Applications of proximal gamma ray soil sensor systems. Eddie Loonstra EGU 2011, SSS5.6 Vienna The Soil Company, Leonard Springerlaan 9, 9727 KB Groningen, The Netherlands ,

Contents 1.Introduction Mole technology 2.Mole Nuclide Maps Apps 3.Mole derived Soil Maps Apps 4.Conclusion

Mole technology Soils contain heavy unstable isotopes. Disintegration of atoms. Radio active radiation: α, β, and γ.

Mole technology Main emitted γ radiation and their half life times: 238 U4.46*10 9 yr 232 Th1.39*10 10 yr 40 K1.3*10 9 yr 137 Cs30 yr

Mole technology 1992 State University Groningen (RuG) -> The Soil Company. Mobile soil sensor system The Mole: –Detector material CsI –Standard spectra crystal specific –Full Spectrum Analysis (Chi- squared algorithm)

Surveys

Mole nuclide maps Quantitative output in Bq/kg: TC, 40 K, 238 U, 232 Th, and 137 Cs.

Mole nuclide maps Quality of soil: –Sport pitches during construction. –Variation Th to predict clay variation. Contamination –Tsjernobyl –High unnatural U content General soil types

Mole nuclide maps Soil abnormalities or disturbances –Dump spots of waste –Old brooks –Archeological sites –Deposits of dredging

Mole derived Soil Maps Regression analysis comparing nuclide information with soil properties. Correlations gamma and physical soil properties relative comparable for different regions and soil types (from Sweden down to India).

Mole derived Soil Maps Texture maps: –Clay%, sand%, grain size, soil type. –R – 0.9. Nutrient maps: –Organic matter, pH, P, K, Mg, Ca. –R – Pedotransfer maps: –bulk density, water retention, field capacity, saturated hydraulic conductivity. –Models WUR. Risk maps: –Compaction, Trichodorides. –Models.

Mole derived Soil Maps Quality of soil, maintenance. Bulb growers: –Barrenness of soil based on % sand, % OM and grain size. Soccer pitches: –% sand, % OM, % clay and grain size. Garden bushes & trees: –% sand, % OM, % clay and grain size.

Mole derived Soil Maps Quality of soil for crop Golfcourse –pH and liming vs street grass Agriculture, risk spots: –Variation pH for onions. –Clay content as habitat for trichodorides for potatoes.

Mole derived Soil Maps Quality of soil for crop Golfcourse –pH and liming vs street grass Agriculture, risk spots: –Variation pH for onions. –Clay content as habitat for trichodorides for potatoes.

Mole derived Soil Maps Precision Agriculture (NL) Variable rate application –Liming –Fertilization –Irrigation –Planting and seeding –Herbicides –Soil preparation to prevent compaction

Mole derived Soil Maps Precision Ag: nitrogen. Starch potatoes production: –Soils high variation in OM –Available nitrogen varies –VRA of liquid fertilizers leads to 3% yield increase Consumer potatoes: –Heterogeneous soils for clay and OM –VRA of liquid fertilizer leads to a 15% financial benefit.

Mole derived Soil Maps Variable planting distance Seed potatoes: –Clay map or water retention base for planting distance. –Size best paid. –Average 4% income increase. –240 – 500 euro/ha benefit. Wheat and sugar beet

Irrigation Consumer potato Egypt –Combining Mole water related soil maps and local weather information and water soil probe. –Applying right amount at the right time –Yield increase 8%, soft rot % drops with 3% to 1-2%.

Mole derived Soil Maps Miscellaneous: Land pricing estate agents Land degradation for nature (phosphates) Pollution of heavy metals.

Conclusions Although not very wide spread in use, Mole gamma ray sensors can be a very powerful device for the quantitative mapping of top soil. Nuclide data are applicable for building models of more or less stable soil properties. Variation of nuclide values or modeled soil properties can be directly applied to get information on soils or indirectly for soil related practices, like precision ag.

Thank you for your attention. The Soil Company, Leonard Springerlaan 9, 9727 KB Groningen, The Netherlands , iSOIL- “Interactions between soil related sciences – Linking geophysics, soil science and digital soil mapping” is a Collaborative Project (Grant Agreement number ) co-funded by the Research DG of the European Commission within the RTD activities of the FP7 Thematic Priority Environment. This publication reflects the author’s views. The European Commission is not liable for any use that may be made of the information contained therein.