【作者】 贾婷；

【导师】 王昌全；

【作者基本信息】 四川农业大学 ， 土壤学， 2009， 硕士

【摘要】 氮是植物生命活动的重要元素之一。施氮可以明显提高饲草玉米的产量和品质,但氮素形态对饲草玉米影响的相关报道甚少,因此研究不同氮形态下饲草玉米的生物学特性及影响其产量和饲用营养价值的因素,为充分发掘饲草玉米的生产潜力,促进品种推广有着非常重要的意义。本实验选择饲草玉米多年生SAUZ1和一年生SAUZ2两个品种,通过近红外光谱分析仪Vector 22/N等方法,研究铵态氮和硝态氮比例分别为1:0、1:0.25、1:0.75和1:1四个处理对饲草玉米SAUMZ1和SAUZ2生长、产量和粗蛋白、质粗纤维、粗脂肪等饲用营养价值的影响。试验取得主要结果如下:1.施氮量为150kg/hm~2和450kg/hm~2时,即在低氮和高氮条件下,均显著的增加了饲草玉米SAUZ1和SAUZ2植株的株高、叶长和叶宽,有利于饲草玉米的生长,且在高氮条件下促进饲草玉米SAUZ1和SAUZ2生长效果更加明显;同时,均显著的增加了饲草玉米SAUZ1和SAUZ2鲜草总产量、单株的鲜重和干重,有利于饲草玉米的增产,且在高氮条件下对饲草玉米SAUZ1和SAUZ2增产效果更加明显;另外,降低了SAUZ1第一次刈割干草的茎叶比和第二次刈割鲜草的茎叶比,而增加了SAUZ2的茎叶比。2.在低氮和高氮条件下,对饲草玉米SAUZ1和SAUZ2饲用品质的影响在不同的刈割时期和不同的部位影响不同。表现为:(1)均显著增加了饲草玉米SAUZ1和SAUZ2茎鞘中CP含量。同时对SAUZ2茎鞘和叶片中EE含量没显著影响,而均显著降低了SAUZ1两次刈割叶片中EE含量和第二次刈割茎鞘EE含量,但其降低幅度明显低于CP含量的增加幅度。(2)显著降低了SAUZ1第二次刈割时茎鞘中NDF的含量,同时均显著降低了SAUZ2茎鞘中ADF和NDF含量。(3)显著增加了SAUZ1第二次刈割时茎鞘和叶片中IVDMD和RFV含量,同时,均显著降低了SAUZ2茎鞘中IVDMD和RFV含量。3.在低氮和高氮条件下,随着硝态氮比例的增加,均有利于饲草玉米的生长,叶长和叶宽均显著增加,当铵态氮和硝态氮的比例为1:1时,饲草玉米SAUZ1和SAUZ2植株达到最高,且叶长和叶宽均达到最大值,此时生长较为旺盛。同时,在低氮和高氮条件下,随着硝态氮比例的增加,饲草玉米鲜草总产量、单株鲜重和干重均显著增加,当铵态氮和硝态氮的比例为1:1时,SAUZ1和SAUZ2鲜草总产量、单株鲜重和干重均达到最大值。4.铵态氮和硝态氮不同比例的配合影响饲草玉米品质,且这种影响因施肥量的高低、品种及刈割时期的不同而不同。具体表现为:(1)在低氮和高氮条件下,随着硝态氮比例的增加,饲草玉米SAUZ1和SAUZ2茎鞘CP含量均显著增加,当铵态氮和硝态氮的比例为1:1时,SAUZ1和SAUZ2茎鞘CP含量达到最大值,而EE含量则相反。(2)在低氮条件下,随着硝态氮比例的增加,SAUZ1两次刈割时茎鞘中ADF和NDF的含量均呈现下降的趋势,当铵态氮和硝态氮的比例为1:0.5—1:0.75时,茎鞘中ADF和NDF的含量最低,有利于提高饲用品质;但随着硝态氮比例的增加,SAUZ2茎鞘中ADF和NDF的含量明显增加,不施或少施硝态氮,主要施铵态氮,这时SAUZ 2的ADF和NDF含量较低。在高氮条件下,随着硝态氮比例的增加,SAUZ 1第一次刈割时和SAUZ2茎鞘中ADF和NDF的含量均显著增加,不施或少施硝态氮,主要施铵态氮时,饲草玉米ADF和NDF含量较低;而SAUZ 1第二次刈割时,随着硝态氮比例的增加,茎鞘中ADF和NDF的含量显著降低,在铵态氮和硝态氮的比例为1:0.75—1:1时,ADF和NDF含量最低。(3)低氮和高氮条件下,随着硝态氮比例的增加,饲草玉米SAUZ1在两次刈割时茎鞘IVDMD和RFV含量均显著增加,增施硝态氮,有利于提高SAUZ1干物质消化率和相对饲用价值。而SAUZ2茎鞘IVDMD和RFV含量随着硝态氮比例的增加,呈现显著降低的趋势,不施或少施硝态氮,有利于提高SAUZ2干物质消化率和相对饲用价值。更多还原

