Quantitative evaluation of macro-nutrient uptake by Cassava in a tropical savanna climate

Authors: JANKET, A - Khon Kaen University; VORASOOT, N - Khon Kaen University; TOOMSAN, B - Khon Kaen University; KAEWPRADIT, W - Khon Kaen University; THEERAKULPISUT, P - Khon Kaen University; Holbrook, Carl - Corley; KVIEN, C - University Of Georgia; JOGLOY, S - Khon Kaen University; BANTERNG, P - Khon Kaen University

Submitted to: Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/25/2021
Publication Date: 11/28/2021
Citation: Janket, A., Vorasoot, N., Toomsan, B., Kaewpradit, W., Theerakulpisut, P., Holbrook Jr, C.C., Kvien, C.K., Jogloy, S., Banterng, P. 2021. Quantitative evaluation of macro-nutrient uptake by Cassava in a tropical savanna climate. Agriculture. 11(12):1199. https://doi.org/10.3390/agriculture11121199.
DOI: https://doi.org/10.3390/agriculture11121199

Interpretive Summary: Matching fertilization with crop needs is important for maximizing yields and reducing fertilizer losses. Seasonal variation in nutrient uptake dynamics is poorly understood and thus, the ability to optimize fertilization strategies is limited. This study aimed to investigate the effects of seasonal variation on macronutrient uptake dynamics in cassava genotypes with full irrigation. The performance of cassava genotypes, i.e. CMR38-125-77, Kasetsart50 and Rayong11, were evaluated in the early rainy (ERS) and post rainy seasons (PRS) for two years using a randomized complete block design with four replicates. Growing seasons had significant effects on nutrient uptakes and their partitioning. In the ERS, the majority of total nutrient uptake occurred at early growth stages, whereas, in the PRS this occurred at mid to late growth stages. CMR38-125-77 had satisfactory performances in nutrient uptakes and nutrient harvest index across growing seasons. This information can be used to further refine fertilizer recommendations in different growing seasons according to crop demand.

Technical Abstract: Matching fertilization with crop needs is important for maximizing yields and reducing fertilizer losses. Seasonal variation in nutrient uptake dynamics is poorly understood and thus, the ability to optimize fertilization strategies is limited. This study aimed to investigate the effects of seasonal variation on macronutrient uptake dynamics in cassava genotypes with full irrigation. The performance of cassava genotypes, i.e. CMR38-125-77, Kasetsart50 and Rayong11, were evaluated in the early rainy (ERS) and post rainy seasons (PRS) for two years using a randomized complete block design with four replicates. Plants were sequentially harvested at 1, 3, 6, 9 and 12 months. Growing seasons had significant effects on nutrient uptakes and their partitioning. On average, total nutrients required per plant to produce 2,831-3,279 g of biomass with 1,244-1,810 g of storage roots in the ERS varied among cassava genotypes ranging from 21-1-24.3 g N, 5.1-5.9 g P2O5, 26.5-29.5 g K2O, 14.1-22.2 g Ca, 6.1-7.6 g Mg and 2.0-2.3 g S. Whereas, total nutrients required per plant to produce 3,353-3,824 g of biomass with 1,604-2,253 g of storage roots in the PRS ranged from 27.1-32.4 g N, 5.2-6.0 g P2O5, 29.1-31.3 g K2O, 11.9-20.3 g Ca, 7.3-9.9 g Mg and 1.2-1.5 g S. In the ERS, the majority of total nutrient uptake occurred at early growth stages, whereas, in the PRS this occurred at mid to late growth stages. At final harvest in the ERS, N (24.7-36.0%), P (26.0-32.3%), K (43.4-51.5%), Ca (12.4-17.6%), Mg (22.2-31.5%) and S (27.2-31.5%) were removed by storage roots, whereas, in the PRS N (30.4-44.4%), P (33.3-41.6%), K (44.7-57.3%), Ca (12.0-15.1%), Mg (20.2-28.1%) and S (12.0-25.4%) were removed. CMR38-125-77 had satisfactory performances in nutrient uptakes and nutrient harvest index across growing seasons. This information can be used to further refine fertilizer recommendations in different growing seasons according to crop demand.