Exploitation of neighbouring subsoil for nutrient acquisition under annual-perennial strip intercropping systems

Little is known of how the deep root systems of perennial crops contribute to deeper and better resource use when intercropped with annuals in arable fields. Therefore, we aimed at measuring the capacity of perennial deep roots, alfalfa (Medicago sativa L.) and curly dock (Rumex crispus L.) to access the nutrient source located under the neighboring annuals at 1.0 and 2.5 m of soil depth. Alfalfa and curly dock were able to access the tracer-labelled source placed at a distance under the annual crop strips. As a result, the reliance on deeper soil layer for nutrient uptake under intercroppings became greater compared with sole-croppings. Combination of an annual cereal (winter rye) and a perennial legume (alfalfa) with contrasting root systems exhibited higher resource complementarity compared with intercroppings having similar root systems or absence of legumes. Our results demonstrated that the deep-rooted perennials when intercropped with annuals can induce vertical niche complementarity, especially at deeper soil layers. This was assumed to be due to the vertically stratified root activity between the crop components, however, the magnitude of the effects depended on choice of crop combinations, and on types of tracers. Future studies should include estimates such as relative yield total and land equivalent ratio to quantitatively determine the effects of resource acquisition under annual-perennial intercropping in arable fields.

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A study of root and shoot interactions between cereals and peas in mixtures

The Journal of Agricultural Science ◽

10.1017/s0021859600073548 ◽

1993 ◽

Vol 120 (1) ◽

pp. 13-24 ◽

Cited By ~ 34

Author(s):

M. P. Tofinga ◽

R. Paolini ◽

R. W. Snaydon

Keyword(s):

Relative Yield ◽

Root Competition ◽

Total Biomass ◽

N Content ◽

Total N ◽

Resource Complementarity ◽

Relative Yield Total ◽

Shoot Competition ◽

Competitive Abilities ◽

Different Sources

SUMMARYWheat, barley and two morphologically contrasting cultivars of peas (leafy and semi-leafless) were grown in pure stands, at standard agricultural densities, and in additive mixtures of cereals with peas. The stands were grown in boxes in the field, and partitions were used to separate the effects of root and shoot interactions. The cereals and peas were either planted at the same time, or one species was planted 10 days before the other. The origin of the N present in each species was determined by applying N fertilizer labelled with 15N.Both cultivars of peas had greater shoot and root competitive abilities than wheat or barley, probably because of their larger seed size; leafy peas had greater shoot and root competitive abilities than semi-leafless peas. Sowing peas after cereals reduced their competitive ability.The relative yield total (RYT) of cereal-pea mixtures, based on total biomass, averaged 1·6 when only the root systems interacted, and 1·4 when only the shoot systems interacted, but did not differ significantly from 10 when both root and shoot systems interacted. RYT values were greater when peas were grown with wheat, rather than with barley, and when peas were sown at the same time as the cereals.Shoot competition from peas increased the N% of cereals, but substantially reduced their total N content, because biomass yield was reduced. Shoot competition from cereals had no effect on the N% of peas, and only slightly reduced their total N content. Shoot competition between cereals and peas had no significant effect upon the proportion of N derived from various sources by either cereals or peas.Root competition from peas significantly reduced both the N% and total N content of cereals. Root competition from cereals had little effect on the N% of peas, but significantly reduced their total N content and increased the proportion of N derived from rhizobial fixation from 76 to 94%. Since cereals and peas largely used different sources of N, resource complementarity for N was probably an important component of intercropping advantage, when the roots of cereals and peas shared soil resources.

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Depth-Dependent C-N-P Stocks and Stoichiometry in Ultisols Resulting from Conversion of Secondary Forests to Plantations and Driving Forces

Forests ◽

10.3390/f12101300 ◽

2021 ◽

Vol 12 (10) ◽

pp. 1300

Author(s):

Xiaogang Ding ◽

Xiaochuan Li ◽

Ye Qi ◽

Zhengyong Zhao ◽

Dongxiao Sun ◽

...

