A grip on soil fertilty Using the Wageningen soil system in Africa - PowerPoint PPT Presentation

Wageningen, The Netherlands A grip on soil fertilty Using the Wageningen soil system in Africa Dr. J.A. (Arjan) Reijneveld

What do we want?

Optimal yields Yield 17.5 15 12.5 10 7.5 5 2.5 0 1850 1875 1900 1925 1950 1975 2000 2025 2050 Years

High crop quality •

Efficient use of nutrients and water

Carbon sequestration in soil ? CARead more on page 28 of the Soil Atlas for the International Year of Soils 2015: RBON SEQUESTRATION IN SOILS http://globalsoilweek.org/soilatlas‐2015

What do we need?

High soil fertility = Nutrient and water holding and supplying capacity of the soil

Soil fertility Chemical Physical Biological N, S, P, K, Mg, Ca texture Soil nematodes Mn, Cu, B, Fe… Organic matter Fungi CEC, pH, Bacterial soil structure … …

How to establish soil fertility?

Soil test Routine soil tests: from the beginning of 20th century

Soil tests: until recently

Soil analysis: until recently - Many different, time consuming, chemical analysis - Need to set up a fully equipped laboratory - Expensive

Soil tests: Nowadays

Concept (1) • Intensity Plant Available 0.01 M CaCl 2 • Buffering power Soil supplying capacity • Quantity Soil stock Near Infra Red (NIR)

Concept (2)

Plant availabe nutrients CaCl 2 • DON • NO 3 • NH 4 • S • P • K • Mg • Na And also Si, Fe, Zn, Mn, Cu, Co, B, Mo, Se Introducing Cd, Al, etc. Based on e.g. Houba et al 1990., Van Erp 2002, Van Rotterdam-Los 2009, Ros 2011 ,

Soil stock Soil in jar of glass, analysed with near infra red method (NIR) In < 20 secondes > 20 soil characteristics

NIR soil characteristics Chemical Physical Biology N‐total soil stock pH Soil Life* S‐total soil stock Total Carbon (TOC) P‐total soil stock Soil Organic Carbon (SOC) P‐soil stock Soil Organic Matter (SOM) K‐soil stock Clay Ca‐total soil stock Silt Ca‐soil stock Sand Mg‐soil stock Effective CEC Na‐soil stock And of course C/N ratio, C/S ratio, Saturation, and more * Bases on Potential Mineralizable Nitrogen (PMN method )

From analysis to report

Report So only 2 methods (CaCl 2 and NIR)

On the report • Soil characteristics • Fertilization recommendation (crop based) • >100 crops and varieties • Soil fertility recommendation (soil based) • Yield Potential • Organic matter balance • Soil structure (soil slaking, soil fracturing, risk on wind erosion) • Water retention curve (pF-curve) (water management)

P

Phosphorus (P) Imroved P-status = improved root development = better uptake of nutrients, and less drought sensitive P recommendation with Wageningen University

Plant available and supplying capacity

Organic matter

Soil organic matter (SOM) status Among others: • Improved soil workability • Less drought sensitive

Decline in SOM content West P C et al. PNAS 2010; 107: 19645-19648

Soil organic matter (SOM) balance Not only a measurement but also information about maintaining soil organic matter content (balance) 2.9 % SOM mineralisation Input through crop residues Shortage, to be filled in with animal manure, compost, green manuring … .

Soil structure

Risk of problems with soil structure ? Calcium treatment 0 – treatment Potassium treatment reatment

Water!

On every report: water retention curve How much mm of water can be irrigated (maximum level) (based on water holding capacity) Too much irrigation • water will leach to deeper soil layers • nutrients will leach

Soil type

Soil type: soil texture triangle

Have your own NIR station

NIR analysis • Analyse soil fertility on YOUR location • Send NIR-data to Wageningen, Netherlands • < 15 minutes, results back on location • We would like to work with you! Cooperation with Simsoft Development in South Africa

Working on

Where to take the soil sample? Differences within a field! Learn from it !

Near Infra Red developments NIR Forage quality from 1995 onwards: > 40 locations worldwide NIR Soil Manure In progress: EC, P saturation, but also Ca and Mg intensity characteristics (instead of CaCl 2 ) Manure analysis with NIR ( project with Wageningen University; same NIR as soil and forage).

Conclusion

Conclusion: • Higher soil fertility = higher production • With NIR technique much insight in soil fertilty • More insight can be used to optimise - Production (yield) - Product quality - Water use - Prudent use of minerals • Results of soil tests should be discussed with farmers and extension services (advisors) to fully exploit its added value

Thank you Arjan Reijneveld Product manager Soil Fertility and Plant Nutrition Eurofins Agro, Wageningen, The Netherlands M + 31 (0)6 52 00 2 111 Arjan.Reijneveld@eurofins‐agro.com