长江中下游甘薯氮磷钾肥施用效果与区域土壤养分丰缺指标研究

Study on Application Effects of N,P and K Fertilizers on Sweet Potato and Abundance-deficiency Indexes of Regional Soil Nutrients in Middle and Lower Reaches of Yangtze River

根据2009—2014年在长江中下游薯区实施的68个氮、磷、钾肥料用量田间试验结果,建立了基于养分丰缺指标法——肥料效应函数的甘薯氮、磷、钾施肥指标体系。结果表明:施用氮肥、磷肥、钾肥均对甘薯具有极显著的增产效果(P<0.01);植薯土壤水解性氮含量的“高”、“低”指标分别为170 mg/kg和100 mg/kg,有效磷含量的临界指标为17 mg/kg,土壤速效钾含量“高”、“低”的指标分别为110 mg/kg和30 mg/kg;高产田块甘薯的氮、磷、钾肥最佳经济推荐施用量分别为N 125 kg/hm^(2)、P_(2)O_(5)160 kg/hm^(2)和K_(2)O 182 kg/hm^(2),中低产田块的氮、磷、钾肥最佳经济推荐施用量分别为N 155 kg/hm^(2)、P_(2)O_(5)120 kg/hm^(2)和K_(2)O 220 kg/hm^(2)。

According to the results of 68 field experiments on N,P and K fertilizer application in the middle and lower reaches of Yangtze River from 2009 to 2014,N,P and K fertilizer application index system was established for sweet potato,which was based on nutrient abundance and deficiency index method and fertilizer effect function.The results show that application of N,P and K fertilizers have significant effects on increasing yield of sweet potato(P<0.01).For potato-growing soil,the“High”and“Low”indexes are 170 mg/kg and 100 mg/kg for available(hydrolytic)nitrogen,110 mg/kg and 30 mg/kg for available potassium,respectively,while the critical index is 17 mg/kg for available phosphorus.The optimal economic recommended rates of nitrogen,phosphorus and potassium are N 125 kg/hm^(2),P_(2)O_(5)160 kg/hm^(2)and K_(2)O 182 kg/hm^(2),respectively,the optimal economic recommended application rates of N,P and K for medium and low yield fields are N 155 kg/hm^(2),P_(2)O_(5) 120 kg/hm^(2)and K_(2)O 220 kg/hm^(2),respectively.