Mineral nutrient uptake and removal by canola, Indian mustard, and Linola in two contrasting environments, and implications for carbon cycle effects on soil acidification

2002 ◽  
Vol 53 (4) ◽  
pp. 459 ◽  
Author(s):  
C. Santonoceto ◽  
P. J. Hocking ◽  
J. Braschkat ◽  
P. J. Randall
Keyword(s):  
Soil Acidification ◽  
Indian Mustard ◽  
Field Studies ◽  
Mineral Nutrients ◽  
Mineral Nutrient ◽  
Mineral N ◽  
Total N ◽  
Low Concentrations ◽  
Seed Yields ◽  
Excess Cations

Field studies of the oilseed crops canola, Indian mustard, and linseed/Linola were conducted over 2 seasons at 2 contrasting sites in the cropping regions of central and southern NSW to determine the uptake of mineral nutrients and quantities removed in seed. The sites were in the Junee region where production of these oilseeds is common, and at Condobolin, which is regarded as marginal for production of the crops. The 2 rates of nitrogen (N) fertiliser applied were either none or rates that growers in the Condobolin and Junee regions would apply to achieve high seed yields after a cereal crop in the rotation when soil mineral N is low. Concentrations of total N, the major cations (K, Ca, Mg, Na) and major anions (P, S, Cl), and the micronutrients Fe, Mn, Zn, and Cu were determined in shoots harvested at flowering and maturity. Nitrate and sulfate were also measured, and estimates were made of excess cation concentrations in the plant material. The ranges of concentrations of excess cations in shoots of the oilseeds at flowering were 83–206 cmolc/kg and 43–121 cmolc/kg for straw at maturity. Linola had lower concentrations of excess cations in vegetative material (83–108 and 43–82 cmolc/kg at flowering and maturity, respectively) than canola or Indian mustard. Concentrations of excess cations in seed of the crops were lower than for vegetative material, and ranged from 30 to 49 cmolc/kg. Nitrogen fertiliser had relatively little effect on concentrations of mineral nutrients or excess cations in either shoots at flowering and maturity, or in seed. However, N fertiliser increased the growth and seed yields of the crops, and thus the amounts of mineral nutrients and excess cations in shoots and seed. The results are discussed in the context of the depletion of soil nutrients due to their removal in harvested seed of the N-fertilised crops. The contribution of excess cation removal in seed to soil acidification is also discussed. It is estimated that the quantity of lime required to neutralise the acidity resulting from removal of 1 t seed is 22.4 kg for canola, 17.0 for Indian mustard, and 20.8 for linseed/Linola. Estimates of the relative contributions of seed removal and N fertiliser to soil acidification are presented.

Accumulation, distribution and redistribution of dry matter and mineral nutrients in fruits of canola (oilseed rape), and the effects of nitrogen fertilizer and windrowing

1993 ◽  
Vol 44 (6) ◽  
pp. 1377 ◽  
Author(s):  
PJ Hocking ◽  
L Mason
Keyword(s):  
Oilseed Rape ◽  
Dry Matter ◽  
Seed Oil ◽  
Dry Weight ◽  
Field Studies ◽  
Mineral Nutrients ◽  
P Efficiency ◽  
Current Recommendation ◽  
Zn And Cu In ◽  
Seed Yields

