轻型栽培和秸秆还田对水稻产量和根系特征的影响

轻型化栽培技术和秸秆还田是水稻生产的发展趋势。为研究轻型化种植和秸秆还田对水稻产量和根系分布的影响,利用设立于2008年的田间定位试验,系统分析了耕作、种植方式和秸秆还田与否下连续3年的早稻产量和根系干物质、根系形态等指标。结果表明:浅耕处理的早稻产量为8000 kg/hm2,比传统深耕处理降低了23~241 kg/hm2,降幅较小。虽然直播、抛秧和插秧的基本苗数不同,但是3种种植方式早稻产量没有明显差异。而秸秆还田可以显著提高水稻产量,与秸秆移除的处理相比,秸秆还田处理的产量3年间平均增加了365 kg/hm2。在水稻根系方面,根干重、总根长、根系表面积和根尖数均集中在表土层(0~5 cm),且呈现出随着土壤深度的增加而显著减小的趋势。与深耕处理相比,浅耕处理在表土层的总根长和根尖数分别提高了23.34%和1.49倍,但3种种植模式没有显著规律。而秸秆还田措施显著增加了表土层的根系干物质,尤其是在浅耕条件下,秸秆还田可以显著增加表土层的根系总长、根系表面积和根尖数。这说明,在江西地区推广轻型化种植模式和秸秆还田措施有利于水稻根系发育,能够达到水稻高产。

Effects of Simplified Cultivation and Returning-straw-to-field on Yield and Root Traits of Rice

The techniques of simplified cultivation and returning -straw-to-field （ RSTF） are the developmental trend of rice production .So as to study the effects of simplified cultivation and RSTF on the yield and root traits of rice , we systematically analyzed the yield , root-system dry matter and root morphology of early rice , which was planted by adopting various tillage modes with or without RSTF for continuous 3 years based on the field location test system established in 2008.The results indicated that the grain yield of early rice was 8000 kg/hm2 in shallow tillage treatment , being 23~241 kg/hm2 lower than that in traditional deep tillage treatment .There was no obvious difference in grain yield of early rice among 3 planting modes （ direct seeding , seedling-thro-wing, and transplanting ） although the quantity of basic seedlings was different .RSTF could significantly enhance the grain yield of rice, and the 3-year average grain yield of rice in RSTF treatment was 365 kg/hm2 higher than that in straw -removing treatment. The root dry weight, total root length, root surface area and root tip quantity of rice all were the highest in the topsoil （0~5 cm in depth） , and they decreased significantly along with the increase in soil depth .Total root length and root tip quantity of rice in the topsoil in shallow tillage treatment were respectively 23.34% and 149.00% more than those in traditional deep tillage treatment . RSTF significantly increased the root -system dry matter of rice in the topsoil , especially under the condition of shallow tillage , and it also could obviously increase the total root length , root surface area and root tip quantity of rice in the topsoil .Therefore, popular-izing the simplified cultivation mode and RSTF measure in Jiangxi could promote root system growth of rice and achieve higher yield .