【Abstract】 This research was carried out on the farm of Sichuan Agriculture University in 2007.The experiment materials were two types of forage maize,including SAUZ1 and SAUZ2,which was annual and perennial plant separately.It includes two aspects:(1)The influence of low nitrogen condition 150 kg/hm~2 and high nitrogen condition 450 kg/hm~2 to SAUMZ1 and SAUZ2 in growth,yield and feeding value.(2) The influence of four nitrogen forms of ammonium nitrogen and nitrate nitrogen ratio at 1:0,1:0.25,1:0.75 and 1:1 to SAUMZ1 and SAUZ2 in growth,yield and feeding value.The main results are as follows:1.The plant height,leaf length and leaf width of forage maize were significantly increased at low nitrogen condition(150 kg/hm~2) and high nitrogen condition(450 kg/hm~2) respectively. Nitrogen application was beneficial to the growth of forage maize,and the efficiency of forage maize growth by high nitrogen condition was better than low nitrogen condition. Simultaneously,the total fresh yield,fresh matter and dry matter weight per plant of forage maize were significantly increased at low nitrogen condition and high nitrogen condition respectively,also the efficiency of yield by high nitrogen condition was better than low nitrogen condition. Moreover,the Shoot/Leaf ratio had been decreased at the first cutting but increased at the second cutting of SAUZ1,besides the Shoot/Leaf ratio had been increased of SAUZ2.2.It was difference in forage quality of different cutting stages and different parts of plant at low nitrogen condition and high nitrogen condition.Presented as:(1) Though the CP content of SAUZ1 and SAUZ2 had been increased,the EE content had been decreased in different degrees to SAUZ1 in stalks and leaves,the increasing extent of CP content was greater than the decreasing extent of EE content.(2) The NDF content in stalks of SAUZ1 had been decreased significantly at the second cutting stage,and the NDF and ADF content in stalks of SAUZ2 had been decreased significantly too.(3)The IVDMD and RFV content in stalks and leaves of SAUZ1 had been increased significantly at the second cutting stage,but decreased significantly in stalks of SAUZ2.3.As the increasing of nitrate nitrogen proportion at low nitrogen condition and high nitrogen condition,it was suitable for the growth of forage maize,because the plant height,leaf length and leaf width were increased significantly.While the proportion of nitrate nitrogen and ammonium nitrogen was 1:1,the forage maize was growing luxuriantly.Moreover,the total fresh yield,fresh matter and dry matter weight per plant of forage maize were significantly increased respectively,and while the proportion of nitrate nitrogen and ammonium nitrogen was 1:1,the total fresh yield,fresh matter and dry matter weight per plant of forage maize reached to maximum.4.The different proportion of nitrate nitrogen and ammonium nitrogen influenced in the forage quality among nitrogen condition,varieties and cutting stages.Presented as:(1) As the increasing of nitrate nitrogen proportion at low nitrogen condition and high nitrogen condition,the CP content in stalks of SAUZ1 and SAUZ2 had been significantly increased,but EE content in stalks was opposite.While the proportion of nitrate nitrogen and ammonium nitrogen was 1:1,the CP content in stalks of SAUZ1 and SAUZ2 reached to maximum.(2) As the increasing of nitrate nitrogen proportion at low nitrogen condition,the stalks of SAUZ1 were downward trend in NDF and ADF content.While the proportion of nitrate nitrogen and ammonium nitrogen was 1:0.5～1:0.75,the NDF and ADF content in stalks of SAUZ1 were the lowest.But the stalks of SAUZ2 obviously increased in NDF and ADF content,and the NDF and ADF content were the lowest while there’s no nitrate nitrogen.As the increasing of nitrate nitrogen proportion at high nitrogen condition,the stalks of SAUZ1 at the first cutting stage and SAUZ2 significantly increased in NDF and ADF content,and the NDF and ADF content were the lowest while there’s no nitrate nitrogen.But the stalks of SAUZ1 was significantly increased in NDF and ADF content at the second cutting stage,while the proportion of nitrate nitrogen and ammonium nitrogen was 1:0.75～1:1 that the NDF and ADF content in stalks of SAUZ1 were the lowest.(3) As the increasing of nitrate nitrogen proportion at low nitrogen and high nitrogen condition,the IVDMD and RFV content in stalks of SAUZ1 had been increased significantly at the two cutting stage.It can improve the vitro dry matter digestible and relative feeding value with increasing application of nitrate nitrogen.But the stalks of SAUZ2 obviously decreased in IVDMD and RFV content,it can improve the vitro dry matter digestible and relative feeding value while there’s no nitrate nitrogen.更多还原