image/svg+xml31 VI/1/2015 INTERDISCIPLINARIA ARCHAEOLOGICA NATURAL SCIENCES IN ARCHAEOLOGY homepage: http://www.iansa.eu Yield and Nutritive Value of Grain, Glumes and Straw of Triticum dicoccum Produced by Prehistoric Technology in Comparison to T. aestivum Produced by Modern Technology Michal Hejcman a,b* , Pavla Hejcmanová c a Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences, Kamýcká 1176, CZ-165 21 Prague 6 – Suchdol, Czech Republic b Department of Archaeology, Faculty of Arts, University of Hradec Králové, Rokitanského 62, CZ-500 03 Hradec Králové, Czech Republic c Faculty of Tropical AgriSciences, Czech University of Life Sciences, Kamýcká 129, Prague 6 – Suchdol, 16521, Czech Republic 1. Introduction Triticum dicoccum (emmer wheat) was the most important cereal species planted by the frst European farmers, followed by T. monococcum (Tempír 1976; van Zeist et al. 1991; Issac et al. 2010; Kočár, Dreslerová 2010). In archaeological records from the Czech Republic and Germany, the dominance of T. dicoccum lasted for at least 6,000 years, from the LBK (Linear Pottery culture, 5,500– 4,900 B.C.) of the Neolithic to the Migration period (A.D. 400–580, Kreuz et al. 2005; Jacomet 2009; Dreslerová, Kočár 2013). In the Czech Republic, cultivation of T. dicoccum probably prevailed in lowlands with high-quality soils, whereas cultivation of Hordeum vulgare was more common at higher altitudes in the Late Bronze and Early Iron ages (Dreslerová et al. 2013). In the Mediterranean region, T. dicoccum had been frequently planted up to the High Middle Ages and then only sporadically in low productive and dry regions (Cubero Corpas et al. 2008; Pena-Chocarro, Zapata 2013). In central Volume VI ● Issue 1/2015 ● Pages 31–45 *Corresponding author. E-mail: hejcman@fzp.czu.cz ARTICLE INFO Article history: Received: 19 th January 2015 Accepted: 30 th August 2015 Keywords: baker wheatemmerharvest indexphosphorusscratch ploughweedy specieszinc ABSTRACT Triticum dicoccum (emmer) was the main crop from the start of the Neolithic period up to the migra- tion period in central Europe, but almost nothing is known about its planting and nutritive value under prehistoric conditions. To fll this gap, we performed an archaeological experiment aimed at comparing the soil properties, grain and straw yields, hulled and harvest index, nutritive values of grain, glume and straw, plant height, and weedy communities, in stands of T. dicoccum established on an old feld used for crop production for several preceding years, and a stand of T. dicoccum established on a feld converted from permanent grassland by hoe-digging. To demonstrate differences between old and modern technologies and cereals, the obtained data were compared with those for a modern variety of T. aestivum planted on a modern feld. Key results and conclusions: (1) digging using a hoe was the easiest way to convert permanent grassland into arable feld. The use of a scratch plough or wooden spade for soil preparation was effective only on the permanent arable feld without dense grass swards. (2) Broadcast seeding was a simple and effective method for the establishment of T. diccocum stands. Spikelets that remained on the soil surface after seeding were eaten by rodents and birds. (3) Triticum dicoccum possessed a high grain-yield compensation ability, a high competitive ability to cope with weeds, and a high value for its grain, particularly with respect to human N, P, Mg, Fe, Cu and Zn nutri- tion. (4) In prehistory, no strict borders between arable felds and grasslands probably existed, as many grassland species were also weeds on arable land, such as Plantago lanceolata and Trifolium repens . (5) The grain yield of T. dicoccum of 1.7–1.8 t ha –1 probably corresponds to the yields of prehistoric farmers on high-quality soils in central Europe. The grain yield of a modern variety of T. aestivum was 4.7 t ha –1 . (6) The nutritive value of glumes was low in comparison to that of grain. We suppose that prehistoric people preferred food made from clean grain. (7) Grain yield represented 75% of spikelet yield. (8) The nutritive value of T. dicoccum and T. aestivum straw was insuffcient for optimum cattle nutrition, especially due to too low N and P concentrations, together with too high fbre and lignin contents. We conclude that straw was used for livestock feeding only if better forage was not available.