Keyword(s):

Soil Depth ◽

Soil Layer ◽

Pinus Elliottii ◽

Slash Pine ◽

Pine Plantations ◽

Secondary Forests ◽

Masson Pine ◽

Soil Layers ◽

Soil C ◽

Significant Difference

Stocks and stoichiometry of carbon (C), nitrogen (N), and phosphorus (P) in ultisols are not well documented for converted forests. In this study, Ultisols were sampled in 175 plots from one type of secondary forest and four plantations of Masson pine (Pinus massoniana Lamb.), Slash pine (Pinus elliottii Engelm.), Eucalypt (Eucalyptus obliqua L’Hér.), and Litchi (Litchi chinensis Sonn., 1782) in Yunfu, Guangdong province, South China. Five layers of soil were sampled with a distance of 20 cm between two adjacent layers up to a depth of 100 cm. We did not find interactive effects between forest type and soil layer depth on soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) concentrations and storages. Storage of SOC was not different between secondary forests and Eucalypt plantations, but SOC of these two forest types were lower than that in Litchi, Masson pine, and Slash pine plantations. Soil C:P was higher in Slash pine plantations than in secondary forests. Soil CNP showed a decreasing trend with the increase of soil depth. Soil TP did not show any significant difference among soil layers. Soil bulk density had a negative contribution to soil C and P stocks, and longitude and elevation were positive drivers for soil C, N, and P stocks. Overall, Litchi plantations are the only type of plantation that obtained enhanced C storage in 0–100 cm soils and diverse N concentrations among soil layers during the conversion from secondary forests to plantations over ultisols.

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Effects of different biomass materials as a salt-isolation layer on water and salt migration in coastal saline soil

PeerJ ◽

10.7717/peerj.11766 ◽

2021 ◽

Vol 9 ◽

pp. e11766

Author(s):

Mao Yang ◽

Runya Yang ◽

Yanni Li ◽

Yinghua Pan ◽

Junna Sun ◽

...

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Salt Concentration ◽

Saline Soil ◽

Soil Depth ◽

Soil Layer ◽

Thick Layer ◽

Peat Layer ◽

Salt Accumulation

The aim of this study was to find a material suited for the prevention of evaporative water loss and salt accumulation in coastal saline soils. One-dimensional vertical water infiltration and phreatic evaporation experiments were conducted using a silty loam saline soil. A 3-cm-thick layer of corn straw, biochar, and peat was buried at the soil depth of 20 cm, and a 6-cm-thick layer of peat was also buried at the same soil depth for comparison. The presence of the biochar layer increased the upper soil water content, but its ability to inhibit salt accumulation was poor, leading to a high salt concentration in the surface soil. The 3-cm-thick straw and 6-cm-thick peat layers were most effective to inhibit salt accumulation, which reduced the upper soil salt concentration by 96% and 93%, respectively. However, the straw layer strongly inhibited phreatic evaporation and resulted in low water content in the upper soil layer. Compared with the straw layer, the peat layer increased the upper soil water content. Thus, burying a 6-cm-thick peat layer in the coastal saline soil is the optimal strategy to retain water in the upper soil layer and intercept salt in the deeper soil layer.

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GRAIN FROM MEDJYBIZH

Archaeology and Early History of Ukraine ◽

10.37445/adiu.2019.03.14 ◽

2019 ◽

Vol 32 (3) ◽

pp. 176-183

Author(s):

S. A. Gorbanenko ◽

Yu. I. Tolkachov

Keyword(s):

