施氮时期对夏玉米饲用营养价值的影响

 采用盆栽法研究了施氮时期对玉米鲁单 5 0饲用营养价值及其生理特性的影响。结果表明 ,施用氮肥显著提高了玉米的生物产量、籽粒产量以及饲用营养品质。拔节期 1次施用氮肥可以获得较高的生物产量 ,有利于提高作为青饲 (贮 )饲料玉米的饲用营养价值 ;在拔节、大口 (或开花 )期 2次或拔节、大口、开花期 3次施氮肥 ,有利于提高作为粮饲兼用玉米的饲用营养价值。施氮时期对玉米的生理特性有着显著影响 ,拔节、大口 (或开花 )期分 2次或拔节、大口、开花期分 3次施氮肥的玉米 ,从乳熟期到蜡熟期保持较高的叶面积指数 ,功能叶片硝酸还原酶(NR)、过氧化氢酶 (CAT)、超氧物歧化酶 (SOD)、过氧化物酶 (POD)活性较高 ,生育后期尤其明显 ,利于玉米籽粒产量的提高和饲用营养品质的改善。

Effects of Different Nitrogen Application Stages on Forage Nutritive Value of Summer Maize

In a pot experiment, the effect of nitrogen fertilizing at different stages on forage nutritive value and physiological characteristics of summer maize (Ludan50) was studied. The main results were as follows: whole maize plant and kernels yields and forage nutritive value of all treatments were significant higher than those of no fertilizing nitrogenous fertilizer. Fertilizing at the jointing stage for one time could raise the dry matter yield of whole maize plant, it could improve forage nutritive value of summer maize to fertilizing at the jointing, male tetrad (or flowering) stage for two times and at the jointing, male tetrad, flowering stage for three times. In the anaphase of growth and development, leaf area index, activity of nitrate reductase(NR), catalase(CAT, superoxide dismutase (SOD), peroxidase (POD) and soluble protein content in ear leaf of maize were higher, which are beneficial to increase of yield of corn and improvement of forage nutritive value of corn.