MANAGEMENT OF SOYBEAN NUTRITION Crop, Soils and Water Management Group Fernando Salvagiotti Crop, Soils and Water Management Group EEA Oliveros INTA ARGENTINA Tecnología Agropecuaria Instituto Nacional de

POTENTIAL WATER LIMITED ACTUAL WATER AND NUTRIENT LIMITED FARMER YIELD CO2 Radiation Temperature Genotype POTENTIAL Defining Factors WATER LIMITED Limiting Factors Water WATER AND NUTRIENT LIMITED Limiting Factors Nutrients FARMER YIELD ACTUAL Reducing Factors Weeds Diseases Insects Pollutants Yield Level Adapted from Van Ittersum, 2013

POTENTIAL WATER LIMITED ACTUAL WATER AND NUTRIENT LIMITED Yield Level CO2 Radiation Temperature Genotype POTENTIAL Defining Factors WATER LIMITED Limiting Factors Water WATER AND NUTRIENT LIMITED Limiting Factors Nutrients NUTRITIONAL + WATER GAP ACTUAL Reducing Factors Weeds Diseases Insects Pollutants Yield Level Adapted from Van Ittersum, 2013

High Mobility nutrients Directly related with yield potential in each field Low Mobility nutrients Directly related with soil nutrient levels above a threshold

Nutritional Gap in Soybean Nitrogen Phosphorus Potassium Sulfur Micronutrients Cations (Ca, Mg)

Sinclair & Horie, 1989

SOYBEAN Lentil Pea Mung Bean Cowpea Pigeon Pea Lima Bean Chickpea Hemp Cotton Flax Peanut Wheat Rye Sunflower Canola Pop Corn Oat Sesame Sorghum Maize Barley Safflower Rice Sinclair & de Witt, 1975

Nutrient Internal requirement HI Nutrient needs 3000 kg ha-1 N kg Mg-1 79 0.75 237 P 7 21 K 33 0.50 99 S 6 18 Ca 14 0.20 42 Mg 8 0.38 24 Cu g Mg-1 22 0.53 66 Mn 130 0.33 390 Zn 52 0.70 156 B 0.31 Fe 260 0.25 780 Mo 4 0.85 12 Cl 205 0.47 615

Seed yield and N uptake in soybean Maximum Dilution 53 kg N per Mg 80 kg N per Mg Seed yield (kg ha-1) Maximum Accumulation 156 kg N per Mg N uptake (kg ha-1) Salvagiotti et al, 2008

Rendimiento y N en soja Salvagiotti et al, 2008

I II III R1 R5 R7 N accumulation rate (kg ha-1 day-1) N uptake BNF Soil N N in pods I II III N accumulation rate (kg ha-1 day-1) R1 R5 R7 Days after emergence Salvagiotti et al, 2009

Nitrogen fixation and Seed yield in soybean 50 kg N per Mg Ciampitti and Salvagiotti et al, 2017 – In press

Nitrogen fixation and N uptake in soybean Ciampitti and Salvagiotti et al, 2017 – In press

ATMOSPHERE SOIL Atmospheric N (N2) FERTILIZER HARVEST Biological fixation Crop uptake Organic N Nitrates (NO3-) Inmovilization SOIL Mineralization

Nitrogen fixation and fertilizer N in soybean 350 N applied in nodulation zone 300 ) -1 250 200 Fixed N (kg ha 150 100 50 400 800 1200 1600 -1 Fertilizer N (kg ha ) Salvagiotti et al, 2008

Soybean history in the field – Response to N fertilization Inoculation Soybean history in the field – Response to N fertilization No previous soybean Soybean 3 previous year Bodrero et al, 1985.

TRADE – OFF between fertilizer N and biological N2 fixation  No constraints for normal growth  Low soil pH  Low efficient Rhizobium strains  Low temperature  Low fertility soils  No soybean history  Drought. 4.5 Mg ha-1 Salvagiotti et al, 2008

Biological N fixation as affected by soil and crop variables Collino et al, 2015

Nutritional Gap in Soybean Nitrogen Phosphorus Potassium Sulfur Micronutrients Cations (Ca, Mg)

Nutrient Internal requirement HI Nutrient needs 3000 kg ha-1 N kg Mg-1 79 0.75 237 P 7 21 K 33 0.50 99 S 6 18 Ca 14 0.20 42 Mg 8 0.38 24 Cu g Mg-1 22 0.53 66 Mn 130 0.33 390 Zn 52 0.70 156 B 0.31 Fe 260 0.25 780 Mo 4 0.85 12 Cl 205 0.47 615

6.6 kg P por Mg Máxima Dilución 3.8 kg P por Mg Máxima Acumulación Yang et al, 2017, Plos One Máxima Acumulación 10 kg P por Mg

Gutierrez Boem & Salvagiotti, 2013 Seed yield response (kg ha-1) P fertilizer rate (kg ha-1) Seed yield response (kg ha-1) P fertilizer rate (kg ha-1) Gutierrez Boem & Salvagiotti, 2013

