Organic nitrogen fertilizers influence nutritional value, water use efficiency, and nitrogen dynamics of drip irrigated lettuce and sweet corn

Farmers usually rely on off-farm sources (fish emulsion, feather meal, blood meal) for the additional N needed during the growing season, and they are willing to pay the extra shipping cost. However, there is another fertilizer option being developed that could allow farmers to produce N on-farm, which is cyanobacteria, formerly known as the blue green algae. The general objectives of this study were to assess effects of organic N fertilizer application and N rates on nutritional value, water use efficiency, N dynamics of sweet corn and lettuce. A two-year field study was conducted in the summers of 2013 and 2014 at the Colorado State University Horticulture Research Center, Fort Collins, CO. The fertilizers used in this study were blood meal, feather meal, fish emulsion, and cyano-fertilizer. Both fish emulsion and cyano-fertilizer were supplied in four split applications over the growing season through drip irrigation, while the blood meal and feather meal were subsurface banded prior to planting. Lettuce and sweet corn were used as an indicator to evaluate effects of organic nitrogen (N) fertilizers on nutritional value, water use efficiency, and N dynamics. The aims of this study were to evaluate the effect of different types of organic N fertilizer on nutritional value; beta-carotene, iron (Fe), zinc (Zn), marketable yield, water use efficiency (WUE), residual soil nitrate-N, N content, and N use efficiency (NUE) of horticultural crops, particularly lettuce and sweet corn.