Research by J. Bates et al. (2016) confirms that Indus populations were the earliest people to use complex multi-cropping strategies across both seasons, growing foods during summer (rice, millets and beans) and winter (wheat, barley and pulses), which required different watering regimes. Bates et al. (2016) also found evidence for an entirely separate domestication process of rice in ancient South Asia, based around the wild species "Oryza nivara". This led to the local development of a mix of "wetland" and "dryland" agriculture of local "Oryza sativa indica" rice agriculture, before the truly "wetland" rice "Oryza sativa japonica" arrived around 2000 BCE.