Abstract
Abstract Long‐term management practices affect the reserve of mineralizable soil N, and so can influence the amount of supplemental N fertilizer required in crop production. This study was conducted to (i) evaluate the residual effects of long‐term N fertilization and winter cover cropping on corn ( Zea mays L.) N nutrition, and (ii) examine the ability of selected soil indices to detect management‐induced differences in soil N availability. In 1986, N fertilizer and winter cover crops were eliminated from plots which, from 1976 through 1985, had received varying tillage treatments, N fertilizer additions, and either hairy vetch ( Vicia villosa Roth), rye ( Secale cereale L.), or no winter cover crop. A history of N fertilization increased corn yield and N uptake (by an average of 20.4 kg N/ha). A history of winter cover cropping with hairy vetch increased corn yield and N uptake (by an average of 28.0 kg N/ha). Rye cover cropping generally had small or inconsistent effects relative to no cover crop. Tillage generally had insignificant effects on corn yield and N uptake. Soil N availability indices were determined on surface samples (0–15 cm) taken 2 wk after corn planting. The anaerobic incubation provided a poor index of N availability. Total soil C and Kjeldahl N were affected by tillage, though not by cover crop or fertilization history, and were marginally correlated with crop response. The autoclave index was only slightly superior to total soil C and Kjeldahl N as a N‐availability index. The soil NO 3 ‐N concentration was highly correlated with corn yield, and N uptake. Though this study was conducted for 1 yr at one site, results indicate that measurement of surface soil NO 3 ‐N made shortly after corn planting can provide a valid index of the effects of past crop and soil management practices on soil N availability to corn.
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Claims 13
Claim · model-written summary
Previous N fertilization increased corn yield.
- Taxon
- corn
Zea mays subsp. mayse0 - Treatment
- A history of N fertilizatione0
- Outcome
- corn yielde0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A history of N fertilization increased corn yield and N uptake (by an average of 20.4 kg N/ha)”
Claim · model-written summary
Previous N fertilization increased corn N uptake by 20.4 kg N/ha on average.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- A history of N fertilizatione0
- Outcome
- N uptakee0
- Direction
- increasede0
- Value
- 20.4 kg N/hae0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A history of N fertilization increased corn yield and N uptake (by an average of 20.4 kg N/ha)”
Claim · model-written summary
Prior hairy vetch cover cropping increased corn yield.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- winter cover cropping with hairy vetche0
- Interactor
- hairy vetch
Vicia villosae0other - Outcome
- corn yielde0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A history of winter cover cropping with hairy vetch increased corn yield and N uptake (by an average of 28.0 kg N/ha)”
Claim · model-written summary
Prior hairy vetch cover cropping increased corn N uptake by 28.0 kg N/ha on average.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- winter cover cropping with hairy vetche0
- Interactor
- hairy vetchVicia villosae0other
- Outcome
- N uptakee0
- Direction
- increasede0
- Value
- 28.0 kg N/hae0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A history of winter cover cropping with hairy vetch increased corn yield and N uptake (by an average of 28.0 kg N/ha)”
Claim · model-written summary
Tillage generally had insignificant effects on corn yield and N uptake.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- Tillagee0
- Outcome
- corn yield and N uptakee0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Tillage generally had insignificant effects on corn yield and N uptake”
Claim · model-written summary
Anaerobic incubation was a poor index of soil N availability.
- Taxon
- cornZea mays subsp. mayse1
- Outcome
- index of N availabilitye0
- Direction
- poore0
Not reportedValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The anaerobic incubation provided a poor index of N availability”
e1“corn ( Zea mays L.) N nutrition”
Claim · model-written summary
Tillage affected total soil C and Kjeldahl N.
- Taxon
- cornZea mays subsp. mayse1
- Treatment
- tillagee0
- Outcome
- Total soil C and Kjeldahl Ne0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Total soil C and Kjeldahl N were affected by tillage”
e1“corn ( Zea mays L.) N nutrition”
Claim · model-written summary
Cover cropping and fertilization history did not affect total soil C and Kjeldahl N.
- Taxon
- cornZea mays subsp. mayse1
- Treatment
- cover crop or fertilization historye0
- Outcome
- Total soil C and Kjeldahl Ne0
- Direction
- note0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Total soil C and Kjeldahl N were affected by tillage, though not by cover crop or fertilization history”
e1“corn ( Zea mays L.) N nutrition”
Claim · model-written summary
Total soil C and Kjeldahl N were marginally correlated with crop response.
- Taxon
- cornZea mays subsp. mayse1
- Treatment
- tillagee0
- Outcome
- crop responsee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Total soil C and Kjeldahl N were affected by tillage, though not by cover crop or fertilization history, and were marginally correlated with crop response”
e1“corn ( Zea mays L.) N nutrition”
Claim · model-written summary
The autoclave index was slightly superior to soil C and Kjeldahl N as an N availability index.
- Taxon
- cornZea mays subsp. mayse1
- Outcome
- N‐availability indexe0
- Direction
- slightly superiore0
- Comparator
- total soil C and Kjeldahl Ne0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The autoclave index was only slightly superior to total soil C and Kjeldahl N as a N‐availability index”
e1“corn ( Zea mays L.) N nutrition”
Claim · model-written summary
Soil NO 3 ‐N concentration was highly correlated with corn yield.
- Taxon
- cornZea mays subsp. mayse0
- Compound
- soil NO 3 ‐N concentratione0
- Outcome
- corn yielde0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The soil NO 3 ‐N concentration was highly correlated with corn yield, and N uptake”
Claim · model-written summary
Soil NO 3 ‐N concentration was highly correlated with corn N uptake.
- Taxon
- cornZea mays subsp. mayse0
- Compound
- soil NO 3 ‐N concentratione0
- Outcome
- N uptakee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The soil NO 3 ‐N concentration was highly correlated with corn yield, and N uptake”
Claim · model-written summary
Surface soil NO 3 ‐N after planting can index management history effects on corn N availability.
- Taxon
- cornZea mays subsp. mayse0
- Outcome
- valid index of the effects of past crop and soil management practices on soil N availability to corne0
- Qualifier
- shortly after corn plantinge0
Not reportedComparatorValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“measurement of surface soil NO 3 ‐N made shortly after corn planting can provide a valid index of the effects of past crop and soil management practices on soil N availability to corn”
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