Establishment Method Affects Oilseed Rape Yield and the Response to Nitrogen Fertilizer

Abstract

Individual plant morphology and crop structure are contrasting between direct sown oilseed rape (Brassica napus L.) (DOR) and transplanted oilseed rape (TOR) in China due to altered plant density and growth duration. is study was conducted to compare the yield performance and response to N fertilizer between DOR and TOR. e e ects of establishment method (direct sowing or transplanting) and N rate (0 or 180 kg N ha -1 ) on yield, dry matter, and N uptake were determined through nine on-farm experiments in China. e DOR produced lower and more inconsistent yields compared with TOR under identical N rates. e yield reduction was 78.7% for DOR and 66.7% for TOR when N fertilizer was omitted, demonstrating that DOR was more sensitive to N de ciency. Furthermore, TOR outperformed DOR in terms of individual growth, dry matter yield, N uptake, harvest index, and N e ciency. Compared with the steady development of TOR, DOR exhibited uctuating dry matter accumulation and N uptake during plant growth, mainly due to the di erences in population dynamics and initial N concentration. e TOR plant density was consistent throughout the growing season, whereas DOR showed 73.3 and 38.5% plant loss in no-N and N-fertilized plots, respectively. Nitrogen application increased DOR plants survival based on improved individual growth. Hence, DOR exhibited a relatively greater response to N fertilizer. In conclusion, crop performance, yield level, and responses to N fertilizer were signi cantly di erent between DOR and TOR, suggesting that the N fertilizer management strategy should be adjusted depending on the establishment method.Key Lab. of Arable Land Conservation (Middle and Lower Reaches of Yangtze River) Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural Univ.,

Nitrogen Fertilizer Management for Enhancing Crop Productivity and Nitrogen Use Efficiency in a Rice-Oilseed Rape Rotation System in China

“…N fertilizer in the form of urea (N 46.4%) was applied to rice in three splits: 50% as a base fertilizer, 25% at tillering stage, and 25% at panicle initiation stage. For oilseed rape seasons, 60% was applied as a base fertilizer, 20% in the over-wintering stage, and 20% at the initiation of stem elongation (Wang et al, 2014 ). All P fertilizer was applied as a base in each cropping season of both crops.…”

“…K fertilizer was applied as follows: 70% before the sowing of rice and oilseed rape, 30% at panicle initiation, and 30% at the top dressing stage for rice and oilseed rape seasons, respectively. Borax was added at a rate of 15 kg B ha −1 as a basal application for the oilseed rape season only, to meet the nutrient requirements for normal growth (Wang et al, 2014 ). Replicate plot sizes measured 20 m 2 (3 m × 6.7 m) for both crops.…”

“…To investigate the overall effects of fertilizer application, plants were sampled at maturity of both crops to determine plant dry matter (kg ha −1 ) and nutrient uptake (kg ha −1 ; Wang et al, 2014 ). Plant samples were washed with deionized water and divided into seeds, stems, pod walls for oilseed rape and grains, and straw for rice.…”

Alteration in yield and oil quality traits of winter rapeseed by lodging at different planting density and nitrogen rates

“…Rapeseed production strongly depends on the application of chemical fertilizers, especially N, which plays an important role in increasing yield 16 , 17 . However, the response of rapeseed to N fertilization depends on many environmental factors.…”

Genotypic variation in photosynthetic limitation responses to K deficiency of Brassica napus is associated with potassium utilisation efficiency

“…To ensure that nutrients other than K can satisfy the need for plant growth, 180 kg N ha -1 , 90 kg P2O5 ha -1 , and 1.6 kg B ha -1 were applied for all treatments (Wang et al 2014). The N, P, K, and B fertilizers used in the experiment consisted of urea (46% N), superphosphate (12% P2O5), potassium chloride (60% K2O), and borax (10.8% B), respectively.…”