Effect of applying potassium sulfate and potassium chloride on grapes

摘要

The purpose of the experiment carried out in seven vineyards in Shandong province was to clarifying the effectiveness of KCl (MOP) and K_2SO_4 (SOP) on the yield and quality of grapes and wine. The results of 2004 show that the state of soil nutrition in the vineyards in Shandong province is poor, the low level of potassium being particularly serious. Applying K fertilizers generally boosted the nutrient contents but difference between the effects of SOP and MOP were not significant. The application of MOP resulted in a several-folds increase in the chloride content but obvious toxicity symptoms on leaves and stems were not observed. The application of K fertilizers increased the chlorophyll contents and led to an increase in the photosynthesic rate by 0.4-1.5 μmol CO_2.m~(-2).s~(-1). The production and quality of the grapes were improved by increasing the potassium applied; the SOP treatments were better than the MOP treatments in this respect. The weight per 100 grapes increased by 4.99%-17.01% and the yield per vine by 8%-25% through potassium application. There was no difference between the application of 150g/vine and 200g/vine.