Abstract
ABSTRACT In the moist savanna zone with a 180 to 190 day growing period, early season cowpea immediately followed by a late season cereal crop can maximize the benefit of the legume to the cereal. Traditional cereal crops for this system are millet and sorghum but new early maize varieties can also be used. A study was conducted to estimate the contribution of the early season cowpea to late season maize during three years on two fields in central Kaduna State in northern Nigeria. Without insecticide application, early season cowpea grain yield averaged almost 500 kg ha−1 over all environments including a site where P deficiency was corrected in the second year. N content of cowpea residues after grain harvest averaged approximately 15 and 30 kg ha−1 at the low-P and moderate-P sites, respectively. Mean maize grain yield without urea or previous cowpea (290 kg ha−1 in five environments) was increased to 760 kg ha−1 with urea application (30 and 60 kg ha−1 treatments combined) and 690 kg ha−1 after early season cowpea (three varieties combined). Maize grain yield after early season cowpea without N application to maize was maintained at levels higher (at p < 0.06) than 30 kg N ha−1 as fertilizer. Thus, cowpea cultivation in the early season appears to be an effective indigenous solution for supplying a small amount of N for cereal production. The study showed the importance of adequate P availability for the rotation system to succeed.
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Claims 8
Claim · model-written summary
Early cowpea yielded almost 500 kg ha−1 without insecticide over all environments.
- Taxon
- cowpea
Vigna unguiculatae0 - Outcome
- grain yielde0
- Value
- almost 500 kg ha−1e0
- Qualifier
- Without insecticide applicatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Without insecticide application, early season cowpea grain yield averaged almost 500 kg ha−1 over all environments”
Claim · model-written summary
Cowpea residues contained approximately 15 kg ha−1 nitrogen at the low-phosphorus site.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“N content of cowpea residues after grain harvest averaged approximately 15 and 30 kg ha−1 at the low-P and moderate-P sites, respectively”
Claim · model-written summary
Cowpea residues contained approximately 30 kg ha−1 nitrogen at the moderate-phosphorus site.
- Taxon
- cowpeaVigna unguiculatae0
- Organ / stage
- residuese0
- Outcome
- N contente0
- Value
- 30 kg ha−1e0
- Setting
- moderate-Pe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“N content of cowpea residues after grain harvest averaged approximately 15 and 30 kg ha−1 at the low-P and moderate-P sites, respectively”
Claim · model-written summary
Urea increased mean maize grain yield from 290 to 760 kg ha−1.
- Treatment
- urea application (30 and 60 kg ha−1 treatments combined)e0
- Outcome
- maize grain yielde0
- Direction
- increasede0
- Value
- 760 kg ha−1e0
- Qualifier
- 290 kg ha−1e0
- Comparator
- without urea or previous cowpeae0
Zea maysOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Mean maize grain yield without urea or previous cowpea (290 kg ha−1 in five environments) was increased to 760 kg ha−1 with urea application (30 and 60 kg ha−1 treatments combined)”
Claim · model-written summary
Previous early cowpea increased mean maize grain yield from 290 to 690 kg ha−1.
- Treatment
- early season cowpeae0
- Outcome
- maize grain yielde0
- Direction
- increasede0
- Value
- 690 kg ha−1e0
- Qualifier
- 290 kg ha−1e0
- Comparator
- without urea or previous cowpeae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Mean maize grain yield without urea or previous cowpea (290 kg ha−1 in five environments) was increased to 760 kg ha−1 with urea application (30 and 60 kg ha−1 treatments combined) and 690 kg ha−1 after early season cowpea (three varieties combined)”
Claim · model-written summary
Maize yield after cowpea without added nitrogen exceeded yield with 30 kg N ha−1 fertilizer at p < 0.06.
- Treatment
- after early season cowpea without N application to maizee0
- Outcome
- Maize grain yielde0
- Direction
- highere0
- Qualifier
- p < 0.06e0
- Comparator
- 30 kg N ha−1 as fertilizere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Maize grain yield after early season cowpea without N application to maize was maintained at levels higher (at p < 0.06) than 30 kg N ha−1 as fertilizer”
Claim · model-written summary
The authors conclude that early cowpea supplies a small amount of nitrogen for cereal production.
- Taxon
- cowpeaVigna unguiculatae0
- Outcome
- supplying a small amount of N for cereal productione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cowpea cultivation in the early season appears to be an effective indigenous solution for supplying a small amount of N for cereal production”
Claim · model-written summary
The authors conclude that adequate phosphorus is important for rotation success.
- Taxon
- CowpeaVigna unguiculatat0
- Outcome
- adequate P availability for the rotation system to succeede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The study showed the importance of adequate P availability for the rotation system to succeed”
t0“Cowpea”
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