Eleventh Century ◽

Winter Rye ◽

Claviceps Purpurea ◽

Archaeological Research ◽

Arable Fields ◽

Winter Crops ◽

One Year ◽

High Level ◽

Brome Grass ◽

Brome Grasses

During the archaeological research of the Medjybizh fortress (fig. 1), palaeoethnobotanical materials were found three times in its yard: in 1991, 2013 and 2015. The first definition was made by G. O. Pashkevich. Mostly rye was identified as well as bromus, sorrel and an ergot fungus claviceps purpurea. From materials ща 2015 about 30 ml of grain were provided, mostly rye, which is approximately 1800—2000 grains. This is a sample of the harvest of one year. Single kernels of hulled barley (5); emmer (2) and soft wheat (1) were identified. Weeds are represented by 3 species, they are convolvulus (19), brome grasses (11) and cleavers (7) (figs. 2—4). Identified weeds are concomitant for cultivated cereals and real anthropochores; they may be useful for therapeutic purposes. Brome grass is a winter plant that pollutes crops of winter rye and wheat. Fields pollution indicates a use of old arable fields: the population lived in this place continuously from the eleventh century. Consequently, the fields exploded about 2—3 centuries. Winter crops also show the use of old arable fields. According to the aggregate of weeds, these fields were located on high places with droughty soils. According to the analysis of topography and soil, these fields were in the western sector on the elevated plateau (supposedly the places of Dolzhok and Pereimska Dacha). Find of the rye also indirectly indicates a high level of development of agriculture. While plowing tools from Medzhybizh are unknown, we should assume the use of plow, which is the most progressive form of them.

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Depth distribution of belowground net primary production across global biomes

10.21203/rs.3.rs-65178/v2 ◽

2021 ◽

Author(s):

Zhongkui Luo ◽

Guocheng Wang ◽

Liujun Xiao ◽

Xiali Mao ◽

Xiaowei Guo ◽

...

Keyword(s):

Primary Production ◽

Depth Distribution ◽

Net Primary Production ◽

Soil Depth ◽

Soil Layer ◽

Soil Nutrient ◽

Data Sets ◽

Large Variability ◽

Belowground Carbon ◽

Belowground Net Primary Production

Abstract The depth distribution of belowground net primary production (BNPP) has been unquantified globally, hindering our understanding of belowground carbon dynamics. We synthesize global observational data sets to infer the depth allocation of BNPP down to 2 m, and map depth-specific BNPP globally at 1 km resolution. We estimate that global average BNPP in the 0–20 soil layer is 1.1 Mg C ha–1 yr–1, accounting for >50% of total BNPP. Across the globe, the depth distribution of BNPP shows large variability, and more BNPP is allocated to deeper layers in hotter and drier regions. Edaphic, climatic and topographic properties (in the order of importance) can explain >80% of such variability in different soil depths; and the direction and magnitude of the influence of individual properties (e.g., precipitation and soil nutrient) are soil depth- and biome-dependent. Our results provide global benchmarks for predictions of whole-soil carbon profiles across global biomes.

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Response Site Analyses of 3D Homogeneous Soil Models

Emerging Science Journal ◽

10.28991/esj-2018-01148 ◽

2018 ◽

Vol 2 (5) ◽

pp. 238 ◽

Cited By ~ 12

Author(s):

Davide Forcellini ◽

Marco Tanganelli ◽

Stefania Viti

Keyword(s):

Soil Type ◽

Soil Depth ◽

Site Response ◽

Soil Layer ◽

Shear Velocity ◽

Seismic Intensity ◽

Eurocode 8 ◽

Seismic Input ◽

Homogeneous Soil ◽

Response Site

The seismic excitation at the surface can be determined through Site Response Analyses (SRA) as to account for the specific soil properties of the site. However, the obtained results are largely affected by the model choice and setting, and by the depth of the considered soil layer. This paper proposes a refined 3D analytical approach, by the application of OPENSEES platform. A preliminary analysis has been performed to check the model adequacy as regards the mesh geometry and the boundary conditions. After the model setting, a SRA has been performed on various soil profiles, differing for the shear velocity and representing the different soil classes as proposed by the Eurocode 8 (EC8). Three levels of seismic hazard have been considered. The seismic input at the bedrock has been represented consequently, through as much ensembles of seven ground motions each, spectrum-compatible to the elastic spectra provided by EC8 for the soil-type A (bedrock). Special attention has been paid to the role of the considered soil depth on the evaluation of the surface seismic input. Different values of depth have been considered for each soil type and seismic intensity, in order to check its effect on the obtained results.

