Abstract
SUMMARY Annual applications of calcium, potassium and nitrogen (as urea) over three years caused significant differences in soil exchangeable cation ratios and in the yields of subsequent groundnut and maize crops. High rates of potassium and nitrogen, combined with low rates of calcium, lowered groundnut yields, and high rates of potassium, enhanced by ploughing in crop-residue ash, seriously reduced the exchangeable Mg: K cation ratio and maize magnesium status. Maize yields were significantly negatively correlated with soil potassium status. The balance between exchangeable cations in these soils is very easily upset by injudicious combinations of fertilizers and management practices.
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Claims 8
Claim · model-written summary
Annual applications of calcium, potassium and nitrogen over three years caused significant differences in soil exchangeable cation ratios.
- Treatment
- Annual applications of calcium, potassium and nitrogen (as urea) over three yearse0
- Outcome
- soil exchangeable cation ratiose0
Not reportedTaxonComparatorDirection
Verbatim
e0“Annual applications of calcium, potassium and nitrogen (as urea) over three years caused significant differences in soil exchangeable cation ratios and in the yields of subsequent groundnut and maize crops”
Claim · model-written summary
The fertilizer applications caused significant differences in the yields of subsequent groundnut crops.
- Taxon
- groundnut
Arachis hypogaeae0 - Treatment
- Annual applications of calcium, potassium and nitrogen (as urea) over three yearse0
- Outcome
- yieldse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Annual applications of calcium, potassium and nitrogen (as urea) over three years caused significant differences in soil exchangeable cation ratios and in the yields of subsequent groundnut and maize crops”
Claim · model-written summary
The fertilizer applications caused significant differences in the yields of subsequent maize crops.
- Treatment
- Annual applications of calcium, potassium and nitrogen (as urea) over three yearse0
- Outcome
- yieldse0
Zea maysNot reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Annual applications of calcium, potassium and nitrogen (as urea) over three years caused significant differences in soil exchangeable cation ratios and in the yields of subsequent groundnut and maize crops”
Claim · model-written summary
High rates of potassium and nitrogen combined with low rates of calcium lowered groundnut yields.
- Taxon
- groundnutArachis hypogaeae0
- Treatment
- High rates of potassium and nitrogen, combined with low rates of calciume0
- Outcome
- groundnut yieldse0
- Direction
- lowerede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“High rates of potassium and nitrogen, combined with low rates of calcium, lowered groundnut yields”
Claim · model-written summary
High rates of potassium, enhanced by ploughing in crop-residue ash, seriously reduced the soil exchangeable Mg:K cation ratio.
- Treatment
- high rates of potassium, enhanced by ploughing in crop-residue ashe0
- Outcome
- exchangeable Mg: K cation ratioe0
- Direction
- seriously reducede0
Not reportedTaxonComparator
Verbatim
e0“high rates of potassium, enhanced by ploughing in crop-residue ash, seriously reduced the exchangeable Mg: K cation ratio and maize magnesium status”
Claim · model-written summary
High rates of potassium, enhanced by ploughing in crop-residue ash, seriously reduced maize magnesium status.
- Treatment
- high rates of potassium, enhanced by ploughing in crop-residue ashe0
- Outcome
- magnesium statuse0
- Direction
- seriously reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high rates of potassium, enhanced by ploughing in crop-residue ash, seriously reduced the exchangeable Mg: K cation ratio and maize magnesium status”
Claim · model-written summary
Maize yields were significantly negatively correlated with soil potassium status.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Maize yields were significantly negatively correlated with soil potassium status”
Claim · model-written summary
The authors conclude that the balance between exchangeable cations in these soils is very easily upset by injudicious combinations of fertilizers and management practices.
- Outcome
- balance between exchangeable cationse0
Not reportedTaxon
Verbatim
e0“The balance between exchangeable cations in these soils is very easily upset by injudicious combinations of fertilizers and management practices”
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See all 127 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.