if you are interested in some of these papers, you can write to
juangalantini@gmail.com
or juan.galantini@cyt.cic.gba.gob.ar
Nitrogen
balance in a plant-soil system under different cover crop-soybean cropping in
Argentina
Cover crops (CC) provide many benefits for the soil
and the following crop but their effects on nitrogen (N) release and balance in
continuous no-tillage soybean (Glycine
max L. Merr.) production are little known. Estimation of the biological
nitrogen fixation (BNF) in intensive agricultural systems under soybean is
essential to understanding the N dynamics and to determining the balances and
crop demands. This study (2006–2011) was performed on a Typic Argiudoll under
no-tillage in the province of Santa Fe, Argentina. The aims were to study the
effect of fall winter CC, such as wheat (W), oats (O), oats + vetch (O + V) and
vetch (V), on the yield and N-content of the following crop (soybean) and to
quantify the contribution of the BNF and N-balance. Three methodologies were
used for BNF estimation: 1) a linear regression model between BNF and N-uptake
by soybean; 2) the natural 15N abundance in soybean and 3) the average BNF in
the Pampa region. Gramineous CC developed more dry matter than pure legume
species, with intermediate values for the gramineous-legume mixture. Biological
fixation provides 60–70% of absorbed N, according to the estimation method.
Within the rainfall range of 500–1000 mm during the soybean cycle, CC did not
affect the grain yield or soybean dry matter production. The partial N-balance
was always positive, with differences between the techniques used for BNF
estimation. Cover crops have contributed to the positive soil N-balance. Gramineous
CC stored 22% more N content in the soil surface layer than the others. Cover
crops showed 15% higher index of N-stratification on the surface compared to
the control soil. Using CC would be an efficient alternative to produce biomass
and to supply N to the soil for the subsequent crop
Cover crops Soybean Biological fixation N-balance
Mollisol
Landriscini M.R., J.A. Galantini, M.E. Duval, J.E. Capurro. 2019. Nitrogen balance in a
plant-soil system under different cover crop-soybean cropping in Argentina.
Applied Soil Ecology 133:124-131.
doi: 10.1016/j.apsoil.2018.10.005
Cover crops in
the Southeastern region of Buenos Aires, Argentina: effects on organic matter
physical fractions and nutrient availability
In the Southeastern region of Buenos Aires province,
soybean monoculture has led to a decline in soil organic matter (SOM) levels in
soil, mostly the labile fractions. The reduction of SOM has a negative impact
on the soil environment. Cover crops (CC) constitute an alternative to maintain
or improve SOM levels. The aim of this study was to determine the effect of oat
as CC on (a) the SOM dynamics and (b) the availability of macro- and
micronutrients in a representative soil of the Southeastern region of Buenos
Aires province. Total organic carbon (TOC) and nitrogen (TON), as well as their
labile and mineral-associated fractions, and macro- and micronutrient
availability were determined. The treatments were soybean monoculture with and
without oat as cover crop. The increases in SOC and TON were 22.7% and 11%,
respectively, when CC was included to the soybean monoculture. These increases
were observed mostly in the labile fractions, with increases of 61.3 and 38.7%
for the particulate coarse organic carbon (PCOg) and particulate fine organic
carbon (PCOf), respectively, and 79.2% for the particulate coarse organic
nitrogen (NOPg). Regarding the nutrients, an increase of 47.6% was observed in
manganese (Mn) in the first 5 cm of soil depth, and a decrease in phosphorous
(P) availability in the same soil layer due to its consumption and retention by
CC. It can be conclude that CC presented a surface soil effect on the dynamic
of SOM, increasing C, N, and available Mn contents, but decreasing soil P
availability
Oat, Soybean monoculture, Particulate organic carbon
and nitrogen
Beltrán
M.J., H. Sainz Rozas, J.A. Galantini, R.I. Romaniuk, P. Barbieri. 2018. Cover
crops in the Southeastern region of Buenos Aires, Argentina: effects on organic
matter physical fractions and nutrient availability. Environmental Earth
Sciences 77:428.
