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A Soil Test for Nitrogen Availability to Corn
Author(s) -
Magdoff F. R.,
Ross D.,
Amadon J.
Publication year - 1984
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1984.03615995004800060020x
Subject(s) - fertilizer , agronomy , soil test , yield (engineering) , environmental science , sowing , sampling (signal processing) , manure , soil water , mathematics , soil science , computer science , biology , materials science , filter (signal processing) , metallurgy , computer vision
Abstract A soil test for N availability to corn ( Zea mays L.), NO ‐ 3 ‐ to 30cm when plants are 15 to 30 cm tall, was evaluated on a wide range of soils at 33 locations in Vermont and one in New York state. The NO ‐ 3 ‐N present at the time of sampling is a result of an integration of all the soil and weather factors that have influenced the availability of N prior to the time for sidedress fertilizer application. There was a typical response relationship between soil test NO ‐ 3 ‐N and corn silage yield on plots that only received limited amounts of starter N fertilizer at planting. The Cate‐Nelson procedure for NO ‐ 3 ‐N vs relative yield (yield without sidedress N/yield with sidedress N) indicated that there was a greater probability of response to N fertilizer when NO ‐ 3 ‐N was less than 36 kg ha −1 than at higher soil test values. The currently used N fertilizer recommendation procedure is based on estimates derived from cropping history, yield goal, soil type, and manure management information provided by farmers. Compared with the current method of estimating N fertilizer needs, recommendations based on the NO ‐ 3 ‐N soil test call for much less N fertilizer application and are more accurate in separating sites with varying response probabilities. As a routine laboratory procedure, the proposed test has numerous advantages over other N availability procedures. However, special procedures are needed, including rapid soil treatment after sampling (to eliminate N transformations), sampling the soil at a different time than for the usual soil test, and a rapid sample turnaround time in the laboratory.