Field studies were made at Ariah Park and Cowra to investigate the accumulation and distribution of dry matter and 12 mineral nutrients in fruits (pods) of canola (oilseed rape), and to assess the significance of redistribution of nutrients from the pod walls to the seeds. Flowers 4-6 from the base of the primary inflorescence were tagged at anthesis, and pods which developed from these were harvested at weekly intervals until maturity. Pods reached maturity 82 days after anthesis of the parent flowers. N fertilizer increased seed yields at both sites, but had negligible effects on the dry matter per pod, pod length, 1000 seed wt, seed number per pod, seed oil concentration, and concentrations of mineral nutrients in the pod walls and seeds. Similarly, there were no differences in these parameters due to locality, with the exceptions that seed oil per cent and concentrations of S and Mn in the pod walls and IVln in seeds were higher at Cowra than at Ariah Park. Pods had attained their maximum length and fresh and dry weights by the end of the first half of their development, but seeds had accumulated only 35% of their mature dry weight at this stage. Seeds gained dry matter after dehydration of the fruit began, but the pod walls did not. Seeds had 61% of the pod's dry matter, >70% of its P, N, Zn, Fe and Mg, 30-55% of its K, S, Mn, Cu and Ca, but <20% of its Na and C1. Dry matter was redistributed from the pod walls with 20% efficiency, and nutrients with from 17% (Cu) to 88% (P) efficiency; however, there was negligible redistribution of K, S, Ca, Na, C1, Fe and Mn from the pod walls. Redistributed dry matter and nutrients from the pod walls could have provided from 11% (dry matter) to 25% (N) of the amount in mature seeds. Concentrations of N, P, Mg, Mn, Zn and Cu in the pod walls declined as they developed, whereas those of Ca and Cl increased. Concentrations of nutrients in developing seeds remained fairly static. Windrowing plants when 40% of the seeds had changed to their mature colour did not affect seed oil per cent or concentrations of nutrients, but reduced seed size and seed yields by 10%. Data from the pod study also support the current recommendation to windrow when 40-60% of seeds reach their mature colour.

Flood irrigation of wheat on a transitional red-brown earth. II. Effect of duration of ponding on availability of soil and fertilizer nitrogen

1991 ◽  
Vol 42 (7) ◽  
pp. 1037 ◽  
Author(s):  
E Humphreys ◽  
FM Melhuish ◽  
ZB Xi ◽  
RJG White ◽  
WA Muirhead
Keyword(s):  
Wheat Yield ◽  
Soil Layer ◽  
Experimental Period ◽  
Field Studies ◽  
Soil N ◽  
N Loss ◽  
Mineral N ◽  
Total N ◽  
Denitrification Potential ◽  
Soil Recovery

Grain yield of wheat growing on a transitional red-brown earth was reduced by long periods of ponding during irrigation. To determine whether fertilizer N loss was a major cause of this yield decline, 15N-labelled urea was applied to microplots at the same time and rate as the crop was topdressed with urea (end of tillerfng, 100 kg N ha-1). In addition, 15N-labelled nitrate was used to assess denitrification potential during and after each irrigation. Prior to the first irrigation (19days after urea application), 76% of the urea N was immobilized in the plants (33%) and soil (43%), 15% was present as soil mineral N, and 9% was not accounted for. The majority (85%) of the urea-derived mineral N was present as ammonium in the 0-0.1 m soil layer. After the first irrigation, amounts of mineral N in the soil remained very low at 3-6 kg N ha-l in the 0-0.2 m layer, with only 5-15% of this in the nitrate form. There was no significant effect of duration of ponding on plant or soii recovery of urea N after any irrigation. Mean plant recovery increased to 52%, over the first 55 days following urea application, while soil recovery declined to 22%. Beyond this stage changes in plant and soil recoveries were negligible. Plant total N content increased throughout the season due to ongoing mineralization of native soil N; however, there was negligible net mineralization of recently immobilized 15N beyond day 55. At physiological maturity, 46% of the N acquired by the plants was derived from the fertilizer. Losses of urea N increased to 25% over the first 55 days, and appeared to be due to nitrification-denitrification. Field studies with labelled nitrate indicated that denitrification potential in the soil was high throughout the experimental period. After the final two irrigations there were some significant (P < 0.05) effects of duration of ponding on N loss from urea, with lowest losses in the sprinkler, 1 h and 12 h treatments. The data indicate that, on the transitional red-brown earth, the adverse effect of long periods of ponding on wheat yield was not due to decreased availability or uptake of fertilizer or soil N in the longer term.

scholarly journals Effects of two wood-based biochars on the fate of added fertilizer nitrogen—a 15N tracing study

