Abstract
In Nebraska there is a great concern about the influence of nitrogen (N) on groundwater quality. Spatial and temporal variability of nitrate-N in farmer fields needs to be quantified to develop optimum sampling plans for both uniform and variable rate N fertilization. This chapter determines the variability of nitrate and nitrate distributions within farmer’s corn fields on selected benchmark soils across the state, and determines seasonal variation in soil nitrate-N levels between fall and spring. It also determines the most appropriate number of samples required to estimate the mean nitrate-N value within prescribed confidence limits, and utilizes geostatistical analysis to determine optimum grid sample spacing for developing variable N fertilizer rates based on residual nitrate-N. The geostatistical analysis coupled with the classical statistical analysis showed no significant differences in similar parameters for the 60 or 90 m lag spacing versus the 30 m lag spacing.
| Original language | English (US) |
|---|---|
| Title of host publication | Site-Specific Management for Agricultural Systems |
| Publisher | wiley |
| Pages | 175-186 |
| Number of pages | 12 |
| ISBN (Electronic) | 9780891182603 |
| ISBN (Print) | 9780891181279 |
| DOIs | |
| State | Published - Sep 1 1995 |
Keywords
- Classical statistical analysis
- Geostatistical analysis
- Grid sample spacing
- Groundwater quality
- Nebraska
- Seasonal variation
- Soil nitrate-nitrogen spatial variability
ASJC Scopus subject areas
- General Engineering
- General Agricultural and Biological Sciences