C:N ratios and carbon distribution profile across rooting zones in oilseed and pulse crops

2011 ◽  
Vol 62 (6) ◽  
pp. 496 ◽  
Author(s):  
Y. T. Gan ◽  
B. C. Liang ◽  
L. P. Liu ◽  
X. Y. Wang ◽  
C. L. McDonald
Keyword(s):  
Crop Residues ◽  
Soil Depth ◽  
High Water ◽  
Triticum Aestivum L ◽  
Rooting Depth ◽  
Similar Response ◽  
Distribution Profile ◽  
Crop Species ◽  
Pulse Crops ◽  
C And N

Knowledge on the C : N ratio of crop residues is of great importance for modelling carbon (C) and nitrogen (N) dynamics of agricultural systems. This study determined (i) the C : N ratios in the seed, straw, and roots of selected broadleaf crops and (ii) the root C and N distribution in the 0–100 cm rooting zone. Three oilseed (Brassica napus canola, Brassica juncea mustard, Linum usitatissimum flax), three pulse crops (Cicer arietinum chickpea, Pisum sativum dry pea, Lens culinaris lentil), and spring wheat (Triticum aestivum L.) were grown under field conditions with low- (rainfall only) and high-water (rainfall plus irrigation) availability. Root C mass decreased substantially with rooting depth, with ~58% of root C mass in the top 20 cm of the soil, 78% in the top 40 cm, and 94% in the top 60 cm. Significant differences in root C mass between crop species occurred in the top 20 cm with canola, mustard, and wheat allocating 66% of their root C total, compared with 55% for dry pea, lentil, and flax, and 41% for chickpea. Root N mass followed a similar response to root C. Seed C : N ratios ranged between 6 and 17, whereas straw C : N ranged between 14 and 55, and root C : N between 17 and 75. Under low-water conditions, canola and mustard had a straw C : N of 33, lower than that of flax (38) and wheat (41). Under higher-water availability, however, mustard and wheat had straw C : N ratios at 55, greater than canola, mustard and flax (47). Three pulses had an average straw C : N ratio of 17, significantly lower than 41 for the oilseeds and 32 for wheat. On average, canola, mustard and wheat had greater root C : N ratios (44) than chickpea (33) and lentil (29), with dry pea having a smallest root C : N ratio (18). Root C : N ratios did not change with soil depth. These detailed measurements on the vertical distribution of root C and N as well as C : N ratios for various crops will assist in improving estimates of inputs for C and N cycling studies.

scholarly journals Soil carbon fluxes and balances of crop rotations under long-term no-till

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
João Paulo Gonsiorkiewicz Rigon ◽  
Juliano Carlos Calonego
Keyword(s):  
Soil Carbon ◽  
Crop Residues ◽  
Carbon Fluxes ◽  
Crop Rotations ◽  
Crop Species ◽  
Forage Sorghum ◽  
C Balance ◽  
C Stocks ◽  
Sunn Hemp ◽  
C And N

Abstract Background A field study with the same crop rotations was conducted to test the hypothesis that the soil Carbon fluxes and balances could vary according to the crop species and also mitigate carbon dioxide (CO2) emission. This study aimed to assess the CO2 emission from crop rotations according to C and N inputs from crop residue, the influences on soil organic carbon (SOC) and total soil nitrogen (TN) stocks, identifying the soybean production systems with positive C balance. Triticale (x Triticosecale) or sunflower (Helianthus annuus) are grown in the fall/winter; sunn hemp (Crotalaria juncea), forage sorghum (Sorghum bicolor), pearl millet (Pennisetum glaucum), or fallow are the spring treatments, and soybean as a main crop in summer. Results We found that high C inputs from crop residues modify the C dynamics in crop rotations by reducing the C output (CO2) and increasing C sequestration in the soil. In general, the higher SOC, C stocks, and TN in soil surface were due to higher C and N inputs from sunn hemp or forage sorghum crop residues in spring. These crops also produced lower accumulated CO2 emissions and, when rotating with triticale in the fall-winter season resulted in a positive C balance, making these soybean crop rotations more efficient. Conclusion Our study suggests the ideal crop species choice in a rotation can mitigate the CO2 emissions by increasing C and N input from crop residues and consequently SOC and C stocks. In particular, crop rotation comprises an important tool to achieve a positive C balance, mitigate CO2 emissions and provide an additional ecosystem service to soybean cultivation option.

