耕作与播种方式、密度和施氮量对稻茬小麦幼苗质量的影响

Effect of Tillage and Seeding Method,Planting Density,and Nitrogen Rate on Seedling Quality of Wheat Following Rice

为了解耕作与播种方式、密度和施氮量对稻茬小麦幼苗质量的影响,在水稻秸秆全量还田条件下,比较分析了不同耕作与播种方式[旋耕两次+2BG-6A型均匀摆播机(TS1)、旋耕两次+2BFG-10(8)230型播种机(TS2)、板茬+2BMF-稻茬免耕条播机(TS3)]、密度(225×10^(4)和300×10^(4)株·hm^(-2))和施氮量(0、112.5、135和157.5 kg·hm^(-2))处理间小麦播种质量和幼苗质量的差异。结果表明,TS1和TS2的出苗率和出苗均匀度高于TS3,但TS3苗高、主茎第1~第3叶面积、单株干重和群体干物质积累量均较高,说明TS1和TS2有助于保证苗数,但幼苗质量欠佳,而TS3下幼苗质量较好,但苗数不足。密度对幼苗个体质量无显著影响,但显著提高群体质量。增加施氮量可显著提高苗高、单株叶面积、单株干重、单株次生根数、群体干物质积累量和叶面积指数,但过量施用氮肥无助于幼苗质量提升,以施氮量135 kg·hm^(-2)为宜。耕播方式、密度和施氮量对苗高、单株干重、单株叶面积、单株次生根数、群体干物质积累量和叶面积指数存在互作效应。由此可见,通过播种密度和施氮量的配套调控,可更好地发挥机械化耕播在小麦生产中的作用,有利于足苗、壮苗实现。

The responses of wheat seeding quality and seedling quality to the tillage and seeding methods[rotary tillage twice+2BG-6A type uniform pendulum seeder(TS1),rotary tillage twice+2BFG-10(8)230 type seeder(TS2),zero tillage+2BMF type no-tillage seeder(TS3)],the planting density(225×10^(4)and 300×10^(4)plants·hm^(-2)),and nitrogen rate(0,112.5,135 and 157.5 kg·hm^(-2))were investigated under the condition of rice straws incorporated into the field.The study aimed to provide references for the mechanized cultivation of wheat following rice.The results showed that:TS1 and TS2 exhibited a higher emergence rate and evenness of seedling in comparison to TS3;but the seedlings growed higher under TS3,which also increased the leaf area of the 1st to 3rd leaves in the main stem with improving dry weight per plant and population dry matter accumulation.These indicate that compared with other tillage and seeding methods,TS1 and TS2 facilitate achieving enough seedlings but with a lower seeding quality;in contrast,seedling quality under TS3 is better but with an insufficient seedling number.There was no significant effects of the planting density on seedling quality,but population quality was significantly changed.The nitrogen application significantly promoted seedling height,leaf area per plant,dry weight per plant,secondary root number per plant,population dry matter accumulation,and leaf area index with the increased nitrogen rate,while excessive application of nitrogen fertilizers did not further improve the seedling quality.It is proposed that the appropriate nitrogen rate is 135 kg·hm^(-2).There were significant interactions between/among tillage and seeding method,planting density,and nitrogen rate to seedling height,dry weight per plant,leaf area per plant,number of secondary roots per plant,population dry matter accumulation,and leaf area index.The positive effects of mechanized tillage and seeding on the wheat production can be further improved through the corresponding seeding density and nitrogen application,which is conducive to the realization of sufficient seedlings and strong seedlings.