北京地区施硫肥对苜蓿品质及消化率的影响

Effect of sulfur fertilizer on Medicago sativa quality and digestibility in the Beijing region

在北京潮土地区施硫肥(S)显著提高了苜蓿粗蛋白和粗灰分含量,降低了粗纤维含量.苜蓿植株体内的S含量从0.19%提高到0.33%左右,增幅达50%～70%;同时施硫肥还提高了K的含量,但降低了P和Na的含量,显著降低了N∶S.植株体内的S 含量只与N、K含量高度正相关.施硫肥显著提高了含硫氨基酸(半胱氨酸和蛋氨酸)的含量;另外,还显著提高了第1,2茬的苏氨酸、丙氨酸和精氨酸的含量,对其他氨基酸含量的影响不一致.除谷氨酸和缬氨酸外,含硫氨基酸与其他氨基酸含量间均呈显著或极显著负相关.施硫肥还显著提高了干物质和有机质的消化率,而对粗蛋白的消化率影响不显著;干物质与有机质消化率与纤维素含量呈高度负相关,而与粗蛋白和粗灰分含量高度正相关.第1～3茬苜蓿适宜的含硫量范围分别为0.23%～0.38%,0.28%～0.37%和0.28%～0.38%,适宜的N∶S为(9.0～12.8)∶1.2种施硫肥的当年利用效率为87.5%和54.7%.

The addition of Sulfur （S） fertilizer was found in this study to significantly increase crude protein and ash concentrations whilst at the same time decrease the crude fiber concentration in M. sativa in the Beijing region. S concentration increased by 50 %-70% compared with the no S application treatment. S application significantly increased potassium （K） and decreased phosphorus and sodium concentrations as well as the N ： S ratio. Significant positive correlations between S, N and K in the plant were shown to occur. S-containing amino acid （Cry and Met） concentrations were significantly increased by S application, while a negative correlation between S-containing amino acids and other amino acids was observed. S application significantly increased the digestibility of dry matter （DM） and organic matter （OM）. There were significant negative correlations between DM and OM digestibility and crude fiber concentration, and positive correlations between DM and OM with both crude protein and ash concentrations. The critical S ranges in M. sativa for the first, second and third clippings were 0.23%-0.38%, 0.28%-0.37% and 0. 28%-0. 38%, respectively and the N ： S ratio ranged from 9.0 to 12.8.