Production and
quality of different cover crops in soybean monoculture
Cover crops (CC) are an alternative to improve soil
organic matter, capture labile nutrients and minimizing its leaching losses
during long-term fallows, typical of agricultural systems with high frequency
soybean (Glycine max L. Merr.). The objective was to evaluate the production
and nutrient content of different CC in simplified system (soybean monoculture)
under no-tillage. CC used were: (T) bread wheat (Triticum aestivum L.), (A) oat
(Avena sativa L.), (V) vetch (Vicia sativa L.) and (A+V) oat + vetch. Upon
drying the CC was determined: production of total aerial dry matter (MS),
biochemical composition (cellulose, hemicellulose and lignin), macro- and
micronutrients. Dry matter production in T and A ranged between 7.2 and 11.1 Mg
ha-1, differing significantly from V with values between 4.1 and 4.6
Mg ha-1. Carbon concentration did not differ between CC (43-45% C).
The amount of N accumulated in aboveground biomass ranged between 102 and 212
kg N ha-1, showing differences only between years. The concentration
of structural polymers clearly differ between CC species, where T and A showed
higher concentrations of cellulose and hemicellulose regarding V. Conversely, V
showed higher concentrations of nonstructural carbohydrates and lignin than
grasses. Winter grasses as CC were more efficient in producing MS and therefore
more effectives to contribute to increased soil organic matter, promoting the
recycling of macro- and micronutrients, preventing the leaching of those most
labile.
wheat-vetch- biochemical composition
Duval M.E., J.A. Galantini, J.E. Capurro, M.J. Beltrán. 2017. Producción
y calidad de diferentes cultivos de cobertura en monocultivo de soja. Ciencias
Agronómicas (FCA-UNR) XXIX 7-13.
Quality of
cover crops in Southwest Bonaerense under no tillage systems
No-tillage system with fall/winter cover crop (CC)
ensures that large amounts of different types of organic residue are supplied to
the soil. The biochemical composition of each residue, especially its C:N ratio
and lignin, plays an important role in nitrogen (N) and carbon (C) soil
dynamics, as well as the availability of nutrients for the next crop. The
objective of this study was to evaluate the quality parameters of CC based on
the quantity and quality of the residue contributed. The experiments were
carried out on Argiudioles typical of the Coronel Suárez (Pcia. de Bs. As.)
Species used as cover crops were: Oats (Avena sativa L.), Hairy vetch (Vicia
sativa L. Thell.), Clover persia ‘‘grazing’’ (Trifolium resupinatum L var.
‘‘Lightning’’), Clover Persia ‘‘coverage’’ (Trifolium resupinatum L. var.
‘‘Laser’’). The determinations were: a) Production of forage (Mg MS ha-1), b)
N, c) neutral detergent fiber (NDF) and acid (FDA), nonstructural carbohydrates
(CNES), carbon (C%) and Lignin. The aerial biomass of Hairy vetch presented the
highest concentrations of N in the dry matter (MS) produced. When the oats were
fertilized they were able to increase the contributions of N to the soil
present in the aerial biomass of the residue to 50%. The aerial biomass of
Hairy vetch presented the highest yields and concentrations of lignin. The
different CC presented C:N and LIG:N ratios that were based on the amount of MS
produced by the aerial biomass of the crop and its phonological state at the
time of drying. The temperature and the moment of evaluation modified quantity
and quality of the residues. The parameters evaluated were sensitive to these
changes.
Cover crops, cellulose, hemicellulose, lignin.
Sá Pereira E. de,
J.A. Galantini, A. Quiroga. 2017.
Calidad de cultivos de cobertura en sistemas de siembra directa del sudoeste bonaerense. Ciencia del
Suelo 35(2) 337-350.
Use of a
three-compartment model to evaluate the dynamics of cover crop residues
Cover crop (CC) residues protect the soil from erosion
and their permanence on the surface is largely influenced by their biochemical
constituents. In this study, the dynamics of CC residue decomposition by
applying mathematical models was described. The kinetics of decomposition of
residues was obtained from a laboratory incubation experiment. Three CC shoot
residues were applied on the soil surface and incubated for 362 days (with
eight sampling times). Oats and vetch residues decomposed the most than clover,
where k values were 3.6 × 10−3, 3.7 × 10−3 and 5.3 × 10−3 day−1, respectively.
