Whether species coculture can overcome the shortcomings of crop monoculture requires additional study. Here, we show how aquatic animals (i.e. carp, crabs, and softshell turtles) benefit paddy ecosystems when cocultured with rice. Three separate field experiments and three separate mesocosm experiments were conducted. Each experiment included a rice monoculture (RM) treatment and a rice-aquatic animal (RA) coculture treatment; RA included feed addition for aquatic animals. In the field experiments, rice yield was higher with RA than with RM, and RA also produced aquatic animal yields that averaged 0.52–2.57 t ha^-1. Compared to their corresponding RMs, the three RAs had significantly higher apparent nitrogen (N)-use efficiency and lower weed infestation, while soil N contents were stable over time. Dietary reconstruction analysis based on ¹³C and ¹⁵N showed that 16.0–50.2% of aquatic animal foods were from naturally occurring organisms in the rice fields. Stable-isotope-labeling (¹³C) in the field experiments indicated that the organic matter decomposition rate was greater with RA than with RM. Isotope ¹⁵N labeling in the mesocosm experiments indicated that rice used 13.0–35.1% of the aquatic animal feed-N. All these results suggest that rice-aquatic animal coculture increases food production, increases N-use efficiency, and maintains soil N content by reducing weeds and promoting decomposition and complementary N use. Our study supports the view that adding species to monocultures may enhance agroecosystem functions.

Agricultural biodiversity has a high importance in social-cultural, economic, and environmental aspects, and can help in adapting to and withstanding climate change. Conserving the GIAHS sites and the important components within them can help conserve the agricultural biodiversity and traditional agricultural culture of the whole country. This study considered Ifugao Rice Terraces, Dong's Rice-Fish-Duck System, and Hani Rice Terraces System as three examples which show that traditional culture can be used to protect agricultural biodiversity, while as a carrier of traditional culture, agricultural biodiversity also conveys and protects the traditional culture of the nation. According to the analyses, through several years of efforts, the status of agricultural biodiversity and traditional culture in them has improved. Then, to further promote agricultural biodiversity conservation and traditional culture protection, several suggestions are made, such as establishing community seed banks; documenting and preserving traditional farming methods, techniques, and tools and developing participatory activities which encourage more farmers to participate in the protection work.

The Yi ethnic group in Liangshan Prefecture, Sichuan Province in Southwest China have cultivated Tartary buckwheat (Fagopyrum tataricum) for at least a thousand years. Tartary buckwheat landraces are maintained through their traditional seed system. Field work and social network methodologies were used to analyze the seed sources and their flows, and to create a seed network map. Self-saving, exchanging with neighbors and relatives, and purchasing from the market were the main means farmers used to save and exchange Tartary buckwheat seeds. The flow of seed within villages was higher than between villages. Wedding dowry was an important pathway for seed flow among all of the villages. Of the 13 Tartary buckwheat landraces maintained, four landraces were exchanged frequently. The seed exchange network structure was affected by the number of Tartary buckwheat landraces, the age of nodal households, geographic environment, culture, and cultural groups. Nodal households play an important role in the conservation and on-farm management of Tartary buckwheat landraces.

Underutilized grain crops are an essential part of the food system that supports humankind. A number of these crops can be found in China, such as barley, buckwheat, broomcorn millet, foxtail millet, oat, and sorghum, which have characteristics such as containing more nutritional elements, being resistant to biotic and abiotic stresses, and having strong adaptability to poor environments. The diversity of these crops provides options for farmers’ livelihoods and healthy food for the population. Although some mentioned crops such as barley, oat, and sorghum are not underutilized crops globally, they could be considered underutilized in China as they were more important in the past and could be revitalized for food and nutrition in the future. This paper reviews current progress in research and development in the areas of germplasm resource conservation, variety improvement, cultivation technologies, processing, and the nutrition and benefits of six underutilized grain crops in China. It is concluded that underutilized grain crops could play a critical role in food and nutritional security in China.

Recent socioeconomic development, increased transport and new agricultural technology are endangering the survival of traditional agriculture and the Yi people’s traditional knowledge of cultivating Tartary buckwheat. The cultural heritage of Tartary buckwheat cultivation among the Yi communities needs to be investigated and protected before its loss. The main objectives of this study are to document the Tartary buckwheat cultivation system, to analyze the agroecosystem networks that support the current system, and to measure the resilience of the ecological, agricultural and social systems using relevant indicators. The Tartary buckwheat cultivation system in Meigu County uses a rotation system, in which various crops are planted alternatively (e.g., Tartary buckwheat, green manure and potato/corn), utilizing bunch planting and furrow drilling technology. Tartary buckwheat has an important position in the major festival activities among the Yi people’s communities. Network analysis on the current agricultural system, ecosystem and social system indicated that the system was stable. The mean score of ecological, agricultural and social stability were 2.50, 2.85 and 2.53, respectively, indicating moderately stability. In contrast, socio-ecological production landscapes and seascapes (SEPLS) resilience indicators in Meigu performed only moderately, with a score of 2.63. The assessment of the resilience of the Tartary buckwheat cultivation system can provide some guidance for policy makers to strengthen biodiversity conservation, sustainable agricultural production and livelihood development (e.g., land use, responding to extreme environmental stresses and improving education levels).