scholarly journals Effect of cotton - cowpea intercropping on C and N mineralisation patterns of residue mixtures and soil

Soil Research ◽  
2009 ◽  
Vol 47 (2) ◽  
pp. 190 ◽  
Author(s):  
L. Rusinamhodzi ◽  
H. K. Murwira ◽  
J. Nyamangara
Keyword(s):  
Rate Constant ◽  
Crop Residues ◽  
Nutrient Use Efficiency ◽  
Field Capacity ◽  
C Sequestration ◽  
N Mineralisation ◽  
N Losses ◽  
Mineral N ◽  
C Mineralisation ◽  
C And N

Carbon and nitrogen mineralisation potential of mixed cotton (Gossypium hirsutum L.) and cowpea (Vigna unguiculata (L.) Walp) crop residues produced under intercropping, as well as a reddish-brown soil classified by FAO as Ferralic Cambisol previously under intercrops, were studied over a 10-week incubation period under controlled conditions (25°C and moisture content of 70% field capacity, 125 mm) in the laboratory. Treatments consisted of cotton residues (100 : 0), cowpea residues (0 : 100), and cotton–cowpea residues (50 : 50, 70 : 30, and 30 : 70). These ratios were based on yields obtained in different cotton–cowpea intercrop treatments from a field study. Cowpea residues (0 : 100) released the highest amount of mineral N of 36.4 mg/kg soil, and cotton residues (100 : 0) least, 19.2 mg/kg soil, while the other mixtures were in between. All treatments except for cowpea residues (0 : 100) and the 30 : 70 mixture showed immobilisation of soil N during the first 2 weeks of incubation. The trend for C mineralisation was similar to that of N, and cowpea residues (0 : 100) released the highest amount, 492 mg C/kg soil, while cotton residues (100 : 0) recorded the least, 315 mg C/kg soil. The C mineralisation patterns of cowpea residues (0 : 100) and 30 : 70 treatments were exponential and were well described by the equation: where CE is exponentially mineralisable C fraction, k is the rate constant, and t is time in days. The mineralisation patterns for other treatments were sigmoidal and were well described by the equation: where CS is sigmoidally mineralisable C fraction; t 0 is time in days required for complete mineralisation of CS , while k is rate constant. The amount of N released from soil previously under cotton–cowpea intercrops and sole crops was approximately one-third of the amount released when the residues were incorporated. The highest amount of N released (12.2 mg/kg soil) was from soil previously under sole cowpea, while soil from the 1 : 1 cotton–cowpea intercrop released 9.9 mg/kg soil and soil from sole cotton released 5.9 mg/kg soil. There was no significant effect (P > 0.05) of previous crop on C mineralisation patterns of the soil. Mixtures slow down N losses and increase nutrient use efficiency of legume residues, especially in the short-term. When cotton is grown as a sole crop, starter N to offset negative effects of initial N-immobilisation at the start of season is required. A better understanding of controlling parameters of decomposition can make it possible to predict C and N mineralisation patterns in mixtures. Reduced C mineralisation in cotton–cowpea mixtures may result in more C sequestration and, hence, SOM build-up and improved sustainability in the long term in intercropping systems.

Productivity and nitrogen use of three different wheat-based rotations in North West Syria

1998 ◽  
Vol 49 (3) ◽  
pp. 451 ◽  
Author(s):  
M. Wood ◽  
C. J. Pilbeam ◽  
H. C. Harris ◽  
J. Tuladhar
Keyword(s):  
Crop Residues ◽  
Wheat Crop ◽  
N Mineralisation ◽  
Soil N ◽  
N Budget ◽  
Mineral N ◽  
North West ◽  
System A ◽  
To Come ◽  
C 50

