Microbial biomass, N mineralization, and the activities of various enzymes in relation to nitrate leaching and root distribution in a slurry-amended grassland

1994 ◽  
Vol 18 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Ellen Kandeler ◽  
Gerfried Eder ◽  
Monika Sobotik
2009 ◽  
Vol 55 (No. 6) ◽  
pp. 223-230 ◽  
Author(s):  
S. Singh Jay ◽  
D.P. Singh ◽  
A.K. Kashyap

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.


1992 ◽  
Vol 40 (2) ◽  
pp. 173-185 ◽  
Author(s):  
J. Hassink

The effect of mowing or grazing and mineral fertilizer level on N mineralization potential and microbial biomass N (N flush) was studied in 1988 on a sandy soil and a sedimentary calcareous silty loam (loam) in the Netherlands. On the loam the residual effect of the treatments on N yield and herbage dry matter accumulation in the following year was also studied. The different management practices were started in 1985 on the sandy soil and in 1986 on the loam. The amount of microbial biomass N was larger under grazing than under mowing. The increase in the amount of microbial biomass N due to grazing was larger for the loam than for the sandy soil. The N-mineralization rate was higher under grazing than under mowing. The difference in N-mineralization rates between grazed and mown fields was 20-30 % in April for both soils, but increased considerably in the sandy soil during the growing season. It was estimated that the difference in N-mineralization between mown and grazed plots under field conditions was 110 and 40 kg N/ha per year in the sandy soil and the loam, respectively. Thus the optimum N fertilizer application rate should be considerably lower under grazing conditions than under mowing conditions, especially on sandy soil. Fertilizer level had no effect on the amount of microbial biomass and rates of N-mineralization. Both grazing compared to mowing and increasing N fertilizer levels above 550 kg N/ha per year affected the N yield and dry matter accumulation in the following year (= residual effects) on the loam. These effects were greater for N yield than for dry matter accumulation. The residual effect of previous fertilizer input was probably caused by the presence of different amounts of N in roots and stubble. The residual effect on N yield under grazing exceeded that under mowing by 28%. (Abstract retrieved from CAB Abstracts by CABI’s permission)


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1386
Author(s):  
Michael Stotter ◽  
Florian Wichern ◽  
Ralf Pude ◽  
Martin Hamer

Cultivation of Miscanthus x giganteus L. (Mis) with annual harvest of biomass could provide an additional C source for farmers. To test the potential of Mis-C for immobilizing inorganic N from slurry or manure and as a C source for soil organic matter build-up in comparison to wheat (Triticum aestivum L.) straw (WS), a greenhouse experiment was performed. Pot experiments with ryegrass (Lolium perenne L.) were set up to investigate the N dynamics of two organic fertilisers based on Mis at Campus Klein-Altendorf, Germany. The two fertilisers, a mixture of cattle slurry and Mis as well as cattle manure from Mis-bedding material resulted in a slightly higher N immobilisation. Especially at the 1st and 2nd harvest, they were partly significantly different compared with the WS treatments. The fertilisers based on Mis resulted in a slightly higher microbial biomass C and microbial biomass N and thus can be identified as an additional C source to prevent nitrogen losses and for the build-up of soil organic matter (SOM) in the long-term.


2020 ◽  
Vol 53 (1) ◽  
pp. 19-27
Author(s):  
Adenike Fisayo Komolafe ◽  
Christopher Olu Adejuyigbe ◽  
Adeniyi Adebowale Soretire ◽  
Isaac OreOluwa Olatokunbo Aiyelaagbe

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.


2011 ◽  
Vol 1 (4) ◽  
pp. 202-207
Author(s):  
N. Ewusi‐Mensah ◽  
V. Logah ◽  
J. O. Fening

This paper reports the short Ã¢â‚¬Â term effects of organic and inorganic fertilizerapplications on the culturable resident bacterial and fungal properties of aFerric Acrisol in the semi Ã¢â‚¬Âdeciduous forest zone of Ghana after three continuouscropping seasons. The treatments were two compost types (i.e. 1:1compost comprising 1 part made up of Chromolaena, Stylosanthes, maizestover mixture and 1 part of cattle manure, 2:1 compost comprising 2 partsof Chromolaena, Stylosanthes, maize stover mixture and 1 part of cattle manure),cowdung, 100% NPK and a control replicated three times in a randomizedcomplete block design. The results showed that total microbial load on alogarithmic scale ranged from 4.6 cfu/g in the control to 5.4 on cowdungtreated plots. Bacterial counts on 2:1 compost applied at 5 t/ha treatedplots recorded 5% more bacteria than the 1:1 compost applied at 5 t/ha.Fungal counts in the control and inorganic treated plots were higher than theorganically amended plots. The highest and lowest microbial biomass C contentswere recorded on cowdung and 1:1 compost at 5 t/ha treated plotsrespectively. Microbial biomass N content ranged from 1.4 Ã¢â‚¬Â 8.2 mg N kg‐1soil with a mean value of 6.2 mg N kg Ã¢â‚¬Â1 soil. Microbial biomass P contentranged from 3.6 Ã¢â‚¬Â 6.3 mg P kg‐1 soil with a mean value of 5 mg P kg‐1 soil.Microbial biomass carbon to organic carbon ratio varied from 18.37 to 85.63.


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