| The whole procedure of rape cultivation in our country is basically artificial,10-12 people are needed per mu. Besides, rural labour shortage caused by labour diversion, serious wasteland in winter and the decrease of rape cultivation area have made fallow fields in area of yangtze river reach a hundred million mu. Therefore, popularizing light and simplified culture model and simplifing working process could encourage farmers planting rape significantly, and the problem of fallow fields in winter can be solved effectively. At present, rape no-tillage cultivation on paddy rice field has been applicated widely in area of yangtze river, but relative cultivation technology according to the model is still rare. In this paper, Huashuang No.5 was mainly used to study different nitrogen table, different ratio of base and topdressing and different model of topdressing effect on the growth and development process of the rapeseed,seed quality and yield, so as to suggest some basis to demonstration and popularizing of this technology. The main results are as follows:Height of rape plant increased as nitrogen level increasing and effects of different ratio of base and topdressing were different. Height of rape plant were higher when more base fertilizer used, and under the condition of the same nitrogen and ratio of base and topdressing height of plowing direct seeding rape was higher than that of no-tillage direct seeding; changes of green leaves numbers and rhizoma thick were similar to height of plant; the ratio of root and crown decreased as the nitrogen level increasing and the less base fertilizer used the larger ratio of root and crown was, ratio of root and crown of plowing direct seeding rape was smaller than no-tillage direct seeding one.Plant dry weight accumulation increased quickly during seedling and bolting, and seldom added after maturing. The lower nitrogen level was, the smaller dry weight accumulation per plant was; fertilized in the same conditions, the basal fertilizer ratio 5:5 was beneficial to dry matter accumulation; plowing model was more beneficial than no-tillage model to dry matter accumulation. Before bolting, the whole dry weight of rape was consisted of dry weight of leaves and root, the ratio of root dry weight decreased as nitrogen level and basal fertilizer increased, while the ratio of leaves dry weight reversed. In wintering period the ratio of root dry weight increased, the more basal fertilizer used, the more distribution of on-earth part dry weight was, the root reversed; total dry weight increased rapidly during flowering period, on-earth part dry weight distribution was more than root, over 80%; the ratio of root dry weight further reduced during maturing period. Changes of plowing dry weight distribution was similar to that of no-tillage.Changes of Chlorophyll content(SPAD value) of functional leaves in different nitrogen level and ratio of base and topdressing were basically constant. In the same bearing period and ratio of base and topdressing condition, SPAD value increased as nitrogen level increased; SPAD value was affected by different ratio of base and topdressing, it increased gradually from seedling emergence to midwinter, in addition, the more fertilizer used, the larger SPAD value was. In no-tillage model,7:3 processing SPAD value was the largest in midwinter, while 3:7 processing was the smallest, regulation of different nitrogen level was similar; plowing ones changed similarly to no-tillage ones.In no-tillage condition, nitrogen in rape plant increased as nitrogen fertilizer increased, and nitrogen content in on-earth part was higher than that in root; in the same nitrogen supply, nitrogen content of 5:5 and 6:4 processings were higher than those of 7:3 and 3:7 processings. During maturing period, nitrogen content of pod husk and seed were higher when more topdressing was used, and processings of no-tillage nitrogen content were lower than plowing ones obviously. Changes of on-earth part nitrogen content in plowing condition was similar to that in no-tillage condition.In no-tillage condition, height of plant and rhizoma thick during maturing period increased as nitrogen level and ratio of basal fertilizer increased, so was lengh of main inflorescence; number of effective pods and seeds per pod increased as nitrogen level increased; seeds per pod increased as ratio of topdressing increased, thousand seed weight among different ratio of base and topdressing did not change obviously. Rape yield characters index of plowing were better than no-tillage ones, but the change regulation was similar. Yield of no-tillage rape increased as nitrogen level increased, the ratio of base and topdressing 5:5 processing had the largest yield when in the same nitrogen level; while 6:4 processing reached the largest yield in plowing condition; in the same nitrogen level and ratio of base and topdressing, yield of plwing was larger than that of no-tillage rape.Different topdressing model had significant impact on economic characters and composing factors of yield of no-tillage rape. Among the processings experimented, T2(bud fertilizer) and T4(December fertilizer and bud fertilizer) processings had larger height of plant, rhizoma thick and primary branches; T5(bud fertilizer and flowering fertilizer) and T7(December fertilizer and bud fertilizer and flowering fertilizer) processing had larger biological yield but the lowest economic coefficient; height of plant, rhizoma thick and primary branches of using December fertilizer once T1 processing and flowering fertilizer once T3 processing, and their biological yield were also lower than others, while economic coefficient were higher than T2(bud fertilizer), T4(December fertilizer and bud fertilizer), T5(bud fertilizer and flowering fertilizer) and T7(December fertilizer and bud fertilizer and flowering fertilizer) processings slightly. When other conditions were the same, in three processings of the model applying topdressing only once, the highest number of pods per plant, seeds number per pod and thousand seed weight were T2(bud fertilizer), T1(December fertilizer) and T3 (flowering fertilizer), respectively, and yield per plant and actual yield of T2 (bud fertilizer)were larger than T1(December fertilizer) and T3(flowering fertilizer) significantly. In three processings of the model applying topdressing twice, the highest number of pods per plant, seeds number per pod and thousand seed weight were T5(bud fertilizer and flowering fertilizer), T4(December fertilizer and bud fertilizer) and T6(December fertilizer and flowering fertilizer), respectively; in terms of ultima yield per plant and actual yield, T4(December fertilizer and bud fertilizer) and T5(bud fertilizer and flowering fertilizer) were not different significantly in transplanting condition, but larger than T6(December fertilizer and flowering fertilizer) significantly; while in direct seeding condition T5 (bud fertilizer and flowering fertilizer)was larger than T4(December fertilizer and bud fertilizer) and T6(December fertilizer and flowering fertilizer) significantly. Compared with other model, in transplanting condition, yield per plant and actual yield of T7(December fertilizer and bud fertilizer and flowering fertilizer) applying topdressing three times were lower than T4(December fertilizer and bud fertilizer) and T5(bud fertilizer and flowering fertilizer), but in direct seeding condition, it was higher than any other processings.Different nitrogen applications had evident impact on the growth and yield formation of no-tillage rape. In the same nitrogen level, yield composing factors, ultima yield per plant and actual yield of no-tillage rape were all higher than those of plowing rape, and nitrogen levels affected in yield composing factors of no-tillage transplanting and direct seeding rape, and ultimately reflected in yield per plant and actual yield, differences among some processings reached significant level. In no-tillage transplanting model, thousand seed weight increased as the nitrogen level increased, but differences between 15kg/667 m2 and 18kg/667 m2 processings were not significant; pods per plant, seeds per pod, yield per plant and actual yield changed showing a peak curve as nitrogen level increased. In no-tillage direct seeding model, regulations of impacts on yield composing factors, yield per plant and population in different nitrogen levels were similar to transplanting model, but the wave crest where pods per plant, seeds per pod, yield per plant and actual yield emerged were different. In this experiment,12kg/667 m2 nitrogen level could make the yield per plant and actual yield of no-tilage transplanting rape reach the top, while no-tillage direct seeding rape had to applying nitrogen 15kg/667 m2.
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