西山坪遗址花粉、种子、植硅体等考古生物指标记录和加速器^14C测年，显示甘肃天水5070cal a BP已开始种植水稻并在5070～4300cal a BP时段持续存在，是目前已知中国西北最老、最西北端的稻作遗存．这一发现将史前稻作农业记录向西拓展了至少2个经度，有助于准确判定5000a BP这一重要时点东亚稻作农业的分布区域，探讨新石器时代稻作农业传播的时间、路径和方式。
The crop types and agricultural characteristic are reconstructed using the archaeobiological proxies of pollen, seed and phytolith at Xishanping site in Gansu Province between 5250 and 4300 cal a BP. The agricultural activity strengthened in Xishanping from 5100 cal a BP. It appeared the earliest cultivation of prehistoric rice in the most northwest China at 5070 cal a BP. The sudden disappearance of conifers and expansion of chestnut trees is likely to be the result of selective hewing of conifers and cultivation of chestnuts at about 4600 cal a BP. There existed 8 crop types of foxtail millet, broomcorn millet, rice, wheat, barley, oats, soybean and buckwheat at Xishanping between 4650 and 4300 cal a BP, which cover the main crop types of the two origin centers of East and West Asia. Not only has the wheat and barley been approved to spread to northwestern China, but the earliest complexity agriculture in Neo-lithic China appeared in Tianshui, Gansu Province.
