酸性红壤上水稻钾钠配施效应的研究

 红壤区低钾土壤施用钠盐，能够促进水稻对钾离子的吸收，并运转至地上部功能叶中，从而提高光合效率；钠离子又可部分取代钾的生理功能，相应降低植株中需钾的临界浓度，这是钾钠配施显效的主要原因。田间试验结果表明：低钾水稻土用25-50%氯化钠代替氯化钾施用，能够达到等量钾肥的效应。

EFFECTS OF COMBINED APPLICATION OF POTASSIUM AND SODIUM ON RICE GROWTH AND NUTRIENT UPTAKE IN RED ACID SOIL

This paper presents the results from the pot experiment and the field trials concerning the effects of combined K-Na fertilization on rice growth and the nutrient uptake in red paddy soils It was shown that the application of Na increased the K uptake by rice plants in low K soils and facilitated the transport of K to the functional leaves of plant shoots, which might in turn increased the photosynthetic efficiency. The physiological function of K. in plants could be substituted partially by Na, particularly with regard to the osmoregulation, resulting in a lower threshold level of K needed by plants. This was considered to be the main reason for the beneficial effects of combined application of K and Na on rice growth. It was concluded from the field trials that in the low K soils up to 25-50 percent of K fertilizer could be replaced by NaCl without losing rice yield.