Abstract
Abstract Improving fertilizer use efficiency has remained a challenge, particularly for small-scale farming in undulating ‘abnormal’ landscapes of East Africa. Milne's 1930s concept on ‘Catena’ was considered as a breakthrough in understanding soil variability and its implication on productivity in East African highlands. However, there is limited information on how the ‘Catena’ features could be used for fine tuning fertilizer recommendations. We initiated multiple on-farm replicated experiments in three wheat-growing districts (Endamohoni, Lemo and Worreilu) in the Ethiopian highlands in 2014, 2015 and 2016 to assess landscape positions affecting crop-nutrient responses, identify yield limiting nutrients across the ‘Catena’ (N, P, K, S and Zn) and quantify effects of landscape positions on resources use efficiency. We clustered farmlands across the ‘Catena’ (Hillslopes, Midslopes and Footslopes) based on land scape positions in the respective locations. Wheat yield was more strongly and significantly affected by landscape positions ( P < 0.001) than by nutrient sources or rates. The crop response to fertilizers was 50 to 300% higher in foot slopes than in hillslopes, depending on locations and inputs levels. With increasing slope, there was a decrease in a crop fertilizer response due to a significant decrease in soil organic carbon, clay content and soil water content, with r 2 of 0.95, 0.86 and 0.96, respectively. The difference in the crop response between landscape positions was significantly higher ( P < 0.05) with higher rates of nutrient applications (>N92 P46) while differences between landscape positions diminish at lower rates. Yield benefits due to application of K was significant only in the dry years ( P < 0.05), while there was hardly any yield benefit from the application of zinc and sulfur. The crop nitrogen recovery fraction and crop water productivity decreased with an increasing slope regardless of nutrient combinations. The results indicated that the landscape position could be considered as a proxy indicator for targeted fertilizer application, particularly in farms with undulating topographic features. Hillslopes are better served by the application of organic fertilizers along with conservation measures as applying higher rates of mineral fertilizer in hillslopes would rather increase the risk of downstream nutrient movement.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 15
Claim · model-written summary
Landscape position affected wheat yield more than nutrient sources or rates.
- Taxon
- Wheat
Triticum aestivume0 - Outcome
- yielde0
- Direction
- more stronglye0
- Comparator
- nutrient sources or ratese0
- Setting
- landscape positionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Wheat yield was more strongly and significantly affected by landscape positions ( P < 0.001) than by nutrient sources or rates”
Claim · model-written summary
Fertilizer response was 50 to 300% higher on footslopes than hillslopes.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- crop response to fertilizerse0
- Direction
- highere0
- Value
- 50 to 300%e0
- Comparator
- hillslopese0
- Setting
- foot slopese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“crop response to fertilizers was 50 to 300% higher in foot slopes than in hillslopes”
t0“wheat”
Claim · model-written summary
Crop fertilizer response decreased as slope increased.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- crop fertilizer responsee0
- Direction
- decreasee0
- Setting
- increasing slopee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With increasing slope, there was a decrease in a crop fertilizer response”
t0“wheat”
Claim · model-written summary
Soil organic carbon decreased with increasing slope.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- soil organic carbone0
- Direction
- decreasee0
- Value
- 0.95e0
- Setting
- increasing slopee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With increasing slope, there was a decrease in a crop fertilizer response due to a significant decrease in soil organic carbon, clay content and soil water content, with r 2 of 0.95, 0.86 and 0.96, respectively”
t0“wheat”
Claim · model-written summary
Soil clay content decreased with increasing slope.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- clay contente0
- Direction
- decreasee0
- Value
- 0.86e0
- Setting
- increasing slopee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With increasing slope, there was a decrease in a crop fertilizer response due to a significant decrease in soil organic carbon, clay content and soil water content, with r 2 of 0.95, 0.86 and 0.96, respectively”
t0“wheat”
Claim · model-written summary
Soil water content decreased with increasing slope.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- soil water contente0
- Direction
- decreasee0
- Value
- 0.96e0
- Setting
- increasing slopee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With increasing slope, there was a decrease in a crop fertilizer response due to a significant decrease in soil organic carbon, clay content and soil water content, with r 2 of 0.95, 0.86 and 0.96, respectively”
t0“wheat”
Claim · model-written summary
Higher nutrient application rates increased differences between landscape positions.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- higher rates of nutrient applications (>N92 P46)e0
- Outcome
- difference in the crop response between landscape positionse0
- Direction
- highere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“difference in the crop response between landscape positions was significantly higher ( P < 0.05) with higher rates of nutrient applications (>N92 P46)”
t0“wheat”
Claim · model-written summary
Differences between landscape positions diminished at lower nutrient rates.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- lower ratese0
- Outcome
- differences between landscape positionse0
- Direction
- diminishe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“differences between landscape positions diminish at lower rates”
t0“wheat”
Claim · model-written summary
Potassium application increased yield only in dry years.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- application of Ke0
- Outcome
- Yield benefitse0
- Direction
- benefitse0
- Qualifier
- dry yearse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Yield benefits due to application of K was significant only in the dry years ( P < 0.05)”
t0“wheat”
Claim · model-written summary
Zinc application yielded hardly any benefit.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- application of zince0
- Outcome
- yield benefite0
- Direction
- hardly anye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“there was hardly any yield benefit from the application of zinc and sulfur”
t0“wheat”
Claim · model-written summary
Sulfur application yielded hardly any benefit.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- application of zinc and sulfure0
- Outcome
- yield benefite0
- Direction
- hardly anye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“there was hardly any yield benefit from the application of zinc and sulfur”
t0“wheat”
Claim · model-written summary
Nitrogen recovery fraction decreased with increasing slope.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- crop nitrogen recovery fractione0
- Direction
- decreasede0
- Setting
- increasing slopee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“crop nitrogen recovery fraction and crop water productivity decreased with an increasing slope”
t0“wheat”
Claim · model-written summary
Crop water productivity decreased with increasing slope.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- crop water productivitye0
- Direction
- decreasede0
- Setting
- increasing slopee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“crop nitrogen recovery fraction and crop water productivity decreased with an increasing slope”
t0“wheat”
Claim · model-written summary
Landscape position can guide targeted fertilizer application.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- targeted fertilizer applicatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“landscape position could be considered as a proxy indicator for targeted fertilizer application”
t0“wheat”
Claim · model-written summary
The authors recommend organic fertilizers and conservation measures on hillslopes.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- application of organic fertilizers along with conservation measurese0
- Setting
- Hillslopese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Hillslopes are better served by the application of organic fertilizers along with conservation measures”
t0“wheat”
The same questions in other papers
sulfur atom · yield · Triticum aestivum (wheat)Results differ
23 papers in the same direction as this paper · 124 in the opposite direction
- positive
- positive
- positive
144 papers more in this group
See all 148 papers →zinc atom · yield · Triticum aestivum (wheat)Results differ
54 papers in the same direction as this paper · 456 in the opposite direction
- positive
- positive
- positive
507 papers more in this group
See all 511 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.