ISSN:
1745-6584
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Energy, Environment Protection, Nuclear Power Engineering
,
Geosciences
Notes:
In 1973, the Suffolk County Department of Environmental Control in cooperation with Cornell University began a study on nitrogen (N) fertilization of potatoes and turfgrasses. The research and demonstration project has shown that current practices result in substantial N losses; and, in many cases, excessive use of N reduces crop yields and turf quality. Annual N losses of 50 lbs. per acre (55.5 kg-N/ha) are sufficient to cause a concentration in the aquifer's surface layer of 10 mg/1 nitrate-N (New York State Drinking Water Standard).The eastern portion of Long Island supports a productive agricultural industry whose main crop is potatoes. Ground-water surveys have shown that the aquifer system of this area is contaminated with nitrate nitrogen. The average potato grower applies 200 to 250 lb-N/a (222 to 278 kg-N/ha) at planting time; and depending upon a number of factors, N recovered in harvested tubers varies from 75 to 150 lb-N/a (83 to 167 kg-N/ha). Losses to the ground water could vary from 50 to 175 lb-N/a (55.5 to 194 kg-N/ha). The study has shown that the application of 150 lb-N/a (167 kg-N/ha) can still maintain maximum potato yields and keep the N loss to ground water below 50 lb-N/a (55.5 kg-N/ha) by improving nitrogen-use efficiency. This is done through splitting N applications so that one-third to one-half is applied at planting and the remainder is applied prior to the period of rapid crop growth and nutrient uptake. On-farm demonstration plots are being used to convince growers to reduce N rates and adopt more efficient application methods.The western portions of Long Island are highly urbanized and turfgrasses may be fertilized at rates up to 350 lb-N/a (389 kg-N/ha). Potential leaching losses are high for turfgrass as N is not recovered in harvested plant materials. Experiments are underway to establish rates of biomass N buildup under several fertilization regimes. Preliminary results indicate that N-use efficiency increases with more frequent but smaller N applications. Encouraging the use of low maintenance turf species appears to be the best long-term solution.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1745-6584.1976.tb03137.x
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