2021 ◽  
Author(s):  
Subin Kalu ◽  
Gboyega Nathaniel Oyekoya ◽  
Per Ambus ◽  
Priit Tammeorg ◽  
Asko Simojoki ◽  
...  
Keyword(s):  
Plant Uptake ◽  
Plant Biomass ◽  
Application Rate ◽  
Control Treatment ◽  
Organic N ◽  
N Leaching ◽  
Soil N ◽  
Mineral N ◽  
Total N ◽  
Application Rates

AbstractA 15N tracing pot experiment was conducted using two types of wood-based biochars: a regular biochar and a Kon-Tiki-produced nutrient-enriched biochar, at two application rates (1% and 5% (w/w)), in addition to a fertilizer only and a control treatment. Ryegrass was sown in pots, all of which except controls received 15N-labelled fertilizer as either 15NH4NO3 or NH415NO3. We quantified the effect of biochar application on soil N2O emissions, as well as the fate of fertilizer-derived ammonium (NH4+) and nitrate (NO3−) in terms of their leaching from the soil, uptake into plant biomass, and recovery in the soil. We found that application of biochars reduced soil mineral N leaching and N2O emissions. Similarly, the higher biochar application rate of 5% significantly increased aboveground ryegrass biomass yield. However, no differences in N2O emissions and ryegrass biomass yields were observed between regular and nutrient-enriched biochar treatments, although mineral N leaching tended to be lower in the nutrient-enriched biochar treatment than in the regular biochar treatment. The 15N analysis revealed that biochar application increased the plant uptake of added nitrate, but reduced the plant uptake of added ammonium compared to the fertilizer only treatment. Thus, the uptake of total N derived from added NH4NO3 fertilizer was not affected by the biochar addition, and cannot explain the increase in plant biomass in biochar treatments. Instead, the increased plant biomass at the higher biochar application rate was attributed to the enhanced uptake of N derived from soil. This suggests that the interactions between biochar and native soil organic N may be important determinants of the availability of soil N to plant growth.

scholarly journals Effects of green-manure and tillage management on soil microbial community composition, nutrients and tree growth in a walnut orchard

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ningguang Dong ◽  
Guanglong Hu ◽  
Yunqi Zhang ◽  
Jianxun Qi ◽  
Yonghao Chen ◽  
...  
Keyword(s):  
Microbial Community ◽  
Green Manure ◽  
Rhizosphere Soil ◽  
Green Manures ◽  
Hairy Vetch ◽  
Mineral N ◽  
Total N ◽  
Organic C ◽  
Nutrient Contents ◽  
Walnut Tree

AbstractThis study characterized the effect of green manures (February orchid, hairy vetch, rattail fescue and a no-green-manure control) and the termination method (flail or disk) on nutrient contents, enzyme activities, microbial biomass, microbial community structure of rhizosphere soil and vegetative growth of walnut tree. All three selected green manures significantly enhanced the water content, organic C, total N and available P. The rattail fescue significantly decreased the mineral N. Total organic C, total N, mineral N and available P were significantly greater under flail than under disk. Hairy vetch and February orchid significantly improved levels of soil β-glucosidase, N-acetyl-glucosaminidase and acid phosphatase activity, whereas rattail fescue improved only β-glucosidase activity. All of the green manures significantly decreased phenoloxidase activity. β-glucosidase, N-acetyl-glucosaminidase and acid phosphatase activities were significantly greater under flail relative to disk. The termination method had no significant effect on phenoloxidase activity. The different types of green manures and termination methods significantly altered the soil microbial biomass and microbial community structure. The green-manure treatments were characterized by a significantly greater abundance of Gram-positive (Gram +) bacteria, total bacteria and saprophytic fungi compared to the control. Hairy vetch significantly decreased the abundance of arbuscular mycorrhizal fungi (AMF) while February orchid and rattail fescue increased their abundance compared to the no-green-manure treatment. The abundance rates of Gram+ bacteria, actinomycetes, saprophytic fungi and AMF were significantly greater in soils under flail than under disk. In terms of vegetative growth of walnut tree, hairy vetch showed the greatest positive effects. The growth of walnut tree was significantly greater under flail relative to disk. Our results indicate that green-manure application benefits the rhizosphere soil micro-ecology, rhizosphere soil nutrient contents and tree growth. Overall, the hairy vetch and flail combined treatment is recommended for walnut orchards in northern China.

