Double-cropping systems based on rye, maize and sorghum: Impact of variety and harvesting time on biomass and biogas yield

• Published in: European journal of agronomy 2019-10, Vol.110, p.125934, Article 125934
• Main Authors: Wannasek, Lukas, Ortner, Markus, Kaul, Hans-Peter, Amon, Barbara, Amon, Thomas
• Format: Article
• Language: English
• Subjects: Anaerobic digestion; Crop maturity; Crop rotation; Double-cropping; Single-cropping; Sorghum
• ISSN: 1161-0301; 1873-7331
• DOI: 10.1016/j.eja.2019.125934

•Clear superiority of DCS over SCS in terms of biomass yield at hot and dry location.•Rye/sorghum achieved higher biomass yields than rye/maize at hot and dry location.•Higher specific methane yield per hectare of DCS rye/sorghum compared to rye/maize.•Maturity level of 5 rye varieties as a function of harvesting date was related.•Maturity, biomass yield, GDD and optimal range for ensiling of 2 DCS were compared. Climate change affects the frequency and intensity of extreme weather, the results of which include production losses and climate-induced crop productivity fluctuations. Double-cropping systems (DCSs) have been suggested as a way to increase biomass-production while simultaneously delivering environmental benefits. In a three-year field-test, two DCSs based on maize and sorghum as the main crop and rye as the preceding winter crop were compared with each other and compared with 2 single-cropping systems (SCSs) of maize or sorghum; there were comparisons of growth dynamics, optimal harvesting and growing time as well as biomass and methane yield. In addition, the impact of variety and harvest time on the winter rye optimal biomass yield was studied. The experiments clearly showed the superiority of the DCS over the SCS. Within the DCS, the rye/sorghum combination achieved significantly higher biomass yields compared to those of the rye/maize combination. The highest dry matter biomass yield was achieved during year 1 at 27.5 ± 2.4 t∙ha−1, during which winter rye contributed 8.3 ± 0.7 t∙ha−1 and sorghum contributed 19.2 ± 1.8 t∙ha−1. At the experimental location, which is influenced by a Pannonia climate (hot and dry), the rye/sorghum DCS was able to obtain average methane yields per hectare, 9300 m3, whereas the rye/maize combination reached 7400 m3. In contrast, the rye, maize and sorghum SCSs achieved methane yields of 4800, 6100 and 6500 m3 ha−1, respectively. The study revealed that the winter rye and sorghum DCS is a promising strategy to counteract climate change and thus guarantee crop yield stability.