Adapted from Vivas et al, 2008 P Bray content after 2 cycles in a Wheat/Soybean-Maize Soybean Rotation Adapted from Vivas et al, 2008 80 kg P fert 160 kg P fert Sin fertilización 20 kg de P en Gramíneas 40 kg de P en Gramíneas No Fertilization 20 kg P in Cereals 40 kg P in Cereals

Nutritional Gap in Soybean Nitrogen Phosphorus Potassium Sulfur Micronutrients Cations (Ca, Mg)

Nutrient Internal requirement HI Nutrient needs 3000 kg ha-1 N kg Mg-1 79 0.75 237 P 7 21 K 33 0.50 99 S 6 18 Ca 14 0.20 42 Mg 8 0.38 24 Cu g Mg-1 22 0.53 66 Mn 130 0.33 390 Zn 52 0.70 156 B 0.31 Fe 260 0.25 780 Mo 4 0.85 12 Cl 205 0.47 615

36 kg P por Mg Maximum Dilution 23 kg K per Mg Maximum Accumulation Yang et al, 2017, Plos One Maximum Accumulation 48 kg K per Mg

Nutritional Gap in Soybean Nitrogen Phosphorus Potassium Sulfur Micronutrients Cations (Ca, Mg)

Nutrient Internal requirement HI Nutrient needs 3000 kg ha-1 N kg Mg-1 79 0.75 237 P 7 21 K 33 0.50 99 S 6 18 Ca 14 0.20 42 Mg 8 0.38 24 Cu g Mg-1 22 0.53 66 Mn 130 0.33 390 Zn 52 0.70 156 B 0.31 Fe 260 0.25 780 Mo 4 0.85 12 Cl 205 0.47 615

Responsive (R) and non responsive to S fertilization (N) sites as arranged by multivariate analysis including soil variables (Vilche et al, 2002) Soil organic matter (%) Agriculture history Structural stability

Balanced nutrition Satisfy nutrient demand for achieving target seed yield Avoid over-fertilization of one nutrient as compared with other nutrient LOW NUTRIENT USE EFFICIENCY – NEGATIVE ENVIRONMENTAL IMPACT

For the nutrients described: NPK : 9.5:1:4.5 NPKS: 19:2:9:1

Nutritional Gap in Soybean Nitrogen Phosphorus Potassium Sulfur Micronutrients Cations (Ca, Mg)

Nutrient Internal requirement HI Nutrient needs 3000 kg ha-1 N kg Mg-1 79 0.75 237 P 7 21 K 33 0.50 99 S 6 18 Ca 14 0.20 42 Mg 8 0.38 24 Cu g Mg-1 22 0.53 66 Mn 130 0.33 390 Zn 52 0.70 156 B 0.31 Fe 260 0.25 780 Mo 4 0.85 12 Cl 205 0.47 615

Seed yield Co-Mo + (kg ha-1) Response to addition of Co-Mo in soybean Seed yield Control (kg ha-1) Seed yield Co-Mo + (kg ha-1)

Response to addition of Zn in soybean Seed yield Control (kg ha-1) Seed yield Zn + (kg ha-1)

Seed yield Control (kg ha-1) Response to addition of B in soybean Seed yield B + (kg ha-1) Seed yield Control (kg ha-1)

Final Comments

Plant – Rhizobia relationship MICROBIOLOGY Plant – Rhizobia relationship SOIL FERTILITY NUTRITIONAL GAP IN SOYBEAN CROP ECO-PHISIOLOGY

Nutritional Gap Soil fertility of each field Yield potential as determined by crop management Nutrient supply by symbionts microorganisms

Environmental conditions that determine potential yield in a particular field put a ceiling in the nutritional gap Soil fertility and the effectiveness of the Rhizobia-Plant interaction will determine the low level of the nutritional gap

Seed yield – Nutrient uptake relationships are generally non-linear, then internal nutrient requirements (kg of nutrient per kg of seed) will progressively decrease

Different magnitude of response depending on soil nutrients Identify which nutrient is actually deficient in each field (calibrated soil or foliar analysis) Different magnitude of response depending on soil nutrients Fertilizer strategy should take into account the mobility of nutrient in the soil

Nitrogen supply from Biological N Fixation is central for crop production and the better the environmental conditions, the larger the contribution of this source

Optimize BNF Process Inoculation with high effective strains High quality inoculants (Bacteria number, preservation) Crop management directed to optimize crop will increase N derived from BNF

Actions for reducing the nutritional gap Chemical fertilizers Organic Amendments Cover crops Inoculation with symbionts microorganisms Liming (in soils with ph below 5!!)

Basic knowledge for managing the nutritional gap Dynamics of nutrients in soils Nutrient requirements of crops Nutrient use efficiency The relative importance of each nutrient in generating seed yield Crop-symbiont relationship

Thank you!! Fernando Salvagiotti salvagiotti.fernando@inta.gob.ar www.inta.gov.ar/oliveros