STUDY ON THE LONG-TERM EFFECT OF SAND AME LIORATION ON CALCAREOUS SANDY SOIL

In a long-term sand amelioration trial set up on calcareous, slightly humus sand, the after-effect of soil cultivation and nutrient supply w as investigated in grain sorghum and peas. The changes in soil propert ies, the development of nutrient content and nutrient uptake in the yi eld were studies, the specific N, P, K, Ca and Mg contents were calcul ated. Based on the results the following conclusions may be drawn: The phosphorus fertilization applied over many years generally with maint aining rates made the readily available AL-soluble phosphorus content of the soil continuously richer, and increased it in 1991 to the well supplied soil level, and even to the very well supplied one, when the higher phosphorus rates were applied. The maintaining potassium fertil ization through many years, generally at a rate of 100 kg/ha K2O, only approximated the moderately supplied level, and remained at poor leve l. The effect of different soil cultivations shallow and deep ploughin gs, and of Egerszegi's deep fertilization cannot be proved in the pers pective of more than 30 years. The nitrogen fertilization applied in i tself seemed to be ineffective in both crops The nitrogen and phosphor us fertilizations jointly applied were the most effective in both crop s and both years. The potassium effect was minimal due to the poor sup ply of the soil and was not significant even in the straw yields. The droughty weather decreased, especially in 1990, the efficiency of fert ilization, even more so in phosphorus-deficient treatments.