ABSTRACT
Two field experiments were used
to study the responses of sweet potato to application of nitrogen and potassium
fertilizer in a humid tropical ultisol in the 1998 and 1999 cropping seasons.
In each year, the experiment was laid out as a 4 x 4 factorial arranged in
randomized complete block design. Treatment comprised four nitrogen levels of
0, 40, 80 and 120 kg N/ha and four potassium levels of 0, 50, 100 and 150 kg
/ha. There were three replications. Nitrogen fertilizer significantly increased
the sweet potato plant size parameters such as dry weights of leaf, stem and
tuber fractions, and total dry matter, number of branches and fresh yield of
tops. Marketable and total tuber yields were significantly increased with all
cases of applied nitrogen compared with where nitrogen was not applied. On the
average, tuber yield was increased with incremental application of nitrogen up
to 80 kg N/ha in 1998 but not beyond the rate of 40 kg N/ha in 1999. On the
average use of 40-80 kg N/ha proved satisfactory. Potassium fertilizer did not
enhance leaf and stem dry matter and number of branches per plant but significantly
increased marketable and total tuber yields. Marketable and total tuber yields
were significantly increased with application of potassium compared with where
potassium was not applied. On the average, potassium applied at the rate of
50-100 kg K/ha was considered satisfactory. For moderate fertilizer use, 40 kg
N/ha and 50 kg K/ha gave reasonable high tuber yields, and would be recommended
for resource poor farmers. For x optimum yields nitrogen at 80 kg N/ha combined
with potassium at 50 to100 kg K/ha would be recommended. Higher rates of
nitrogen did not result in further yield improvements. High input of
fertilizer, especially potassium, significantly increased the proportion of
marketable tubers in the overall tuber yield.
MICHAEL, U (2023). Effect Of Inorganic Nitrogen And Potassium On Yield Of Sweet Potato Upomoea Batatas (L.) LAM) In A Tropical Ultisol.. Repository.mouau.edu.ng: Retrieved Sep 08, 2024, from https://repository.mouau.edu.ng/work/view/effect-of-inorganic-nitrogen-and-potassium-on-yield-of-sweet-potato-upomoea-batatas-l-lam-in-a-tropical-ultisol-7-2
UNIVERSITY, MICHAEL. "Effect Of Inorganic Nitrogen And Potassium On Yield Of Sweet Potato Upomoea Batatas (L.) LAM) In A Tropical Ultisol." Repository.mouau.edu.ng. Repository.mouau.edu.ng, 06 Jul. 2023, https://repository.mouau.edu.ng/work/view/effect-of-inorganic-nitrogen-and-potassium-on-yield-of-sweet-potato-upomoea-batatas-l-lam-in-a-tropical-ultisol-7-2. Accessed 08 Sep. 2024.
UNIVERSITY, MICHAEL. "Effect Of Inorganic Nitrogen And Potassium On Yield Of Sweet Potato Upomoea Batatas (L.) LAM) In A Tropical Ultisol.". Repository.mouau.edu.ng, Repository.mouau.edu.ng, 06 Jul. 2023. Web. 08 Sep. 2024. < https://repository.mouau.edu.ng/work/view/effect-of-inorganic-nitrogen-and-potassium-on-yield-of-sweet-potato-upomoea-batatas-l-lam-in-a-tropical-ultisol-7-2 >.
UNIVERSITY, MICHAEL. "Effect Of Inorganic Nitrogen And Potassium On Yield Of Sweet Potato Upomoea Batatas (L.) LAM) In A Tropical Ultisol." Repository.mouau.edu.ng (2023). Accessed 08 Sep. 2024. https://repository.mouau.edu.ng/work/view/effect-of-inorganic-nitrogen-and-potassium-on-yield-of-sweet-potato-upomoea-batatas-l-lam-in-a-tropical-ultisol-7-2