刈割次数对甘肃庆阳地区光敏型高丹草产量及品质的影响

Effect of Cutting Frequency on Yield and Quality of Photoperiod-sensitive Sorghum-sudan Hybrids in Qingyang, Gansu

在甘肃庆阳黄土高原雨养农业区,以光敏型高丹草品种"大卡BMR"和"海牛"为对象,采用全生育期刈割一茬和两茬处理,测定各茬次产草量、粗蛋白质(CP)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和糖锤度(BX),计算总可消化养分(TDN)含量,分析刈割茬次和品种对产草量、品质的影响。结果表明:品种对鲜草产量影响极显著(P<0.01);刈割茬次对鲜草和干物质产量影响极显著(P<0.01);总鲜草产量以刈割两茬最高,平均为128.87t/hm^2;总干物质产量以刈割一茬最高,平均为27.65t/hm^2;品种间鲜草和干物质产量对刈割茬次的响应程度不一致。品种对CP、ADF和TDN含量影响极显著(P<0.01),对NDF和BX影响显著(P<0.05);刈割茬次对各营养成分含量均影响极显著(P<0.01);不同品种的CP、NDF和TDN含量对刈割茬次响应不一致。品种对CP和TDN产量影响不显著,刈割茬次对二者影响极显著(P<0.01);CP产量以刈割两茬之和最高,平均为2.52t/hm^2;TDN产量以刈割一茬最高,平均为14.07t/hm^2。综合分析表明,从生产优质饲草料和单位面积营养物质产出的角度考虑,以粗蛋白质和总可消化养分产量为目标时,选择品种大卡BMR并采用刈割两茬的生产方式最佳;以干物质和总可消化养分产量为目标时,选择品种大卡BMR并采用刈割一茬的生产方式最佳。

The objective of this study was to investigate the effect of cutting frequency on the yield and quality of photoperiod-sensitive sorghum-sudan hybrids in the rain-fed agriculture region on the loess plateau in Qingyang city, Gansu.Two hybrids cultivars (Big Kahuna BMR and Monster) were grown under two cutting regime (Forced once and twice in the whole growth period), the content of crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and brix scale (BX) were measured and total digestible nutrient (TDN) was calculated.Results showed that the fresh yield of different variety was different (P<0.01);the effect of cutting frequency on the fresh and dry matter yield was significant (P<0.01);the total fresh yield was the highest under cutting twice treatments, and the average yield was 128.87t/hm^2, but the one-cut total dry matter yield was the highest and the average was 27.65t/hm^2.The response of the fresh yield and the dry matter yield of different cultivars to cutting frequency was different.CP, ADF and TDN content of different cultivars were significantly different (P<0.01), and the contents of NDF and BX were significantly different (P<0.05);the effect of cutting frequency on the content of nutrient components was significant (P<0.01);The response of the response of CP, NDF and TDN contents of different cultivars to cutting frequency was not consistent.The yield of CP and TDN was not significantly affected by the cultivars, but significantly affected by cutting frequency (P<0.01).The CP yield was highest with the sum of cutting twice with an average 2.52t/hm^2, and the TDN yield was highest in cutting once with an average 14.07t/hm^2.In conclusion, considering the production of high quality forage and nutrient output per unit area, when taking the CP and TDN yield as the target, Big Kahuna BMR should be selected and cut twice in growth period;when the target was the yield of DM and TDN, the optima selection was the variety of Big Kahuna BMR with the cutting at one time.