Soil-N cycling in temperate alley cropping agroforestry and monoculture croplands

2021 ◽  
Author(s):  
Xenia Bischel ◽  
Marife D. Corre ◽  
Marcus Schmidt ◽  
Edzo Veldkamp
Keyword(s):  
Environmental Effects ◽  
Western Europe ◽  
Management Practices ◽  
Alley Cropping ◽  
Pore Space ◽  
Agroforestry Systems ◽  
N Cycling ◽  
Soil N ◽  
Soil C ◽  
Gene Abundance

<p>Monoculture croplands are commonly associated with deleterious environmental effects due to high fertilization rates. Agroforestry (alternate alleys of trees and crops or alley cropping) has the potential to mitigate the negative environmental effects from agriculture. Understanding the soil-N cycling aids in assessing how the soil function of nutrient cycling is impacted when monoculture system is converted into agroforestry. Currently, there is no systematic comparison in soil-N cycling rates between monoculture and agroforestry croplands in Western Europe. Our study aimed to investigate gross rates of soil-N cycling between agroforestry and monoculture croplands. We measured gross rates of soil-N cycling, using 15N isotopic pool dilution in May-June 2017, at three sites in Germany (Wendhausen, Dornburg, and Forst with Vertic Cambisol, Calcaric Phaeozem, Gleyic Cambisol soils, respectively); each site has paired monoculture and agroforestry systems (established in 2008, 2007, and 2010 at the respective sites). In each management system at each site, we had four replicate plots; for agroforestry system, we conducted measurements in the tree row and within the crop row at 1 m, 4 m, and 7 m from the tree row. The crop management practices in agroforestry crop row and monoculture were the same at each site.</p><p>For gross rates of ammonium cycling, differences were observed between agroforestry tree row, crop row and monoculture at the site with Vertic Cambisol soil. Higher gross N mineralization rates were observed in monoculture than agroforestry tree row whilst agroforestry tree row exhibited higher gross NH<sub>4</sub><sup>+</sup> immobilization rates than agroforestry crop row (P < 0.02). This was correlated to higher soil C/N ratio and higher water-filled pore space in the tree row. Tree rows also tend to have higher microbial biomass at all sites. Gross rates of nitrate cycling were higher in the tree row than in the crop row and monoculture at the site with Calcaric Phaeozem soil. This showed a similar pattern with the gene abundance of ammonium oxidizing archeae (AOA), supporting a niche differentiation of AOA by utilizing ammonium mineralized from soil organic matter rather than from fertilizer source. At the site with Vertic Cambisol soil, dissimilatory nitrate reduction to ammonium was very high in the tree row. These changes in soil-N cycling and AOA gene abundance in the tree rows suggest that trees in sites with older agroforestry systems had enhanced the cycling of N in the soil.</p>

Effects of restorative agroecosystems on soil characteristics and plant production on a degraded soil in the Georgia Piedmont, USA

2009 ◽  
Vol 24 (3) ◽  
pp. 186-196 ◽  
Author(s):  
K.L. Jacobsen ◽  
C.F. Jordan
Keyword(s):  
Management Practices ◽  
Alley Cropping ◽  
Conservation Tillage ◽  
Soil Characteristics ◽  
Plant Production ◽  
Hot Pepper ◽  
Organic Management ◽  
Soil C ◽  
Winter Cover ◽  
Georgia Piedmont

