M.E. Saraiva Ferreira
The abusive use of nitrogen application in the traditional pea growing areas in Western Portugal required a study for its optimization. Besides, the frequent occurence of low phosphorus levels also claimed for examination.

Field trials have been established with 4 nitrogen levels (0,30, 60 and 90 kg ha-1) and 3 phosphorus levels (60, 90 and 120 kg ha-1), during two years. Dark Skin Perfection and Vitalis were the elected varieties, commonly used in that area.

During the growing period plants were sampled and analysed for dry matter and macronutrients. Full flower, pod swell and pod fill were the stages studied. Seasonal variations indicated that N and K decreased as the season progressed while P, Ca and Mg remained relatively constant.

At harvest time, productions were examined for whole plants and for marketable produce (peas). The latter showed no significant difference between nutrient levels.

Macronutrient export values by top plants (kg ha-1) were calculated and compared with other data sources.

Results confirmed the low requirements of pea crops for nitrogen fertilizers.

Saraiva Ferreira, M.E. (1988). VARIATION IN MACRONUTRIENT CONTENTS IN PEAS FOR PROCESSING. Acta Hortic. 220, 267-274
DOI: 10.17660/ActaHortic.1988.220.36

Acta Horticulturae