nitrogen · Yield · Ipomoea batatas (sweet potato)

Effects of application of nitrogenous fertilizer and soil type on the top growth and tuber-formation and-thickening in sweetpotato · 1963

• positive
  Nearly doubled fractional nitrogen increased tuber yield on sandy soil regardless of potassium amount.
• negative
  Nearly doubled fractional nitrogen decreased tuber yield on clay soil unless potassium was increased.

Changes in Yields and Fertilizer Responses with Continuous Cropping in Uganda · 1969

• positive
  N, P, and K fertilizers maintained yields as well as farmyard manure.

  compared with farmyard manure treatment

Use of Sweet Potato (Ipomoea batatas) Leaf Tips as Vegetables II. Evaluation of Yield and Nutritive Quality · 1979

• positive
  Application of 120 kg N/ha gave higher tip yields than no nitrogen, mainly through more and larger tips.

  compared with no nitrogen

Influence of N Source, N Rate, and K Rate on the Yield and Mineral Concentration of Sweet Potato · 1984

• positive
  Yield was higher at 101 kg N/ha than at 202 kg N/ha.

  compared with 202 kg N/ha

• no effect
  Nitrogen source did not influence yield.

cited by 1 paper here

On-farm fertilizer management for continuous sweet potato herbage supply · 1990

• positive
  Nitrogen application increased sweet potato herbage yield relative to control.

  compared with the control

• negative
  Return on investment declined at 120 kg N/ha per application to 26%.
• negative
  Return on investment declined at 150 kg N/ha per application to 8%.

The Influence of Nitrogen Rate and Timing on `Beauregard' Sweetpotato Yield and Quality · 1995

• positive
  At least 14 kg N/ha increased yield relative to zero nitrogen.

  compared with control (0 kg N/ha)

• no effect
  Yields did not differ across nitrogen rates from 14 to 56 kg per hectare.

Nutrient Uptake and Productivity as Affected by Nitrogen and Potassium Application Levels in Maize/Sweet Potato Intercropping System · 2001

• positive
  Sweet potato productivity was better with 100kg N and 120 kg O application.

Integrated nutrient management research on sweet potato at Hobu, Morobe Province · 2001

• positive
  The highest yields occurred at 100 kilograms of nitrogen per hectare.

YIELD-IMPROVING EFFECT OF RHIZOSPHERE ASSOCIATE NITROGEN-FIXING BACTERIA ON MAIZE WHEAT AND SWEET POTATO · 2003

• positive
  Bacterial inoculation increased sweet potato yield by 68.3%～77.5%.

The Implication of Nitrogen Adjuvant on Sweet Potato Stem Rot Culture · 2005

• positive
  Nitrogen adjuvant increased sweet potato production in tropical areas, sometimes significantly.

Quality characteristics and yield attributes of sweetpotato (Ipomoea batatas L.) genotypes grown under sustainable cultural conditions · 2007

• positive
  Low N produced higher U.S. number 1 root yield than no N or high N.

  compared with ‘non’ and ‘high’ N treatments

Response of sweetpotato to fertilizer application in Malawi. · 2008

• positive
  At Makoka, 60 kg N /ha increased yield by 6.8 t /ha (34.9%).
• no effect
  Nitrogen did not affect tuber yield at Chitedze and Chitala.

Optimizing Nitrogen Fertilization for Production of White and Orange-Fleshed Sweet Potato in Southeast Nigeria · 2009

• positive
  Storage root yield increased with nitrogen up to 80 kg N ha−1 in 2005 when background soil N was 0.056%.
• no effect
  In 2006 storage root yield did not increase beyond 40 kg N ha−1 when background N was 0.104%.

  compared with 40 kg N ha−1No difference from an alternative treatment

Nutrient deficiencies limiting the growth of sweetpotato vines on important soil types in the highlands of Papua New Guinea · 2010

• positive
  Omitting N, P, S, Mn, Zn, Mo or Ni reduced shoot yield on Aqoll.

  compared with the controlAbout lacking this nutrient, so it counts the other way round

• positive
  Omitting N, P, Ca, S, B or Mn reduced sweetpotato shoot yield on Aquept.

  compared with the controlAbout lacking this nutrient, so it counts the other way round

Effect of Lime, Inorganic, and Organic Sources on Soil Fertility, Yield, Quality, and Nutrient Uptake of Sweet Potato in Alfisols · 2011

• positive
  Integrated use of nitrogen, phosphorus, potassium and farmyard manure gave a significantly higher sweet potato tuber yield (18.7 Mg ha-1).
• positive
  Incorporating lime with half the nitrogen, phosphorus and potassium and farmyard manure raised yield response by 12% over unlimed plots.

  compared with unlimed plots

• positive
  Incorporating green manure with 100% nitrogen, phosphorus and potassium raised sweet potato yield response by 10% over nitrogen, phosphorus and potassium alone.

  compared with nitrogen, phosphorus, and potassium

• positive
  Incorporating lime with half the nitrogen, phosphorus and potassium and neem cake raised yield response by 10% over unlimed plots.

  compared with unlimed plots

• positive
  Incorporating farmyard manure with 100% nitrogen, phosphorus and potassium raised sweet potato yield response by 23% over nitrogen, phosphorus and potassium alone.

  compared with nitrogen, phosphorus, and potassium

• positive
  Incorporating lime with half the nitrogen, phosphorus and potassium and green manure raised yield response by 13% over unlimed plots.

  compared with unlimed plots

• positive
  Incorporating neem cake with 100% nitrogen, phosphorus and potassium raised sweet potato yield response by 2% over nitrogen, phosphorus and potassium alone.

  compared with nitrogen, phosphorus, and potassium

Study on Balanced Fertilization of Sweet potato · 2013

• positive
  N + P + K raised fresh base yield.
• positive
  The N + P + K treatment increased yield by 7.04%.