AbstractThis work presents the results of a three-year field study of agroecosystems designed to restore soil organic matter (SOM) to degraded soils of the Georgia Piedmont. The systems combine a suite of management practices previously demonstrated to increase SOM when studied individually, and examine the effects of these techniques when used in combination in a cropping systems context on soil characteristics, crop production and weed biomass. The systems' components include organic management, alley cropping with perennial legumes, conservation tillage, use of winter cover crops, straw mulch and two compost application rates. Vegetable crops grown were a rotation of okra, hot pepper and a corn and winter squash intercrop. The systems were not able to maintain soil C or N without the addition of compost. Systems incorporating alley cropping, organic management, conservation tillage and compost maintained soil C, and increased in soil C when mulch was not applied. In organic, conservation tillage without alley cropping, soil C did not change significantly, even with annual 44.8 Mg ha−1 of compost additions. Patterns for soil N followed those of soil C. The study demonstrated that alley cropping can maintain and sequester soil C and N beyond organic conservation tillage alone, and more than conventionally tilled, chemically fertilized treatments. Crop yields did not vary by treatment due to high variation within treatments. Winter cover crop residue provided an effective weed barrier for 4 to 6 weeks in the spring, but additional hand weeding was required throughout the summer. The results of this systems-level study demonstrated interactions between management practices when used in combination that would not have been observed when studied individually. It also demonstrates that agroforestry techniques, conservation tillage and compost applications can increase soil C in degraded, clayey soils while they are in cultivation.

scholarly journals Introduction of Dalbergia odorifera enhances nitrogen absorption on Eucalyptus through stimulating microbially mediated soil nitrogen-cycling

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xianyu Yao ◽  
Qianchun Zhang ◽  
Haiju Zhou ◽  
Zhi Nong ◽  
Shaoming Ye ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Ph ◽  
N Cycling ◽  
N Availability ◽  
Soil N ◽  
Total N ◽  
Available N ◽  
Soil C ◽  
Hot Season ◽  
Dalbergia Odorifera

Abstract Background There is substantial evidence that Eucalyptus for nitrogen (N) absorption and increasing the growth benefit from the introduction of N-fixing species, but the underlying mechanisms for microbially mediated soil N cycling remains unclear. Methods We investigated the changes of soil pH, soil water content (SWC), soil organic carbon (SOC), total N (TN), inorganic N (NH4+-N and NO3−-N), microbial biomass and three N-degrading enzyme activities as well as the biomass and N productivity of Eucalyptus between a pure Eucalyptus urophylla × grandis plantation (PP) and a mixed Dalbergia odorifera and Eucalyptus plantation (MP) in Guangxi Zhuang Autonomous Region, China. Results Compared with the PP site, soil pH, SWC, SOC and TN in both seasons were significantly higher at the MP site, which in turn enhanced microbial biomass and the activities of soil N-degrading enzymes. The stimulated microbial activity at the MP site likely accelerate soil N mineralization, providing more available N (NH4+-N in both seasons and NO3−-N in the wet-hot season) for Eucalyptus absorption. Overall, the N productivity of Eucalyptus at the MP site was increased by 19.7% and 21.9%, promoting the biomass increases of 15.1% and 19.2% in the dry-cold season and wet-hot season, respectively. Conclusion Our results reveal the importance of microbially mediated soil N cycling in the N absorption on Eucalyptus. Introduction of D. odorifera enhances Eucalyptus biomass and N productivity, improve soil N availability and increased soil C and N concentration, which hence can be considered to be an effective sustainable management option of Eucalyptus plantations.

CARBON STOCKS, LITTERFALL AND PRUNING RESIDUES IN MONOCULTURE AND AGROFORESTRY CACAO PRODUCTION SYSTEMS

2018 ◽  
Vol 55 (3) ◽  
pp. 452-470 ◽  
Author(s):  
ULF SCHNEIDEWIND ◽  
WIEBKE NIETHER ◽  
LAURA ARMENGOT ◽  
MONIKA SCHNEIDER ◽  
DANIELA SAUER ◽  
...  
Keyword(s):  
Management Practices ◽  
Stand Structure ◽  
Production Systems ◽  
Plant Biomass ◽  
Farming Systems ◽  
C Sequestration ◽  
Agroforestry Systems ◽  
Soil C ◽  
C Stocks ◽  
Pruning Residues

