西藏主要河谷农区套复种多熟种植研究初探

Exploitation and utilization of summer fallow farmland on main river valley areas in Tibet

根据西藏主要河谷农区夏闲地及其资源现状,利用多年旬积温和旬降水量,从热量和水分两方面评价夏闲地开发利用的可能性,以拉萨和山南地区为代表区域。结果表明：在冬麦区多熟作物组合86种,其积温参数变幅为2 000-4 750℃,平均为3 475.1℃,需水参数变幅为456-744 mm,平均值为636 mm;冬春麦兼种区,多熟作物组合有23种,其积温参数变幅为2 050-3 850℃,平均为2 778.7℃,需水参数的变幅为446-580 mm,平均值为528 mm。拉萨冬小麦/箭舌豌豆种植比例试验表明,66%∶33%种植比例产量和水分利用率表现最优;拉萨和山南乃东县春青稞间、套作箭舌豌豆、马铃薯、玉米试验中,粮食产量套作方式比单作、间作方式表现好,以春青稞/马铃薯和春青稞/玉米为优,饲草饲料产量单作方式优于间、套作方式。

According to the present situation of agricultural resources and summer fallow land on mainriver valley areas in Tibet,it is climatically possible for summer fallow land to implement perennial cropping system in thermal and moisture conditions,using perennial accumulated temperature and rainfall in ten days.Lhasa and Lhoka regions locate in main field in middle river valley areas of Tibet.The analytical results show： As for the 86 types of perennial cropping patterns in winter wheat areas,the range of accumulated temperature is from 2 000℃ to 4 750℃,mean accumulated temperature is 3 475.1℃.The change of rainfall in this region is from 456 to 744 mm,average rainfall is 636 mm While there are 23 patterns in winter and spring wheat mixed planting areas,their range of accumulated temperature is from 2 050℃ to 3 850℃,mean accumulated temperature is 2 778.7℃.The change of rainfall is from 446 to 580 mm,the average rainfall is 528 mm.Results in the field experiments of this areas for summer fallow farmland in 2006 showed that the optimum cropping ratio of winter wheat intercropping common vetch in Lhasa was 66% to 33%;spring barley intercropping maize was an optimum cropping patterns in spring barley intercropping maize,potato and common vetch in Lhasa and Shannan.But spring barley intercropping common vetch had higher economic value in three cropping patterns in Shannan region.Forage yield of sole cropping is higher than intercropping with grain.