| Full text | |
| Author(s): |
Fernandes, Fabiana M.
[1]
;
Soratto, Rogerio P.
[2, 1]
;
Fernandes, Adalton M.
[2]
;
Souza, Emerson F. C.
[3]
Total Authors: 4
|
| Affiliation: | [1] Sao Paulo State Univ UNESP, Coll Agr Sci, Dept Crop Sci, Ave Univ, 3780, BR-18610034 Botucatu, SP - Brazil
[2] Sao Paulo State Univ UNESP, Ctr Trop Roots & Starches, Botucatu, SP - Brazil
[3] Univ Minnesota, Dept Soil Water & Climate, St Paul, MN 55108 - USA
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | AGRONOMY JOURNAL; v. 113, n. 2 MAR 2021. |
| Web of Science Citations: | 0 |
| Abstract | |
Potato (Solanum tuberosum L.) is a N intensive crop, and meeting its requirements with N fertilization is the primary practice to improve N recovery and achieve suitable tuber yield. A 3-site-year (SY) study was conducted to assess soil plant analysis development (SPAD)-502 chlorophyll meter efficacy for providing potato leaf real-time N status to adjust N timing and rate using nitrogen sufficiency index (NSI) thresholds of 90 or 95%. We evaluated effects of in-season SPAD-based N managements, as well as a reference with non-limiting N application, a fixed-timing (planting and hilling) conventional N fertilization, and a zero-N control on crop N uptake, tuber yield, and N-use efficiency of potato cultivar Agata grown in tropical clay soils. Tuber yields were similar in both SPAD-based managements. Under no intensive rainfall events after N applications, SPAD-based managements reduced N applications by 38-63% and resulted in comparable tuber set, bulking, and yield relative to conventional N fertilization. Additionally, SPAD-based management at a NSI threshold of 90% resulted in greater potato N-uptake efficiency and tuber yield per unit of N applied. SPAD-502 sensor was efficient for detecting plant N status when environmental conditions were more conducive for potato production and optimized N management by reducing application rates. However, with less favorable temperature and solar radiation for potato cultivation, and with intensive rainfall events following N application, SPAD readings did not guide to a proper N fertilization and resulted in reduced tuber yield. Therefore, under such conditions, a more accurate method for detecting plant N status should be used. (AU) | |
| FAPESP's process: | 16/15396-5 - Techniques for in-season assessment of nitrogen status and nitrogen need of potato crop |
| Grantee: | Rogério Peres Soratto |
| Support Opportunities: | Scholarships abroad - Research |