Abstract
Nitrogen (N) deficiency is a major problem in organic and low-input farming systems. Growing spring cereals with undersown legumes has a positive effect on soil fertility, enriching it with nitrogen, through symbiosis of legumes with nodule bacteria. Two hypotheses were tested: 1) undersowing of red clover increases the protein content of barley grains and 2) mineral N has negative aftereffect on growth of legume plants. The aim of this study was to investigate the effect of organic (cattle manure, off-season cover crop) and mineral N in organic and conventional farming systems on (i) barley (Hordeum vulgare L.) grain yield and quality, (ii) biomass yield formation of undersown red clover (Trifolium pratense L.) and (iii) the aftereffect of mineral and organic N fertilisers on the red clover crop biomass yield in the following year. The experiment was established in 2008 at the Estonian University of Life Sciences (5822 N, 2640 E) on the soil described as Stagnic Albic Luvisol (LV ab-st) (WRB, 2014) with sandy loam surface texture, 1.38% C, 0.13% N, 133 mg kg -1 P, 210 mg kg -1 K and pH KCl 6.0. The crops were treated using different farming systems: three organic (Org0, OrgI and OrgII) and four conventional (N0, N40, N80 and N120); nitrogen sources during crop cycle period: N0 and Org0 = symbiotically fixed atmospheric N 2 , N40 = N 2 + mineral N 40 kg ha -1 N, N80 = N 2 + mineral N 80 kg ha -1 N, N120 = N 2 + mineral N 120 kg ha -1 N, OrgI = N 2 + N taken up by cover crops (N CC ) and OrgII = N 2 + N CC + N applied with manure (N m ). Our study revealed that grain yield of barley was strongly affected by undersown red clover; because of competition for nutrients in cereallegume mixture the grain yield of barley in organic system was 11-61% lower than that in conventional system. The seed rate of undersown red clover (2.84 million viable seed per ha) was too high. The content of protein depended on the availability of mineralised nitrogen. The mean protein content of barley grains over the trial years and treatments was 99 1.6 g kg -1 in the conventional system, which was 17% higher than that in the organic system. Undersowing of red clover had no significantly positive effect on the grain yield and protein content of barley. Mineral N fertiliser had no negative aftereffect on growth of the red clover crop the following year. Mean above ground biomass yield over the trial years for the red clover crop 2 nd cut was 17% higher in the conventional system than in the organic system.
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Claims 6
Claim · model-written summary
Undersowing red clover had no significantly positive effect on barley grain yield and protein content.
- Taxon
- barley
.jpg?width=60)
Hordeum vulgaree0 - Treatment
- Undersowing of red clovere0
- Outcome
- grain yield and protein contente0
- Direction
- no significantly positive effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Undersowing of red clover had no significantly positive effect on the grain yield and protein content of barley”
Claim · model-written summary
Barley grains in the conventional system had 17% higher protein content than in the organic system.
- Taxon
- barleyHordeum vulgaree2
- Treatment
- conventional systeme2
- Outcome
- protein content of barley grainse2
- Direction
- highere2
- Value
- 17%e2
- Qualifier
- 99 1.6 g kg -1e2
- Comparator
- organic systeme2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“The mean protein content of barley grains over the trial years and treatments was 99 1.6 g kg -1 in the conventional system, which was 17% higher than that in the organic system”
Claim · model-written summary
Red clover above-ground biomass at the second cut was 17% higher in the conventional system than in the organic system.
- Taxon
- red clover
Trifolium pratensee3 - Treatment
- conventional systeme3
- Outcome
- above ground biomass yielde3
- Direction
- highere3
- Value
- 17%e3
- Comparator
- organic systeme3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“Mean above ground biomass yield over the trial years for the red clover crop 2 nd cut was 17% higher in the conventional system than in the organic system”
Claim · model-written summary
Mineral N fertiliser had no negative aftereffect on red clover growth in the following year.
- Taxon
- red cloverTrifolium pratensee4
- Treatment
- Mineral N fertilisere4
- Outcome
- growth of the red clover crope4
- Direction
- no negative aftereffecte4
- Qualifier
- the following yeare4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Mineral N fertiliser had no negative aftereffect on growth of the red clover crop the following year”
Claim · model-written summary
Barley grain protein content depended on the availability of mineralised nitrogen.
- Taxon
- BarleyHordeum vulgaret0
- Treatment
- availability of mineralised nitrogene5
- Outcome
- content of proteine5
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Barley undersown with red clover in organic and conventional systems”
e5“The content of protein depended on the availability of mineralised nitrogen”
Claim · model-written summary
Undersown red clover seed rate of 2.84 million viable seed per ha was too high.
- Taxon
- red cloverTrifolium pratensee6
- Treatment
- 2.84 million viable seed per hae6
- Outcome
- seed ratee6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“The seed rate of undersown red clover (2.84 million viable seed per ha) was too high”
The same questions in other papers
Trifolium pratense · quality: protein · Hordeum vulgare (barley)Positive and negative results
2 in the opposite direction
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fertilization · growth · Trifolium pratense (red clover)Positive and negative results
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- positive
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8 papers more in this group
See all 12 papers →cultivation system · quality: protein · Hordeum vulgare (barley)Results agree
1 paper in the same direction as this paper
- positive
cultivation system · yield · Trifolium pratense (red clover)Results agree
1 paper in the same direction as this paper
- positive
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.