The relative feeding value of kale (Brassica oleracea) containing normal and low concentrations of S-methyl-L-cysteine sulphoxide (SMCO)

1984 ◽  
Vol 102 (3) ◽  
pp. 635-643 ◽  
Author(s):  
T. N. Barry ◽  
T. R. Manley ◽  
K. R. Millar ◽  
R. H. Smith
Keyword(s):  
Haemolytic Anaemia ◽  
Severe Anaemia ◽  
Blood Concentrations ◽  
Total N ◽  
Dimethyl Disulphide ◽  
Low Concentrations ◽  
Lower Blood ◽  
Feeding Value ◽  
Endocrine Factors ◽  
Oral Supplements

SummaryKale of normal and low S-methyl-L-cysteine sulphoxide (SMCO) content was produced by growing the same cultivar in soils of normal (20–30 mg/kg) and low (5–10 mg/ kg) soil sulphate-S concentration. Compared with normal S plots, kale grown in low S plots showed little or no reduction in D.M. yield or total N content, but contained lower concentrations of inorganic sulphate, SMCO and glucosinolates.Replicated plots of normal and low SMCO kale were grazed by lambs for 12-week periods in two consecutive years, using a fixed crop allowance of 2·5 kg D.M./animal/ day. All animals were given injections of copper and iodine, and oral supplements of selenium, to ensure that effects upon animal performance could largely be attributed to differences in kale SMCO concentration.SMCO concentration in the diet consumed by lambs grazing normal and low SMCO kale was respectively 0·60 and 0·35% D.M. Following the onset of kale feeding, all animals developed subclinical haemolytic anaemia which stabilized by week 6, and was more marked during weeks 1–6 than during weeks 7–12. Animals grazing low SMCO kale showed a less severe anaemia than those grazing normal SMCO kale, which was associated with lower blood concentrations of dimethyl disulphide and Heinz bodies, and higher reduced glutathione (GSH) and packed cell volume (PCV) levels. Liveweight gain and wool growth were greater for lambs grazing low than normal SMCO kale during weeks 1–6, corresponding to the period of most severe haemolytic anaemia, but during weeks 7–12 there were no differences between the two groups.It was concluded that SMCO content depressed kale feeding value, with most of the depression occurring in the first 6 weeks of grazing, and that in these experiments the lambs were able to adapt to kale containing 0·6% D.M. as SMCO after 6 weeks of feeding. Endocrine factors involved in this adaptation are discussed.

Response of alfalfa and sugar beet to field dodder (Cuscuta campestris Yunck.) parasitism: a physiological and anatomical approach

2019 ◽  
Vol 99 (2) ◽  
pp. 199-209 ◽  
Author(s):  
Marija Saric-Krsmanovic ◽  
Dragana Bozic ◽  
Ljiljana Radivojevic ◽  
Jelena Gajic Umiljendic ◽  
Sava Vrbnicanin
Keyword(s):  
Sugar Beet ◽  
Mineral Nutrients ◽  
Flowering Plant ◽  
Mineral Nutrient ◽  
Vascular Bundles ◽  
Nutrient Contents ◽  
Cuscuta Campestris ◽  
Organic Nutrients ◽  
Leaf Parameters ◽  
Anatomical Parameters