The three-compartment model (nonstructural carbohydrates, cellulose–hemicellulose
and lignin) to simulate residue decomposition presented a close fit between
simulated and measured data. The decomposition rate constant (k) of CC can be
used to estimate how long residues will remain in the field and how they could
affect soil organic carbon.
Residue decomposition; oats; vetch; clover
Sa Pereira E, J.A. Galantini, M. Duval. 2017. Use of a three-compartment model to
evaluate the dynamics of cover crop residues. Archives of Agronomy and Soil
Science 63(11)1623-1629.
Decomposition
from legume and non-legume crop residues: effects on soil organic carbon
fractions under controlled conditions
Cover crop (CC) residues protect the soil from erosion
and their permanence on the surface is largely influenced by their biochemical
constituents. We performed a study under controlled conditions to investigate
the dynamics of legume and non-legume CC residues decomposition and the
transformations of the soil labile organic carbon fractions in the surface
layer (0-15 cm). The experiment was carried out on a Typic Argiudoll (clay
loam, 27.4 g kg-1 soil organic matter, 14 mg kg-1 extractable phosphorus and
6.5 pH) placed in undisturbed pots (1570 cm3) in a greenhouse under controlled
conditions of temperature (25 ± 1 °C). We evaluated three CC species (oat,
Avena sativa L.; vetch, Vicia sativa L.; Persian clover, Trifolium resupinatum
L.) and a no-CC control (fallow). Shoot residues were applied on the soil
surface at 5.4, 5.4 and 2.7 g dry matter (equivalent to 6, 6 and 3 Mg ha-1 for oat,
vetch and clover, respectively) and incubated for 362-days (eight sampling
times). The water content in the pots was maintained periodically by weight at
60% of soil water-holding capacity. The soil samples were analyzed for
particulate organic carbon (POC), and total and soluble carbohydrates (CHt and
CHs, respectively). Oat and vetch residues decomposed faster than clover, with
the decomposition rate constant (k) values of 1.3, 1.4 and 1.9 year-1,
respectively. At the end of the experiment, POC concentration was lower in
vetch (1.83 g kg-1) and clover (1.96 g kg-1) than in oat (2.21 g kg-1) and
fallow (3.00 g kg-1), indicating a loss of 45-64% from their initial values.
Soil CHt was influenced by residue quality, where the periods of greatest
residue decay (vetch 21-59 days and oat 93-130 days) corresponded to higher
soil CHt. Hence, this organic carbon fraction is sensitive to residue
decomposition and can be indicators of changes in soil organic matter over
short periods of time.
Sa Pereira E, M. Duval, J.A. Galantini. 2017. Decomposition from legume and non-legume
crop residues: effects on soil organic carbon fractions under controlled
conditions. Spanish Journal of Soil Science 7(2) 86-96.
https://doi.org/10.3232/SJSS.2017.V7.N2.06
Changes in
soil pH and phosphorus availability during decomposition of cover crop residues
The aim of this study was to
determine the effect of winter cover crop (CC) residues on soil pH and
phosphorus (P) availability. Three incubation assays were performed in pots
using two CC: vetch (V) (Vicia villosa
Roth.) and oats (Oa) (Avena sativa
L.). Soil samples were taken from 10 sites at 0–20-cm depth. The rate of
residues were 0 (D0), 10 (D1), 20 (D2), 30 (D3), and 40 (D4) g dry matter kg−1
soil and the soil sampling was after 10, 20, 30, 60, 90, and 120 days of
incubation. Soil pH, extractable P (Pe), and soil organic matter (SOM) and its
fractions were determined. The pH increase was correlated with the rate applied
(D1 < D2 < D3 < D4). No differences were found for pH comparing V and
Oa residues with low residue rates. Soil pH changes were dependent from initial
pH and SOM fractions in different soils across the incubation period. The
multiple regression models showed that the pH changes were dependent on initial
pH level and SOM fractions with a high R2 (0.81). CC residues and
its quantities produced different changes on pH – especially at the beginning
of the incubation – which influenced the P availability.
Vanzolini J.I., J.A. Galantini, J.M. Martínez, L. Suñer. 2017. Changes in soil pH and
phosphorus availability during decomposition of cover crop residues. Archives
of Agronomy and Soil Science 63 (13) 1864-1874.