Productivity of 3 different 2-year crop rotations, namely continuous wheat, wheat-chickpea, and wheat-fallow, was measured over 4 consecutive seasons beginning in 1991-92 at the ICARDA station, Tel Hadya, Syria. Nitrogen (N) fertiliser (30 kg N/ha at sowing) was broadcast every other year in the continuous wheat only. 15N-labelled fertiliser was used to quantify the amount of nitrogen supplied to the crops through current and past applications of fertiliser and by N2 fixation. The remaining N in the crop was assumed to come from the soil. In any single season, wheat yields were unaffected by rotation or N level. However, 2-year biomass production was significantly greater (32%, on average) in the continuously cropped plots than in the wheat-fallow rotation. On average, <10% of the N in the wheat crop came from fertiliser in the season of application, and <1·2 kg N/ha of the residual fertiliser was recovered by a subsequent wheat crop. Chickpea fixed 16-48 kg N/ha, depending on the season, but a negative soil N budget was still likely because the amount of N removed in the grain was usually greater than the amount of atmospheric N2 fixed. Uptake of soil N was similar in the cereal phase of all 3 rotations (38 kg N/ha, on average), but over the whole rotation at least 33% more soil N was removed from continuously cropped plots than from the wheat-fallow rotation, suggesting that the latter is a more sustainable system. A laboratory study showed that although wheat and chickpea residues enhanced the gross rate of N mineralisation by c. 50%, net rates of N mineralisation were usually negative. Given the high C/N ratio of the residue, immobilisation, rather than loss processes, is the likely cause of the decline in the mineral N content of the soil. Consequently, decomposition of crop residues in the field may in the short term reduce rather than increase the availability of N for crop growth.

Effect of leaching and clay content on carbon and nitrogen mineralisation in maize and pasture soils

Soil Research ◽  
2001 ◽  
Vol 39 (3) ◽  
pp. 535 ◽  
Author(s):  
R. L. Parfitt ◽  
G. J. Salt ◽  
S. Saggar
Keyword(s):  
Clay Content ◽  
N Mineralisation ◽  
Incubation Experiment ◽  
Nitrogen Mineralisation ◽  
Total N ◽  
Carbon And Nitrogen ◽  
Maize Sample ◽  
C Mineralisation ◽  
C And N

We conducted a 7-week laboratory incubation experiment to evaluate the effect of leaching on net C and N mineralisation in soils. The soils were collected from adjacent fields of long-term pasture and maize, where each field contained an Inceptisol and an Andisol. The concentration of clay mineral was 200 g/kg halloysite in the Inceptisol and 120 g/kg allophane in the Andisol. Half the samples were leached weekly with 0.002 M CaCl2 at a suction of 20 kPa to remove soluble products, and half were not leached. Carbon mineralisation was determined from CO2-C evolved each week. Net N mineralisation was measured for the leached samples from the NH4-N and NO3-N in the CaCl2 extracts, and for the batch of non-leached samples by extraction in 0.5 M K2SO4. Carbon and net N mineralisation were greater in the soils under pasture than in soils under maize. The proportion of total C mineralised as CO2-C, and of total N mineralised as NH4-N and NO3-N, followed the order Inceptisol-pasture > Inceptisol-maize > Andisol-pasture > Andisol-maize, suggesting that allophane and Al ions reduced net mineralisation. Dissolved organic carbon (DOC) produced during incubation, as a proportion of total C, was greatest for the Inceptisol-maize sample and least for the Andisol-pasture sample. Non-leaching resulted in the accumulation of acids and solutes, and decreased C mineralisation for the Inceptisol samples.

Influence of dicyandiamide on nitrogen transformation and losses in cow-urine-amended soil cores from grazed pasture

2009 ◽  
Vol 49 (3) ◽  
pp. 253 ◽  
Author(s):  
Jagrati Singh ◽  
S. Saggar ◽  
N. S. Bolan
Keyword(s):  
Sandy Loam ◽  
Field Capacity ◽  
N Leaching ◽  
N2o Emissions ◽  
Gaseous Emissions ◽  
Soil Cores ◽  
N Losses ◽  
Mineral N ◽  
Undisturbed Soil ◽  
N Transformations

In New Zealand, urine deposited by grazing animals represents the largest source of nitrogen (N) losses, as gaseous emissions of ammonia (NH3) and nitrous oxide (N2O), and leaching of nitrate (NO3−).We determined the effect of dicyandiamide (DCD) on gaseous emissions from pasture with increasing rates of urine-N application, mineral N transformations and potential leaching of N using undisturbed soil cores of Manawatu sandy loam at field capacity. The treatments included four levels of urine-N applied at 0 (control), 14.4, 29.0 and 57.0 g N/m2 with and without DCD at 2.5 g/m2. Results showed a significant (P < 0.05) increase in NH3 and N2O-N emissions as urine application was increased. The addition of DCD to corresponding urine treatments reduced N2O emissions by 33, 56 and 80%, respectively. The addition of DCD with urine to the intact soil cores at field capacity moisture content resulted in a significant increase in the soil ammonium-N (NH4+-N) concentration but little change in NH3 emissions. Addition of DCD to urine reduced potential NO3−-N leaching by 60–65% but potential NH4+-N leaching increased by 2–3.5 times. There was no difference in pasture dry matter production with and without DCD treatments.

