苏南水网地区农田钾素资源概况及潜力

STATUS AND POTENTIALITY OF FIELD POTASSIUM RESOURCES IN HYDROGRAPHIC NET REGION IN SOUTH OF JIANGSU PROVINCE

苏南水网地区,土壤供钾潜力较低,加之复种指数较高,雨水过多,土壤钾素匮缺严重,其中因径流和渗漏损失的钾素养分占钾肥施入量的54.4%。而我国钾矿资源贫乏,钾肥的生产量还不到需要量的1/10,随着作物产量的提高和农产品品质的改善,作物的需钾量将逐渐增大,因此,单纯依靠钾肥来满足作物对钾素日益增长的需要是远远不够的,迫切需要开发利用富钾资源以缓解钾素的供需矛盾。苏南水网地区的水资源、秸秆、绿肥、塘泥等均为丰富的钾素资源,其中平原地区通过水分循环可补充14.5kg/hm2的钾素;秸秆若以2250kg/hm2的数量归还,则稻秆、麦秆和油菜秆钾素的归还量分别达45kg/hm2、31.4kg/hm2和26.1kg/hm2;水网地区还具有丰富的水生绿肥资源,这些水生绿肥具有较强的吸收和富集水域钾素的能力,若能对其进行充分合理的开发利用,不但使农田流失到水域的钾素及其它养分重新回归农田,而且还可以对富营养水体进行生物修复,达到净化水域的目的;另外,水网地区水网纵横,河泥、湖泥、塘泥等钾素贮量丰富。本文通过对钾素资源的利用现状及其潜力进行分析,找出钾素资源利用中存在的问题及其相应的对策,为缓解钾素供需矛盾、促进农业持续稳定的发展提供依据。

Low potentiality of soil potassium, high multiple crop index, overrain led to scarcity of soil potassium in hydrographic net region in south of Jiangsu Province. Potassium loss made by runoff and leakage accounted for 54.4 per cent of potassium application. Owing to scarcity of potassium mine, raising of crop yield and quality improvement of agricultural products, it is not more than 1 out of 10 for potassium fertilizer to satisfy the need of crops. So it is necessary to find resources with enrichment potassium to relax potassium tension.Water,straw,green manure and pond mud are all aboundant potassium resources.Water cycling can supply 14.5 kg/hm\+2 potassium in flatlands region.If there are 2 250 kg/hm\+2 straw returned,the potassium reverted to field will be 45,31.4,and 26.1 kg/hm\+2 respectively for rice,wheat and rape straw.There also is plenty of water green manure,which has high capacity to enrich potassium in water area.If there is enough water green manure returned to field,not only will the potassium lost from field return,but also the eutrophic water will be purified.There also are prolific mud came from river,lake and pond,which contain ample potassium,in hydrographic net region.Status,potentiality,problems and countermeasures of potassium resources use were studied in this paper to provide basis for relaxing potassium tension and promoting agricultural sustainability.