AN EVALUATION OF NITROGEN FERTILITY MANAGEMENT IN COMMERCIAL POTATO FIELDS

Authors : Brian MARSH

Pages : 52-63

View : 54 | Download : 10

Publication Date : 2019-06-18

Article Type : Research Paper

Abstract :Nitrogen fertility is an important component for optimum potato yield and quality. Best management practices are necessary in regards to N applications to achieve these goals without applying excess N which may contribute to ground water contamination. Eight potato fields in the Southern San Joaquin Valley were sampled for nitrogen inputs and uptake, tuber and vine dry matter and residual soil nitrate-N. The fields had substantial soil nitrate-N prior to the potato crop. Nitrogen fertilizer was applied prior to planting and in irrigation water as needed based on in-season petiole sampling in accordance with published recommendations. Average total nitrogen uptake was 259 kg ha -1 in 55.6 Mg ha -1 tuber yield and nitrogen use efficiency was good at 62 percent. Seventy-one percent of the total plant nitrogen uptake was removed from the field in the tubers. Soil nitrate-N increased 8 percent from pre-plant to post-harvest averaged across all fields and was generally situated in the lower soil profile below the effective potato rooting depth. Irrigation timing and amount was generally good at most locations. Pre-plant soil analysis is important information to be used in making N fertilizer recommendations. Rotation crops having deeper rooting growth would be able to utilize nitrogen that remained in the soil profile. 
Keywords : Irrigation management, leaching potential, nitrogen

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