The physiological and anatomical impact of field dodder (Cuscuta campestris Yunck.) on alfalfa and sugar beet was examined under controlled conditions. The following parameters were checked: physiological — content of pigments (chlorophyll a, chlorophyll b, and carotenoids) and mineral nutrients: nitrogen, phosphorus, potassium, and percent of organic and mineral nutrients; and anatomical — thickness of the epidermis and cortex, diameter of the stem and central cylinder of alfalfa plants, diameter of tracheids and phloem cells, area of xylem and phloem, and hydraulic conductance of petiole bundles in petiole vascular bundles of sugar beet plants. Leaf parameters were also measured on both host plants: thickness of upper and underside leaf epidermis, thickness of palisade, spongy and mesophyll tissue, and diameter of vascular bundle cells. Pigments content and anatomical parameters were measured 7, 14, 21, 28, 35, and 42 d after infestation (DAI), while mineral nutrient contents were determined 20 and 40 DAI. Field dodder caused a significant reduction in pigments content in infested alfalfa (15%–68%) and sugar beet plants (1%–54%). The results obtained in this study confirmed that this parasitic flowering plant has a strong effect on most anatomical parameters of the stem and leaf of alfalfa and leaf and petiole of sugar beet. Also, it was revealed that field dodder increased the contents of N, P2O5, K2O, and organic nutrients in infested alfalfa plants, while infested sugar beet plants had higher contents of N and organic nutrients compared with non-infested plants.

scholarly journals A comparison of nitrogen and carbon reserves in acid sulphate and non acid sulphate soils in western Finland

2008 ◽  
Vol 14 (1) ◽  
pp. 57 ◽  
Author(s):  
M. PAASONEN-KIVEKÄS ◽  
M. YLI-HALLA
Keyword(s):  
Groundwater Level ◽  
Agricultural Practices ◽  
Density Field ◽  
Mineral N ◽  
Total N ◽  
N Retention ◽  
Acid Sulphate ◽  
Agricultural Catchments ◽  
Acid Sulphate Soils ◽  
C And N

Previous studies suggest that nitrogen (N) loads from acid sulphate soil (AS soil) catchments in Finland are higher than those from other agricultural catchments. This study seeks to explain this difference by measuring carbon (C) and N profiles in both an AS soil and a neighbouring non AS soil. In Lapua, western Finland, two adjacent fields (Dystric Cambisols), subjected to similar agricultural practices, were analysed to the depth of 240 cm for pH, total C (Ctot), total N (Ntot), NH4 +-N, NO3 --N, sulphur and bulk density. Field A, an AS soil, contained sulfidic materials and 0.9% Ctot below 170 cm, while Field B, not an AS soil, had 0.3% Ctot in the subsoil and no sulfides. In these soils, the groundwater level declined below 200 cm in summer, subjecting the subsoil to oxidation. This study revealed large stocks of Ctot, Ntot, and mineral N in the subsoil, particularly in the AS soil. At 20–240 cm, Field A contained 292 tons of Ctot ha-1 and 25 tons of Ntot ha-1, while Field B had 152 tons of Ctot ha-1 and 11 tons of Ntot ha-1. Field A contained up to 435 kg of mineral N ha-1 in autumn, while in Field B there was only up to 137 kg of mineral N ha-1. In Field A, NH4 +-N dominated strongly, while NO3 --N dominated in Field B. It is suggested that the greater concentration of mineral N in the AS soil is due to 1) a greater stock of total (mineralizable) N and 2) the slower rate of nitrification resulting in substantial NH4 +-N retention on cation exchange sites.;

scholarly journals Residual effect of clover-rich leys on soil nitrogen and successive grain crops

2008 ◽  
Vol 17 (1) ◽  
pp. 73 ◽  
Author(s):  
A. NYKÄNEN ◽  
A. GRANSTEDT ◽  
L. JAUHIAINEN
Keyword(s):  
Field Experiments ◽  
Clayey Soil ◽  
N Uptake ◽  
Residual Effect ◽  
Red Clover ◽  
N Leaching ◽  
N Fixation ◽  
Mineral N ◽  
Total N ◽  
Biological N Fixation

