During June and July 2024, Professor Long Li and Dr. Rui-Peng Yu organized two field trips to visit the maize/soybean intercropping experiment in Zhangye, Gansu Province, PR China, which is included as one of the meta-experiments in WP 2 in IntercropVALUES Project. In June, Prof. Long Li invited Prof. David Tilman at the University of Minnesota; and in July, he invited Prof. Ming-Gang Xu at Shanxi Agricultural University to visit the experiment.
China Agricultural University is one of the participants in WP2, and this experiment aims to investigate the effects of simultaneously increasing nitrogen application rates and crop density on productivity and ecosystem services. Over 200 participants, including researchers and graduate students from China Agricultural University, Gansu Agricultural University, and Gansu Academy of Agricultural Sciences, took part in the two field trips.
Picture above: Field trip to visit the soybean/maize intercropping experiment in Zhangye, Gansu, PR China.
The experiment was established in 2017, with three factorial design with three replications. The first factor was four N application rates (0, 180, 240, 300 kg N/ha for sole maize; 0, 40, 80, 120 kg N/ha for sole soybean; 0, 110, 160, 210 kg N/ha for maize/soybean intercropping for conventional plant density; 0. 220, 320, 420 kg N/ha for maize/soybean intercropping for increased plant density) and four crop combinations (i.e. sole maize, sole soybean, maize/soybean intercropping for conventional plant density, and maize/soybean intercropping for increased plant density). Several monoculture and intercropping plots with no, half, and full N application rates are selected in the IntercropVALUES project.
Picture above: Field photo of maize/soybean intercropping.
Following the comments of Prof. David Tilman and Prof. Ming-Gang Xu, we will investigate and evaluate N2O emission and N balance in this experiment. We will also measure the physical (e.g., soil aggregates), chemical (e.g., soil organic carbon and total N), and biological (e.g., enzymes and soil microbial composition) properties of soils. The team from CAU, led by Professor Long Li, will also explore how N application rate and cropping system interactively affect multiple ecosystem services. This research aims to improve our understanding of establishing a desirable intercropping system with lower nitrogen inputs and environmentally friendly farming practices.
This news item was written by Rui-Peng Yu and Long Li (China Agricultural University).