Abstract
ABSTRACT The effects of biochar and nitrogen application on yields of upland rice and cowpea and on soil fertility were determined in a greenhouse in Macaíba, RN, Brazil. The trial consisted of the succession of two crops in a completely randomized design and a factorial scheme, with four replicates. Initially, four doses of biochar and four doses of nitrogen were tested for cultivation of rice. Subsequently, four doses of biochar and two doses of nitrogen were tested in half of the pots maintained for planting cowpea. Soil was sampled after rice harvest for half of the pots and at end of the trial for the remaining pots. We evaluated the following parameters: mass of hundred grains of rice, dry shoot mass, panicle number, number of filled spikelets and of empty spikelets, and grain production. Determinations for cowpea were: pod number per pot, grain number per pod, and grain production per pot. Measured soil parameters were: pH, contents of organic carbon, P, K, Ca, Mg, Na, cation exchange capacity, and exchangeable sodium percentage. Biochar addition did not influence yield components of upland rice and cowpea, but resulted in increased soil N retention, which influenced rice dry shoot mass, spikelets sterility, panicle number, and grain mass. Biochar also promoted increased soil pH, potassium content, and exchangeable sodium percentage and decreased calcium and magnesium concentrations.
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Claims 9
Claim · model-written summary
Biochar addition did not influence yield components of upland rice.
- Taxon
- upland rice
Oryza sativae0 - Treatment
- Biochar additione0
- Outcome
- yield componentse0
- Direction
- did not influencee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Biochar addition did not influence yield components of upland rice and cowpea”
Claim · model-written summary
Biochar addition did not influence yield components of cowpea.
- Taxon
- cowpea
Vigna unguiculatae0 - Treatment
- Biochar additione0
- Outcome
- yield componentse0
- Direction
- did not influencee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Biochar addition did not influence yield components of upland rice and cowpea”
Claim · model-written summary
Biochar addition resulted in increased soil N retention in the upland rice and cowpea succession.
- Taxon
- upland riceOryza sativae0
- Treatment
- Biochar additione0
- Outcome
- soil N retentione0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Biochar addition did not influence yield components of upland rice and cowpea, but resulted in increased soil N retention”
Claim · model-written summary
Increased soil N retention influenced rice dry shoot mass.
- Taxon
- riceOryza sativae0
- Outcome
- dry shoot masse0
- Qualifier
- increased soil N retentione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased soil N retention, which influenced rice dry shoot mass, spikelets sterility, panicle number, and grain mass”
t0“UPLAND RICE”
Claim · model-written summary
Increased soil N retention influenced rice spikelets sterility.
- Taxon
- riceOryza sativae0
- Outcome
- spikelets sterilitye0
- Qualifier
- increased soil N retentione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased soil N retention, which influenced rice dry shoot mass, spikelets sterility, panicle number, and grain mass”
t0“UPLAND RICE”
Claim · model-written summary
Increased soil N retention influenced rice panicle number.
- Taxon
- riceOryza sativae0
- Outcome
- panicle numbere0
- Qualifier
- increased soil N retentione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased soil N retention, which influenced rice dry shoot mass, spikelets sterility, panicle number, and grain mass”
t0“UPLAND RICE”
Claim · model-written summary
Increased soil N retention influenced rice grain mass.
- Taxon
- riceOryza sativae0
- Outcome
- grain masse0
- Qualifier
- increased soil N retentione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased soil N retention, which influenced rice dry shoot mass, spikelets sterility, panicle number, and grain mass”
t0“UPLAND RICE”
Claim · model-written summary
Biochar increased soil pH, potassium content and exchangeable sodium percentage.
- Taxon
- UPLAND RICEOryza sativat0
- Treatment
- Biochare0
- Outcome
- soil pH, potassium content, and exchangeable sodium percentagee0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Biochar also promoted increased soil pH, potassium content, and exchangeable sodium percentage and decreased calcium and magnesium concentrations”
t0“UPLAND RICE”
Claim · model-written summary
Biochar decreased soil calcium and magnesium concentrations.
- Taxon
- UPLAND RICEOryza sativat0
- Treatment
- Biochare0
- Outcome
- calcium and magnesium concentrationse0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Biochar also promoted increased soil pH, potassium content, and exchangeable sodium percentage and decreased calcium and magnesium concentrations”
t0“UPLAND RICE”
The same questions in other papers
biochar · yield · Vigna unguiculata (cowpea)Positive and negative results
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11 papers in the same direction as this paper · 135 in the opposite direction
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See all 147 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.