Soil organic matter
quality, macro and micronutrient availability in response to the inclusion of
wheat as cover crop
Cover crops
appear as an option to improve the balance of carbon (C) and its quality. The
aim of this study was to study the effect of wheat as a cover crop on the
dynamics of organic matter and the availability of some macro and micro
nutrients under different crop rotations. This work was carried out in a
long-term experiment under non-tillage system. Treatments were: soybean-soybean
(S-S), soybean-cover crop-soybean (S-CC-S), corn-soybean-wheat/soybean
(C-S-W/S) and corn/cover crop-soybean-wheat/soybean (C-CC-S-W/S). As principal
results, it was observed that the fraction of organic carbon between 53 and 105
mm (COPf) was significantly increased when CC were added to soybean
monoculture. The carbon fraction of less than 53 mm (COa), was higher when
cover crop were incorporated to the rotations. Soybean monoculture had a value
of total organic carbon (COPg + COPf) of 11.1 g kg-1, being the
lowest value of all treatments and significantly lower than S-CC-S (17 g kg-1).
Soil macronutrients concentration had no differences between treatments.
Rotations with grasses and legumes (M-S-T/S) determined in general a greater
accumulation of zinc (Zn) and manganese (Mn) (2.2 and 63 mg kg-1
respectively) than soybean monoculture (1.4 and 50 mg kg-1) in the
depth of 0-5 cm. The concentration of these micronutrients was positively
correlated with organic matter content. In this year of study, the CC did not
seem to have affected the concentration of micronutrients, thus successive
analysis should be performed in order to study the effect of CC in
micronutrients dynamics in time.
Organic fractions, nutrient
availability, crop rotations
Beltrán M., L. Brutti, R. Romaniuk, S. Bacigaluppo, F. Salvagiotti, H.
Sainz-Rosa, J.A. Galantini. 2016. Efecto del trigo como cultivo de cobertura
sobre la dinámica de la materia orgánica en el suelo y la disponibilidad de
macro y micronutrientes. Ciencia del Suelo 34(1) 67-79.
Use of
different winter cover crops species in soybean monoculture: effects on soil
organic carbon and its fractions
The current agricultural production systems in the Pampas Region have
been significantly simplified by cultivating large land areas under no tillage
(NT), where soybean is the predominant crop. These systems with long periods of
fall-winter fallow and poor annual input of carbon (C) into the soil lead to
soil degradation, thereby affecting physical and chemical properties. A 6-year
cover crop study was carried out on a Typic Argiudoll under NT in the south of
Santa Fe, Argentina. Various winter species were used as cover crops: wheat
(W), oat (O), vetch (V), an oat + vetch mixture (O + V) and a control (Ct)
treatment without a cover crop. We examined the influence of cover crops on the
following soil organic C-fractions: coarse particulate organic carbon (POCc),
fine particulate organic carbon (POCf) and mineral-associated organic carbon
(MOC) from 2008 to 2011. Aboveground carbon input by the cover crops was
related to the June to October rainfalls. In general, the W and O treatments
supplied a higher amount of C to the soil; these gramineous species produced 22
and 86% more biomass than O + V and V. The water cost of including cover crops
ranged from 13 to 93 mm compared with Ct. However, this water-use did not
affect soybean yields. On average, gramineous species (pure stand or mixture)
supplied more than 3.0 Mg C ha−1 year−1 to the soil,
whereas V supplied less than 2.0 Mg C ha−1 year−1. Increase in the
mean annual C-input by residues into the soil (cover crop + soybean) explained
most SOC variation (R2 = 0.61; p < 0.05). This relationship was
more evident with labile soil organic fractions, both for POCc (R2 =
0.91; p < 0.001) and POCc + POCf (R2 = 0.81; p < 0.001). The
stratification ratios of SOC (SI, 0–5:10–20 cm) reflected differences among
treatments, where >2.0 for W; 1.7 for O, O + V and V, and <1.5 for Ct.
Soil physical fractionation by particle size showed that cover crops affected
the most dynamic fraction directly associated with residue input (POCc) at 0–5
and 5–10 cm. At 0–5 cm, the effects were observed in the most transformed
fractions (MOC and POCf) 4 years after the experiment started, whereas at 0–20
cm, differences in the labile fractions (POCc and POCf) were found at the end of
the experiment (6 years). Although C-input by the cover crops fueled
decomposition of labile soil organic fractions, concentration of surface SOC
and its associated fractions (POCc, POCf and MOC) was modified after 6 years.
