流沙和改良后土壤无机磷形态分级及其有效性研究

Fractionation and Availability of Soil Inorganic Phosphorus in Sand Soil and Improved One

应用蒋柏藩和顾益初提出的石灰性土壤无机磷分级方法，对沙坡头地区流沙及改良土壤无机磷分级进行了研究，并对其有效性做出评价。结果表明，流沙中Ｃａ２－Ｐ占无机磷总量的３．１％，Ｃａ８－Ｐ占１１．４％，ＡＩ－Ｐ占７．０％，Ｆｅ－Ｐ占５．３％，Ｏ－Ｐ占０．１４％和Ｃａ１０－Ｐ占７３．２％；改良土壤中Ｃａ２－Ｐ占无机磷总量的１．７％，Ｃａ８－Ｐ占７．２％，ＡＩ－Ｐ占５．１％，Ｆｅ－Ｐ占３．８％，Ｏ－Ｐ占０．０８％和Ｃａ１０－Ｐ占８２．１２％。其中Ｃａ２－Ｐ与Ｃａ８－Ｐ是作物磷素营养的主要来源，Ａ１－Ｐ、Ｆｅ－Ｐ为缓效磷源，而 Ｏ－Ｐ和 Ｃａ１０－Ｐ只是一种潜在磷源。生物试验表明，改良土的供肥能力强，肥力水平高；而流沙对施肥反应敏感，产量增加显著。

Using Jiang Bofan and Gu Yichu's fractionation method for calcareous soil's inorganic phosphorus, we have studied the efficacy of aeolian soil's inorganic phosphorus in the processes of shifting sand fixation in Shapotou region. The results indicated that Ca2-P accounts for 3.1 % of total inorganic phosphorus, Ca8-P 11.4%, ALP 7.0%, Fe-P 5.3%,Ｏ－Ｐ０.14% and Ca１０-P 73.2% in shifting sand soil, respectively; Ca2-P accounts for 1.7% of total inorganic phosphorus, Cas-P 7.2%, AI-P 5. 1%, Fe-P 3.8%, Ｏ－Ｐ 0.08% and Ca10-P 82.12% in ameliorated soil, respectively. Among these Ca2-P and Ca8-P are main fraction of crop phosphorus nutrition, Al-P and Fe-P are postpone phosphorus, O-P and Ca10-P are all potential phosphorus.