Abstract
Abstract The relative availability of nitrogen (N) from indigenous soil organic N, immobilized fertilizer N, currently applied fertilizer N, and crop residues is largely unknown. A nonirrigated experiment was conducted on a silty clay loam at Lincoln, NE, with both continuous soybean [ Glycine max (L.) Merr.] and corn ( Zea mays L.), in which crops were produced with no tillage after surface application of 0, 0.5, 1.0, or 1.5 times the quantity of aboveground crop residue produced the previous year. In 1980 and 1981, depleted 15 N NH 4 NO 3 (at 45 kg N ha −1 ) and crop residues were managed so that labeled isotope taken up in the 1981 crop could be separated into that from crop residues, from 1st‐yr fertilizer that had become immobilized, from fertilizer N applied the 2nd yr, and from indigenous soil N (plus fixed N for soybean). Grain and straw (stover) production of both crops in 1981 were increased 2000 to 3000 kg ha −1 by increasing crop residue rate. Almost all the N in soybean residues was mineralized and taken up by the second crop, with most of this uptake occurring after mid‐July. Uptake by soybean of labeled N immobilized in soil organic matter the previous year increased from about 2 to 6 kg N ha −1 as residue rate increased, possibly originating mainly from N temporarily immobilized in microbial biomass. Uptake by soybean of current‐year fertilizer N also increased slightly with residue rate. The fraction of total N in soybean derived from indigenous soil (plus fixed) N decreased with increased residue rate from about 85% for no residues to 55% for the 1.5 residue rate. For corn, essentially none of the N immobilized in corn residues was recovered by the next crop at any residue rate. Uptake of labeled N immobilized in soil organic matter was not affected by residue rate, but uptake from 1981 fertilizer treatment increased about 6 kg ha −1 with increased residue rate. Over 80% of the total N uptake by corn in 1981 came from indigenous soil N, regardless of residue rate.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 10
Claim · model-written summary
Increasing residue rate raised soybean grain and straw production by 2000 to 3000 kg ha −1.
- Taxon
- Soybean
Glycine maxt0 - Treatment
- increasing crop residue ratee0
- Outcome
- Grain and straw (stover) productione0
- Direction
- increasede0
- Value
- 2000 to 3000 kg ha −1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grain and straw (stover) production of both crops in 1981 were increased 2000 to 3000 kg ha −1 by increasing crop residue rate”
t0“Corn and Soybean”
Claim · model-written summary
Increasing residue rate raised corn grain and stover production by 2000 to 3000 kg ha −1.
- Taxon
- Corn
Zea mays subsp. mayst0 - Treatment
- increasing crop residue ratee0
- Outcome
- Grain and straw (stover) productione0
- Direction
- increasede0
- Value
- 2000 to 3000 kg ha −1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grain and straw (stover) production of both crops in 1981 were increased 2000 to 3000 kg ha −1 by increasing crop residue rate”
t0“Corn and Soybean”
Claim · model-written summary
Almost all nitrogen in soybean residues mineralized and was taken up by the next crop, mostly after mid-July.
- Taxon
- soybeanGlycine maxe0
- Outcome
- N in soybean residues was mineralized and taken upe0
- Qualifier
- after mid‐Julye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Almost all the N in soybean residues was mineralized and taken up by the second crop, with most of this uptake occurring after mid‐July”
Claim · model-written summary
Soybean uptake of previously immobilized labeled nitrogen rose from about 2 to 6 kg N ha −1 with residue rate.
- Taxon
- soybeanGlycine maxe0
- Treatment
- residue ratee0
- Outcome
- Uptake by soybean of labeled N immobilized in soil organic mattere0
- Direction
- increasede0
- Value
- about 2 to 6 kg N ha −1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Uptake by soybean of labeled N immobilized in soil organic matter the previous year increased from about 2 to 6 kg N ha −1 as residue rate increased”
Claim · model-written summary
Soybean uptake of current-year fertilizer nitrogen increased slightly with residue rate.
- Taxon
- soybeanGlycine maxe0
- Treatment
- residue ratee0
- Outcome
- Uptake by soybean of current‐year fertilizer Ne0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Uptake by soybean of current‐year fertilizer N also increased slightly with residue rate”
Claim · model-written summary
The soybean nitrogen fraction from indigenous soil plus fixation fell from about 85% without residues to 55% at the 1.5 residue rate.
- Taxon
- soybeanGlycine maxe0
- Treatment
- increased residue ratee0
- Outcome
- fraction of total N in soybean derived from indigenous soil (plus fixed) Ne0
- Direction
- decreasede0
- Value
- about 85% for no residues to 55%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The fraction of total N in soybean derived from indigenous soil (plus fixed) N decreased with increased residue rate from about 85% for no residues to 55% for the 1.5 residue rate”
Claim · model-written summary
Essentially no nitrogen immobilized in corn residues was recovered by the next crop.
- Taxon
- cornZea mays subsp. mayse0
- Outcome
- N immobilized in corn residues was recovered by the next crope0
- Qualifier
- at any residue ratee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For corn, essentially none of the N immobilized in corn residues was recovered by the next crop at any residue rate”
Claim · model-written summary
Residue rate did not affect uptake of labeled nitrogen immobilized in soil organic matter by corn.
- Taxon
- CornZea mays subsp. mayst0
- Treatment
- residue ratee0
- Outcome
- Uptake of labeled N immobilized in soil organic mattere0
- Direction
- not affectede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Uptake of labeled N immobilized in soil organic matter was not affected by residue rate”
t0“Corn and Soybean”
Claim · model-written summary
Corn uptake of 1981 fertilizer nitrogen increased about 6 kg ha −1 with residue rate.
- Taxon
- CornZea mays subsp. mayst0
- Treatment
- increased residue ratee0
- Outcome
- uptake from 1981 fertilizer treatmente0
- Direction
- increasede0
- Value
- about 6 kg ha −1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“uptake from 1981 fertilizer treatment increased about 6 kg ha −1 with increased residue rate”
t0“Corn and Soybean”
Claim · model-written summary
Indigenous soil nitrogen supplied over 80% of corn nitrogen uptake irrespective of residue rate.
- Taxon
- cornZea mays subsp. mayse0
- Outcome
- total N uptake by corne0
- Value
- Over 80%e0
- Qualifier
- regardless of residue ratee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Over 80% of the total N uptake by corn in 1981 came from indigenous soil N, regardless of residue rate”
The same questions in other papers
organic · yield · Glycine max (soybean)Results differ
64 papers in the same direction as this paper · 6 in the opposite direction · 5 reporting no difference from an alternative
- negative
- no effect
- no effect
72 papers more in this group
See all 76 papers →organic · yield · Zea mays (maize)Positive and negative results
329 papers in the same direction as this paper · 32 in the opposite direction · 11 reporting no difference from an alternative
- negative
- no effect
- no effect
369 papers more in this group
See all 373 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.