Abstract:

In order to improve the yield and quality of forage, and to create the most benefit for Bothriochloa ischaemum, this experiment used randomized block design with the urea, ammonium sulfate and calcium ammonium nitrate fertilizers, with nitrogen levels at 0, 30, 60, 120 and 240 kg N·hm^-2 for the cultured B. ischaemum. The results showed that the highest hay-yield was 13.5 t·hm^-2 at 60 kg N·hm^-2 of urea, followed by AS-N₆₀ and CAN-N₁₂₀. In term of crude protein (CP), crude fat (EE), neutral detergent fiber (NDF), and acid detergent fiber (ADF) of B.ischaemum, the best performance were at the U-N₆₀ level when applying U, and at the AS-N₁₂₀ level when applying AS. When CAN was applied, the contents of EE and NDF were optimum at 60 kg N·hm^-2, while the contents of CP and ADF were the best at 120 kg N·hm^-2. By combining yield, nutritional quality and economic benefits, it is most appropriate to apply 60 kg N·hm^-2 of urea.

Key words: Nitrogen forms, Nitrogen application rate, Bothriochloa ischaemum, Yield, Nutrient content

摘要：

为了提高饲草产量和品质，为白羊草（Bothriochloa ischaemum）生产创造最大效益，本实验采用随机区组设计，分别用尿素（U）、硫酸铵（AS）、硝酸铵钙（CAN）3种形态氮肥分别以0，30，60，120，240 kg N·hm^-2施氮水平对田间栽培的白羊草进行施肥处理。结果表明：施60 kg N·hm^-2尿素的干草产量最高达到13.5 t·hm^-2，其次为AS-N₆₀和CAN-N₁₂₀。对于白羊草的粗蛋白质（CP）、粗脂肪（EE）、中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）含量，施U时均以U-N₆₀水平时最佳，施AS时均以AS-N₁₂₀水平最高。施用CAN时，其EE、NDF在60 kg N·hm^-2的含量最适宜，而CP和ADF的含量在120 kg N·hm^-2含量最好。结合产量、营养品质及经济效益，以施用60 kg N·hm^-2的尿素较适宜。

关键词: 氮肥形态, 施氮量, 白羊草, 产量, 营养成分