Effect of conservative agriculture on nitrate leaching: The Lombardy case study (Northern Italy) Marco Acutis

Effect of conservative agriculture on nitrate leaching:
 The Lombardy case study (Northern Italy)
Marco Acutis marco.acutis@unimi.it
 With: M. Chiodini
 C. Schillaci
 S. Brenna
 C.Tieghi
 A. Perego

Introduzione
 CONSERVATION AGRICULTURE

 CONSERVATION AGRICULTURE: Adaptation and
 • Reduced to zero soil tillage Mitigation
 • No soil layers mixing strategy to
 • Crop rotation climate change
 • Avoiding bare soil by maintaining vegetative
 cover, mulch, crop residues

Decrease in GHG
 SOC sequestration
 emissions

 Decrease in nitrate
 leaching

Introduzione
 CONSERVATION AGRICULTURE

 In the World: 116,9 millions of ha

 Rest of the World 3.8
 Canada 13.5
 Europe 1.2
 USA 26.5
 China 1.3

Paraguay 2.4 Brazil 25.5

Argentina 25.8 Australia 17.0

 62% of cultived surface in
 USA, 80% in Argentina (Derpsch, R. and Friedrich, T., 2010)

Contenuto di azoto nitrico nella soluzione
Field monitoring circolante
 - Suction cups at 20, 40 e 70 cm
 - NO3-N soil solution concentration measured each 15 days -21 days 08/2016)
 - NO3–N leaching at 70 cm with the function proposed by Lord and Shepherd (1993)

 ℎ = 0.5 ( 1 + 2 ) Τ 100

 c1 , c2 (mg N-NO3 l-1) two consecutive samples
 v (mm) water drained from
 Missing data of NO3-N leaching obtained with linear interpolation

 x2
 Suction cups
 TDR100

Risultati: Stima della lisciviazione dell’azoto
Field monitoring: Mantua clay loam soil, winter wheat
 nitrico
 12 160
 10 140

 leached (kg ha-1)
 120

 Rainfall (mm)
 8 100
 NO3-N 6 80
 4 60
 40
 2 20
 0 0
 Feb Mar Apr May Jun Jul Aug

 Rainfall
 Precipitazioni MT1 NT1 MT2 NT2 CONV

 O

 S
 N

 E

 MT1: 12 kg ha-1 CONV: 16 Kg ha-1
 NT1: 19 kg ha-1
 MT2: 4 kg ha-1
 NT2: 12 kg ha-1
 0 100 200 300
 m

Field monitoring: Mantua clay loam soil,
 Risultati: valutazione della produzionewinter wheat
 Winter wheat grain yield
 8000
 7000
 6000
 5000
 kg ha-1

 4000
 a a b
 3000
 2000
 1000
 0
 MT NT CONV
 N recovery
 200 92% 96% 100%
 87% 99%
 94%
 160 80%
 N (kg ha-1)

 120 60%

 80 40%

 40 20%

 0 0%
 MT 1 MT 2 NT 1 NT 2 CONV
 Granella
 Grain Paglia
 Straw Fertilizzante
 N Fertilizer Efficienza
 N recoveryapparente
 / N Fertilizer

Convenience of Conservative Agriculture in Lombardy

 Maize – no subsidies
 1750

 1500
 Conventional
 Agricoltura
 1250
 Convenzionale
 € ha-1

 1000 Minimum
 Minimum tillage
 tillage
 lordo (€/ha)

 750
 margin

 Sod seeding
 Semina su sodo
 500
 Margine
 Gross

 250

 0

 -250

 -500
 100 120 140 160 180 200 220 240 260 280
 prezzo€(€/t)
 Maize price t-1

Convenience of Conservative Agriculture in Lombardy

Simulazione dei processi del carbonio nei suoli agrari
 ARMOSA: model
 gestiti secondo features
 pratiche convenzionali e conservative

-Water dynamic: Richards’ equation
(SWAP, Van Dam et al., 1997; Van Dam and Feddes, 2000)

-Evapotraspiration: Allen et al., 1998

-Soil temperature: SWAT (Arnold et al., 1988)

-Crop growth: (WOFOST, Van Keulen and Wolf, 1986); hourly calculation of
intercepted radiation and photosyntesis in 5 layers of canopy;

-Phenology: stages are described by BBCH scale (from 0 to 100);

-N and C cycling: each fertilizer application represents a specific pool of
organic matter (modified from SOILN, Eckersten et al., 1996).