image/svg+xmlIANSA 2015 ● VI/1 ● 31–45Michal Hejcman, Pavla Hejcmanová: Yield and Nutritive Value of Grain, Glumes and Straw of Triticum dicoccum Produced by Prehistoric Technology in Comparison to T. aestivum Produced by Modern Technology 32 Europe T. dicoccum was a marginal crop during the Middle and New Ages and its planting survived only in low productive and isolated regions up to the twentieth century. The last traditional planting of T. dicoccum was recorded in the mountain regions of Slovakia in the second half of the twentieth century (Tempír 1976; Hajnalová, Dreslerová 2010).Although T. dicoccum was one of the most important crops in European Prehistory, almost nothing is known about the nutritive value of its grain, glumes and straw under the conditions produced by prehistoric technology. While some archaeological experiments with the planting of T. dicoccum using medieval and prehistoric technologies have been performed, the results of such experiments have usually been restricted to only publication of grain yields (Reynolds 1992; Cubero Corpas et al. 2008; Ehrmann et al. 2014). It is supposed that straw could have been used for the winter feeding of livestock, but the forage quality of T. dicoccum straw, and the possible consequences for its use in livestock feeding in prehistory has not, according to the literature, been evaluated. Recently, T. dicoccum has been investigated as an alternative forage crop harvested as green fodder in dry Mediterranean regions with a shortage of high-quality forage (Cazzato et al. 2013). Triticum dicoccum is a hulled (glume) wheat, and post-harvest processing (dehusking) is necessary to obtain clean grain without glumes (Hillman 1984; Peña-Chocarro, Zapata 2003). Did prehistoric people consume clean grain or grain with glumes? To answer this question, a comparison of the nutritive value of glumes and grains is necessary, because the consumption of grain with glumes can affect the nutritional value of the food produced. According to our information, the analysis of the nutritive value of glumes has never been performed, even for T. dicoccum planted using modern technology. The nutritive value of plant biomass for human and livestock nutrition can be assessed according to the content of macro- (N, P, K, Ca and Mg), micro- (Fe, Zn, Cu and Mn) and risk (Cd, Pb) elements (Hejcman et al. 2010). In addition, the forage quality of livestock fodder can be evaluated according to neutro (NDF) and acid (ADF) detergent fbre and by lignin (ADL) content, which determines the digestibility of organic matter (Hejcmanová et al. 2014). Broadcast seeding was probably the most frequently used seeding technique in Prehistory, particularly under plough agriculture (Bogaard 2004). According to Reynolds (1992), losses of caryopses, which are normally eaten by birds and rodents from the soil surface, can reach up to 75% using this technique. Many current agronomists consider T. dicoccum to be prehistoric and therefore, an old-fashioned crop; hence, T. dicoccum has not been subjected to intensive modern breeding in contrast to T. aestivum (Zaharieva et al. 2010; Konvalina et al. 2013). Contemporary landraces can therefore be used in archaeological experiments, as their yield potential is considered to be similar to that of landraces in prehistory. In recent years, T. dicoccum has been investigated in particular as an alternative low-yielding cereal that is suitable for marginal areas and organic farming due to its high resistance against disease, low N and water requirement, and a high competitive ability against weeds in comparison to T. aestivum (Marino et al. 2009; 2011; Konvalina et al. 2012a; 2012b). In addition, the grain of T. dicoccum is characterised by higher concentrations of N, Fe and Zn in comparison to T. aestivum ; thus T. dicoccum can be used to alleviate human Zn and Fe defciency (Suchowilska et al. 2012).Taking into account the insuffcient information on the nutritive value of T. dicoccum when planted under prehistoric technology, we decided to perform an experiment. We have selected a region in the northern part of the Czech Republic on chernozem soil, where T. dicoccum has been cultivated from the Neolithic to the Migration period (Tempír 1982). The experiment was performed in the open-air archaeological museum of Březno near Louny and its scientifc