Legume-based leys form the basis for crop rotations in organic farming as they fix nitrogen (N) from the atmosphere for the succeeding crops. The age, yield, C:N, biological N fixation (BNF) and total N of red clover-grass leys were studied for their influence on yields, N uptake and N use efficiency (NUE) of the two sequential cereal crops planted after the leys. Mineral N in deeper soil (30-90 cm) was measured to determine N leaching risk. Altogether, four field experiments were carried out in 1994-1998 at two sites. The age of the ley had no significant effect on the yields and N uptake of the two subsequent cereals. Surprisingly, the residual effect of the leys was negligible, at 0–20 kg N ha-1yr-1. On the other hand, the yield and C:N of previous red clover-grass leys, as well as BNF-N and total-N incorporated into the soil influenced subsequent cereals. NUEs of cereals after ley incorporation were rather high, varying from 30% to 80%. This might indicate that other factors, such as competition from weeds, prevented maximal growth of cereals. The mineral N content deeper in the soil was mostly below 10 kg ha-1 in the sandy soil of Juva, but was 5-25 kg ha-1 in clayey soil of Mietoinen.;

scholarly journals Indian Mustard and Allyl Isothiocyanate Inhibit Sclerotium rolfsii

2002 ◽  
Vol 127 (1) ◽  
pp. 27-31 ◽  
Author(s):  
Stephanie G. Harvey ◽  
Heather N. Hannahan ◽  
Carl E. Sams
Keyword(s):  
Treatment Effect ◽  
Radial Growth ◽  
Mycelial Growth ◽  
Sclerotium Rolfsii ◽  
Indian Mustard ◽  
Allyl Isothiocyanate ◽  
Potato Dextrose Agar ◽  
Soilborne Pathogen ◽  
Low Concentrations ◽  
Sclerotial Germination

Allyl isothiocyanate (AITC) is the predominant isothiocyanate produced by damaged tissues of Indian mustard (Brassica juncea (L) Czerniak). This study investigated Indian mustard and AITC mediated suppression of mycelial growth and sclerotial germination of Sclerotium rolfsii Saccardo, a common soilborne pathogen. Indian mustard (IM) treatments of 0, 0.1, 0.2, 0.6, 1.0, 2.0, 4.1, 5.1, 10.2, 20.4, 40.8, 81.6, and 163.3 g·L-1 (weight of reconstituted mustard per liter of air) were evaluated for suppression of mycelial growth. Treatment effect was evaluated by measuring the radial growth of mycelia. Sclerotia were placed in culture tubes containing 18 g autoclaved soil and covered with an additional 5 g soil. AITC at concentrations of 0, 4.0, 16.0, 64.0, 256.0, 1024.0, or 4096.0 μmol·L-1 was injected into the tubes. Treated sclerotia were removed from tubes and plated on potato dextrose agar to determine viability. Mycelial growth was inhibited with IM treatments (P < 0.01). Inhibiting concentrations (IC) of IM for mycelial growth inhibition of 50% and 90% were 0.7 and 1.0 g·L-1, respectively, with death resulting with >2 g·L-1. Inhibition attributable to AITC alone was lower than that achieved by IM producing equivalent amounts of AITC. Germination of sclerotia was negatively correlated with AITC concentration (r = 0.96; P < 0.01). The IC50 and IC90, of AITC were 249.0 and 528.8 μmol·L-1, respectively, at 42 hours. The lethal concentration for sclerotia was not reached; only suppression occurred at the highest treatment concentrations. Sclerotium rolfsii mycelia were sensitive to the IM volatiles and were suppressed at low concentrations. Sclerotia were more resistant than the mycelia and required higher concentrations of AITC to suppress germination.

