河西灌漠土钾素状况及当季施肥效应

The potassium condition of irrigated desert soil in the Hexi district and the annual effects of potassium fertilizers

多点调查表明，河西灌漠土全钾比70年代末平均降低了24.4%，速效钾平均下降了41.2%。剖面分布为：耕作层全钾平均为1.30%，20～60cm土层平均1.27%～1.38%，底土平均1.26%；缓效钾平均为946～1 006mg/kg，剖面差异不大；速效钾 0～20cm土层为145mg/kg，20～100cm平均101～114mg/kg。春小麦、玉米、甜菜、洋芋单作当季施钾均无明显增产效应；带田玉米施化学钾肥增产8.5%，施土粪增产9.7%～11.3%，但增效不稳定。

：The results of soil survey by S-shaped point cluster method show that the total potassium content of irrigated desert soil in the Hexi district has decreased by the average of 24.4%, and the active potassium content has decreased by the average of 41.2% from the end of 1970s' to now. the general condition of potassium distribution in the soil profiles present as follows: the average of total potassium content is 1.30% in the arable layer; 1.27% to 1.38% in the soil layer from 20cm to 60cm depth and 1.26% in the layer of bottom soil; the average of the slow-release potassium content range from 946mg/kg to 1006mg/kg, and the differences between soil layers are not worth of mentioning; the active potassium content in the soil layer from 0cm to 20cm depth is 145mg/kg, and the average in the layer from 20cm to 100cm depth range from 101mg/kg to 114kg/kg. The results of field experiments indicate that applying potassium fertilizers in the same year had not obvious effects on yield increase of spring wheat, maize, beet and potato in monoculture; while the yield of maize belt-planted, appled with chemical potassium fertilizers, can increase by 8.5%, and with organism fertilizer it can increase by 9.7% to 11.3%, but the effects of increase is unstable.