Simulazione dei processi del carbonio nei suoli agrari
 ARMOSA: simulation of conventional vs
 gestiti secondo pratiche convenzionali e conservative
 conservation agriculture practices

Tillage (depth, timing, layers mixing and perturbation
degree) and settling change the bulk density and the SOC
mineralization rate

Effect of SOC on daily calculation BD

Daily calculation of hydrological parameters
as a function of SOC and BD

ARMOSA: input and output data Perego et al., 2013

2002-2016, 8 sites soil water content
Soil water Meteorological data
 drainage water
content m3 m-3 soil NO3-N
 calib: soil database soil NH4-N
 1400 N mineralization
  crop database N uptake
 valid: N leaching
 2100 N denitrification
 data N fertilization N volatilization
 N, C humus
mg NO3-N L-1 above ground biomass
 ARMOSA
 calib: Process-based model yield
 600 LAI
  Harvest Index
 valid: ET
 1200 water stress index
 data N stress index

ARMOSA calibration
 Annual N leaching
 kg NO3-N ha-1 y-1

 600

 400
 simulated

 y = 1.2446x - 25.15
 200 R² = 0.9673

 0
 0 100 200 300 400 500
 observed
Perego et al., 2013
 RRMSE CRM r slope EF
 26.62 -0.06 0.98 1.24 0.88

Field study and modelling analysis in CA:
 Risultati: valutazione
LIFE+ Project HelpSoil
 della produzione
 1 Torino (sandy loam)
 a a 2 Pavia (loam clayey)
 b 5 3 Mantua (clay loam)
 1 2 3
 4 Ferrara(sandy clayey)
 4 5 Udine (silty sandy clayey)

 M1=observed meteo data 2005-2015
 M2=rcp4.5 scenario, HadGEM2 2020-2050 (+1.1 C°, -15% in
 summer, + 3% in spring and autumn)

 ROT1=maize, winter wheat, soybean,
 ROT2=maize, winter cover crop, soybean,
 winter wheat, foxtail millet, winter cover crop

 Conv=ploughing at 30 cm
 MT=harrowing at 15 cm
 NT=sod seeding

Modelling leaching under Conservation Agriculture:
 LIFE+ Project HelpSoil
kg ha-1 maize
14000
12000
 Mean annual grain yield
10000 kg DM ha-1
 8000
 6000 CONV CA (= mean of MT and NT)
 4000 decrease in yield only in soybean
 2000
 (-10%, p

Modelling leaching under Conservation Agriculture:
 Risultati: valutazione
LIFE+ Project HelpSoil
 della produzione
 Mean annual leaching kg NO3-N ha-1
 100

 2005-2015
 80
 2020-2050
 60

 40

 20

 0
 Conv
 CT MT NT Conv
 CT MT NT
 ROT1 ROT2

 Significant increase from actual to future climate only under ROT1
 (+13%)
 MT=NT < Conv (p

Risultati:
Modelling valutazione
 analysis della
 at territorial scaleproduzione

 Mean annual leaching
 kg NO3-N ha-1
 < 20
 20 – 40
Conventional Tillage 40 - 60 Reduced Tillage
 60 – 80
 > 80
 (mean of MT and NT)
 Alps and Apennines

Discussion and Conclusions
Conservative Agriculture is a valuable option even if…. and
because:

• yield are in some case lower than in Conventional agriculture
• We have to win the no glyphosate challenge..
• Increasing of soil fertility (ad SOC, but not everywhere)
• Increase biodiversity
• Reduction of not renewable energy sources usage
• Reduction of greenhouse gas and ammonia emission
• High resistance and resilience to climate change
• Reduction of nitrate leaching
• Conservative + organic farming ?

This study was realized in
Risultati: valutazione della produzione
 the context of HelpSoil Life
 Project
 And with the FACCE-JPI
 MACSUR

 THANKS FOR YOUR ATTENTION