aim was to compare soil properties, grain and straw yields, hulled index, nutritive values of grain, glumes and straw, harvest index, plant height. and weedy communities, in stands of T. dicoccum established on an old and a new feld. The old feld was a plot that had been used for crop production for several preceding years (hereafter referred to as “the old feld”). The new feld was a stand of T. dicoccum established on a feld converted from permanent grassland by hoe-digging directly before seeding (hereafter referred to as “the new feld”). To demonstrate differences between old and modern technologies and cereals, the data obtained from the experiment with T. dicoccum were compared with those of a modern variety of T. aestivum planted using modern technology in the neighbourhood of the archaeological experiment (hereafter referred to as “the modern feld”). The obtained results are discussed with respect to prehistoric agricultural practices. 2. Materials and methods2.1 Study site The experiment was established at the open-air museum of Březno near Louny in the NW of the Czech Republic (50°21'34.560"N, 13°44'43.621"E). The museum was established on the right bank of the Ohře (Eger) river in an area of large-scale archaeological excavations performed from the 1950s to the 1970s (Pleinerová, Pavlů 1979; Pleinerová 2000). The area surrounding the museum was densely inhabited from the Neolithic up to the Slavic period (the ninth century A.D.). The altitude of the study site is 190 m asl, the mean annual temperature is 9°C, and mean annual precipitation is 470 mm. The area is well known for its highly fertile chernozem soils suitable for the production of high-quality baker’s wheat. Weather conditions in the year of planting were favourable for cereal production as there was enough precipitation in the spring. 2.2 Field experiment We established four 2×2 m experimental plots on the “old feld”, which had been used for the growing of crops in the
image/svg+xmlIANSA 2015 ● VI/1 ● 31–45Michal Hejcman, Pavla Hejcmanová: Yield and Nutritive Value of Grain, Glumes and Straw of Triticum dicoccum Produced by Prehistoric Technology in Comparison to T. aestivum Produced by Modern Technology 33 museum for at least ten years before the establishment of our own experiment. The soil was prepared on the day of sowing using a scratch plough (Figure 1a). The depth of ploughing was up to 10 cm. In the close vicinity, another four, 2×2 m plots as a “new feld” were established. They were converted from permanent grassland by the use of a medieval iron hoe. The depth of digging was up to 10 cm (Figure 1c). Originally, we intended to convert the grassland into arable feld by use of a scratch plough and/or a prehistoric or early medieval wooden spade (Figure 1c), but this was too labour- intensive and ploughing of the grassland was impossible. The experimental “new” and “old felds” were compared with the “modern feld”, located at a distance of 60 m from the experimental plots. The modern feld was prepared for seeding by ploughing using modern machinery to a depth of 30 cm. Broadcast seeding of T. dicoccum spikelets onto the new and old felds was performed on 24 th April 2014 (Figure 1d). We used the variety Rudico, which is well adapted to Czech conditions (Stehno 2007) and originates from the collection of old landraces collected by the Crop Research Institute, Prague-Ruzyně. The seeding rate was at the upper recommended limit of 400 germinable caryopses per m 2 (Stehno 2007). The seeding material was harvested at the Crop Research Institute, Prague-Ruzyně, one year before the establishment of the experiment and the germination of caryopses was 97%. After seeding, the spikelets were harrowed into the soil using iron/wooden rakes. In the modern feld, winter wheat, T. aestivum , was seeded in early October 2013, in rows with an inter-row distance of 12.5 cm. We used winter wheat for comparison as this is the most frequently planted wheat form in the Czech Republic under farm conditions. The seeding rate was 300 germinable caryopses per m 2 . The modern feld was under standard conventional farm management and was fertilized by mineral N at an application rate of 100 kg N ha –1 and pesticides were applied if necessary. The old and new felds did not receive any fertilizer or pesticide application or any mechanical weeding.