SUMMARYAgroforestry systems (AFS) can serve to decrease ecosystem carbon (C) losses caused by deforestation and inadequate soil management. Because of their shade tolerance, cacao plants are suitable to be grown in AFS, since they can be combined with other kinds of trees and shrubs. The potential for C sequestration in cacao farming systems depends on various factors, such as management practices, stand structure and plantation age. We compared conventionally and organically managed cacao monoculture systems (MCS) and AFS in Sara Ana (Bolivia) with respect to C stocks in plant biomass and to amounts of litterfall and pruning residues. The total aboveground C stocks of the AFS (26 Mg C ha−1) considerably exceeded those of the MCS (~7 Mg C ha−1), although the biomass of cacao trees was greater in the MCS compared to the AFS. Due to higher tree density, annual litterfall in the AFS (2.2 Mg C ha−1 year−1) substantially exceeded that in the MCS (1.2 Mg C ha−1 year−1). The amounts of C in pruning residues (2.6 Mg C ha−1 year−1 in MCS to 4.3 Mg C ha−1 year−1 in AFS) was more than twice those in the litterfall. Annual nitrogen (N) inputs to the soil through pruning residues of cacao and N-fixing trees were up to 10 times higher than the N inputs through external fertiliser application. We conclude that appropriate management of cacao AFS, involving the pruning of leguminous trees, will lead to increases in biomass, litter quantity and quality as well as soil C and N stocks. Thus, we recommend stimulating the expansion of well-managed AFS to improve soil fertility and enhance C sequestration in soils.

scholarly journals Nitrogen isotopic composition of plants and soil in an arid mountainous terrain: sunny slope versus shady slope

2017 ◽  
Author(s):  
Chongjuan Chen ◽  
Yufu Jia ◽  
Yuzhen Chen ◽  
Imran Mehmood ◽  
Yunting Fang ◽  
...  
Keyword(s):  
Environmental Effects ◽  
Regional Scale ◽  
Local Environment ◽  
Global Scale ◽  
Influential Factors ◽  
N Cycling ◽  
N Availability ◽  
Soil N ◽  
The Difference ◽  
Soil Δ15n

Abstract. Nitrogen cycling is tightly associated with environment. Sunny slope of a given mountain could significantly differ from shady slope in environment. Thus, N cycling should also be different between the two slopes. Since leaf δ15N, soil δ15N and △δ15Nleaf-soil (△δ15Nleaf-soil = leaf δ15N − soil δ15N) could reflect the N cycling characteristics, we put forward a hypothesis that leaf δ15N, soil δ15N and △δ15Nleaf-soil should differ across the two slopes. However, such a comparative study between two slopes has never been conducted yet. In addition, environmental effects on leaf and soil δ15N derived from studies at global scale were often found to be different from that at regional scale. This led to our argument that environmental effects on leaf and soil δ15N could depend on local environment. To confirm our hypothesis and argument, we measured leaf and soil δ15N on the sunny and shady slopes of Mount Tianshan. Remarkable environment differences between the two slopes provided an ideal opportunity for our test. The study showed that leaf δ15N, soil δ15N and △δ15Nleaf-soil on the sunny slope were greater than that on the shady slope although the difference in soil δ15N was not significant. The result confirmed our hypothesis and suggested that the sunny slope has higher soil N transformation rates and soil N availability than the shady slope. Besides, this study observed that the significant influential factors of leaf δ15N were temperature, precipitation, leaf N, leaf C / N and silt / clay ratio on the shady slope, whereas on the sunny slope only leaf C / N was related to leaf δ15N. The significant influential factors of soil δ15N were temperature, precipitation and silt / clay ratio on the shady slope, whereas on the sunny slope MAP and soil moisture exerted significant effects. Precipitation exerted contrary effects on soil δ15N between the two slopes. Thus, this study supported our argument that the relationships between leaf and soil δ15N and environmental factors are local-dependent.

