Zhang Fusuo Center for Resources, Environment and Food Security China Agricultural University Dec. 7, 2015 Increase crop productivity and sustainability by balanced fertilization

Outline  Role of fertilizer in crop production  Imbalanced fertilization and phosphorus efficiency management  Future needs to produce more： A succesful case

Without N, 4 billion people would be starved to death (Erisman et al 2008) Fertilizers help feed the world

-N +N -P +P Maize growth was improved by N and P input

Zingore et al 2014 Effect of N applied as mineral fertilizer and cattle manure and their combination on maize grain yields in soils of varying fertility in Sub-Saharan Africa Crop yield increased with nutrient supply

Outline  Role of fertilizer in crop production  Imbalanced fertilization and phosphorus efficiency management  Future needs to produce more

Nitrogen surplus in world major croplands Sutton et al 2013

MacDonald et al 2012

Nutrient imbalances in China due to high input BrazilChinaFranceGermanyIndiaMyanmarUSA Cereal yield N input P 2 O 5 input Total N surplus P surplus Data were from FAO and IFA, The method of calculating nutrient balances was from Cui et al 2014; Wu et al 2015; Zhan, 2015.

P Phosphorous is an essential nutrient for plant development and productivity

Phosphorus is a key factor for crop production Moderate P fertilisation No P fertilisation High P fertilisation

In heavily P limited soils, small addition of P can boost crop yields Small addition of 10 kg P/ha/yr could increase maize yields by 12% in South America and 26% in Africa With N addition, this would save 29 millions ha from cropland expansion and provide food for +200 millions people (van der Velde et al., 2013)

P deficiency Leaf growth Leaf area Light interception (source for C) Leaf demand for C Root growth Maintained (or slightly enhanced)on short time Reduced on long time Root/shoot ratio Synoptic diagram of P deficiency effects on plant growth and development Pellerin et al 1999

+P-P Increased biomass allocation to roots in low P

Al/Fe oxides Allophane Source: De Sousa, 2011 Soils with strong P adsorption

Global coverage of highly sorbing soils

Soils with strong P precipitation CaCO 3 MgCO 3 Calcisols Calcarosols Source: Jorge.Mataix Source: ISRIC

Global coverage of calcareous soils Source: FAO

Where is P “fixation” a real problem? X X X       Source: Vorosmarty CJ, McIntyre PB, et al. (2010) Nature 467(7315),

Improving P efficiency by releasing “fixed” P/reducing sorption The scorecard Placement of P e.g. banding Cultivation to mineralise organic P Changing fertilizer formulation - fluids Changing fertilizer formulation – slow release (for leaching) New fertilizer formulations - chelates, slow release (to reduce sorption) Inoculants/biostimulants to release “fixed” P Inoculants/biostimulants to release stable organic P

Source: bioag.novozymes.com Field evidence of placement effects

22 ‚Homoeopathic‘ P fertilization rate for improved root growth, 2-3 kg P (+N,K)/ha, placed P placement (including P as starter fertilizer) P placement is a well established agronomic measure for enhanced P acquisition in farmers’ practices on sites with inhibited root growth (low soil temperature, drought, soil compaction etc.) or soils with high P adsorption capacity such as in West Africa)

Granular MAP Fluid MAP Field evidence of efficiency of formulations Source : Bob Holloway Holloway et al Plant and Soil 236,

The locus Pup1 (P uptake 1) confers tolerance to P deficiency Nipponbare NIL-Pup1 Kasalath Near Isogenic Line for Pup1 Locus (NIL-Pup1): Genetically 97% identical to Nipponbare but with insertions from tolerant donor variety Kasalath at Pup1 (Chromosome 12)

25 Faba bean Faba bean acidified its rhizosphere via proton exudation from roots, whereas maize did not. This enhanced crop yield and P acquisition. Maize (Li et al., 2007 PNAS) Intercropping faba bean with maize resulted in a better growth (17%) and P uptake (28 %) of maize: an agronomic measure for enhanced P acquisition widely used in Chinese agriculture (e.g. Gansu province)! Yield increase:

26 Yield N uptake kgN/ha P uptake kgP 2 O 5 /ha Maize Faba Bean Increase in （ % ） Fertilizer saved Intercrop increse both yield and nutrient uptake

Outline  Role of fertilizer in crop production  Imbalanced fertilization and best nutrient management for balanced fertilization  Future needs to produce more

(Sanchez, Nature Plants ) SS Africa Latin America South & Southeast Asia China USA, EU

A successful case of chemical fertilizer as the key factor of food production (Quzhou county) Quzhou, A typical county in the north China Plain with 93,074 households farmers

Soil salinization Soil fertility improved Double high Manure-based management, supply intensity from 15 m 3 to 60 m 3 ha -1 : chemical fertilizer shorted; irrigation shorted Chemical fertilizer-based management ， 150 kg N ha -1, 45 kg P 2 O 5 ha kg N ha -1, 150 kg P 2 O 5 ha -1 Nutrient deficiency Nutrient replenishment Nutrient excessive Quzhou Yearbook, 2014 Changes of grain yield and nutrient management strategy

Contribution of fertilizer to grain production Grain production could be explained 22%, 88% and 39% by fertilizer consumption during 1905s-1980s, 1980s-2000s, 2000s-2010s, irrespectively.

24% 26% 9% 126% 58% 9% Yield response to fertilizer varied with time Xin, 1977; Yang, 1994; Yue, 2012; Deng, 2015 No significant yield difference between fertilized and non-fertilized treatments was observed in 90s-10s

Nutrient imbalance in Quzhou croplands Quzhou Yearbook, 2014; the method of calculating nutrient balance was from Cui et al 2014; Wu et al 2015; Zhan et al 2015;

Feed crops to feed people and feed soil and environment in the other countries

Thanks for your attention ! Acknowledgments NSFC, MoA, MoE, MOST