Abstract
Pigeonpea (Cajanus cajan L. Millsp) and sorghum (Sorghum bicolor L. Moench). are grown as intercrops on soils typified by low nitrogen (N). particularly Alfisols and Vertisols of the semi-arid tropical areas of India and East Africa. Proper management of fertilizer N in sorghum/pigeonpea intercropping systems is essential to enhancing biological nitrogen fixing ability of pigeonpea, and to increasing grain yields of sorghum.In a 3-year study, we examined the effect of time and rates of fertilizer N application on biological N fixation (BNF) and fertilizer N recovery by pigeonpea and sorghum grown as a sole crop, and as an intercrop on an Alfisol in India. In 1993, N (50 kg N ha−1) was all applied at planting (basal) or at 40 days after sowing (delayed). During 1994–1995, four N rates 0, 25, 50, and 100 kg ha−1 were applied (i) 100% at planting (basal) or (ii) 67% at 40 days, and 33% at 60 days after sowing (delayed).Delaying N fertilization until 40 days after sowing (DAS), rather than applying at sowing significantly increased (p < 0.001) total dry matter, grain yield (GY) and total N content (TNC) of the sorghum, but not of pigeonpea. Highest GY and TNC was recorded at an N rate of 50 kg ha −1 with sole crop sorghum, and at 25 kg ha−1 for intercrop sorghum. Delaying N fertilization to sorghum significantly (p < 0.001) increased 15N recovery in the shoot from 15 to 32% in sole crop, and 10 to 32% in intercrop. Similarly, there was a significant (p < 0.001) increase in N recovery (calculated without 15N, but by the difference between the nonfertilized N and fertilized plots) from 43–59% in sole crop and from 28–71% in intercrop sorghum. Pigeonpea fixed between 120–170 kg ha−1 of atmospheric N throughout the cropping season. Nitrogen application to the sorghum row, but not to the pigeonpea, enhanced BNF by pigeonpea and maximized fertilizer recovery by sorghum in a sorghum/pigeonpea intercropping.
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Claims 13
Claim · model-written summary
Delayed N application increased sorghum total dry matter.
- Treatment
- Delaying N fertilization until 40 days after sowing (DAS)e0
- Outcome
- total dry mattere0
- Direction
- increasede0
- Comparator
- applying at sowinge0
SorghumOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Delaying N fertilization until 40 days after sowing (DAS), rather than applying at sowing significantly increased (p < 0.001) total dry matter, grain yield (GY) and total N content (TNC) of the sorghum”
Claim · model-written summary
Delayed N application increased sorghum grain yield.
- Treatment
- Delaying N fertilization until 40 days after sowing (DAS)e0
- Outcome
- grain yield (GY)e0
- Direction
- increasede0
- Comparator
- applying at sowinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Delaying N fertilization until 40 days after sowing (DAS), rather than applying at sowing significantly increased (p < 0.001) total dry matter, grain yield (GY) and total N content (TNC) of the sorghum”
Claim · model-written summary
Delayed N application increased sorghum total N content.
- Treatment
- Delaying N fertilization until 40 days after sowing (DAS)e0
- Outcome
- total N content (TNC)e0
- Direction
- increasede0
- Comparator
- applying at sowinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Delaying N fertilization until 40 days after sowing (DAS), rather than applying at sowing significantly increased (p < 0.001) total dry matter, grain yield (GY) and total N content (TNC) of the sorghum”
Claim · model-written summary
The same delayed application did not significantly increase pigeonpea traits.
- Taxon
- pigeonpea
Cajanus cajane0 - Treatment
- Delaying N fertilization until 40 days after sowing (DAS)e1
- Outcome
- total dry matter, grain yield (GY) and total N content (TNC)e1
- Comparator
- applying at sowinge1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“but not of pigeonpea.”
e1“Delaying N fertilization until 40 days after sowing (DAS), rather than applying at sowing significantly increased (p < 0.001) total dry matter, grain yield (GY) and total N content (TNC) of the sorghum”
Claim · model-written summary
Sole sorghum had its highest grain yield and N content at 50 kg ha −1.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Highest GY and TNC was recorded at an N rate of 50 kg ha −1 with sole crop sorghum”
Claim · model-written summary
Intercrop sorghum had its highest grain yield and N content at 25 kg ha−1.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“at 25 kg ha−1 for intercrop sorghum”
e1“Highest GY and TNC was recorded”
Claim · model-written summary
Delayed N increased sole sorghum shoot 15N recovery from 15 to 32%.
- Treatment
- Delaying N fertilizatione0
- Outcome
- 15N recovery in the shoote0
- Direction
- increasede0
- Value
- 15 to 32%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Delaying N fertilization to sorghum significantly (p < 0.001) increased 15N recovery in the shoot from 15 to 32% in sole crop”
Claim · model-written summary
Delayed N increased intercrop sorghum shoot 15N recovery from 10 to 32%.
- Treatment
- Delaying N fertilizatione1
- Outcome
- 15N recovery in the shoote1
- Direction
- increasede1
- Value
- 10 to 32%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“10 to 32% in intercrop”
e1“Delaying N fertilization to sorghum significantly (p < 0.001) increased 15N recovery in the shoot”
Claim · model-written summary
Delayed N increased sole sorghum difference based N recovery from 43–59%.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“significant (p < 0.001) increase in N recovery (calculated without 15N, but by the difference between the nonfertilized N and fertilized plots) from 43–59% in sole crop”
e1“Delaying N fertilization to sorghum”
Claim · model-written summary
Delayed N increased intercrop sorghum difference based N recovery from 28–71%.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“from 28–71% in intercrop sorghum”
e1“significant (p < 0.001) increase in N recovery”
e2“Delaying N fertilization to sorghum”
Claim · model-written summary
Pigeonpea fixed 120–170 kg ha−1 atmospheric N across the season.
- Taxon
- PigeonpeaCajanus cajane0
- Outcome
- atmospheric Ne0
- Value
- 120–170 kg ha−1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pigeonpea fixed between 120–170 kg ha−1 of atmospheric N throughout the cropping season.”
Claim · model-written summary
Applying N to sorghum rows but not pigeonpea enhanced pigeonpea BNF.
- Taxon
- pigeonpeaCajanus cajane0
- Treatment
- Nitrogen application to the sorghum rowe0
- Outcome
- BNF by pigeonpeae0
- Direction
- enhancede0
- Comparator
- not to the pigeonpeae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen application to the sorghum row, but not to the pigeonpea, enhanced BNF by pigeonpea”
Claim · model-written summary
Applying N to sorghum rows but not pigeonpea maximized sorghum fertilizer recovery.
- Treatment
- Nitrogen application to the sorghum rowe0
- Outcome
- fertilizer recovery by sorghume0
- Direction
- maximizede0
- Comparator
- not to the pigeonpeae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen application to the sorghum row, but not to the pigeonpea, enhanced BNF by pigeonpea and maximized fertilizer recovery by sorghum”
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417 papers in the same direction as this paper · 21 in the opposite direction · 7 reporting no difference from an alternative
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See all 446 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.