Root mass for oilseed and pulse crops: Growth and distribution in the soil profile

2009 ◽  
Vol 89 (5) ◽  
pp. 883-893 ◽  
Author(s):  
Y T Gan ◽  
C A Campbell ◽  
H H Janzen ◽  
R Lemke ◽  
L P Liu ◽  
...  
Keyword(s):  
Root Growth ◽  
Soil Profile ◽  
Root Biomass ◽  
Rooting Depth ◽  
Growth Stages ◽  
Root Mass ◽  
Distribution Profile ◽  
Brassica Napus L ◽  
Organic C ◽  
Pulse Crops

Crop roots transport water and nutrients to the plants, produce nutrients when they decompose in soil, and provide organic C to facilitate the process of C sequestration in the soil. Many studies on these subjects have been published for cereal crops, but little is known for oilseed and pulse crops. This study was conducted at Swift Current, Saskatchewan, in 2006 and 2007 to characterize the root growth and distribution profile in soil for selected oilseed and pulse crops. Three oilseed [canola (Brassica napus L.), mustard (Brassica juncea L.), flax (Linum usitatissimum L.)], three pulse crops [chickpea (Cicer arietinum L), dry pea (Pisum sativum L.) lentil (Lens culinaris Medik.)], and spring wheat (Triticum aestivum L.) were grown in 100 cm deep × 15 cm diameter lysimeters pushed into a silt loam soil. Crops were studied under rainfed and irrigated conditions. Lysimeters were removed from the field and sampled for above-ground (AG) and root mass at different depths at five growth stages. Root mass was highest for canola (1470 kg ha-1) and wheat (1311 kg ha-1), followed by mustard (893 kg ha-1) and chickpea (848 kg ha-1), and was lowest for dry pea (524 kg ha-1) and flax (440 kg ha-1). The root mass of oilseeds and pulses reached a maximum between late-flowering and late-pod stages and then decreased to maturity, while wheat root mass decreased to maturity after reaching a maximum at boot stage. On average, about 77 to 85% of the root mass was located in the 0-40 cm depth. Canola, mustard, and wheat rooted to 100 cm, while the pulses and flax had only 4 to 7% of the root mass beyond the 60 cm depth. Irrigation only increased root mass in the 0-20 cm depth. Roots developed more rapidly than AG biomass initially, but the ratio of root biomass to AG biomass decreased with plant maturity. At maturity, the ratio of root biomass to AG biomass was 0.11 for dry pea, and between 0.20 and 0.22 for the other crops tested. Our findings on rooting depths and root mass distribution in the soil profile should be useful for modelling water and nutrient uptake by crops, estimating C inputs into soil from roots, and developing diverse cropping systems with cereals, oilseeds and pulses for semiarid environments.Key words: Root growth, root biomass, rooting depth, chickpea, lentil, pea, canola, mustard, flax, root:shoot ratio

scholarly journals Biopore-Induced Deep Root Traits of Two Winter Crops

Agriculture ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 634
Author(s):  
Ning Huang ◽  
Miriam Athmann ◽  
Eusun Han
Keyword(s):  
Soil Depth ◽  
Root Traits ◽  
Rooting Depth ◽  
Crop Species ◽  
Deep Root ◽  
Rooting Density ◽  
Arable Fields ◽  
Soil Monolith ◽  
Winter Crops

Deeper root growth can be induced by increased biopore density. In this study, we aimed to compare deep root traits of two winter crops in field conditions in response to altered biopore density as affected by crop sequence. Two fodder crop species—chicory and tall fescue—were grown for two consecutive years as preceding crops (pre-crops). Root traits of two winter crops—barley and canola, which were grown as subsequent crops (post-crops)—were measured using the profile wall and soil monolith method. While barley and canola differed greatly in deep root traits, they both significantly increased rooting density inside biopores by two-fold at soil depths shallower than 100 cm. A similar increase in rooting density in the bulk soil was observed below 100 cm soil depth. As a result, rooting depth significantly increased (>5 cm) under biopore-rich conditions throughout the season of the winter crops. Morphological root traits revealed species-wise variation in response to altered biopore density, in which only barley increased root size under biopore-rich conditions. We concluded that large-sized biopores induce deeper rooting of winter crops that can increase soil resource acquisition potential, which is considered to be important for agricultural systems with less outsourced farm resources, e.g., Organic Agriculture. Crops with contrasting root systems can respond differently to varying biopore density, especially root morphology, which should be taken into account upon exploiting biopore-rich conditions in arable fields. Our results also indicate the need for further detailed research with a greater number of species, varieties and genotypes for functional classification of root plasticity against the altered subsoil structure.

