施肥和覆盖模式对旱地冬小麦花后干物质转移、糖代谢及其籽粒产量的影响

选择不同的施肥(无机+有机)和覆盖模式,2012-2015年在典型的西北半干旱雨养农业区甘肃省农业科学院小麦研究所清水试验站进行大田试验,研究不同施肥+覆盖模式对旱地冬小麦干物质转移、糖代谢及其籽粒产量的影响,并分析糖含量与产量、物质转移之间的相关关系。结果表明,比较对照T_1(不施任何肥料),不同的施肥+覆盖模式均不同程度地提高了籽粒产量,依次为高量化肥+有机肥(T_6)等量化肥+有机肥(T_4)高量化肥+地膜覆盖(T_5)等量化肥+地膜覆盖(T_3)常规化肥(T_2)不施肥(T_1)。增施有机肥(T_4、T_6)提高后期干物质转移量、转移比率、贡献率,增加粒重,并保证较高的有效成穗,从而增加籽粒产量,处理T_6、T_4分别比对照T_1增产119.22%和118.24%。地膜覆盖(T_3、T_5)增加了花后不同时期叶片、茎秆、叶鞘、颖壳干物质累积量和单穗粒数,为籽粒产量的提高奠定了基础。相反,地膜覆盖(T_3、T_5)降低干物质转移比率和贡献率。增施氮肥(T_3~T_6)提高了叶片干物质累积量,但过多的氮肥不利于籽粒增重,并降低了干物质转移比率和贡献率。不同的施肥+覆盖模式(T_2~T_6)降低了灌浆中前期(10、20d)各个营养器官可溶性糖和蔗糖含量,延缓了前期叶片和叶鞘可溶性糖和蔗糖下降的速度,叶片、茎秆、叶鞘、颖壳可溶性糖含量下降最快的时期均在花后30~40d,籽粒在花后10~20d。相关分析表明,产量、株高、单位面积穗数、穗长、旗叶面积均与中前期(花后10、20d)叶片、茎秆、叶鞘可溶性糖和蔗糖含量呈极显著和显著负相关。本研究结果证实,在甘肃旱地雨养农业区,结合有机肥施用(T_4、T_6),适当增加氮、磷用量完全能达到地膜覆盖对籽粒产量的增加,是更为持续、稳产的旱地小麦栽培模式。

Effects of different patterns of fertilization and mulching on the post-anthesis dry matter remobilization,sugar metabolism and grain yield of winter wheat in dry lands

To study the effects on winter wheat of different combinations of fertilizer,manure and mulching on the dynamics of dry matter accumulation and remobilization,water-soluble sugar content (WSC),sucrose sugar content (SSC) and seed yield,a field experiment was carried out during 2012-2015 at the Qingshui Experimental Station of the Gansu Academy of Agricultural Science (located in a typical semi-arid and rain-fed farming area).Different combinations of fertilizer (chemical+ manure) and mulching were applied.Compared to T1 (no fertilizer,control),grain yield under the other treatments increased in the following order:high level of chemical fertilizer combined with manure (T6)＞equal application of chemical fertilizer and manure (T4)＞high application of chemical fertilizer with plastic mulching (T5)＞equal application of chemical fertilizer with plastic mulching (T3)＞conventional application of chemical fertilizer (T2)＞T1.Manure application increased postanthesis accumulation of dry matter,dry matter remobilization rate,contribution rate to grain filling,grain weight per seed and spike number per square meter,thus increasing the grain yield.Compared to T1,T6 and T4 resulted in yield increases of 119.22％ and 118.24％ respectively.Plastic mulching (T3,T5) increased postanthesis accumulation of dry matter in the leaf,stem,sheath and glume,and grain number per spike,setting the foundation for yield improvement.However,plastic mulching also decreased the remobilization rate of dry matter and its contribution rate to grain filling.Nitrogen fertilizer application (T3-T6) increased the accumulation of dry matter in leaves,but excessive levels were detrimental to grain weight and decreased the remobilization rate and contribution rate to grain filling.Different combinations of fertilizer+mulching (T2-T6) decreased the water-soluble sugar content (WSC) and sucrose sugar content (SSC) of different vegetative organs during the mid-early period of filling (from 10 to 20 d after anthesis) and delayed the decrease in WSC and SSC in the leaf and sheath.The sharpest decrease in WSC and SSC in the leaf,stem,sheath and glume occurred from 30 to 40 d after anthesis,while in seeds it occurred from 10 to 20 d after anthesis.The yield,plant height,spike number per unit area,spike length and flag leaf area were significantly and negatively correlated with WSC and SSC in the leaf,stem and sheath from 10 to 20 d after anthesis.In the semi-arid and rain-fed farming area of Gansu,optimal application of nitrogen and phosphorus fertilizers,combined with manure application,is capable of achieving the same increase in yield achieved with plastic mulching and is a more sustainable way to produce wheat in dry lands.