O. Odugbenro ◽  
Zhihua Liu ◽  
Yankun Sun
Keyword(s):  
Microbial Biomass ◽  
Microbial Biomass C ◽  
Microbial Biomass N ◽  
Clay Loam ◽  
Corn Straw ◽  
Clay Loam Soil ◽  
Mineral N ◽  
Total N ◽  
Loam Soil ◽  
C And N

An incubation study was conducted to determine the influence of biochar and corn straw on CO2-C emission, soil organic C, microbial biomass C and N, total N, and mineral N (NH4+-N and NO3--N) in a clay loam soil. Six treatments viz., CK (Control); S (Soil + 1% straw); B1 (Soil + 0.5% biochar); B2 (Soil + 2% biochar); SB1 (Soil + 1% straw + 0.5% biochar); SB2 (Soil + 1% straw + 2% biochar) were tested with three replications. Results showed that straw addition to soil with or without biochar increased CO2-C emission while sole-biochar addition (2%) reduced it. Straw and biochar also increased the soil microbial biomass C and N but greatest increase in microbial biomass N (111.9 µg g-1) was recorded by biochar-straw combination. SOC and total N significantly increased following biochar and straw additions which suggest that organic amendments can improve soil chemical properties. Additionally, for soil mineral N, biochar reduced NH4+-N and NO3--N concentrations while straw increased NH4+-N concentration but greatly reduced that of NO3--N.

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