Soil N2O emissions from temperate cropland agroforestry and monoculture systems

2021 ◽  
Author(s):  
Guodong Shao ◽  
Guntars Martinson ◽  
Jie Luo ◽  
Xenia Bischel ◽  
Dan Niu ◽  
...  
Keyword(s):  
Western Europe ◽  
Temporal Dynamics ◽  
Pore Space ◽  
Tree Age ◽  
Soil Types ◽  
N2o Emissions ◽  
N Availability ◽  
Soil N ◽  
Mineral N ◽  
Climate Conditions

<p>Monoculture cropland is a major contributor to agriculture-related sources of N<sub>2</sub>O emission, a potent greenhouse gas and an agent of ozone depletion. Cropland agroforestry has the potential to minimize deleterious environmental impacts. Presently, there is no systematic comparison of soil N<sub>2</sub>O emission between cropland agroforestry (CAF) and monoculture systems (MC) in Western Europe. Our study aimed to (1) quantify the spatial-temporal dynamics of soil N<sub>2</sub>O fluxes, and (2) determine their soil controlling factors in CAF and MC. We selected three sites with different soil types (Phaeozem, Cambisol, and Arenosol) in Germany. Each site has paired CAF and MC (agroforestry sites consisted of 12-m wide tree row and 48-m wide crop row and were established in 2007, 2008 and 2019 in these soil types, respectively). In each management system at each site, we had four replicate plots. In the CAF, we conducted measurements in the tree row and within the crop row at 1 m, 7 m, and 24 m from the tree row. We measured soil N<sub>2</sub>O fluxes monthly over 2 years (March 2018‒February 2020) using static vented chambers method. Following gas sampling, we also measured soil temperature, water-filled pore space (WFPS), and mineral N (NH<sub>4</sub><sup>+</sup> and NO<sub>3</sub><sup>-</sup>) within the same day. Across all sites, soil moisture and N availability were major drivers of soil N<sub>2</sub>O fluxes. Both CAF and MC were net sources of soil N<sub>2</sub>O at all sites. At the site with Phaeozem soil, annual soil N<sub>2</sub>O emissions from CAF in both years (1.84 ± 0.35 and 1.17 ± 0.30 kg N ha<sup>−</sup><sup>1</sup> yr<sup>−</sup><sup>1</sup>) were greater than MC (0.89 ± 0.09 and 0.34 ± 0.05 kg N ha<sup>−</sup><sup>1</sup> yr<sup>−</sup><sup>1</sup>) (<em>P</em> = 0.03). At the site with Cambisol soil, annual soil N<sub>2</sub>O emission did not differ between MC (0.49 ± 0.07 kg N ha<sup>−</sup><sup>1</sup> yr<sup>−</sup><sup>1</sup>) and CAF (0.73 ± 0.13 kg N ha<sup>−</sup><sup>1</sup> yr<sup>−</sup><sup>1</sup>) in 2018/2019 (<em>P</em> = 0.20) whereas in 2019/2020 MC was 134% greater than CAF (2.92 ± 0.45 and 1.25 ± 0.08 kg N ha<sup>−</sup><sup>1</sup> yr<sup>−</sup><sup>1</sup>, respectively; <em>P</em> = 0.03). The inter-annual differences were largely related to crop types and to climate conditions. At the site with Arenosol soil, there was no difference between CAF and MC. Our results indicated that CAF may decrease, maintain and/or increase soil N<sub>2</sub>O emissions compared to MC depending on tree age, soil characteristics, management and precipitation.</p>

Impacts of pine species, stump removal, cultivation, and fertilization on soil properties half a century after planting

2012 ◽  
Vol 42 (4) ◽  
pp. 675-685 ◽  
Author(s):  
J.R. Butnor ◽  
K.H. Johnsen ◽  
F.G. Sanchez ◽  
C.D. Nelson
Keyword(s):  
Management Practices ◽  
Basal Area ◽  
Soil Nutrient ◽  
Pinus Palustris ◽  
Pinus Elliottii ◽  
Species Selection ◽  
Soil N ◽  
Long Term Effects ◽  
Soil C ◽  
Pine Species