Short Communication: Comparative soil water use by annual crops at a semiarid site in Montana

2012 ◽  
Vol 92 (4) ◽  
pp. 803-807 ◽  
Author(s):  
P. R. Miller ◽  
J. A. Holmes
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Spring Wheat ◽  
Short Communication ◽  
Soil Depth ◽  
Cropping Systems ◽  
Triticum Aestivum L ◽  
Rooting Depth ◽  
Northern Great Plains ◽  
Annual Crops

Miller, P. R. and Holmes, J. A. 2012. Short Communication: Comparative soil water use by annual crops at a semiarid site in Montana. Can. J. Plant Sci. 92: 803–807. Results for soil water use in the semiarid northern Great Plains are presented in detailed tabular format for 15 crops in an ideal environment for comparative water use assessment. The effective rooting depth of winter wheat (Triticum aestivum L.) varied relative to spring wheat; it was often similar and never less. Sunflower (Helianthus annuus L.) averaged 43 mm greater soil water use below 0.9 m compared with spring wheat. Conversely, lentil (Lens culinaris Medik.) and pea (Pisum sativum L.) averaged 27 mm and 48 mm less soil water than spring wheat to a 1.2-m soil depth, respectively. Observed differences in effective rooting depth for alternative crops carry important implications for wheat-based cropping systems.

Carbon sequestration in a Brown Chernozem as affected by tillage and rotation

1995 ◽  
Vol 75 (4) ◽  
pp. 449-458 ◽  
Author(s):  
C. A. Campbell ◽  
B. G. McConkey ◽  
R. P. Zentner ◽  
F. B. Dyck ◽  
F. Selles ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Depth ◽  
Cropping System ◽  
Well Being ◽  
Triticum Aestivum L ◽  
Conventional Tillage ◽  
Organic N ◽  
Organic C ◽  
C And N

Soil organic matter is important because it influences the productivity and physical well-being of soils. Recently, increased attention has focussed on soil organic matter as a possible sink for C02-C. Despite this interest, there is a lack of data for quantifying the effect of tillage on soil organic matter. Between 1981 and 1994, two tillage experiments were conducted at Swift Current, Saskatchewan, on Swinton loam, an Orthic Brown Chernozemic soil. Organic C and N were monitored periodically to quantify the effects of crop rotation [continuous spring wheat (Cont W) (Triticum aestivum L.) vs. fallow–wheat (F-W)] and tillage management [no-tillage (NT) vs. conventional tillage (CT) involving primarily use of a cultivator and rodweeder]. The effect of snow management on soil organic matter was also evaluated in one experiment, but this factor was not significant. Organic matter changes were mainly observed in the 0- to 7.5-cm soil depth. Carbon and N were greater in both concentrations and amounts in Cont W than in F–W; the latter cropping system was employed on this land during the previous 70–80 yr. In the 0- to 7.5-cm depth, the amount of organic matter was only moderately greater in NT than CT in the Cont W systems while in the F-W systems tillage was not significant (P > 0.10). During the 12-yr period, Cont W (average of NT and CT) gained about 2 t ha−1 more C in the top 15 cm of soil than F-W (average of NT and CT), with most of the increase occurring in the first 5 yr. Further, Cont W (NT) gained about 1.5 t ha−1 more C than Cont W (CT), and F-W (NT) gained about 0.5 t ha−1 more than F-W (CT). When a system that was maintained as Cont W (NT) for 9 yr was changed to Cont W (CT) for 3 yr and then summerfallowed (CT) for 1 yr, soil organic matter declined (P < 0.05). Our observations, supported by calculations based on crop residue production, indicated that an increase in organic C, averaging about 0.4–0.5 t ha−1 yr−1, has occurred in the top 15 cm of soil in Cont W (NT) between 1982 and 1993. However, because of uncertainty in our estimated C levels at the start of the experiment, the nature of the rate of C increase (linear or curvilinear) is not known. Key words: Organic C, organic N, no-till, summerfallow

scholarly journals Highly Water Dispersible Functionalized Graphene by Thermal Thiol-Ene Click Chemistry

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2830
Author(s):  
Farzaneh Farivar ◽  
Pei Lay Yap ◽  
Tran Thanh Tung ◽  
Dusan Losic
Keyword(s):  
Click Reaction ◽  
High Water ◽  
Pristine Graphene ◽  
Functionalized Graphene ◽  
Specific Chemical ◽  
Simple Modification ◽  
Water Dispersible ◽  
Chemical Hazards ◽  
Water Dispersibility ◽  
C And N