scholarly journals Solid fraction of separated digestate as soil improver: implications for soil fertility and carbon sequestration

2020 ◽  
Author(s):  
Caleb Elijah Egene ◽  
Ivona Sigurnjak ◽  
Inge C. Regelink ◽  
Oscar F. Schoumans ◽  
Fabrizio Adani ◽  
...  
Keyword(s):  
Organic Matter ◽  
Sandy Loam ◽  
Pig Manure ◽  
N Leaching ◽  
N Mineralisation ◽  
Mineral N ◽  
Loam Soil ◽  
C Mineralisation ◽  
N Immobilisation ◽  
Mineralisation Potential

Abstract Purpose This study investigated the C and N mineralisation potential of solid fractions (SFs) from co-digestated pig manure after P-stripping (P-POOR SF) in comparison with P-rich SFs, as a means to estimate their organic matter stability in soil. Compost (COMP) and biochar (BCHR) (made from P-POOR SF) were also included in the study as reference biosolids. Methods The SFs were incubated in a sandy-loam soil under moist conditions to determine production of CO2 and mineral N. At specified intervals, CO2 evolution in the mixtures was measured via the alkali trap method and titration over a period of 81 days, while mineral N was measured using a flow analyser after KCl extraction over a period of 112 days. Results The various SFs showed similar patterns of C mineralisation (15–26% of added total C in 81 days) that were clearly higher than for COMP and BCHR (6% and 7%, respectively). Temporary N immobilisation was observed in biosolids with a high C/N ratio. The effective organic matter (EOM) of the SFs was calculated based on the C mineralisation data and varied between 130 and 369 kg Mg−1. Conclusions The SF with a reduced P content had a high EOM/P ratio which is beneficial in areas where P status of the soil is already high. Moreover, the N mineralisation patterns confirm that a high C/N ratio may also reduce risks for N leaching due to temporary N immobilisation.

scholarly journals Effect of Mineral N on C and N Dynamics of Rice and Wheat Residues under Different Moisture Levels

2020 ◽  
Vol 63 (3) ◽  
pp. 226-237
Author(s):  
Ljaz Ali ◽  
Ghulam Nabi
Keyword(s):  
Soil Moisture ◽  
Crop Residue ◽  
Crop Residues ◽  
Moisture Level ◽  
Residue Management ◽  
High Moisture ◽  
Mineral N ◽  
N Dynamics ◽  
High Moisture Level ◽  
C And N

Crop residue mineralization affects soil carbon (C) and nitrogen (N) dynamics during crop residue management in crop production. C and N mineralization dynamics of rice and wheat residues incorporated with and without mineral N under two moisture conditions were evaluated under laboratory conditions. Mineral N was applied @ 0.015 g/Kg (»30 Kg/ha), whereas soil moisture was maintained at high (» – 15 KPa, near field capacity) and at low (» – 500 KPa)moisture levels during course of study.Periodic determinations on CO2 – C and N mineralized were performed over a period of 120 days. The highest peaks for CO2 – C occurred during first week of the study which then reduced gradually until it attained an equilibrium. High moisture level enhanced CO2 – C flux by 14% than low moisture level. Combined application of crop residues and mineral N released 17% more CO2 – C than crop residue treatments without mineral N.In residue applied treatments, immobilization was 40% higher at high moisture level than that at low moisture level. Application of rice and wheat residues in combination with mineral N caused both immobilizations followed by mineralization phases at both moisture levels. At high moisture level, maximum immobilization occurred during initial 15 days, while at low moisture level it continued till about 30 days. After day15, mineralization started which continued to increase during remaining period of study at high moisture and at low moisture mineralization initiated from day 60 onward. Mineralization in rice residue was faster than that in wheat residues. Immobilization of N continued progressively in residue alone treated soils at both moisture levels during study period. In residue treated soils, increase in soil moisture increased soil organic carbon (SOC) and soil water stable aggregates (WSA) significantly by 14% and 55% over control respectively.Combined application of crop residues and mineral N increased SOC by 43% and WSA by 59%. This study indicated that incorporation of crop residues along with addition of mineral N in the presence of optimum moisture promoted its faster decomposition with a quicker mineral N release, more organic matter build up and soil structure improvement than crop residues incorporated without mineral N. 