To better understand the long-term effects of species selection and forest management practices on soil quality and soil C retention, we analyzed soil samples from an experimental planting of loblolly ( Pinus taeda L.), longleaf ( Pinus palustris Mill.), and slash ( Pinus elliottii Engelm.) pines under different management intensities in Mississippi. The treatments included stump removal and cultivation (CULT), a one-time application of fertilizer combined with stump removal and cultivation (CULT+F), and a control (CON). After 49 years, pine species had no significant effect on any soil physical or chemical parameter examined, despite species differences in basal area. CULT exhibited significantly higher soil bulk density and lower soil C and soil N than CON and CULT+F in the upper 10 cm of soil. Stump removal is not a common practice in southern pine silviculture today; however, as demand for bioenergy fuels or feedstocks increases, more complete biomass utilization will be considered. Residual stumps play an important role in soil nutrient and C retention in pine plantations. Our results show that stump removal can lead to reduced soil C (–21%) and soil N (–35%) compared with controls, although it is possible to mitigate nutrient losses on poor sites with fertilization.

scholarly journals Mulching with pruned fronds promotes the internal soil N cycling and soil fertility in a large-scale oil palm plantation

2021 ◽  
Author(s):  
Greta Formaglio ◽  
Edzo Veldkamp ◽  
Muhammad Damris ◽  
Aiyen Tjoa ◽  
Marife D. Corre
Keyword(s):  
Microbial Biomass ◽  
Soil Fertility ◽  
Oil Palm ◽  
Large Scale ◽  
Management Practices ◽  
N Cycling ◽  
Organic N ◽  
Soil N ◽  
Total N ◽  
Organic C

AbstractIntensive management practices in large-scale oil palm plantations can slow down nutrient cycling and alter other soil functions. Thus, there is a need to reduce management intensity without sacrificing productivity. The aim of our study was to investigate the effect of management practices on gross rates of soil N cycling and soil fertility. In Jambi province, Indonesia, we established a management experiment in a large-scale oil palm plantation to compare conventional practices (i.e. high fertilization rates and herbicide weeding) with reduced management intensity (i.e. reduced fertilization rates and mechanical weeding). Also, we compared the typical management zones characterizing large-scale plantations: palm circle, inter-row and frond-stacked area. After 1.5 years of this experiment, reduced and conventional management showed comparable gross soil N cycling rates; however, there were stark differences among management zones. The frond-stacked area had higher soil N cycling rates and soil fertility (high microbial biomass, extractable C, soil organic C, extractable organic N, total N and low bulk density) than inter-row and palm circle (all p ≤ 0.05). Microbial biomass was the main driver of the soil N cycle, attested by its high correlation with gross N-cycling rates (r = 0.93–0.95, p < 0.01). The correlations of microbial N with extractable C, extractable organic N, soil organic C and total N (r = 0.76–0.89, p < 0.01) suggest that microbial biomass was mainly regulated by the availability of organic matter. Mulching with senesced fronds enhanced soil microbial biomass, which promoted nutrient recycling and thereby can decrease dependency on chemical fertilizers.

scholarly journals Interrelationships among soil nitrogen transformation rates, functional gene abundance and soil properties in a tropical forest with exogenous N inputs

2019 ◽  
Author(s):  
Yanxia Nie ◽  
Xiaoge Han ◽  
Jie Chen ◽  
Mengcen Wang ◽  
Weijun Shen
Keyword(s):  
N Deposition ◽  
N Cycling ◽  
Functional Gene ◽  
Soil N ◽  
Wet Season ◽  
Inorganic N ◽  
N Transformations ◽  
Gene Abundance ◽  
Functional Gene Abundance ◽  
N Additions