Functionalization of pristine graphene to achieve high water dispersibility remains as a key obstacle owing to the high hydrophobicity and absence of reactive functional groups on the graphene surface. Herein, a green and simple modification approach to prepare highly dispersible functionalized graphene via thermal thiol-ene click reaction was successfully demonstrated on pristine graphene. Specific chemical functionalities (–COO, –NH2 and –S) on the thiol precursor (L-cysteine ethyl ester) were clicked directly on the sp2 carbon of graphene framework with grafting density of 1 unit L-cysteine per 113 carbon atoms on graphene. This functionalized graphene was confirmed with high atomic content of S (4.79 at % S) as well as the presence of C–S–C and N–H species on the L-cysteine functionalized graphene (FG-CYS). Raman spectroscopy evidently corroborated the modification of graphene to FG-CYS with an increased intensity ratio of D and G band, ID/IG ratio (0.3 to 0.7), full-width at half-maximum of G band, FWHM [G] (20.3 to 35.5) and FWHM [2D] (64.8 to 90.1). The use of ethanol as the reaction solvent instead of common organic solvents minimizes the chemical hazards exposure to humans and the environment. This direct attachment of multifunctional groups on the surface of pristine graphene is highly demanded for graphene ink formulations, coatings, adsorbents, sensors and supercapacitor applications.

scholarly journals EPR Spectroscopy as a Tool to Characterize the Maturity Degree of Humic Acids

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3410
Author(s):  
Bozena Debska ◽  
Ewa Spychaj-Fabisiak ◽  
Wiesław Szulc ◽  
Renata Gaj ◽  
Magdalena Banach-Szott
Keyword(s):  
Humic Acids ◽  
Epr Spectroscopy ◽  
Plant Material ◽  
Crop Residues ◽  
Triticum Aestivum L ◽  
Epr Spectra ◽  
Thuja Plicata ◽  
Anthropogenic Factors ◽  
Paramagnetic Resonance ◽  
Spin Concentration

The major indicator of soil fertility and productivity are humic acids (HAs) arising from decomposition of organic matter. The structure and properties of HAs depend, among others climate factors, on soil and anthropogenic factors, i.e., methods of soil management. The purpose of the research undertaken in this paper is to study humic acids resulting from the decomposition of crop residues of wheat (Triticum aestivum L.) and plant material of thuja (Thuja plicata D.Don.ex. Lamb) using electron paramagnetic resonance (EPR) spectroscopy. In the present paper, we report EPR studies carried out on two types of HAs extracted from forest soil and incubated samples of plant material (mixture of wheat straw and roots), both without soil and mixed with soil. EPR signals obtained from these samples were subjected to numerical analysis, which showed that the EPR spectra of each sample could be deconvoluted into Lorentzian and Gaussian components. It can be shown that the origin of HAs has a significant impact on the parameters of their EPR spectra. The parameters of EPR spectra of humic acids depend strongly on their origin. The HA samples isolated from forest soils are characterized by higher spin concentration and lower peak-to-peak width of EPR spectra in comparison to those of HAs incubated from plant material.

scholarly journals Perennial herbaceous legumes as live soil mulches and their effects on C, N and P of the microbial biomass

2003 ◽  
Vol 60 (1) ◽  
pp. 139-147 ◽  
Author(s):  
Gustavo Pereira Duda ◽  
José Guilherme Marinho Guerra ◽  
Marcela Teixeira Monteiro ◽  
Helvécio De-Polli ◽  
Marcelo Grandi Teixeira
Keyword(s):  
Microbial Biomass ◽  
Soil Depth ◽  
Vegetation Management ◽  
Pueraria Phaseoloides ◽  
Organic C ◽  
Arachis Pintoi ◽  
Factorial Combination ◽  
C And N ◽  
Microbial C ◽  
Macroptilium Atropurpureum

