Abstract
Nutrient management of cassava has received little attention compared with cereal crops. We evaluated cassava yield potential and nutrient use efficiency when supplied with nitrogen, phosphorus and potassium at high rates and when supplied with increasing rates of K. On-farm experiments were conducted at six locations in Nigeria across the major cassava growing agro-ecologies of Western Africa (Tropical Rainforest – Cross River, Forest Transition Savanna – Edo, and Guinea Savanna – Benue) during two seasons (2016–2017 and 2017–2018). Nitrogen, P and K fertilizers were applied at various rates, including treatments with and without added secondary and micronutrients. Storage root dry matter (DM) yields ranged between 11 and 35 t DM ha−1. The largest yields were obtained with a mean agronomic efficiency of 60, 162 and 51 kg DM of storage roots per kg of N, P and K applied, with average uptakes of 364, 44 and 242 kg N, P and K ha−1 respectively. Storage root yield responses to applied N, P and K fertilizers (2–18, 3–16 and 3–22 t DM ha−1, respectively) varied across the locations, reflecting variability in potential yields and applied NPK ratios. Addition of a mixture of secondary and micronutrients did not affect cassava yields. We found that the caloric energy yield of cassava per kg of N applied is 2.7 times larger than the value reported for maize. Increasing the supply of K gave a high agronomic efficiency of N even when supplied at high rates, supporting the theory of “increasing returns to scale” of De Wit. We conclude that cassava has a major role in future food security of sub-Saharan Africa, with potentially larger DM yields, a better recovery of applied nutrients and larger energy yield per kg of applied N fertilizer when compared with grains.
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Claims 14
Claim · model-written summary
Cassava storage-root dry matter yield ranged from 11 to 35 t DM per hectare.
- Taxon
- cassava
Manihot esculentat0 - Outcome
- Storage root dry matter (DM) yieldse0
- Value
- 11 and 35 t DM ha−1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Storage root dry matter (DM) yields ranged between 11 and 35 t DM ha−1.”
t0“cassava”
Claim · model-written summary
Agronomic N efficiency at largest yields averaged 60 kg storage-root dry matter per kg N applied.
- Taxon
- cassavaManihot esculentat0
- Outcome
- agronomic efficiencye0
- Value
- 60e0
- Qualifier
- kg DM of storage roots per kg of N, P and K appliede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a mean agronomic efficiency of 60, 162 and 51 kg DM of storage roots per kg of N, P and K applied”
t0“cassava”
Claim · model-written summary
Agronomic P efficiency at largest yields averaged 162 kg storage-root dry matter per kg P applied.
- Taxon
- cassavaManihot esculentat0
- Outcome
- agronomic efficiencye0
- Value
- 162e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a mean agronomic efficiency of 60, 162 and 51 kg DM of storage roots per kg of N, P and K applied”
t0“cassava”
Claim · model-written summary
Agronomic K efficiency at largest yields averaged 51 kg storage-root dry matter per kg K applied.
- Taxon
- cassavaManihot esculentat0
- Outcome
- agronomic efficiencye0
- Value
- 51e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a mean agronomic efficiency of 60, 162 and 51 kg DM of storage roots per kg of N, P and K applied”
t0“cassava”
Claim · model-written summary
Average N uptake was 364 kg per hectare.
- Taxon
- cassavaManihot esculentat0
- Outcome
- uptakese0
- Value
- 364e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“average uptakes of 364, 44 and 242 kg N, P and K ha−1 respectively”
t0“cassava”
Claim · model-written summary
Average P uptake was 44 kg per hectare.
- Taxon
- cassavaManihot esculentat0
- Outcome
- uptakese0
- Value
- 44e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“average uptakes of 364, 44 and 242 kg N, P and K ha−1 respectively”
t0“cassava”
Claim · model-written summary
Average K uptake was 242 kg per hectare.
- Taxon
- cassavaManihot esculentat0
- Outcome
- uptakese0
- Value
- 242e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“average uptakes of 364, 44 and 242 kg N, P and K ha−1 respectively”
t0“cassava”
Claim · model-written summary
Applied N produced storage-root yield responses of 2–18 t DM per hectare, varying by location.
- Taxon
- cassavaManihot esculentat0
- Treatment
- applied Ne0
- Outcome
- Storage root yield responsese0
- Direction
- responsese0
- Value
- 2–18e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Storage root yield responses to applied N, P and K fertilizers (2–18, 3–16 and 3–22 t DM ha−1, respectively) varied across the locations”
t0“cassava”
Claim · model-written summary
Applied P produced storage-root yield responses of 3–16 t DM per hectare, varying by location.
- Taxon
- cassavaManihot esculentat0
- Treatment
- Pe0
- Outcome
- Storage root yield responsese0
- Direction
- responsese0
- Value
- 3–16e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Storage root yield responses to applied N, P and K fertilizers (2–18, 3–16 and 3–22 t DM ha−1, respectively) varied across the locations”
t0“cassava”
Claim · model-written summary
Applied K produced storage-root yield responses of 3–22 t DM per hectare, varying by location.
- Taxon
- cassavaManihot esculentat0
- Treatment
- K fertilizerse0
- Outcome
- Storage root yield responsese0
- Direction
- responsese0
- Value
- 3–22e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Storage root yield responses to applied N, P and K fertilizers (2–18, 3–16 and 3–22 t DM ha−1, respectively) varied across the locations”
t0“cassava”
Claim · model-written summary
Adding secondary and micronutrients did not affect cassava yields.
- Taxon
- cassavaManihot esculentae0
- Treatment
- mixture of secondary and micronutrientse0
- Outcome
- cassava yieldse0
- Direction
- did not affecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Addition of a mixture of secondary and micronutrients did not affect cassava yields.”
Claim · model-written summary
Cassava caloric energy yield per kg N applied was 2.7 times the reported maize value.
- Taxon
- cassavaManihot esculentae0
- Outcome
- caloric energy yield of cassava per kg of N appliede0
- Direction
- largere0
- Value
- 2.7 timese0
- Comparator
- maizee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“caloric energy yield of cassava per kg of N applied is 2.7 times larger than the value reported for maize”
Claim · model-written summary
Increasing K supply maintained high N agronomic efficiency even at high N rates.
- Taxon
- cassavaManihot esculentat0
- Treatment
- Increasing the supply of Ke0
- Outcome
- agronomic efficiency of Ne0
- Direction
- highe0
- Qualifier
- even when supplied at high ratese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increasing the supply of K gave a high agronomic efficiency of N even when supplied at high rates”
t0“cassava”
Claim · model-written summary
The authors concluded cassava could contribute substantially to future food security in sub-Saharan Africa.
- Taxon
- cassavaManihot esculentae0
- Outcome
- major role in future food security of sub-Saharan Africae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cassava has a major role in future food security of sub-Saharan Africa”
The same questions in other papers
micronutrient · yield · Manihot esculenta (cassava)Positive and negative results
2 papers in the same direction as this paper · 2 in the opposite direction
- positive
- positive
- no effect
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See all 5 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.