Carbon and nitrogen mineralisation in sand, silt, and clay fractions of soils under maize and pasture

Soil Research ◽  
2001 ◽  
Vol 39 (2) ◽  
pp. 361 ◽  
Author(s):  
R. L. Parfitt ◽  
G. J. Salt
Keyword(s):  
Particle Size ◽  
Clay Fraction ◽  
Good Evidence ◽  
N Mineralisation ◽  
Mineral N ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Carbon And Nitrogen ◽  
N Release ◽  
C Mineralisation

Although several studies have quantified either C mineralisation or net N mineralisation in particle-size fractions, no work has examined simultaneous C and net N mineralisation. Therefore, we conducted an 18-week laboratory incubation to compare simultaneous mineralisation in sand, silt, and clay fractions. The soils (silt loams) were collected from fields of long-term pasture and maize. Sand, silt, and clay were separated by mild dispersion in water followed by centrifugation. Samples were incubated at 25°C in the dark in a quartz matrix, and were leached every 2 weeks with 0.004 M CaCl 2 at a suction of 20 kPa to remove soluble products. C mineralisation was determined from CO 2 -C evolved each 2 weeks, and mineral N was measured in the leachate. C mineralisation, on a C basis, followed the order sand > clay > silt, and was related (r 2 = 0.88) to the proportion of O-alkyl C (carbohydrate C) estimated from 13 C NMR. The low mineralisation in the silt may also have been a result of the physical protection of substrates in small pores in this fraction. The rates of N release were initially rapid from the maize soil fractions, and were consistent with the high initial mineral-N contents; subsequently, the rates were slower, and probably related to C mineralisation. For the pasture soil, N mineralisation followed the order clay>silt>sand, and was inversely related to the C: N ratios. Immobilisation appeared to take place in the sand fraction, whereas a large part of the net N mineralisation occurred in the clay fraction. There is now good evidence that rates of C and net N mineralisation differ within discrete particle size fractions, and data on such fractions could be useful for constructing soil organic matter models.

Carbon and nitrogen transformations in New Zealand plantation forest soils from sites with different N status

1998 ◽  
Vol 28 (7) ◽  
pp. 967-976 ◽  
Author(s):  
Neal A Scott ◽  
Roger L Parfitt ◽  
Des J Ross ◽  
Gareth J Salt
Keyword(s):  
Forest Floor ◽  
Forest Ecosystems ◽  
Mineral Soil ◽  
Plantation Forest ◽  
N Losses ◽  
Mineral N ◽  
N Transformations ◽  
Clear Cutting ◽  
C And N ◽  
N Status

Interactions between soil nutrient cycling processes are likely to influence N losses following disturbance in forest ecosystems. During a 340-day laboratory incubation, we examined C and N transformations in three sandy soils of different N status from Pinus radiata D. Don plantations before clear-cutting. The soils were a high N status Andisol (losing -N in streamwater) and a fertilized and unfertilized Entisol. In contrast to other forest ecosystems, -N accumulated readily in all mineral soils and in the Andisol forest floor but did not accumulate until day 63 and 210 in the fertilized and unfertilized Entisol forest floor, respectively. However, gross nitrification occurred from day 42 in both Entisol treatments. Net nitrification in the Entisol forest floor began when substrate C/N ratio declined to about 40, possibly because of decreased C availability and decreased competition for both -N and -N in conjunction with a lower microbial C/N ratio. Carbon and gross N mineralization rates (per unit of C or N, respectively) correlated positively (r2 = 0.93) in mineral soil but correlated negatively in the forest floor, probably because of major differences in C and N quality and potential differences in microbial community structure. The mean residence time of N in mineral-N pools was higher for soils from the N-rich site, in part because of lower microbial N demand. These results suggest that sudden removal of C inputs (such as at harvest) may cause greater disruption of internal soil N cycles on nutrient poor sites, increasing the proportional losses of N as compared to nutrient-rich sites.

