Nitrogen gains and losses in sugarcane (Saccharum sp.) agroecosystems on the coast of Peru@@@Ganacias y perdidas de nitrógeno en un agroecosistema de caña de azucar en la costa del Perú

Irrigated sugarcane crops on the Peruvian coastal desert require 300 kg N-fertilizer ha−1 for economically-optimum yields. About 24 kg N ha−1 is added to the systemvia irrigation water from rivers and deep wells. 1.2% of the total N in the soil is in available form during the growing season. N extracted by the aerial part of the plants ranges from 210–246 kg N ha−1 crop−1;ca. 70% of this is removed in the harvest, and most of the remainder is lostvia pre-harvest burning.