This effect became noticeable during the third year when the plots under cover
crops showed a higher stratification index than the traditional fallow.
Palabras clave Trigo, Fracciones labiales; Siembra directa
Duval M., J.A. Galantini, Julia E. Capurro, J.M. Martinez, F.M. López. 2016. Use of different winter
cover crops species in soybean monoculture: effects on soil organic carbon and
its fractions. Soil & Tillage Research 161:95-105
doi:10.1016/j.still.2016.04.006
Use of cover
crops in soybean monoculture: effects on water and carbon balance
The cover crops
(CC) is a good alternative to improve the lack of coverage and carbon balance
in soils under no tillage with soybean (Glycine
max L. Merr.) monoculture, predominant in the Pampean Region. In this study
(2006-2011) the effect of winter cover crops -wheat (T), oats (A), vetch (V)
and oats+vetch (A+V)- on water consumption, dry matter production and its
impact on the of soil organic carbon contents (TOC) was evaluated. Biomass
production of the CC was closely related to rainfall recorded between the months
of June and October. In general, T and A treatments contributed greater amount
of soil cover, on average, these grasses biomass were 24 and 91% higher
compared with A+V and V. The water cost of including CC was 13-93 mm compared
to traditional fallow (Ct). At the time of sowing of soybean, in general, Ct
presented the highest water content. However, this treatment showed a loss of
moisture by evaporation without biomass production, which is used by the CC to
fix carbon between 18 and 303 kg C ha-1 depending on the year
conditions. The use of CC -T, A and A+V- increased the TOC at 0-20 cm depth at
rates of 597 to 98 kg C ha-1yr-1, while it decreased at
824 and 289 kg C ha-1 yr-1 without CC or using legumes
(V), respectively. For conservation or increase the TOC, use of CC such as A,
A+V and T would be a feasible option given that exceeds the minimum source C
input of4,5 Mg C ha-1 necessary to maintain the TOC in soils south
of Santa Fe.
Argiudoll; winter cover crops; available water;
organic carbon
Duval M.E., J.E. Capurro, J.A. Galantini, J.M. Andriani. 2015.
Utilización de cultivos de cobertura en monocultivo de soja: Efectos sobre el
balance de carbono. Ciencia del Suelo 32 (2) 247-261.
Cover crop effects on yield and corn n accumulation in Southwestern Buenos Aires
Cover crop effects on yield and corn n accumulation in Southwestern Buenos Aires
Cover crops (CC) have an effect on nitrogen (N)
accumulation and on successive crop yields. The aim of this study was to
evaluate yields, yield components and N accumulation of maize using as previous
crops different CC and evaluating the response to N fertilization. Five
experiments were conductedd on a Typic Argiudioll (USDA Soil Taxonomy) of
Coronel Suárez. The species used as CC were: Oats (Avena sativa), Hairy vetch
(Vicia sativa) and control (chemical fallow). The experimental design consisted
of split-plots in three randomized complete blocks, with main plots
corresponding to the cover crops treatment and subplots to the fertilizer
treatment (N applied at the V4-V6 corn stage). The treatments in the main plots
were the CC. The effects of CC varied according to the corn yield component..
Hairy vetch and N fertilization at different rates increased the N absorption
efficiency. A greater N absorption was not always related to increases in corn
yields, probably due to the climatic variability among years. There was a
tendency for greater corn yields with hairy vetch as a preceding cover crop. N
application reduced hairy vetch N recovery during the second year and increased
N recovery during the first and third year. Fertilizer application effects
varied among previous crops with a low response to N when the previous crop was
hairy vetch, a variable response when in fallow and a significant response when
the previous crop was oats.
Key words. Cover crops, corn, hairy vetch,
clover, oats, yield, nitrogen.
Sá Pereira E. de, J.A. Galantini, A. Quiroga, M.R. Landriscini. 2014. Efecto
de los cultivos de cobertura otoño invernales, sobre el rendimiento y
acumulación de N en maíz en el sudoeste bonaerense. Ciencia del Suelo 32 (2) 219-231.
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