The use of living mulch with legumes is increasing but the impact of this management technique on the soil microbial pool is not well known. In this work, the effect of different live mulches was evaluated in relation to the C, N and P pools of the microbial biomass, in a Typic Alfisol of Seropédica, RJ, Brazil. The field experiment was divided in two parts: the first, consisted of treatments set in a 2 x 2 x 4 factorial combination of the following factors: live mulch species (Arachis pintoi and Macroptilium atropurpureum), vegetation management after cutting (leaving residue as a mulch or residue remotion from the plots) and four soil depths. The second part had treatments set in a 4 x 2 x 2 factorial combination of the following factors: absence of live mulch, A. pintoi, Pueraria phaseoloides, and M. atropurpureum, P levels (0 and 88 kg ha-1) and vegetation management after cutting. Variation of microbial C was not observed in relation to soil depth. However, the amount of microbial P and N, water soluble C, available C, and mineralizable C decreased with soil depth. Among the tested legumes, Arachis pintoi promoted an increase of microbial C and available C content of the soil, when compared to the other legume species (Pueraria phaseoloides and Macroptilium atropurpureum). Keeping the shoot as a mulch promoted an increase on soil content of microbial C and N, total organic C and N, and organic C fractions, indicating the importance of this practice to improve soil fertility.

scholarly journals Vertisols and Cambisols had contrasting short term greenhouse gas responses to crop residue management

2020 ◽  
Vol 66 (No. 5) ◽  
pp. 222-233 ◽  
Author(s):  
Giuseppe Badagliacca ◽  
Robert Martin Rees ◽  
Dario Giambalvo ◽  
Sergio Saia
Keyword(s):  
Faba Bean ◽  
Crop Residues ◽  
Residue Management ◽  
Short Term ◽  
N Dynamics ◽  
Total N ◽  
Soil C ◽  
Residue Decomposition ◽  
Soil C And N ◽  
C And N

In sustainable agriculture crop residues management should consider the interactions between soil and residue properties, which can affect the decomposition and global greenhouse gases (GHGs) emission. Through a laboratory experiment, we investigated the effect of the management (incorporation and surface placement) of wheat and faba bean residues on their decomposition and CO<sub>2</sub>, CH<sub>4</sub> and N<sub>2</sub>O emissions from two soils, a Chromic Vertisol and an Eutric Cambisol. In the Vertisol, wheat residues increased the CO<sub>2</sub> emission more than faba bean when left on the surface whereas no differences among residues were observed when incorporated. In the Cambisol, faba bean emitted more than wheat when left in the surface and less when incorporated. Total CH<sub>4</sub> emissions were higher in faba bean in Cambisol for both management and only when applied in the surface in Vertisol. Total N<sub>2</sub>O emission in the Vertisol was higher when faba bean was incorporated, and wheat was left on the surface. In the Cambisol, wheat addition increased total N<sub>2</sub>O emissions by 20% compared to faba bean, with no differences between managements. Our study confirmed that contrasting properties among tested soils resulted in significant interactions with residues own degradability and their placement affecting residue decomposition, soil C and N dynamics, and GHGs emission.

scholarly journals Study of C, N, P and K Release from Residues of Newly Proposed Cover Crops in a Spanish Olive Grove

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1041 ◽  
Author(s):  
Antonio Rodríguez-Lizana ◽  
Miguel Ángel Repullo-Ruibérriz de Torres ◽  
Rosa Carbonell-Bojollo ◽  
Manuel Moreno-García ◽  
Rafaela Ordóñez-Fernández
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Crop Residues ◽  
Soil Cover ◽  
Brachypodium Distachyon ◽  
Nutrient Release ◽  
Grab Sampling ◽  
P Release ◽  
Olive Groves ◽  
C And N

Cover crops (CC)s are increasingly employed by farmers in olive groves. Spontaneous soil cover is the most commonly used CC. Its continuous utilization changes ruderal flora. It is necessary to study new CCs. Living CCs provide C and nutrients to soil during decomposition. Information on this issue in olive groves is scarce. A 4-year field study involving grab sampling of Brachypodium distachyon, Sinapis alba and spontaneous CC residues was conducted to study C and nutrient release from cover crop residues. Throughout the decomposition cycles, C, N and P release accounted for 40 to 58% of the C, N and P amounts in the residues after mowing. Most K was released (80–90%). Expressed in kg per hectare, the release of C and N in Brachypodium (C: 4602, N: 181, P: 29, K: 231) and Sinapis (C: 4806, N: 152, P: 18, K: 195) was greater than that in spontaneous CC (C: 3115, N: 138, P: 21, K: 256). The opposite results were observed for K. The Rickman model, employed to estimate the amount of C, N and P in residues, yielded a good match between the simulated and measured values. In comparison to spontaneous CC, the newly proposed CCs have a higher potential to provide soil with C and N.

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