摘要
本文通过盆栽耗竭试验和土壤培养试验研究了五种含钾量差异较大的土壤供钾特点和固钾能力。试验结果表明：（１）黑麦草根系发达而密集，它对土壤钾的利用能力很强，能在短期内吸收大量钾，而致使土壤缺钾，在缺钾严重时土壤交换性钾和缓效钾还能达到“最低值”，“最低值”因受质地和粘土矿物组成及含量的影响而有较大差异。（２）作物吸收钾中，层间钾所占比例很大，其中又以１ｍｏｌ／ＬＨＮＯ＿３煮沸一次不能提取的钾为主。所以在合理评价土壤供钾能力时必须要考虑层间钾的有效性和存在形态。（３）土壤固钾量是随钾的耗竭，而增加，土壤不同水分条件下的固钾量为干湿交替＞恒湿＞淹水。
he potassium release characteristics and fixation abilities of five soils were
stu-died by using depletion experiments and soil incubation experiments. The results
weresunarnarized as follows:With tbe extensive root systems ryegrass could draw up inuch of
potassium fromthe soil potassiuin pool with in a short time. During the exhaustion cropping the
soildeficient in potassiuin would quickly reach the lowest potassium value. In general.the
lowest value of exchangeable potassium occurred at second harvesting and that
ofnonexchangeable potassium was obtained at third cutting, the lowest value changedwith the
type of clay minerals.Potassium absorbed by plants mainly came from the soil interlayer
potassium,among this, the potassium which could not be extracted by boiling with
1mol/LHNO_3 was dominant. The more tbe soil K depleted, the more the applied
potassiumfized by soil. Under different water conditions, the amount of fixation of
fertilizedPotassium was in the order of alternative dry and wet > constant wet > submerged.
出处
《土壤学报》
CAS
CSCD
北大核心
1994年第1期42-49,共8页
Acta Pedologica Sinica
关键词
层间钾
耗竭
固钾
钾有效性
土壤
interlayer Potassium, Depletion, Potassium Fixation, PotassiumAvailability