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A regionally explicit, global SWI calibration based on ISMN observations

10.5194/egusphere-egu21-496 ◽

2021 ◽

Author(s):

Manolis G. Grillakis

Keyword(s):

Soil Moisture ◽

Soil Water ◽

Large Scale ◽

Root Zone ◽

Soil Depth ◽

European Space Agency ◽

Soil Layer ◽

Added Value ◽

Water Index ◽

Soil Moisture Data

Remote sensing has proven to be an irreplaceable tool for monitoring soil moisture. The European Space Agency (ESA), through the Climate Change Initiative (CCI), has provided one of the most substantial contributions in the soil water monitoring, with almost 4 decades of global satellite derived and homogenized soil moisture data for the uppermost soil layer. Yet, due to the inherent limitations of many of the remote sensors, only a limited soil depth can be monitored. To enable the assessment of the deeper soil layer moisture from surface remotely sensed products, the Soil Water Index (SWI) has been established as a convolutive transformation of the surface soil moisture estimation, under the assumption of uniform hydraulic conductivity and the absence of transpiration. The SWI uses a single calibration parameter, the T-value, to modify its response over time.Here the Soil Water Index (SWI) is calibrated using ESA CCI soil moisture against in situ observations from the International Soil Moisture Network and then use Artificial Neural Networks (ANNs) to find the best physical soil, climate, and vegetation descriptors at a global scale to regionalize the calibration of the T-value. The calibration is then used to assess a root zone related soil moisture for the period 2001 &#8211; 2018.The results are compared against the European Centre for Medium-Range Weather Forecasts, ERA5 Land reanalysis soil moisture dataset, showing a good agreement, mainly over mid-latitudes. The results indicate that there is added value to the results of the machine learning calibration, comparing to the uniform T-value. This work contributes to the exploitation of ESA CCI soil moisture data, while the produced data can support large scale soil moisture related studies.

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The Soil Moisture during Dry Spells Model and Its Verification

Resources ◽

10.3390/resources9070085 ◽

2020 ◽

Vol 9 (7) ◽

pp. 85

Author(s):

Małgorzata Biniak-Pieróg ◽

Mieczysław Chalfen ◽

Andrzej Żyromski ◽

Andrzej Doroszewski ◽

Tomasz Jóźwicki

Keyword(s):

Soil Moisture ◽

Least Squares Method ◽

Soil Depth ◽

Soil Layer ◽

Atmospheric Precipitation ◽

Soil Surface ◽

Model Verification ◽

Individual Measurement ◽

Dry Spells ◽

Dry Spell

The objective of this study was the development and verification of a model of soil moisture decrease during dry spells—SMDS. The analyses were based on diurnal information of the occurrence of atmospheric precipitation and diurnal values of soil moisture under a bare soil surface, covering the period of 2003–2019, from May until October. A decreasing exponential trend was used for the description of the rate of moisture decrease in six layers of the soil profile during dry spells. The least squares method was used to determine, for each dry spell and soil depth, the value of exponent α , which described the rate of soil moisture decrease. Data from the years 2003–2015 were used for the identification of parameter α of the model for each of the layers separately, while data from 2016–2019 were used for model verification. The mean relative error between moisture values measured in 2016–2019 and the calculated values was 3.8%, and accepted as sufficiently accurate. It was found that the error of model fitting decreased with soil layer depth, from 8.1% for the surface layer to 1.0% for the deepest layer, while increasing with the duration of the dry spell at the rate of 0.5%/day. The universality of the model was also confirmed by verification made with the use of the results of soil moisture measurements conducted in the years 2009–2019 at two other independent locations. However, it should be emphasized that in the case of the surface horizon of soil, for which the process of soil drying is a function of factors occurring in the atmosphere, the developed model may have limited application and the obtained results may be affected by greater errors. The adoption of calculated values of coefficient α as characteristic for the individual measurement depths allowed calculation of the predicted values of moisture as a function of the duration of a dry spell, relative to the initial moisture level adopted as 100%. The exponential form of the trend of soil moisture changes in time adopted for the analysis also allowed calculation of the duration of a hypothetical dry spell t, after which soil moisture at a given depth drops from the known initial moisture θ0 to the predicted moisture θ. This is an important finding from the perspective of land use.

