红薯生育中后期,系指块根膨大期,是形成产量的关键时期,对夺取红薯高产再高产至关重要。 1 追施裂缝肥。当薯块膨大后,土壤出现裂缝,此时沿垄土裂缝灌施3％～5％的硫酸钾、或15％～20％草木灰浸出液,亦可用1％磷酸二氢钾液,顺垄缝灌入,每667m~2灌施液肥100～150kg。对有早衰现象的红薯,应灌施2％的氮磷钾混合液。 2 叶面喷肥。红薯生育后期,根部吸肥能力减弱,实施叶面喷肥,是确保块根 Sweet potato growth in the late, refers to the tuberous bulging period, the formation of a critical period of production, the capture of sweet potato high yield and then crucial. 1 topdressing cracks fertilizer. When the tubers expand, the soil cracks, this time along the ridge cracks irrigation 3% ~ 5% potassium sulfate, or 15% ~ 20% ash leaching solution, can also be used 1% potassium dihydrogen phosphate, Shun furrow irrigation Into, every 667m ~ 2 irrigation liquid fertilizer 100 ~ 150kg. For the phenomenon of premature aging sweet potato, should be applied 2% of the NPK mixture. 2 foliar fertilizer. Later sweet potato growth, root absorption capacity weakened, the implementation of foliar fertilizer is to ensure that the roots