不同种植密度对青贮玉米品质的影响

Effects of Different Planting Densities on the Quality of Silage Maize

本研究以青贮玉米‘中原单32’(ZYD32)和‘大京九26’(DJJ26)为试验材料,设置低密(67 500株/hm2)、中密(90 000株/hm^2)和高密(112 500株/hm2) 3个种植密度,研究了不同种植密度对青贮玉米23项营养品质指标的影响。结果表明,青贮玉米的营养品质和品种自身特性以及种植密度相关,其中品种对可溶蛋白占总蛋白的比例(SP)、脂肪(Fat)含量的影响达到显著或极显著水平,密度对瘤胃可降解蛋白占总蛋白的比例(DP)、钾(K)含量的影响达到显著或极显著水平。品种、密度同时对粗蛋白(CP)、总可消化养分(TDN)、水溶性碳水化合物(WSC)、非纤维性碳水化合物(NFC)、淀粉(SH)、单糖(ESC)、酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)、木质素(LN)、48 h中性洗涤纤维的消化率(NDFD)、灰分(Ash)、钙(Ca)含量的影响达到显著或极显著水平。随着种植密度的升高,两品种的瘤胃可降解蛋白占总蛋白的比例(DP)、酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)、木质素(LN)、钙(Ca)、镁(Mg)、钾(K)含量均呈现逐渐升高的趋势,总可消化养分(TDN)、非纤维性碳水化合物(NFC)、淀粉(SH)、灰分(Ash)含量均呈现逐渐降低的趋势,水溶性碳水化合物(WSC)、单糖(ESC)、48 h中性洗涤纤维的消化率(NDFD)、每吨产奶量含量均呈现先升高再降低的变化趋势。粗蛋白(CP)、脂肪(Fat)含量方面2品种随密度变化的表现不一致‘,ZYD32’的粗蛋白(CP)、脂肪(Fat)含量随密度的升高而降低,‘DJJ26’的粗蛋白(CP)、脂肪(Fat)含量则无显著性变化。综上所述,不同青贮玉米品种‘ZYD32’和‘DJJ26’均在种植密度为90 000株/hm^2时所获得的青贮玉米品质最好,在种植密度为67 500株/hm^2时,2品种的每吨干物质产奶量最高。

Using ’ZYD32’ and ’DJJ26’ as experimental materials,three planting densities,low density(67 500 plants/hm2),medium density(90 000 plants/hm2) and high density(112 500 plants/hm2),were set up to study the effects of different planting densities on 23 nutritional quality indexes of silage maize.The results showed that the nutritional quality of silage maize was correlated with its own characteristics and planting density.The effects of varieties on SP and Fat contents were significant or extremely significant,and the effects of density on DP and M contents were significant or extremely significant.Varieties and densities also had significant or extremely significant effects on the contents of CP,TDN,WSC,NFC,SH,ESC,ADF,NDF,LN,NDFD,Ash and Ca.With the increase of planting density,the contents of DP,ADF,NDF,LN,Ca,Mg and K of the two varieties increased gradually,while the contents of TDN,NFC,SH and Ash decreased gradually.The contents of WSC,ESC,NDFD,and milk yield per ton increased first and then decreased.The CP and Fat contents of ’ZYD32’ decreased with the increase of density,but the CP and Fat contents of ’DJJ26’ did not change significantly.In conclusion,the quality of silage maize obtained by different silage maize varieties ’ZYD32’ and ’DJJ26’ was the best when planting density was 90 000 hm-2,and the dry matter yield per ton was the highest when planting density was 67 500 hm-2.