苏南地区稻田土壤肥力演变、养分平衡和合理施肥

采用宏观数据、研究参数与微观调查数据相结合的方法，分析区域肥力演变、养分平衡与合理施肥量。结果表明，1982-1996无锡市土壤氮素及有机质含量增加较快，磷素增加较慢，钾素含量普遍下降；1990-1997年无锡市和常州市稻田氮素普遍盈余，钾素普遍亏缺，磷素无锡市盈余，常州市亏缺；以此为依据，1996年无锡市氮磷钾肥的合理投入量分别是488．9、113．1和235．1kg·hm^-2；常州市分别为499．4、112．5和234．2kg·hm^-2，由于土壤中氮素积累、钾素亏缺现象明显，实际施氮量和施钾量要显著低于和显著高于合理施氮量和施钾量。

Soil fertility evolution, nutrient balance and reasonable fertilization in paddy field in southern area of Jiangsu Province

With the integration of macro-statistical data, micro-survey data and parameters obtained from previous studies, the soil fertility evolution and nutrient balance in paddy fields in southern Jiangsu were analyzed to provide evidence of scientific fertilizer application. It was showed that from 1982 to 1996, the total nitrogen and organic matter contents in Wuxi paddy fields had a rapid increase, phosphorus had a slow increase, and potassium had a general decrease. Soil nutrient balance analysis in Wuxi and Changzhou cities showed that nitrogen was commonly surplus, potassium was generally inadequate, and phosphorus was different from nitrogen and potassium. Phosphorus was surplus in Wuxi city and inadequate in Changzhou city. On the basis of nutrient balance, the reasonable nitrogen, phosphorus and potassium fertilizer application amount was 488.9, 113.1 and 235.1 kg.hm-2 in Wuxi, and 499.4, 112.5 and 234.2 kg.hm-2 in Changzhou paddy fields, respectively. Due to the nitrogen accumulation and potassium absence in soil, the nitrogen and potassium application amount should be lower and higher than the above reasonable nitrogen and potassium application amount.