@inproceedings{77cddd2e663448d884fab56db26443c7,
title = "Spatial variability of the Illinois Soil Nitrogen Test: Implications for soil sampling",
abstract = "The Illinois Soil Nitrogen Test (ISNT) is available for maize (Zea mays L.) nitrogen fertilization. However sampling recommendations have not been defined. On fourteen Illinois production fields, ISNT was normally distributed with an 18% coefficient of variation. Mean ISNT ranged from 98 mg kg-1 to 255 mg kg-1. At least ten samples are required to determine the mean ISNT for a given field with a precision of 24 mg kg-1. ISNT has a strong spatial structure, as indicated by the bounded variograms, the relatively low nugget/sill ratio (less than 30% in ten fields) and mean range of 150 m.",
keywords = "Illinois Soil Nitrogen Test, Soil sampling, Variable rate nitrogen fertilization",
author = "Ruffo, {Mat{\'i}as L.} and Bollero, {Germ{\'a}n A.} and Bullock, {Donald G.}",
year = "2005",
language = "English (US)",
isbn = "9789076998695",
series = "Precision Agriculture 2005, ECPA 2005",
pages = "751--757",
booktitle = "Precision Agriculture 2005",
note = "5th European Conference on Precision Agriculture, ECPA 2005 ; Conference date: 09-06-2005 Through 12-06-2005",
}