普通、控释尿素配比对玉米物质积累及产量的影响

以普通尿素和包膜控释尿素为供试材料,设置5种普通尿素与控释尿素配比处理,分别为CRU0—100%普通尿素,CRU1—75%普通尿素+25%控释尿素,CRU2—50%普通尿素+50%控释尿素,CRU3—25%普通尿素+75%控释尿素和CRU4—100%控释尿素,以CK1—不施氮肥和CK2—常规施氮(普通尿素60%基施+40%大喇叭口期追施)为对照,研究控释尿素与普通尿素配施对玉米农艺性状、干物质积累分配及产量的影响。结果表明:(1)施氮显著提高了玉米株高、穗位高和叶面积,与常规施氮处理相比,普通、控释尿素配施可提高株高、穗位高、茎粗和叶面积,其中75%控释尿素处理提高显著。(2)与常规施氮处理相比,普通、控释尿素配施处理促进吐丝期干物质积累,最终增加成熟期总干物质量,其中以CRU2和CRU3处理最好。(3)与常规施氮处理相比,普通、控释尿素配施处理的干物质在叶片和茎秆中的分配比例均较低,而籽粒的分配比例较高,以CRU3处理比例最高。(4)随控释尿素比例增加,玉米产量、千粒重、穗粒数、穗长和穗粗均呈先升后降的趋势;25%,50%,75%,100%的控释尿素比例处理产量较常规施氮处理分别增产3.70%,8.83%,11.23%,5.43%。因此,普通尿素掺混75%比例的控释尿素进行一次底施,既能满足玉米植株生长需求,提高干物质积累,优化干物质分配,又可促进增产。

Effects of Combined Application of Control-released Urea and Urea on Dry Matter Accumulation and Yield of Maize

Controlled-release urea (CRU) and urea (U) were used to investigate the effects of five proportions of controlled-release urea blended with urea (100% CRU, 25% U+75% CRU, 50% U+50% CRU, 75% U+25% CRU, 100% U) and two controls (no N fertilization , CK1), conventional fertilization (CK2, 60% U as basal and 40% U top-dressed ) on agronomic characters, dry matter accumulation and distribution, and yield in maize. Results were as follows: (1)Nitrogen supply could increase the plant height, ear height, and leaf area, compared to the CK2 treatment, the combination applications of controlled-release urea with urea could increase the plant height, ear height, stalk diameter, and leaf area, improvement effect of the mixing ratio of 75% treatments were the most strong among them. (2)Compared to the CK2 treatment, the combination applications of controlled-release urea with urea could meet demand of life on jointing stage, promote dry matter accumulation on silking stage, and dry matter quantity were improved finally, improvement effect of the mixing ratio of 50%-75% treatments were the most strong among them. (3)Compared to the CK2 treatment, the dry matter of the combination applications of controlled-release urea with urea were lower on distribution proportion of the stalk and leaf, however, the distribution proportion of grain increased, the most in the mixing ratio of 75% treatments. (4)With different ratio of controlled-release urea were always higher, the yield, 1 000-kernel weight, the grains per spike, ear length, and ear diameter increased firstly and then gradually decreased. The yield of the mixing ratio of 25%, 50%, 75%, and 100% increased by 3.70%, 8.83%, 11.23%, and 5.43% than the CK2. Therefore, applying controlled-release urea with a mixing ratio of 75% of basal dressing was most beneficial to meet the demand of life of maize, promote dry matter accumulation and distribution, and also could increase yield.