Preliminary trials on methods of applying fertilizer to potatoes

Four preliminary trials were conducted at Campinas to compare the usual method of fertilizing potatoes, which consists in the addition of the NPK-mixture to the furrows, with the placement on both sides of the row about 2 inches from the seed and 1 inch below the seed level. For the yields, in two experiments with rainy weather after planting both methods gave similar results; in the other two, however, relatively dry weather followed planting and the sideplacement averaged 25% more than the usual method. No diferences were observed in the final stands, but the emergence of the sprouts was considerably delayed where the fertilizer was applied in the furrows, principally in the tests in which dry weather followed planting.