Use of potash fertilizers through different application methods for high yield and quality crops

Abstract

Potassium and nitrogen are two major nutrients in crop production, since a deficiency in one or both nutrients causes yield losses. In vegetable cropping, both nutrients play also a key role on quality parameters. Application methods can enhance the uptake of some elements or can correct deficiencies in particular situations. As for other field crops, a balanced N x K fertilization enhances growth and improves the uptake of both nutrients, which in turn reduces nitrate losses during and after the cropping season. The quality of the yield is also depending on the N/K ratio and the fertilizer grades.

Field experiments were carried out in 1996 and 1997 on potato in order to study the influence of various potash grades (potassium sulfate, potassium chloride, potassium nitrate) applied through drip irrigation. In other experiments, the effect of potassium applied as foliar spray was studied on vegetables and tobacco. The following measurements were recorded: yield parameters, K contents, and main quality parameters according to the crop.

The response of the three grades of potash have shown a positive effect of potassium on quality and yield on potato. Potassium sulfate appears as the most suitable grade of potash as far as keeping quality and tuber size are concerned. Foliar applications of potassium can also improve yield and quality, especially in heavy clay soils where potassium is not readily available for the plants, or in sandy soils.