Abundance of C-13 and N-15 in emmer, spelt and naked barley grown on differently manured soils: towards a method for identifying past manuring practice

作者：Kanstrup Marie^*; Thomsen Ingrid K; Andersen Astrid J; Bogaard Amy; Christensen Bent T

来源：Rapid Communications in Mass Spectrometry, 2011, 25(19): 2879-2887.

DOI：10.1002/rcm.5176

The shortage of plant-available nutrients probably constrained prehistoric cereal cropping but there is very little direct evidence relating to the history of ancient manuring. It has been shown that the long-term addition of animal manure elevates the delta N-15 value of soil and of modern crops grown on the soil. We have examined the delta N-15 and delta C-13 values of soil and of the grain and straw fractions of three ancient cereal types grown in unmanured, PK amended and cattle manured plots of the Askov long-term field experiment. Manure increased biomass yields and the delta N-15 values of soil and of grain and straw fractions of the ancient cereal types; differences in delta N-15 between unmanured and PK treatments were insignificant. The offset in straw and grain delta N-15 due to manure averaged 7.9 and 8.8 parts per thousand, respectively, while the soil offset was 1.9 parts per thousand. The soil and biomass delta C-13 values were not affected by nutrient amendments. Grain weights differed among cereal types but increased in the order: unmanured, PK, and animal manure. The grain and straw total-N concentration was generally not affected by manure addition. Our study suggests that long-term application of manure to permanently cultivated sites would have provided a substantial positive effect on cereals grown in early agriculture and will have left a significant N isotopic imprint on soil, grains and straw. We suggest that the use of animal manure can be identified by the N-15 abundance in remains of ancient cereals (e. g. charred grains) from archaeological sites and by growing test plants on freshly exposed palaeosols.

• 出版日期2011-10-15