Gross rates of soil N2O emission and uptake and denitrification gene abundance in temperate cropland agroforestry and monoculture systems

2021 ◽  
Author(s):  
Jie Luo ◽  
Lukas Beule ◽  
Guodong Shao ◽  
Edzo Veldkamp ◽  
Marife D. Corre
Keyword(s):  
Greenhouse Gas ◽  
Management Systems ◽  
Soil N ◽  
Soil Mineral N ◽  
Soil Mineral ◽  
Mineral N ◽  
Total N ◽  
Soil P ◽  
Gene Abundance ◽  
Denitrification Gene

&lt;p&gt;Monoculture croplands are considered as major sources of the greenhouse gas, nitrous oxide (N&lt;sub&gt;2&lt;/sub&gt;O). The conversion of monoculture croplands to agroforestry systems, e.g., integrating trees within croplands, is an essential climate-smart management system through extra C sequestration and can potentially mitigate N&lt;sub&gt;2&lt;/sub&gt;O emissions. So far, no study has systematically compared gross rates of N&lt;sub&gt;2&lt;/sub&gt;O emission and uptake between cropland agroforestry and monoculture. In this study, we used an in-situ &lt;sup&gt;15&lt;/sup&gt;N&lt;sub&gt;2&lt;/sub&gt;O pool dilution technique to simultaneously measure gross N&lt;sub&gt;2&lt;/sub&gt;O emission and uptake over two consecutive growing seasons (2018 - 2019) at three sites in Germany: two sites were on Phaeozem and Cambisol soils with each site having a pair of cropland agroforestry and monoculture systems, and an additional site with only monoculture on an Arenosol soil prone to high nitrate leaching. Our results showed that cropland agroforestry had lower gross N&lt;sub&gt;2&lt;/sub&gt;O emissions and higher gross N&lt;sub&gt;2&lt;/sub&gt;O uptake than in monoculture at the site with Phaeozem soil (P &amp;#8804; 0.018 &amp;#8211; 0.025) and did not differ in gross N&lt;sub&gt;2&lt;/sub&gt;O emissions and uptake with cropland monoculture at the site with Cambisol soil (P &amp;#8805; 0.36). Gross N&lt;sub&gt;2&lt;/sub&gt;O emissions were positively correlated with soil mineral N and heterotrophic respiration which, in turn, were correlated with soil temperature, and with water-filled pore space (WFPS) (r = 0.24 &amp;#8210; 0.54, P &lt; 0.01). Gross N&lt;sub&gt;2&lt;/sub&gt;O emissions were also negatively correlated with nosZ clade I gene abundance (involved in N&lt;sub&gt;2&lt;/sub&gt;O-to-N&lt;sub&gt;2&lt;/sub&gt; reduction, r = -0.20, P &lt; 0.05). These findings showed that across sites and management systems changes in gross N&lt;sub&gt;2&lt;/sub&gt;O emissions were driven by changes in substrate availability and aeration condition (i.e., soil mineral N, C availability, and WFPS), which also influenced denitrification gene abundance. The strong regression values between gross N&lt;sub&gt;2&lt;/sub&gt;O emissions and net N&lt;sub&gt;2&lt;/sub&gt;O emissions (R&lt;sup&gt;2 &lt;/sup&gt;&amp;#8805; 0.96, P &lt; 0.001) indicated that gross N&lt;sub&gt;2&lt;/sub&gt;O emissions largely drove net soil N&lt;sub&gt;2&lt;/sub&gt;O emissions. Across sites and management systems, annual soil gross N&lt;sub&gt;2&lt;/sub&gt;O emissions and uptake were controlled by clay contents which, in turn, correlated with indices of soil fertility (i.e., effective cation exchange capacity, total N, and C/N ratio) (Spearman rank&amp;#8217;s rho = -0.76 &amp;#8211; 0.86, P &amp;#8804; 0.05). The lower gross N&lt;sub&gt;2&lt;/sub&gt;O emissions from the agroforestry tree rows at two sites indicated the potential of agroforestry in reducing soil N&lt;sub&gt;2&lt;/sub&gt;O emissions, supporting the need for temperate cropland agroforestry to be considered in greenhouse gas mitigation policies.&lt;/p&gt;

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