底肥分层条施提高冬小麦干物质积累及产量

【目的】探讨底肥按比例分层条施对冬小麦群体动态变化、干物质积累与分配及籽粒产量的调节作用，为创建合理的耕层供肥条件提供理论依据。【方法】于2014～2015年和2015～2016年冬小麦生长季，在大田条件下，设置5种底肥施用方式:不施底肥 (T1)；底肥单层条施在地表下8、16和24 cm (T2、T3和T4)；底肥按1∶2∶3分为三份，分别施在地表下8、16和24 cm土层 (T5)。各处理均于拔节期随灌溉水追施氮肥，施肥量一致。调查了小麦关键生育期的生长和发育状况以及养分利用率。【结果】底肥单层条施时，在一定范围内随施肥深度增加，冬小麦分蘖和成穗数减少，但穗粒数显著增加，开花后干物质同化量提高，成熟期单茎干物质在各器官中的分配量增加，尽管开花后营养器官贮存的干物质向籽粒中的转移再分配受到抑制，但籽粒产量仍有一定程度的提高。与T4相比，T5的穗粒数和千粒重无明显变化，但植株分蘖和成穗数显著提高，开花后单位面积干物质积累量和籽粒产量均显著增加。【结论】通过优化养分在耕层土壤的分布，调节各生育阶段的养分供给，进而协调开花后干物质同化与营养器官临时贮存干物质再分配，及穗数与穗粒重之间的关系，在增加穗数的同时仍保持较高的穗粒数和千粒重，是底肥按比例分层条施实现冬小麦高产的重要原因。

Basal fertilization in strips at different soil depths to increase dry matter accumulation and yield of winter wheat

[Objectives]The effect of basal fertilizer layered at different soil depths and in stripes with different proportion on the dry matter accumulation and yield of winter wheat was studied in this paper, in order to provide a theoretical basis for reasonable fertilizer application in topsoil.[Methods]A 2-year field study was carried out from 2014 to 2016. Five treatments were set up: no basal fertilizer (T1); basal fertilizer was applied in stripes in 8 cm depth (T2), 16 cm (T3) and 24 cm (T4); basal fertilizer was divided into three parts with the proportion of 1:2:3 and applied in stripes of 8, 16 and 24 cm depths of soil (T5). All the treatments were top-dressed with the same amount of nitrogen fertilizer in jointing stage. The growth and nutrient use efficiency in the key growing stages of wheat were investigated.[Results]Among treatments of T2, T3 and T4, the tiller and ear number of winter wheat were reduced with the increase of fertilization depth, but the grain number per spike was significantly increased; the dry matter assimilation after the anthesis and the allocation amount of dry matter in different organs at the maturity were improved; the grain yields were increased, although the redistribution of dry matter from vegetative organs to grain after the anthesis were restrained. Compared to T4, the grain number per spike and 1000-grain weight were not significantly increased in T5, while the tillers and the ear number were increased significantly; the amount of dry matter accumulation and grain yield were significantly increased as well.[Conclusions]Layered and in proportion basal fertilization could increase ear number, the grain number per spike and 1000-grain weight, which coordinates the relationship between the dry matter assimilation and the dry matter redistribution from vegetative organs to grains after the anthsis. Therefore, optimizing the distribution of nutrient in the whole root layer of soil could regulate nutrient supply at each growth stage of winter wheat, thus lead to high yield.