Topdressing fertilization with nitrogen and potassium levels in sweet-potato Adubação de cobertura na batata-doce com doses combinadas de nitrogênio e potássio · 2013

• positive
  The highest sweet-potato productivity increase was reached with topdressing of 100 kg N ha-1 plus 120 kg K2O ha-1.
• positive
  Sweet-potato productivity responded to topdressing with nitrogen and potassium.
• positive
  The greatest increases in sweet-potato productivity occurred when N and K doses were combined.

Water Use Efficiency and Yield of Sweetpotato as Affected by Nitrogen and Potassium Application · 2015

• positive
  Nitrogen at 100 kg N ha-1 and potassium at 160 kg K ha-1 gave the highest tuber yields under both water regimes.
• negative
  Nitrogen beyond 100 kg N ha-1 reduced tuber yields.

Long-Term Effect of Lime, Mycorrhiza, and Inorganic and Organic Sources on Soil Fertility, Yield, and Proximate Composition of Sweet Potato in Alfisols of Eastern India · 2015

• positive
  Graded NPK increased mean tuber yield by 130 percent over control.

  compared with control

• positive
  Graded NPK increased mean tuber yield by 44 percent over control.

  compared with control

• positive
  Graded NPK increased mean tuber yield by 106 percent over control.

  compared with control

Comparative Effect of Organic and In-Organic Fertilizer Treatment on the Growth and Tuberyeild of Sweet Potato (Ipomea Batata L) · 2016

• positive
  Urea fertilizer gave the highest number of tubers per plant.

Determination of limiting nutrient to Sweetpotato (L.) growth on Samoa Oxisol using a Ipomoea batatas Nutrient Omission Technique · 2017

• positive
  Omitting N, P, K, S, B, Fe, Mn, Mo or Ni reduced storage-root yield relative to ALL, without a significant difference.

  compared with ALLAbout lacking this nutrient, so it counts the other way round

Influence of Two Nitrogen Forms on Hormone Metabolism in Potential Storage Roots and Storage Root Number of Sweetpotato · 2018

• positive
  Ammonium N gave the highest storage root yield at harvest.

cited by 1 paper here

Split application of reduced nitrogen rate improves nitrogen uptake and use efficiency in sweetpotato · 2019

• positive
  Split nitrogen application improved four nitrogen use efficiency measures.

  compared with basal application

• positive
  Split application at the reduced rate significantly raised yield by 16.6–19.0%.
• negative
  Basal 20% nitrogen reduction decreased yield.

cited by 2 papers here

Low Nitrogen Fertilization Alter Rhizosphere Microorganism Community and Improve Sweetpotato Yield in a Nitrogen-Deficient Rocky Soil · 2020

• positive
  Adding 15 kg/ha urea to rocky soil increases sweetpotato yield by half, up to 33.3 t/ha.

cited by 1 paper here

Split Application under Reduced Nitrogen Rate Favors High Yield by Altering Endogenous Hormones and C/N Ratio in Sweet Potato · 2020

• positive
  Split reduced nitrogen raised storage-root yield by 22.1%.

  compared with conventional basal N management

cites 1 paper here

Evaluation of yield and nitrogen utilisation with urease and nitrification inhibitors in sweet potato crop ( Ipomoea batatas L.) · 2020

• positive
  Urea with both inhibitors had the highest yield at 30,923 Kg · ha −1.

  compared with control (without fertilizer)

• positive
  Yield components were highest under urea with double inhibitors in both years.

  compared with control (without fertilizer)

cites 1 paper here

The Application of Nitrogen Source in Regulating Lignin Biosynthesis, Storage Root Development and Yield of Sweet Potato · 2022

• positive
  Ammonium nitrogen produced the highest storage root yield.

cites 1 paper herecited by 1 paper here

Determining the Profitability of Different NPSB and Nitrogen Fertilizer Rates on Yield and Yield Attributes of SweetPotato (Ipomoea batatas L.) in the Midland Areas of Guji Southern Oromia, Ethiopia · 2024

• positive
  The 100 kg ha-1 NPSB plus 46 kg ha-1 nitrogen treatment gave the best marginal rate of returns, reported as 17872%.

Optimizing nitrogen and irrigation application for drip irrigated sweet potato with plastic film mulching in eastern China · 2024

• positive
  At 60 % soil wetting, tuber yield was higher with 180 kg hm −2 nitrogen than with 90 or 270 kg hm −2.

  compared with N-application rates of 90 kg hm −2 and 270 kg hm −2

cites 3 papers here

Response of Sweetpotato [Ipomoea batatas (L.) Lam.] to Five Rates Each of Nitrogen and Phosphorus under Guinea and Sudan Savannah Agroecological Zones of Ghana · 2024

• positive
  Nitrogen rates increased shoot yield by 49–197% in Nyankpala.
• positive
  Nitrogen rates increased storage root yield by 30–48% in Bawku.
• positive
  Nitrogen rates increased storage root yield by 3–17% in Nyankpala.
• positive
  Nitrogen rates of 30–120 kg∙ha−1 increased shoot yield by 31–125% in Bawku.

cites 1 paper here

Response of Sweet Potato (Ipomoea Batatas L.) Variety to Nitrogen and Farmyard Manure Fertilizer Application in Mulo District, Ethiopia · 2025

• positive
  Nitrogen and farmyard manure fertilizer application significantly impacted growth, yield and yield components.