摘要
福建省多数稻田土壤供钾能力为中下水平。在61个代表性土样中,缓效性钾<30mgK/100g,占71%;速效性钾<8mgK/100g,占57%;其中以烂泥田最低,黄泥田次之。只有埭田、乌泥田和潮沙田等供钾能力较高。供试土壤更换水分状态,都能促进非交换性钾的释放。释钾顺序为干湿交替>湿润>淹水。净释钾量乌泥田最多,烂泥田和黄泥田最少。不同土壤水分状态对肥料钾的固定同释钾顺序一致。供试土壤培育4个月,其固钾率为灰泥田(40～55%)>乌泥田(12～18%)>潮沙田、灰黄泥田、黄泥田、烂泥田(3～15%)。
The majority of 61 repersentative paddy soils in Fujian was low or slightly moderate in K status.Analysis data showed that 71% of soil samples contained less than 30 mgK/100g of nonexchangeable K,and 57% of contained less than 8 mgK/100g of exchangeable K.Muddy and yellow paddy soils were among others the lowest in K status,while the soils der- ived from fluvio-marine deposit possessed the relatively high capacity of K supplying.Alternation of wetting and drying enhanced the release of soil nonexchangeable K,while constant wetting or submerging had less effect. Marine and fertile paddy soils released higher amount of K than others. When K was added to the soils and incubated for 120 days,various percen- tages of added K that was fixed were in the order as following:marine paddy soil(40—55%)>fertile paddy soil(12—18%)>muddy soil derived from Lateritic red soil or Quaternary red clay(3—15%).Different soil moisture regimes influenced soil K fixation to the different extent with the greatest by alternation of wetting and drying and then by constant wetting, and the least by submerging.
关键词
水稻
土壤
水分
钾
paddy soil
soil moisture regime
potassium
