Study Of The High Yield And High Efficiency Technology Of The Bowl-Seedling Mechanical Transplanting In Japonica Hybrid Rice

Rice is the major grain crops in China.It is very important for food security.In this study,Yongyou2640 was used to study the effects of different level of nitrogen applied as basic and tillering dressing(BT)and different seedling quantity and hole spacing on the absorption and utilization of nitrogen in rice in the condition of the bowl-seedling mechanical transplanting.On this basis,study the effects of different types of slow-release fertilizer and the fertilization methods on yield,nitrogen uptake and utilization in rice.To define the rational allocation and fertilization laws of the bowl-seedling mechanical transplanting.Further,exploring integration technology for mechanical transplanting and fertilizing.The results as follows:To study high-yielding reasonable configuration,Set combination treatment with different number of seedlings with different hole spacing.The results show that:hole spacing had significant influence on yield.decreasing hole spacing could increase the effective panicles,then affected the total spikelets,yield increased.The effective panicles increased with the increase of the number of seedlings,but the spikelets per panicle decreased.So it had no significant difference in yield.Tillering rate,spikelets per panicle and single stem matter weight were improved by reducing the number of seedlings.Reducing hole spacing could increase the effective panicles,but reduced the Tillering rate.It had no significant influence on spikelets per panicle and single stem matter weight.Number of seedlings and hole spacing had significant interactions on yield.Three seedlings per hole get a higher yield under the larger spacing(16.5 cm)condition,but under the condition of medium spacing(14 cm)and a smaller spacing(12 cm)the optimum number of seedlings was 2-2.5 per hole.To investigate the effects of different level of nitrogen applied as basic and tillering dressing(BT)on yield,nitrogen uptake and utilization of japonica hybrid rice under the bowl-seedling mechanical transplanting.We took a highest standard which the total nitrogen 279 kg hm-2,the basic and tillering nitrogen 189 kg hm-2,set the different gradients of basic and tillering nitrogen.The results show that:the decrease of the basic and tillering nitrogen decreased dry matter accumulation at each growth stage of rice.It was not help for increasing the panicles and improving yield by decreasing the basic and tillering fertilizer.With the decrease of BT,nitrogen uptake of rice and the ratio of nitrogen uptake in the heading-mature period decreased,but increased the proportion of nitrogen uptake in the jointing-heading period.The BT productivity of grains and nitrogen productivity of grains had no significant difference with the decrease of BT,such as the BT use efficiency and nitrogen use efficiency.Under the experimental conditions,yield reduced with the decrease of BT.But there were no significant difference in yield,the ratio of nitrogen uptake in the heading-mature period,the BT productivity of grains and its use efficiency,nitrogen productivity of grains and nitrogen use efficiency between BT5 and BT4.Therefore,there is some space on reducing nitrogen fertilizer on rice.Appropriate reduction in the amount of BT has no significant impact on yield and NUE.Field experiments were conducted with hybrid Japonica rice Yongyou2640 in 2013 and 2014.We took conventional fractionated fertilization as a control,slow-releasing blending fertilizer,polymer-coated urea,sulfur-coated urea were applied as basal fertilizer at one time(B-BSRB,B-PCU,B-SCU)and as basal fertilizer with topdressing urea at 7 days after transplanting(BT-BSRB,BT-PCU,BT-SCU)to study the effects of them on dynamic tillers,SPAD,dry matter accumulation,yield and the uptake and utilization of nitrogen in the same nitrogen application.The results show that:Compared with CK,under the single basal application of slow-release fertilizer,tillers increased faster,the leaf had higher SPAD,shoot had more matter accumulation in the early stage,but in the later stage,SPAD slowed down,and shoot had less matter accumulation at the sulfur-coated urea treatment,so its yield and nitrogen use efficiency were lower than CK;SPAD increased obviously after the panicle initiation stage,there were more matter accumulation in the later stage,but tillers increased slower and shoot had less matter accumulation in the early stage,it had less panicles per m2 at the polymer-coated urea treatment,so its yield and nitrogen use efficiency were lower than CK;Tillers increased faster in the early stage,and there were more matter accumulation and higher SPAD in the growth period at the slow-releasing blending fertilizer treatment.As a result,the seed setting rate and grain weight were guaranteed,the panicles per m2 and spikelets per panicle increased at the same time,so its yield and nitrogen use efficiency were higher than CK.(2)Compared with the single basal application of slow-release fertilizer,slow-release fertilizer combined with tillering fertilizer urea increased day matter accumulation and nitrogen absorption,and yield were increased.RE,AE and PFP of BT-BSRB respectively improved 9.8%-24.6%,9.9%-27.6%,3.4%-7.7%than B-BSRB;There were no significant difference between BT-SCU and B-SCU;RE of BT-PCU reduced 25.6%-52.3%,there were no significant difference in AE and PFP between BT-PCU and B-PCU.Under the same N level,yield and nitrogen use efficiency are higher treating with slow-releasing blending fertilizer than CK,and slow-releasing blending fertilizer combined with conventional urea as tillering fertilizer application treatment is better than single basal application of slow-releasing blending fertilizer.