Manipulation of rhizosphere organisms to enhance glomalin production and C sequestration: Pitfalls and promises

2014 ◽  
Vol 94 (6) ◽  
pp. 1025-1032 ◽  
Author(s):  
F. L. Walley ◽  
A. W. Gillespie ◽  
Adekunbi B. Adetona ◽  
J. J. Germida ◽  
R. E. Farrell
Keyword(s):  
Plant Growth ◽  
Mycorrhizal Fungi ◽  
Plant Growth Promoting Rhizobacteria ◽  
C Sequestration ◽  
Ionization Mass ◽  
Edge Structure ◽  
Organic C ◽  
Soil C ◽  
N Storage ◽  
C And N

Walley, F. L., Gillespie, A. W., Adetona, A. B., Germida, J. J. and Farrell, R. E. 2014. Manipulation of rhizosphere organisms to enhance glomalin production and C-sequestration: Pitfalls and promises. Can. J. Plant Sci. 94: 1025–1032. Arbuscular mycorrhizal fungi (AMF) reportedly produce glomalin, a glycoprotein that has the potential to increase soil carbon (C) and nitrogen (N) storage. We hypothesized that interactions between rhizosphere microorganisms, such as plant growth-promoting rhizobacteria (PGPR), and AMF, would influence glomalin production. Our objectives were to determine the effects of AMF/PGPR interactions on plant growth and glomalin production in the rhizosphere of pea (Pisum sativum L.) with the goal of enhancing C and N storage in the rhizosphere. One component of the study focussed on the molecular characterization of glomalin and glomalin-related soil protein (GRSP) using complementary synchrotron-based N and C X-ray absorption near-edge structure (XANES) spectroscopy, pyrolysis field ionization mass spectrometry (Py-FIMS), and proteomics techniques to characterize specific organic C and N fractions associated with glomalin production. Our research ultimately led us to conclude that the proteinaceous material extracted, and characterized in the literature, as GRSP is not exclusively of AMF origin. Our research supports the established concept that GRSP is important to soil quality, and C and N storage, irrespective of origin. However, efforts to manipulate this important soil C pool will remain compromised until we more clearly elucidate the chemical nature and origin of this resource.

Factors controlling N mineralization, nitrification, and nitrogen losses in an Oxisol amended with sewage sludge

Soil Research ◽  
2001 ◽  
Vol 39 (3) ◽  
pp. 519 ◽  
Author(s):  
J. Sierra ◽  
S. Fontaine ◽  
L. Desfontaines
Keyword(s):  
Sewage Sludge ◽  
Field Experiment ◽  
Water Content ◽  
N Mineralization ◽  
Initial Period ◽  
Factorial Experiment ◽  
Net N Mineralization ◽  
N Losses ◽  
Mineral N ◽  
The Difference

Laboratory incubations and a field experiment were carried out to determine the factors controlling N mineralization and nitrification, and to estimate the N losses (leaching and volatilization) in a sewage-sludge-amended Oxisol. Aerobically digested sludge was applied at a rate equivalent to 625 kg N/ha. The incubations were conducted as a factorial experiment of temperature (20˚C, 30˚C, and 40˚C) soil water (–30 kPa and –1500 kPa) sludge type [fresh (FS) water content 6230 g/kg; dry (DS) water content 50 g/kg]. The amount of nitrifiers was determined at the beginning and at the end of the experiment. The incubation lasted 24 weeks. The field study was conducted using bare microplots (4 m) and consisted of a factorial experiment of sludge type (FS and DS) sludge placement (subsurface, I+; surface, I–). Ammonia volatilization and the profile (0–0.90 m) of mineral N concentration were measured during 6 and 29 weeks after sludge application, respectively. After 24 weeks of incubation at 40˚C and –30 kPa, net N mineralization represented 52% (FS) and 71% (DS) of the applied N. The difference between sludges was due to an initial period of N immobilization in FS. Nitrification was more sensitive than N mineralization to changes in water potential and it was fully inhibited at –1500 kPa. The introduction of a large amount of nitrifiers with FS did not modify the rate of nitrification, which was principally limited by soil acidity (pH 4.9). Although N mineralization was greatest at 30˚C, nitrification increased continuously with temperature. Nitrogen mineralization from DS was well described by the double-exponential equation. For FS, the equation was modified to take into account an immobilization-remineralization period. Sludge placement significantly affected the soil NO-3/NH+4 ratio in the field: 16 for I+ and 1.5 for I–, after 11 weeks. In the I– treatment, nitrification of the released NH+4 was limited by soil moisture because of the dry soil mulch formed a few hours after rain. At the end of the field experiment, the estimated losses of N by leaching were 432 kg N/ha for I+ and 356 kg N/ha for I–. Volatilization was not detectable in the I+ microplots and it represented only 0.5% of the applied N in the I– microplots. The results showed that placement of sludge may be a valuable tool to decrease NO-3 leaching by placing the sludge under unfavourable conditions for nitrification.

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