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Italian ryegrass (Lolium multiflorum L.) seed crops are often routinely fertilized with a predetermined amount of
nitrogen (N) fertilizer in spring. However, nitrate leaching and increasing N fertilizer prices require rationalized
fertilizer applications without compromises in seed yield. The objectives of this study were (1) to determine the
seed yield response to N fertilization, and (2) to evaluate if NDVI values can reliably predict the N status in
Italian ryegrass seed crops. During eight years, field trials were conducted with two cultivars ‘Melclips’ and
‘Melquatro’, and seven N strategies applied after the forage cut as single or split application: 0, 60, 60 +30, 90,
90 + 30, 120 and 150 kg N ha−1. NDVI values were obtained with a ‘GreenSeeker’ optical sensor. Maximum
seed yield was attained at 141 kg N ha−1 total available N (92 kg N ha−1 fertilized). Higher fertilizations only
increased NNI values but not seed yield. Split-application strategies were equal to single-applications in terms of
seed yield, which indicates that remedial fertilizations at the two-three node stage are effective. NNI values at all
growth stages predicted seed yield adequately: maximum seed yield was attained at NNI values of 0.86 in the
2–3 node stage, 0.72 at the beginning of heading, and 0.59 at full ear emergence. NDVI values were correlated
with NNI values, but were also heavily influenced by trial year. Therefore, is it impossible to establish NDVI
thresholds to decide on remedial N fertilization.
nitrogen (N) fertilizer in spring. However, nitrate leaching and increasing N fertilizer prices require rationalized
fertilizer applications without compromises in seed yield. The objectives of this study were (1) to determine the
seed yield response to N fertilization, and (2) to evaluate if NDVI values can reliably predict the N status in
Italian ryegrass seed crops. During eight years, field trials were conducted with two cultivars ‘Melclips’ and
‘Melquatro’, and seven N strategies applied after the forage cut as single or split application: 0, 60, 60 +30, 90,
90 + 30, 120 and 150 kg N ha−1. NDVI values were obtained with a ‘GreenSeeker’ optical sensor. Maximum
seed yield was attained at 141 kg N ha−1 total available N (92 kg N ha−1 fertilized). Higher fertilizations only
increased NNI values but not seed yield. Split-application strategies were equal to single-applications in terms of
seed yield, which indicates that remedial fertilizations at the two-three node stage are effective. NNI values at all
growth stages predicted seed yield adequately: maximum seed yield was attained at NNI values of 0.86 in the
2–3 node stage, 0.72 at the beginning of heading, and 0.59 at full ear emergence. NDVI values were correlated
with NNI values, but were also heavily influenced by trial year. Therefore, is it impossible to establish NDVI
thresholds to decide on remedial N fertilization.
Oorspronkelijke taal | Engels |
---|---|
Tijdschrift | Field Crops Research |
Volume | 211 |
Pagina's (van-tot) | 37-47 |
Aantal pagina’s | 11 |
ISSN | 0378-4290 |
Publicatiestatus | Gepubliceerd - 2017 |
Trefwoorden
- B390-plantenteelt
Vingerafdruk
Bekijk de onderzoeksthema's van 'Seed yield response to N fertilization and potential of proximal sensing in Italian ryegrass seed crops'. Samen vormen ze een unieke vingerafdruk.Projecten
- 1 Afgerond
-
WEB_ZAADTEELT: Zaadteeltonderzoek
Rijckaert, G. (Voormalig Onderzoeker) & Van Waes, J. (Voormalig Projectverantwoordelijke)
1/02/09 → 31/12/17
Project: Onderzoek