杭州市不同农业地貌区耕地土壤肥力的差异及施肥对策*

为了解杭州市耕地土壤肥力的空间差异,指导科学施肥,比较分析了杭州市滨海平原、水网平原、河谷平原和丘陵山地等4个农业地貌区间耕地土壤pH值、有机质、全氮、有效磷、速效钾和CEC等主要肥力指标状况。结果表明,杭州市耕地土壤酸化以丘陵山地和河谷平原区最为明显；滨海平原区耕地土壤有机质、全氮及保肥能力明显低于其它地区；除水网平原区外,其它地区速效钾普遍偏低；因施肥水平的差异各农业地貌内土壤有效磷都有较大的变化。总体上,耕地土壤肥力水平以水网平原区为最高。文中提出了各农业地貌区的施肥对策：在滨海平原应重视基础地力的提升,增加有机肥料的投入；水网平原区内应重视测土施肥工作,根据土壤养分实际状况针对性地施用肥料；丘陵山地和河谷平原区,需重视石灰的施用,对土壤酸度进行核正,适当增加钾肥的用量。

Differences in soil fertility and fertilization countermeasure of cultivated land in different landforms of Hangzhou region

In order to understand the spatial variation in soil fertility of cultivated land in the Hangzhou region, and provide the basis for scientific fertilization, a comparison of differences in pH value, organic matter, total N, available P, available K and CEC of the soils was carried out among four landforms, including plain with water network, coastal plain, valley plain and hilly areas. The results showed that soil acidification in cultivated land in valley plain and hilly area was most obvious in the Hangzhou region. The contents of organic matter and total nitrogen and fertilizer retention capacity (CEC) were significantly lower than those of other areas. Besides the plain with water network, soil available K of the cultivated land was generally low. Soil available P in each of four agricultural landform areas varied greatly, and affected by fertilization. On the whole, fertility of cultivated soil in water net plain is the highest in the region. Some fertilization countermeasures for each of agricultural landform areas were put forward. It was important to increase input of organic fertilizers and improve basic fertility of the cultivated land in the coastal plain. Soil testing and fertilization was an important work in the plain with water network, and application rate of fertilizers should be determined according to the actual status of soil nutrient. Using limestone to decrease soil acidity and appropriately increase the dosage of potassium fertilizer should be available ways to modify soil quality of the cultivated land in valley plain and hilly areas.