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Quantity and distribution of fine root biomass in the intermediate stage of beech virgin forest Badínsky prales

Journal of Forest Science ◽

10.17221/31/2009-jfs ◽

2009 ◽

Vol 55 (No. 11) ◽

pp. 502-510 ◽

Cited By ~ 3

Author(s):

P. Jaloviar ◽

L. Bakošová ◽

S. Kucbel ◽

J. Vencurik

Keyword(s):

Root Length ◽

Root Biomass ◽

Fine Root ◽

Soil Depth ◽

Mineral Soil ◽

Soil Layer ◽

Intermediate Stage ◽

Fine Root Biomass ◽

Virgin Forest ◽

Fine Root Length

The fine root biomass represents 3,372 kg/ha in the intermediate stage of the beech virgin forest with different admixture of goat willow, where the vast majority of this biomass is located in the uppermost mineral soil layer 0–10 cm. The variability of the fine root biomass calculated from 35 sample points represents approximately 90% of the mean value and reaches the highest value within the humus layer. The total fine root length investigated in 10 cm thick soil layers decreases with increasing soil depth. A significant linear relationship between the fine root length (calculated per 1 cm thick soil layer and 1 m2 of stand area) and the soil depth was confirmed, although the correlation is rather weak. The number of root tips decreases with increasing soil depth faster than the root length. As the number of tips per 1 cm of root length remains in the finest diameter class without significant changes, the reason is above all a decreased proportion of the finest root class (diameter up to 0.5 mm) from the total fine root length within the particular soil layer.

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The Depth of Water Taken up by Walnut Trees during Different Phenological Stages in an Irrigated Arid Hilly Area in the Taihang Mountains

Forests ◽

10.3390/f10020121 ◽

2019 ◽

Vol 10 (2) ◽

pp. 121 ◽

Cited By ~ 4

Author(s):

Yang Liu ◽

Xuemei Zhang ◽

Shuang Zhao ◽

Huabing Ma ◽

Guohui Qi ◽

...

Keyword(s):

Soil Water ◽

Soil Depth ◽

Isotope Composition ◽

Irrigation Management ◽

Soil Layer ◽

Root Water Uptake ◽

Phenological Stages ◽

Hilly Area ◽

Fruit Maturity ◽

Hydrogen And Oxygen Isotope

Understanding how the soil environment impacts root water uptake location and magnitude is important for better management of plant irrigation. In this study, stable hydrogen and oxygen isotope composition were used to determine seasonal variations in the depth of water taken up by walnut trees during different phenological stages in an irrigated arid hilly area in the Taihang Mountains in China. The contributions of soil water at different depths to the water taken up were quantified by the MixSIAR Bayesian isotope mixing model. The results indicated that water taken up by the walnut trees was sourced mainly from soil water in the 0–20 cm soil layer at the sprouting and leaf expansion stages (62.95%), and the 20–40 cm soil layer at blossoming and fruit-bearing (43.45%), fruit expansion (41.8%), and fruit maturity (39.15%) stages. The mean soil depth of the water taken up by the walnut trees gradually decreased as the phenological stages advanced. The proportions of various soil layer water contributions to the walnut trees differed throughout the phenological stages, and the proportion of deeper soil water contributions gradually increased as the phenological stages of walnut trees advanced. The results of the present study indicated that water sources for walnut trees varied by depth during different phenological stages. In addition to soil moisture, soil temperature may also be an important factor affecting the depth of water taken up by walnut trees. The results also provided scientific implications for water-saving irrigation management.

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