1987年,由省农委列项,农业厅主持,省土壤肥料工作站承包的100万亩瘠薄梯田改造项目,经过天水、平凉两地市连续3年组织实施,到1989年底,累计完成改造面积315.58万亩,平均每年达到105.18万亩,超计划5.2%。粮食亩产在1984～1986年平均亩产92.3公斤的基础上提高到了1989年的152.2公斤,实现亩增产粮食59.9公斤,3年累计增长率 In 1987, the reform project of 1 million mu of infertile barren terraces contracted by the Provincial Department of Agriculture under the chair of the Agriculture Department and the Provincial Soil Fertilizer Workstation was organized and implemented for three consecutive years by Tianshui and Pingliang cities. By the end of 1989, a total renovation area of ​​315.58 Mu, an average of 105.18 mu per year, exceeding the plan of 5.2%. The per-mu yield of grain increased from 152.2 kg in 1989 to an average of 92.3 kg per mu in 1984-1986, achieving 59.9 kg of mu in grain and 3 years of cumulative growth rate