Abstract. Elevated nitrogen (N) deposition affects soil N transformations in the N-rich soil of tropical forests. However, the change in soil functional microorganisms responsible for soil N cycling remains largely unknown. Here, we investigated the variation in soil inorganic N content, net N mineralization (Rm), net nitrification (Rn), inorganic N leaching (Rl), N2O efflux and N-related functional gene abundance in tropical forest soil over a two-year period with four levels of N addition. The responses of soil N transformations (in situ Rm, Rn and Rl) to N additions were delayed during the first year of N inputs. The Rm, Rn, and Rl increased with the medium nitrogen (MN) and high nitrogen (HN) treatments relative to the control treatments in the second year of N additions. Furthermore, the Rm, Rn, and Rl were higher in the wet season than in the dry season. The Rm and Rn were predominately driven by the lower C : N ratio under N addition in the dry season but by higher microbial biomass in the wet season. Throughout the study period, high N additions increased the annual N2O emissions by 78 %. Overall, N additions significantly facilitated soil N availability (Rm and Rn) and N loss (Rl and N2O emission), which had a stimulating effect on N transformations. In addition, the MN and HN treatments increased the ammonia-oxidizing archaea (AOA) abundance by 17.3 % and 7.5 %, respectively. Meanwhile, the HN addition significantly increased the abundance of nirK-denitrifiers but significantly decreased the abundance of ammonia-oxidizing bacteria (AOB) and nosZ-containing N2O reducers. To some extent, the variation in functional gene abundance was related to the corresponding N transformation processes. Partial least squares path modelling (PLS-PM) indicated that inorganic N contents had significant negative direct effects on the abundances of N-related functional genes in the wet season, implying that chronic N deposition would have a negative effect on the N-cycling-related microbes and the function of N transformation.

scholarly journals Soil Health Management Enhances Microbial Nitrogen Cycling Capacity and Activity

mSphere ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Jialin Hu ◽  
Virginia L. Jin ◽  
Julie Y. M. Konkel ◽  
Sean M. Schaeffer ◽  
Liesel G. Schneider ◽  
...  
Keyword(s):  
Cover Crop ◽  
Management Practices ◽  
Health Management ◽  
Soil Health ◽  
N Fertilization ◽  
N Cycling ◽  
Soil N ◽  
Hairy Vetch ◽  
Inorganic N

ABSTRACT Soil microbial transformations of nitrogen (N) can be affected by soil health management practices. Here, we report in situ seasonal dynamics of the population size (gene copy abundances) and functional activity (transcript copy abundances) of five bacterial genes involved in soil N cycling (ammonia-oxidizing bacteria [AOB] amoA, nifH, nirK, nirS, and nosZ) in a long-term continuous cotton production system under different management practices (cover crops, tillage, and inorganic N fertilization). Hairy vetch (Vicia villosa Roth), a leguminous cover crop, most effectively promoted the expression of N cycle genes, which persisted after cover crop termination throughout the growing season. Moreover, we observed similarly high or even higher N cycle gene transcript abundances under vetch with no fertilizer as no cover crop with N fertilization throughout the cover crop peak and cotton growing seasons (April, May, and October). Further, both the gene and transcript abundances of amoA and nosZ were positively correlated to soil nitrous oxide (N2O) emissions. We also found that the abundances of amoA genes and transcripts both positively correlated to field and incubated net nitrification rates. Together, our results revealed relationships between microbial functional capacity and activity and in situ soil N transformations under different agricultural seasons and soil management practices. IMPORTANCE Conservation agriculture practices that promote soil health have distinct and lasting effects on microbial populations involved with soil nitrogen (N) cycling. In particular, using a leguminous winter cover crop (hairy vetch) promoted the expression of key functional genes involved in soil N cycling, equaling or exceeding the effects of inorganic N fertilizer. Hairy vetch also left a legacy on soil nutrient capacity by promoting the continued activity of N cycling microbes after cover crop termination and into the main growing season. By examining both genes and transcripts involved in soil N cycling, we showed different responses of functional capacity (i.e., gene abundances) and functional activity (i.e., transcript abundances) to agricultural seasons and management practices, adding to our understanding of the effects of soil health management practices on microbial ecology.

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