Abstract
Site-specific use of nitrification inhibitors has been proposed as one means of reducing the cost of nitrification inhibitor use on fields that vary in their potential for leaching or denitrification. This study evaluated one approach for site-specific use of the nitrification inhibitor nitrapyrin (2-chloro-6-[trichloromethyl] pyridine) based on slope and surface texture. Treatments of uniform and variable N fertilizer and nitrapyrin were applied to field length strips in a center-pivot irrigated field planted to maize (Zea mays L.) from 1995 to 1998. Nitrapyrin application was controlled spatially according to an arbitrary leaching potential derived from slope and surface soil texture. Growing seasons were grouped into dry, wet, or average precipitation years. Alternative approaches for nitrapyrin management zones based on fuzzy cluster analysis of grain yield or soil apparent electrical conductivity (ECa) were compared with the slope-texture management zone approach. There were small effects of nitrapyrin application method (none, uniform or variable) on grain yield. Uniform nitrapyrin application increased yield in a wet year. Fuzzy cluster analysis of grain yield or soil ECa identified unique patterns of yield or soil ECa Yield clusters corresponded to patterns of water availability or excess. There were small effects of N or nitrapyrin application method on soil residual NO3-N. Yield Cluster 3 soils had higher residual NO3-N levels all 4 yr. In a wet year (1996) NO3-N levels were lowest in yield Cluster 2 soils—in the other 3 yr of the study, there was no difference in NO3-N levels between yield Clusters 1 and 2. Soil ECa clusters corresponded closely to soil series. There were significant correlations between soil ECa and yield clusters. Fuzzy cluster analysis has the potential to define management zones for use of nitrification inhibitors from relatively easily obtained spatial yield or soil ECa, rather than expensive grid sampling of soil chemical and physical properties.
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Claims 12
Claim · model-written summary
Nitrapyrin application method had small effects on maize grain yield.
Zea maysNot reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Treatments of uniform and variable N fertilizer and nitrapyrin were applied to field length strips in a center-pivot irrigated field planted to maize (Zea mays L.)”
e1“There were small effects of nitrapyrin application method (none, uniform or variable) on grain yield”
Claim · model-written summary
Uniform nitrapyrin increased yield in a wet year.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“maize (Zea mays L.)”
e1“Uniform nitrapyrin application increased yield in a wet year”
Claim · model-written summary
Fuzzy clustering of grain yield identified spatial yield patterns.
- Outcome
- unique patterns of yielde1
Not reportedComparatorValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“maize (Zea mays L.)”
e1“Fuzzy cluster analysis of grain yield or soil ECa identified unique patterns of yield or soil ECa”
Claim · model-written summary
Fuzzy clustering of soil ECa identified spatial soil ECa patterns.
- Outcome
- soil ECae1
Not reportedComparatorValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“maize (Zea mays L.)”
e1“Fuzzy cluster analysis of grain yield or soil ECa identified unique patterns of yield or soil ECa”
Claim · model-written summary
Yield clusters corresponded to patterns of water availability or excess.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“maize (Zea mays L.)”
e1“Yield clusters corresponded to patterns of water availability or excess”
Claim · model-written summary
N or nitrapyrin application method had small effects on soil residual NO3-N.
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“maize (Zea mays L.)”
e1“There were small effects of N or nitrapyrin application method on soil residual NO3-N”
Claim · model-written summary
Yield Cluster 3 soils had higher residual NO3-N in all four years.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“maize (Zea mays L.)”
e1“Yield Cluster 3 soils had higher residual NO3-N levels all 4 yr”
Claim · model-written summary
In 1996, yield Cluster 2 soils had the lowest NO3-N levels.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“maize (Zea mays L.)”
e1“In a wet year (1996) NO3-N levels were lowest in yield Cluster 2 soils”
Claim · model-written summary
NO3-N levels did not differ between yield Clusters 1 and 2 in the other three years.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“maize (Zea mays L.)”
e1“in the other 3 yr of the study, there was no difference in NO3-N levels between yield Clusters 1 and 2”
Claim · model-written summary
Soil ECa clusters corresponded closely to soil series.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“maize (Zea mays L.)”
e1“Soil ECa clusters corresponded closely to soil series”
Claim · model-written summary
Soil ECa and yield clusters were significantly correlated.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“maize (Zea mays L.)”
e1“There were significant correlations between soil ECa and yield clusters”
Claim · model-written summary
Fuzzy clustering may define management zones from spatial yield or soil ECa.
- Outcome
- define management zonese1
- Comparator
- expensive grid sampling of soil chemical and physical propertiese1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“maize (Zea mays L.)”
e1“Fuzzy cluster analysis has the potential to define management zones for use of nitrification inhibitors from relatively easily obtained spatial yield or soil ECa, rather than expensive grid sampling of soil chemical and physical properties”
The same questions in other papers
nitrapyrin · yield · Zea mays (maize)Results differ
33 papers in the same direction as this paper · 9 in the opposite direction
- positive
- no effect
- no effect
39 papers more in this group
See all 43 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.