保水剂用量对冬小麦生长及水肥利用的影响

为探明保水剂施用条件下冬小麦生长与水肥利用的特征,采用田间试验,以不施保水剂和氮肥为对照,研究了单施氮肥(T2:225 kg·km^-2)和其与不同用量保水剂配施(T3:N+保水剂30 kg·hm^-2、T4:N+保水剂60 kg·hm^-2、T5:N+保水剂90 kg· hm^-2)处理对冬小麦生长、土壤矿质氮含量以及水肥利用等影响。结果表明:保水剂与氮肥的施用显著提高了小麦各生育期的小麦总群体、株高、叶面积、土壤矿质氮含量及水肥利用率等。各处理中,以T4处理对于总群体数、株高、穗长和穗粒数的提高效果最为显著,而T5处理对于小麦叶面积和千粒重的提高作用明显。随小麦生育期的推进,保水剂处理的根冠比均较对照低,尤其是T3处理。而各生育期土壤矿质氮平均含量表现为T4＞T3＞T5＞T2＞CK。最终小麦产量、氮肥农学效率、氮素生产力和水分利用效率,随保水用量的增加而先增后将,且均匀以T4处理最高,其分别比单施氮肥处理(T2)14.5％、55.9％、34.6％和25.0％。说明各处理中,以T4处理对小麦的生长、增产及水肥利用的效果最佳。

Impacts of dosage of water-retaining agent on growth and water and fertilizer utilization of winter wheat

order to investigate impacts of water-retaining agent on characteristics of growth and water and fertilizer utilization of winter wheat, different dosage of water-retaining agent(T3:30kg·km^-2,T4:60kg·km^-2,T5:90 kg·km^-2)combined with nitrogen fertilizer(225kg·km^-2)were tested on winter wheat in a field experiment. Winter wheat growth, soil available nitrogen, water and nitrogen fertilizer utilization were studied and no nitrogen and water-retaining agent(CK)usage was control. The results indieated that application of water-retaining agent and nitrogen fertilizer in-creased total group number, plant height, leaf area, soil available nitrogen, yield and WUE. The total group number, plant height, leaf area, ear length and grain number per panicle in T4 were higher in other treatments, and leaf area and 1 000 grain mass were increased most in T5. With advancement of wheat growth period, root-shoot ratio of wheat was lower in water-retaining agent treatment than control, especially in T3. The order of average content of soil available ni- trogen in various growth of wheat was as follows:T4>T3>T5>T2>control. With inerease of water-retaining agent dosage, wheat yield, nitrogen agronomic efficiency, nitrogen productivity and water use efficiency were first increased and the reduced. All of these paramelers were increased most in T4. Compared to single nitrogen treatment(T2), they were increased by 14.5%, 55.9%, 34.6% and 25.0%, respectively. in conclusin, T4 had best effect on growth, yeid and water and fertilizer utilization of winter wheat compared with other treatrments.